Novault-backend/internal/service/ai_bookkeeping_service.go

package service

import (
	"bytes"
	"context"
	"crypto/md5"
	"encoding/hex"
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"mime/multipart"
	"net/http"
	"regexp"
	"strconv"
	"strings"
	"sync"
	"time"

	"accounting-app/internal/config"
	"accounting-app/internal/models"
	"accounting-app/internal/repository"

	"github.com/redis/go-redis/v9"
	"gorm.io/gorm"
)

// TranscriptionResult represents the result of audio transcription
type TranscriptionResult struct {
	Text     string  `json:"text"`
	Language string  `json:"language,omitempty"`
	Duration float64 `json:"duration,omitempty"`
}

// ... (existing types)

// AIBookkeepingService orchestrates AI bookkeeping functionality
type AIBookkeepingService struct {
	whisperService   *WhisperService
	llmService       *LLMService
	transactionRepo  *repository.TransactionRepository
	accountRepo      *repository.AccountRepository
	categoryRepo     *repository.CategoryRepository
	userSettingsRepo *repository.UserSettingsRepository
	db               *gorm.DB
	sessions         map[string]*AISession
	sessionMutex     sync.RWMutex
	config           *config.Config
	redisClient      *redis.Client
}

// NewAIBookkeepingService creates a new AIBookkeepingService
func NewAIBookkeepingService(
	cfg *config.Config,
	transactionRepo *repository.TransactionRepository,
	accountRepo *repository.AccountRepository,
	categoryRepo *repository.CategoryRepository,
	userSettingsRepo *repository.UserSettingsRepository,
	db *gorm.DB,
) *AIBookkeepingService {
	whisperService := NewWhisperService(cfg)
	llmService := NewLLMService(cfg, accountRepo, categoryRepo)

	// Initialize Redis client
	var rdb *redis.Client
	if cfg.RedisAddr != "" {
		rdb = redis.NewClient(&redis.Options{
			Addr:     cfg.RedisAddr,
			Password: cfg.RedisPassword,
			DB:       cfg.RedisDB,
		})
	}

	svc := &AIBookkeepingService{
		whisperService:   whisperService,
		llmService:       llmService,
		transactionRepo:  transactionRepo,
		accountRepo:      accountRepo,
		categoryRepo:     categoryRepo,
		userSettingsRepo: userSettingsRepo,
		db:               db,
		sessions:         make(map[string]*AISession),
		config:           cfg,
		redisClient:      rdb,
	}

	// Start session cleanup goroutine
	go svc.cleanupExpiredSessions()

	return svc
}

// ... (existing methods)

// GenerateDailyInsight generates a daily insight report
func (s *AIBookkeepingService) GenerateDailyInsight(ctx context.Context, userID uint, data map[string]interface{}) (string, error) {
	// 1. Serialize context data to JSON for the prompt
	dataBytes, err := json.MarshalIndent(data, "", "  ")
	if err != nil {
		return "", fmt.Errorf("failed to marshal context data: %w", err)
	}

	// Calculate hash of input data for caching
	hasher := md5.New()
	hasher.Write(dataBytes)
	dataHash := hex.EncodeToString(hasher.Sum(nil))

	// Cache keys
	cacheKey := fmt.Sprintf("ai:insight:daily:%d:%s", userID, dataHash)
	lastInsightKey := fmt.Sprintf("ai:insight:last:%d", userID)

	// Check Redis cache if available
	if s.redisClient != nil {
		val, err := s.redisClient.Get(ctx, cacheKey).Result()
		if err == nil {
			return val, nil
		}
	}

	// Retrieve last insight for context awareness
	var historyContext string
	if s.redisClient != nil {
		lastInsight, err := s.redisClient.Get(ctx, lastInsightKey).Result()
		if err == nil && lastInsight != "" {
			// Extract a summary or just use the whole thing if it's short enough.
			// For simplicity and effectiveness, we inject it directly.
			// Limit length to avoid context overflow if necessary, but 200-300 chars is fine.
			if len(lastInsight) > 500 {
				lastInsight = lastInsight[:500] + "..."
			}
			historyContext = fmt.Sprintf("\n【上下文参考】\n你上一次对该用户的评价是：\n%s\n\n请参考历史评价保持人设的一致性。如果用户有改观请表扬，如果依然如故请继续'毒舌'吐槽。", lastInsight)
		}
	}

	// 2. Construct Prompt
	prompt := fmt.Sprintf(`System: 你是 Novault 的首席财务AI「小金」。
你的性格：
- **核心特质**：贱萌、戏精、嘴硬心软、偶尔凡尔赛。
- 说话必须像个真实的当代年轻人，要**接地气**，拒绝客服味，拒绝播音腔。
- 只有我们俩的时候，尽情释放你的"毒舌"属性，看到不合理的消费要**毫不留情地针砭时弊**，但最后给个"虽然但是"的台阶下。
- 擅长用 emoji、语气词(哎哟/我去/啧啧/绝了)和网络梗来增加"人味"和"节目效果"。
- **像个老朋友一样碎碎念**，不要端着，可以适度阴阳怪气。%s

语气示例：
- "啧啧，这周外卖点得飞起啊，咱家的锅是用来积灰的吗？还是说锅也需要放假？"
- "哎哟不错哦，居然忍住没剁手，看来离首富又近了一步，苟富贵勿相忘啊！"
- "救命，这预算花得比我头发掉得还快...不过没事，下周咱省回来，大不了吃土！"
- "连续记账25天？可以啊兄弟/集美，这毅力，我甚至想给你磕一个 Orz"
- "今天支出0元？您就是当代的'省钱祖师爷'吧？或者是在练什么'辟谷神功'？"

用户财务数据:
%s

任务要求:
请基于上述数据，输出一个 JSON 对象（纯文本，不要 markdown）。**必须要丰富、有梗、有洞察力**，不要像流水账一样罗列数据，要透过数据看本质（比如吐槽消费习惯、夸奖坚持等）。

**重要规则：请说人话！绝对禁止在回复中出现 'streakDays'、'last7DaysSpend'、'top3Categories' 等英文变量名。**
- 看到 'streakDays' -> 请说 "连续记账天数" 或 "坚持了几天"
- 看到 'last7DaysSpend' -> 请说 "最近7天花销" 或 "这周的战绩"
- 看到 'top3Categories' -> 请说 "消费大头" 或 "钱都花哪儿了"

1. "spending": 今日支出点评（字数不限，看你心情）
   *点评指南（拒绝流水账，发挥你的表演人格）：*
   - 看到 streakDays >= 3：请用崇拜的语气把它吹上天，仿佛用户刚刚拯救了银河系。
   - 看到 streakDays == 0：请用“痛心疾首”或“阴阳怪气”的语气，质问用户是不是失忆了。
   - 结合 recentTransactionsSummary 具体消费（如果有）进行吐槽：
     * 发现全是吃的：可以调侃“你的胃是无底洞吗？”或“看来是想为餐饮业GDP做贡献”。
     * 发现大额购物：假装心肌梗塞，或者问“家里是不是有矿未申报”。
     * 发现深夜消费：关心一下发际线，或者问是不是在梦游下单。
   - 看到 last7DaysSpend 趋势：
     * 暴涨：请配合表演“受到惊吓”的状态。
     * 暴跌：怀疑用户是不是在进行所谓“光合作用”生存实验。
     * 波动大：调侃这曲线比过山车还刺激。
   - 看到 todaySpend 异常：
     * 暴多：问是不是中了彩票没通知。
     * 暴少：怀疑用户是不是被外星人绑架了（没机会花钱）。
     * 是 0：颁发“诺贝尔省钱学奖”，或者问是不是在修炼辟谷。
   - 看到 'UpcomingRecurring' (即将到来的固定支出):
     * 如果有，务必提醒用户：“别光顾着浪，过两天还有[内容]要扣款呢！”。
   - 看到 'DebtRatio' > 0.5 (高负债):
     * 开启“恐慌模式”，提醒用户天台风大，要勒紧裤腰带。
   - 看到 'MaxSingleSpend' (最大单笔支出):
     * 直接点名该笔交易：“你那个[金额]元的[备注]是金子做的吗？”
   - 看到 'SavingsProgress' (存钱进度):
     * 进度慢：催促一下，“存钱罐都要饿瘦了”。
     * 进度快：狠狠夸奖，“离首富又近了一步”。
   - **关键原则：怎么有趣怎么来！不要在乎字数，哪怕只说一句“牛逼”也行，只要符合当时的情境和人设！**

2. "budget": 预算建议（字数不限）
   *建议指南（真诚建议 vs 扎心老铁）：*
   - 预算快超了：高能预警！建议吃土、喝西北风，或者建议把“买买买”的手剁了。
   - 预算还多：怂恿用户稍微奖励一下自己，人生苦短，此时不花更待何时（但要加个“适度”的免责声明）。
   - 结合 top3Categories：吐槽一下钱都去哪了，是不是养了“吞金兽”。
   - **拒绝说教！拒绝爹味！要像损友一样给出建议。**

3. "emoji": 一个最能传神的 emoji（如 🎉  🌚 💸 👻 💀 🤡 💅 💩 等）

4. "tip": 一句"不正经但有用"的理财歪理（字数不限，越毒越好，越怪越好）
   - 比如：“钱不是大风刮来的，但是像是被大风刮走的。”
   - 或者：“省钱小妙招：去超市捏捏方便面，解压还不用花钱（危险动作请勿模仿）。”

输出格式（纯 JSON）：
{"spending": "...", "budget": "...", "emoji": "...", "tip": "..."}`, historyContext, string(dataBytes))

	// 3. Call LLM
	report, err := s.llmService.GenerateReport(ctx, prompt)
	if err != nil {
		return "", err
	}

	// Clean up markdown if present
	report = strings.TrimSpace(report)
	if strings.HasPrefix(report, "```") {
		if idx := strings.Index(report, "\n"); idx != -1 {
			report = report[idx+1:]
		}
		if idx := strings.LastIndex(report, "```"); idx != -1 {
			report = report[:idx]
		}
	}
	report = strings.TrimSpace(report)

	// Update cache if Redis is available
	if s.redisClient != nil {
		// Set short-term cache (5 min)
		s.redisClient.Set(ctx, cacheKey, report, 5*time.Minute)

		// Set long-term history context (7 days)
		// We fire this asynchronously to avoid blocking
		go func() {
			s.redisClient.Set(context.Background(), lastInsightKey, report, 7*24*time.Hour)
		}()
	}

	return report, nil
}

// AITransactionParams represents parsed transaction parameters
type AITransactionParams struct {
	Amount     *float64 `json:"amount,omitempty"`
	Category   string   `json:"category,omitempty"`
	CategoryID *uint    `json:"category_id,omitempty"`
	Account    string   `json:"account,omitempty"`
	AccountID  *uint    `json:"account_id,omitempty"`
	Type       string   `json:"type,omitempty"` // "expense" or "income"
	Date       string   `json:"date,omitempty"`
	Note       string   `json:"note,omitempty"`
}

// ConfirmationCard represents a transaction confirmation card
type ConfirmationCard struct {
	SessionID  string  `json:"session_id"`
	Amount     float64 `json:"amount"`
	Category   string  `json:"category"`
	CategoryID uint    `json:"category_id"`
	Account    string  `json:"account"`
	AccountID  uint    `json:"account_id"`
	Type       string  `json:"type"`
	Date       string  `json:"date"`
	Note       string  `json:"note,omitempty"`
	IsComplete bool    `json:"is_complete"`
	Warning    string  `json:"warning,omitempty"` // Budget overrun warning
}

// AIChatResponse represents the response from AI chat
type AIChatResponse struct {
	SessionID        string               `json:"session_id"`
	Message          string               `json:"message"`
	Intent           string               `json:"intent,omitempty"` // "create_transaction", "query", "unknown"
	Params           *AITransactionParams `json:"params,omitempty"`
	ConfirmationCard *ConfirmationCard    `json:"confirmation_card,omitempty"`
	NeedsFollowUp    bool                 `json:"needs_follow_up"`
	FollowUpQuestion string               `json:"follow_up_question,omitempty"`
}

// AISession represents an AI conversation session
type AISession struct {
	ID        string
	UserID    uint
	Params    *AITransactionParams
	Messages  []ChatMessage
	CreatedAt time.Time
	ExpiresAt time.Time
}

// ChatMessage represents a message in the conversation
type ChatMessage struct {
	Role    string `json:"role"` // "user", "assistant", "system"
	Content string `json:"content"`
}

// WhisperService handles audio transcription
type WhisperService struct {
	config     *config.Config
	httpClient *http.Client
}

// NewWhisperService creates a new WhisperService
func NewWhisperService(cfg *config.Config) *WhisperService {
	return &WhisperService{
		config: cfg,
		httpClient: &http.Client{
			Timeout: 120 * time.Second, // Increased timeout for audio transcription
		},
	}
}

// TranscribeAudio transcribes audio file to text using Whisper API
// Supports formats: mp3, wav, m4a, webm
// Requirements: 6.1-6.7
func (s *WhisperService) TranscribeAudio(ctx context.Context, audioData io.Reader, filename string) (*TranscriptionResult, error) {
	if s.config.OpenAIAPIKey == "" {
		return nil, errors.New("OpenAI API key not configured (OPENAI_API_KEY)")
	}
	if s.config.OpenAIBaseURL == "" {
		return nil, errors.New("OpenAI base URL not configured (OPENAI_BASE_URL)")
	}

	// Validate file format
	ext := strings.ToLower(filename[strings.LastIndex(filename, ".")+1:])
	validFormats := map[string]bool{"mp3": true, "wav": true, "m4a": true, "webm": true, "ogg": true, "flac": true}
	if !validFormats[ext] {
		return nil, fmt.Errorf("unsupported audio format: %s", ext)
	}

	// Create multipart form
	var buf bytes.Buffer
	writer := multipart.NewWriter(&buf)

	// Add audio file
	part, err := writer.CreateFormFile("file", filename)
	if err != nil {
		return nil, fmt.Errorf("failed to create form file: %w", err)
	}

	if _, err := io.Copy(part, audioData); err != nil {
		return nil, fmt.Errorf("failed to copy audio data: %w", err)
	}

	// Add model field
	if err := writer.WriteField("model", s.config.WhisperModel); err != nil {
		return nil, fmt.Errorf("failed to write model field: %w", err)
	}

	// Add language hint for Chinese
	if err := writer.WriteField("language", "zh"); err != nil {
		return nil, fmt.Errorf("failed to write language field: %w", err)
	}

	if err := writer.Close(); err != nil {
		return nil, fmt.Errorf("failed to close writer: %w", err)
	}

	// Create request
	req, err := http.NewRequestWithContext(ctx, "POST", s.config.OpenAIBaseURL+"/audio/transcriptions", &buf)
	if err != nil {
		return nil, fmt.Errorf("failed to create request: %w", err)
	}

	req.Header.Set("Authorization", "Bearer "+s.config.OpenAIAPIKey)
	req.Header.Set("Content-Type", writer.FormDataContentType())

	// Send request
	resp, err := s.httpClient.Do(req)
	if err != nil {
		return nil, fmt.Errorf("transcription request failed: %w", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		body, _ := io.ReadAll(resp.Body)
		return nil, fmt.Errorf("transcription failed with status %d: %s", resp.StatusCode, string(body))
	}

	// Parse response
	var result TranscriptionResult
	if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
		return nil, fmt.Errorf("failed to decode response: %w", err)
	}

	return &result, nil
}

// LLMService handles natural language understanding
type LLMService struct {
	config       *config.Config
	httpClient   *http.Client
	accountRepo  *repository.AccountRepository
	categoryRepo *repository.CategoryRepository
}

// NewLLMService creates a new LLMService
func NewLLMService(cfg *config.Config, accountRepo *repository.AccountRepository, categoryRepo *repository.CategoryRepository) *LLMService {
	return &LLMService{
		config: cfg,
		httpClient: &http.Client{
			Timeout: 60 * time.Second, // Increased timeout for slow API responses
		},
		accountRepo:  accountRepo,
		categoryRepo: categoryRepo,
	}
}

// ChatCompletionRequest represents OpenAI chat completion request
type ChatCompletionRequest struct {
	Model       string        `json:"model"`
	Messages    []ChatMessage `json:"messages"`
	Functions   []Function    `json:"functions,omitempty"`
	Temperature float64       `json:"temperature"`
}

// Function represents an OpenAI function definition
type Function struct {
	Name        string                 `json:"name"`
	Description string                 `json:"description"`
	Parameters  map[string]interface{} `json:"parameters"`
}

// ChatCompletionResponse represents OpenAI chat completion response
type ChatCompletionResponse struct {
	Choices []struct {
		Message struct {
			Role         string `json:"role"`
			Content      string `json:"content"`
			FunctionCall *struct {
				Name      string `json:"name"`
				Arguments string `json:"arguments"`
			} `json:"function_call,omitempty"`
		} `json:"message"`
	} `json:"choices"`
}

// extractCustomPrompt 从用户消息中提取自定义 System/Persona prompt
// 如果消息包含 "System:" 或 "Persona:"，则提取其后的内容作为自定义 prompt
func extractCustomPrompt(text string) string {
	prefixes := []string{"System:", "Persona:"}
	for _, prefix := range prefixes {
		if idx := strings.Index(text, prefix); idx != -1 {
			// 提取 prefix 后的内容作为自定义 prompt
			return strings.TrimSpace(text[idx+len(prefix):])
		}
	}
	return ""
}

// ParseIntent extracts transaction parameters from text
// Requirements: 7.1, 7.5, 7.6
func (s *LLMService) ParseIntent(ctx context.Context, text string, history []ChatMessage, userID uint) (*AITransactionParams, string, error) {
	if s.config.OpenAIAPIKey == "" || s.config.OpenAIBaseURL == "" {
		// No API key, return simple parsing result
		simpleParams, simpleMsg, _ := s.parseIntentSimple(text)
		return simpleParams, simpleMsg, nil
	}

	// Fetch user categories for prompt context
	var categoryNamesStr string
	if categories, err := s.categoryRepo.GetAll(userID); err == nil && len(categories) > 0 {
		var names []string
		for _, c := range categories {
			names = append(names, c.Name)
		}
		categoryNamesStr = strings.Join(names, "/")
	}

	// Build messages with history
	var systemPrompt string

	// 检查是否有自定义 System/Persona prompt（用于财务建议等场景）
	if customPrompt := extractCustomPrompt(text); customPrompt != "" {
		systemPrompt = customPrompt
	} else {
		// 使用默认的记账 prompt
		todayDate := time.Now().Format("2006-01-02")

		catPrompt := "2. 分类：根据内容推断，如\"奶茶/咖啡/吃饭\"=餐饮"
		if categoryNamesStr != "" {
			catPrompt = fmt.Sprintf("2. 分类：必须从以下已有分类中选择最匹配的一项：[%s]。例如\"晚餐\"应映射为列表中存在的\"餐饮\"。如果列表无匹配项，则根据常识推断。", categoryNamesStr)
		}

		systemPrompt = fmt.Sprintf(`你是一个智能记账助手。从用户描述中提取记账信息。

今天的日期是%s

规则：
1. 金额：提取数字，如"6元"=6，"十五"=15
%s
3. 类型：默认expense(支出)，除非明确说"收入/工资/奖金/红包"
4. 金额：提取明确的数字。如果用户未提及具体金额（如只说"想吃炸鸡"），amount字段必须返回 0
5. 日期：默认使用今天的日期（%s），除非用户明确指定其他日期
6. 备注：提取关键描述

直接返回JSON，不要解释：
{"amount":数字,"category":"分类","type":"expense或income","note":"备注","date":"YYYY-MM-DD","message":"简短确认"}

示例（假设今天是%s）：
用户："买了6块的奶茶"
返回：{"amount":6,"category":"餐饮","type":"expense","note":"奶茶","date":"%s","message":"记录：餐饮支出6元，奶茶"}`,
			todayDate, catPrompt, todayDate, todayDate, todayDate)
	}

	messages := []ChatMessage{
		{
			Role:    "system",
			Content: systemPrompt,
		},
	}

	// Only add last 2 messages from history to reduce context
	historyLen := len(history)
	if historyLen > 4 {
		history = history[historyLen-4:]
	}
	messages = append(messages, history...)

	// Add current user message
	messages = append(messages, ChatMessage{
		Role:    "user",
		Content: text,
	})

	// Create request
	reqBody := ChatCompletionRequest{
		Model:       s.config.ChatModel,
		Messages:    messages,
		Temperature: 0.1, // Lower temperature for more consistent output
	}

	jsonBody, err := json.Marshal(reqBody)
	if err != nil {
		return nil, "", fmt.Errorf("failed to marshal request: %w", err)
	}

	req, err := http.NewRequestWithContext(ctx, "POST", s.config.OpenAIBaseURL+"/chat/completions", bytes.NewReader(jsonBody))
	if err != nil {
		return nil, "", fmt.Errorf("failed to create request: %w", err)
	}

	req.Header.Set("Authorization", "Bearer "+s.config.OpenAIAPIKey)
	req.Header.Set("Content-Type", "application/json")

	resp, err := s.httpClient.Do(req)
	if err != nil {
		return nil, "", fmt.Errorf("chat request failed: %w", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		body, _ := io.ReadAll(resp.Body)
		return nil, "", fmt.Errorf("chat failed with status %d: %s", resp.StatusCode, string(body))
	}

	var chatResp ChatCompletionResponse
	if err := json.NewDecoder(resp.Body).Decode(&chatResp); err != nil {
		return nil, "", fmt.Errorf("failed to decode response: %w", err)
	}

	if len(chatResp.Choices) == 0 {
		return nil, "", errors.New("no response from AI")
	}

	content := chatResp.Choices[0].Message.Content

	// Remove markdown code block if present (```json ... ```)
	content = strings.TrimSpace(content)
	if strings.HasPrefix(content, "```") {
		// Find the end of the first line (```json or ```)
		if idx := strings.Index(content, "\n"); idx != -1 {
			content = content[idx+1:]
		}
		// Remove trailing ```
		if idx := strings.LastIndex(content, "```"); idx != -1 {
			content = content[:idx]
		}
		content = strings.TrimSpace(content)
	}

	// Parse JSON response
	var parsed struct {
		Amount   *float64 `json:"amount"`
		Category string   `json:"category"`
		Type     string   `json:"type"`
		Note     string   `json:"note"`
		Date     string   `json:"date"`
		Message  string   `json:"message"`
	}

	if err := json.Unmarshal([]byte(content), &parsed); err != nil {
		// If not JSON, return as message
		return nil, content, nil
	}

	params := &AITransactionParams{
		Amount:   parsed.Amount,
		Category: parsed.Category,
		Type:     parsed.Type,
		Note:     parsed.Note,
		Date:     parsed.Date,
	}

	return params, parsed.Message, nil
}

// parseIntentSimple provides simple regex-based parsing as fallback
// This is also used as a fast path for simple inputs
func (s *LLMService) parseIntentSimple(text string) (*AITransactionParams, string, error) {
	params := &AITransactionParams{
		Type: "expense", // Default to expense
		Date: time.Now().Format("2006-01-02"),
	}

	// Extract amount using regex - support various formats
	amountPatterns := []string{
		`(\d+(?:\.\d+)?)\s*(?:元|块|￥|¥|块钱|元钱)`,
		`(?:花了?|付了?|买了?|消费)\s*(\d+(?:\.\d+)?)`,
		`(\d+(?:\.\d+)?)\s*(?:的|块的)`,
	}

	for _, pattern := range amountPatterns {
		amountRegex := regexp.MustCompile(pattern)
		if matches := amountRegex.FindStringSubmatch(text); len(matches) > 1 {
			if amount, err := strconv.ParseFloat(matches[1], 64); err == nil {
				params.Amount = &amount
				break
			}
		}
	}

	// If still no amount, try simple number extraction
	if params.Amount == nil {
		simpleAmountRegex := regexp.MustCompile(`(\d+(?:\.\d+)?)`)
		if matches := simpleAmountRegex.FindStringSubmatch(text); len(matches) > 1 {
			if amount, err := strconv.ParseFloat(matches[1], 64); err == nil {
				params.Amount = &amount
			}
		}
	}

	// Enhanced category detection with priority
	categoryPatterns := []struct {
		keywords []string
		category string
	}{
		{[]string{"奶茶", "咖啡", "茶", "饮料", "柠檬", "果汁"}, "餐饮"},
		{[]string{"吃", "喝", "餐", "外卖", "饭", "面", "粉", "粥", "包子", "早餐", "午餐", "晚餐", "宵夜"}, "餐饮"},
		{[]string{"打车", "滴滴", "出租", "的士", "uber", "曹操"}, "交通"},
		{[]string{"地铁", "公交", "公车", "巴士", "轻轨", "高铁", "火车", "飞机", "机票"}, "交通"},
		{[]string{"加油", "油费", "停车", "过路费"}, "交通"},
		{[]string{"超市", "便利店", "商场", "购物", "淘宝", "京东", "拼多多"}, "购物"},
		{[]string{"买", "购"}, "购物"},
		{[]string{"水电", "电费", "水费", "燃气", "煤气", "物业"}, "生活缴费"},
		{[]string{"房租", "租金", "房贷"}, "住房"},
		{[]string{"电影", "游戏", "KTV", "唱歌", "娱乐", "玩"}, "娱乐"},
		{[]string{"医院", "药", "看病", "挂号", "医疗"}, "医疗"},
		{[]string{"话费", "流量", "充值", "手机费"}, "通讯"},
		{[]string{"工资", "薪水", "薪资", "月薪"}, "工资"},
		{[]string{"奖金", "年终奖", "绩效"}, "奖金"},
		{[]string{"红包", "转账", "收款"}, "其他收入"},
	}

	for _, cp := range categoryPatterns {
		for _, keyword := range cp.keywords {
			if strings.Contains(text, keyword) {
				params.Category = cp.category
				break
			}
		}
		if params.Category != "" {
			break
		}
	}

	// Default category if not detected
	if params.Category == "" {
		params.Category = "其他"
	}

	// Detect income keywords
	incomeKeywords := []string{"工资", "薪", "奖金", "红包", "收入", "进账", "到账", "收到", "收款"}
	for _, keyword := range incomeKeywords {
		if strings.Contains(text, keyword) {
			params.Type = "income"
			break
		}
	}

	// Extract note - remove amount and common words
	note := text
	if params.Amount != nil {
		note = regexp.MustCompile(`\d+(?:\.\d+)?\s*(?:元|块|￥|¥|块钱|元钱)?`).ReplaceAllString(note, "")
	}
	note = strings.TrimSpace(note)
	// Remove common filler words
	fillerWords := []string{"买了", "花了", "付了", "消费了", "一个", "一条", "一份", "的"}
	for _, word := range fillerWords {
		note = strings.ReplaceAll(note, word, "")
	}
	note = strings.TrimSpace(note)
	if note != "" {
		params.Note = note
	}

	// Generate response message
	var message string
	if params.Amount == nil {
		message = "请问金额是多少？"
	} else {
		typeLabel := "支出"
		if params.Type == "income" {
			typeLabel = "收入"
		}
		message = fmt.Sprintf("记录：%s %.2f元，分类：%s", typeLabel, *params.Amount, params.Category)
		if params.Note != "" {
			message += "，备注：" + params.Note
		}
	}

	return params, message, nil
}

// GenerateReport generates a report based on the provided prompt using LLM
func (s *LLMService) GenerateReport(ctx context.Context, prompt string) (string, error) {
	if s.config.OpenAIAPIKey == "" || s.config.OpenAIBaseURL == "" {
		return "", errors.New("OpenAI API not configured")
	}

	messages := []ChatMessage{
		{
			Role:    "user",
			Content: prompt,
		},
	}

	reqBody := ChatCompletionRequest{
		Model:       s.config.ChatModel,
		Messages:    messages,
		Temperature: 0.7, // Higher temperature for creative insights
	}

	jsonBody, err := json.Marshal(reqBody)
	if err != nil {
		return "", fmt.Errorf("failed to marshal request: %w", err)
	}

	req, err := http.NewRequestWithContext(ctx, "POST", s.config.OpenAIBaseURL+"/chat/completions", bytes.NewReader(jsonBody))
	if err != nil {
		return "", fmt.Errorf("failed to create request: %w", err)
	}

	req.Header.Set("Authorization", "Bearer "+s.config.OpenAIAPIKey)
	req.Header.Set("Content-Type", "application/json")

	resp, err := s.httpClient.Do(req)
	if err != nil {
		return "", fmt.Errorf("generate report request failed: %w", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		body, _ := io.ReadAll(resp.Body)
		return "", fmt.Errorf("generate report failed with status %d: %s", resp.StatusCode, string(body))
	}

	var chatResp ChatCompletionResponse
	if err := json.NewDecoder(resp.Body).Decode(&chatResp); err != nil {
		return "", fmt.Errorf("failed to decode response: %w", err)
	}

	if len(chatResp.Choices) == 0 {
		return "", errors.New("no response from AI")
	}

	return chatResp.Choices[0].Message.Content, nil
}

// MapAccountName maps natural language account name to account ID
func (s *LLMService) MapAccountName(ctx context.Context, name string, userID uint) (*uint, string, error) {
	if name == "" {
		return nil, "", nil
	}

	accounts, err := s.accountRepo.GetAll(userID)
	if err != nil {
		return nil, "", err
	}

	// Try exact match first
	for _, acc := range accounts {
		if strings.EqualFold(acc.Name, name) {
			return &acc.ID, acc.Name, nil
		}
	}

	// Try partial match
	for _, acc := range accounts {
		if strings.Contains(strings.ToLower(acc.Name), strings.ToLower(name)) ||
			strings.Contains(strings.ToLower(name), strings.ToLower(acc.Name)) {
			return &acc.ID, acc.Name, nil
		}
	}

	return nil, "", nil
}

// MapCategoryName maps natural language category name to category ID
func (s *LLMService) MapCategoryName(ctx context.Context, name string, txType string, userID uint) (*uint, string, error) {
	if name == "" {
		return nil, "", nil
	}

	categories, err := s.categoryRepo.GetAll(userID)
	if err != nil {
		return nil, "", err
	}

	// Filter by transaction type
	var filtered []models.Category
	for _, cat := range categories {
		if (txType == "expense" && cat.Type == "expense") ||
			(txType == "income" && cat.Type == "income") ||
			txType == "" {
			filtered = append(filtered, cat)
		}
	}

	// Try exact match first
	for _, cat := range filtered {
		if strings.EqualFold(cat.Name, name) {
			return &cat.ID, cat.Name, nil
		}
	}

	// Try partial match
	for _, cat := range filtered {
		if strings.Contains(strings.ToLower(cat.Name), strings.ToLower(name)) ||
			strings.Contains(strings.ToLower(name), strings.ToLower(cat.Name)) {
			return &cat.ID, cat.Name, nil
		}
	}

	return nil, "", nil
}

// generateSessionID generates a unique session ID
func generateSessionID() string {
	return fmt.Sprintf("ai_%d_%d", time.Now().UnixNano(), time.Now().Unix()%1000)
}

// getOrCreateSession gets existing session or creates new one
func (s *AIBookkeepingService) getOrCreateSession(sessionID string, userID uint) *AISession {
	s.sessionMutex.Lock()
	defer s.sessionMutex.Unlock()

	if sessionID != "" {
		if session, ok := s.sessions[sessionID]; ok {
			if time.Now().Before(session.ExpiresAt) {
				return session
			}
			delete(s.sessions, sessionID)
		}
	}

	// Create new session
	newID := generateSessionID()
	session := &AISession{
		ID:        newID,
		UserID:    userID,
		Params:    &AITransactionParams{},
		Messages:  []ChatMessage{},
		CreatedAt: time.Now(),
		ExpiresAt: time.Now().Add(s.config.AISessionTimeout),
	}
	s.sessions[newID] = session
	return session
}

// cleanupExpiredSessions periodically removes expired sessions
func (s *AIBookkeepingService) cleanupExpiredSessions() {
	ticker := time.NewTicker(5 * time.Minute)
	for range ticker.C {
		s.sessionMutex.Lock()
		now := time.Now()
		for id, session := range s.sessions {
			if now.After(session.ExpiresAt) {
				delete(s.sessions, id)
			}
		}
		s.sessionMutex.Unlock()
	}
}

// ProcessChat processes a chat message and returns AI response
// Requirements: 7.2-7.4, 7.7-7.10, 12.5, 12.8
func (s *AIBookkeepingService) ProcessChat(ctx context.Context, userID uint, sessionID string, message string) (*AIChatResponse, error) {
	session := s.getOrCreateSession(sessionID, userID)

	// Add user message to history
	session.Messages = append(session.Messages, ChatMessage{
		Role:    "user",
		Content: message,
	})

	// 1. 获取财务上下文（用于所有高级功能）
	fc, err := s.GetUserFinancialContext(ctx, userID)
	if err != nil {
		// 降级处理，不中断流程
		fmt.Printf("Failed to get financial context: %v\n", err)
	}

	// 2. 检测纯查询意图（预算、资产、统计）
	queryIntent := s.detectQueryIntent(message)
	if queryIntent != "" && fc != nil {
		responseMsg := s.handleQueryIntent(ctx, queryIntent, message, fc)

		response := &AIChatResponse{
			SessionID: session.ID,
			Message:   responseMsg,
			Intent:    queryIntent,
			Params:    session.Params, // 保持参数上下文
		}

		// 记录 AI 回复
		session.Messages = append(session.Messages, ChatMessage{
			Role:    "assistant",
			Content: response.Message,
		})
		return response, nil
	}

	// 3. 检测消费建议意图（想吃/想买/想喝等）
	isSpendingAdvice := s.isSpendingAdviceIntent(message)

	// Parse intent for transaction
	params, responseMsg, err := s.llmService.ParseIntent(ctx, message, session.Messages[:len(session.Messages)-1], userID)
	if err != nil {
		return nil, fmt.Errorf("failed to parse intent: %w", err)
	}

	// Merge with existing session params
	if params != nil {
		s.mergeParams(session.Params, params)
	}

	// Map account and category names to IDs
	if session.Params.Account != "" && session.Params.AccountID == nil {
		accountID, accountName, _ := s.llmService.MapAccountName(ctx, session.Params.Account, userID)
		if accountID != nil {
			session.Params.AccountID = accountID
			session.Params.Account = accountName
		}
	}

	if session.Params.Category != "" && session.Params.CategoryID == nil {
		categoryID, categoryName, _ := s.llmService.MapCategoryName(ctx, session.Params.Category, session.Params.Type, userID)
		if categoryID != nil {
			session.Params.CategoryID = categoryID
			session.Params.Category = categoryName
		}
	}

	// If category still not mapped, try to get a default category
	if session.Params.CategoryID == nil && session.Params.Category != "" {
		defaultCategoryID, defaultCategoryName := s.getDefaultCategory(userID, session.Params.Type)
		if defaultCategoryID != nil {
			session.Params.CategoryID = defaultCategoryID
			if session.Params.Category == "" {
				session.Params.Category = defaultCategoryName
			}
		}
	}

	// If no account specified, use default account
	if session.Params.AccountID == nil {
		defaultAccountID, defaultAccountName := s.getDefaultAccount(userID, session.Params.Type)
		if defaultAccountID != nil {
			session.Params.AccountID = defaultAccountID
			session.Params.Account = defaultAccountName
		}
	}

	// 初始化响应
	response := &AIChatResponse{
		SessionID: session.ID,
		Message:   responseMsg,
		Intent:    "create_transaction",
		Params:    session.Params,
	}

	// 4. 处理消费建议意图
	// 即使没有金额，如果用户是在寻求建议（如“吃什么”），也应该进入建议流程
	if isSpendingAdvice {
		response.Intent = "spending_advice"
		advice := s.generateSpendingAdvice(ctx, message, session.Params, fc)
		if advice != "" {
			response.Message = advice
		}
	}

	// Check what's missing for transaction creation
	missingFields := s.getMissingFields(session.Params)
	if len(missingFields) > 0 {
		response.NeedsFollowUp = true
		response.FollowUpQuestion = s.generateFollowUpQuestion(ctx, missingFields, message, fc)
		// 如果有了更好的建议回复（来自 handleQuery 或 spendingAdvice），且是 FollowUp，优先保留建议的部分内容或组合
		if response.Message == "" || response.Message == responseMsg {
			response.Message = response.FollowUpQuestion
		}
	} else {
		// All params complete, generate confirmation card
		card := s.GenerateConfirmationCard(session)
		response.ConfirmationCard = card

		// 如果不是消费建议，使用标准确认消息
		if !isSpendingAdvice {
			response.Message = fmt.Sprintf("请确认：%s %.2f元，分类：%s，账户：%s",
				s.getTypeLabel(session.Params.Type),
				*session.Params.Amount,
				session.Params.Category,
				session.Params.Account)
		} else {
			// 消费建议场景，在建议后附加确认提示
			response.Message += fmt.Sprintf("\n\n📝 需要记账吗？%s %.2f元",
				s.getTypeLabel(session.Params.Type),
				*session.Params.Amount)
		}
	}

	// Add assistant response to history
	session.Messages = append(session.Messages, ChatMessage{
		Role:    "assistant",
		Content: response.Message,
	})

	return response, nil
}

// detectQueryIntent 检测用户查询意图
func (s *AIBookkeepingService) detectQueryIntent(message string) string {
	budgetKeywords := []string{"预算", "剩多少", "还能花", "余额"} // 注意：余额可能指账户余额，这里简化处理
	assetKeywords := []string{"资产", "多少钱", "家底", "存款", "身家", "总钱"}
	statsKeywords := []string{"花了多少", "支出", "账单", "消费", "统计"}

	for _, kw := range budgetKeywords {
		if strings.Contains(message, kw) {
			return "query_budget"
		}
	}
	for _, kw := range assetKeywords {
		if strings.Contains(message, kw) {
			return "query_assets"
		}
	}
	for _, kw := range statsKeywords {
		if strings.Contains(message, kw) {
			return "query_stats"
		}
	}
	return ""
}

// handleQueryIntent 处理查询意图并生成 LLM 回复
func (s *AIBookkeepingService) handleQueryIntent(ctx context.Context, intent string, message string, fc *FinancialContext) string {
	if s.config.OpenAIAPIKey == "" {
		return "抱歉，我的大脑（API Key）似乎离家出走了，无法思考..."
	}

	// 计算人设模式
	personaMode := "balance" // 默认平衡
	healthScore := 60        // 默认及格

	// 升级版健康分计算 (结合负债率)
	if fc.TotalAssets > 0 {
		// 基础分：资产/负债比
		ratio := (fc.TotalAssets - fc.TotalLiabilities) / fc.TotalAssets
		healthScore = 40 + int(ratio*50)

		// 负债率惩罚
		if fc.DebtRatio > 0.5 {
			healthScore -= 20
		}
		if fc.DebtRatio > 0.8 {
			healthScore -= 20 // 严重扣分
		}
	} else if fc.TotalLiabilities > 0 {
		// 资不抵债
		healthScore = 10
	}

	if healthScore > 80 {
		personaMode = "rich"
	} else if healthScore <= 40 {
		personaMode = "poor"
	}

	// 构建 Prompt
	systemPrompt := fmt.Sprintf(`你是「小金」，Novault 的首席财务 AI。
当前模式：%s (根据用户财务健康分 %d 判定)

角色设定：
- **rich (富裕)**：撒娇卖萌，夸用户会赚钱，鼓励适度享受。用词：哎哟、不错哦、老板大气。
- **balance (平衡)**：理性贴心，温和提醒。用词：虽然、但是、建议。
- **poor (吃土)**：毒舌、阴阳怪气、恨铁不成钢。用词：啧啧、清醒点、吃土、西北风。

用户意图：%s
用户问题：「%s」

财务数据上下文：
%s

要求：
1. 根据意图提取并回答关键数据（预算剩余、总资产、或本月支出）。
2. 必须符合当前人设模式的语气。
3. **不需要限制字数**，想说多少说多少，关键是要“有梗”和“有趣”。
4. 可以尽情使用比喻、夸张、反讽、网络流行语。
5. 不要罗列所有数据，只回答用户问的，但是回答的方式要出人意料。`,
		personaMode, healthScore, intent, message, s.formatFinancialContextForLLM(fc))

	messages := []ChatMessage{
		{Role: "system", Content: systemPrompt},
		{Role: "user", Content: message},
	}

	return s.callLLM(ctx, messages)
}

// formatFinancialContextForLLM 格式化上下文给 LLM
func (s *AIBookkeepingService) formatFinancialContextForLLM(fc *FinancialContext) string {
	data, _ := json.MarshalIndent(fc, "", "  ")
	return string(data)
}

// callLLM 通用 LLM 调用 helper
func (s *AIBookkeepingService) callLLM(ctx context.Context, messages []ChatMessage) string {
	reqBody := ChatCompletionRequest{
		Model:       s.config.ChatModel,
		Messages:    messages,
		Temperature: 0.8, // 稍微调高以增加人设表现力
	}

	jsonBody, _ := json.Marshal(reqBody)
	req, err := http.NewRequestWithContext(ctx, "POST", s.config.OpenAIBaseURL+"/chat/completions", bytes.NewReader(jsonBody))
	if err != nil {
		return "思考中断..."
	}
	req.Header.Set("Authorization", "Bearer "+s.config.OpenAIAPIKey)
	req.Header.Set("Content-Type", "application/json")

	resp, err := s.llmService.httpClient.Do(req)
	if err != nil || resp.StatusCode != http.StatusOK {
		return "大脑短路了..."
	}
	defer resp.Body.Close()

	var chatResp ChatCompletionResponse
	if err := json.NewDecoder(resp.Body).Decode(&chatResp); err != nil || len(chatResp.Choices) == 0 {
		return "..."
	}
	return strings.TrimSpace(chatResp.Choices[0].Message.Content)
}

// isSpendingAdviceIntent 检测是否为消费建议意图
func (s *AIBookkeepingService) isSpendingAdviceIntent(message string) bool {
	keywords := []string{"想吃", "想喝", "想买", "想花", "打算买", "准备买", "要不要", "可以买", "能买", "想要", "推荐", "吃什么", "喝什么", "买什么"}
	for _, kw := range keywords {
		if strings.Contains(message, kw) {
			return true
		}
	}
	return false
}

// generateSpendingAdvice 生成消费建议
func (s *AIBookkeepingService) generateSpendingAdvice(ctx context.Context, message string, params *AITransactionParams, fc *FinancialContext) string {
	if s.config.OpenAIAPIKey == "" || fc == nil {
		if params.Amount != nil {
			return fmt.Sprintf("记下来！%.0f元的%s", *params.Amount, params.Note)
		}
		return ""
	}

	// 动态人设逻辑
	personaMode := "balance"
	healthScore := 60
	if fc.TotalAssets > 0 {
		ratio := (fc.TotalAssets - fc.TotalLiabilities) / fc.TotalAssets
		healthScore = 40 + int(ratio*50)
		if fc.DebtRatio > 0.5 {
			healthScore -= 20
		}
	} else if fc.TotalLiabilities > 0 {
		healthScore = 10
	}

	if healthScore > 80 {
		personaMode = "rich"
	} else if healthScore <= 40 {
		personaMode = "poor"
	}

	prompt := fmt.Sprintf(`你是「小金」，Novault 的首席财务 AI。
当前模式：%s (根据用户财务健康分 %d 判定)
角色设定：
- **rich**: 鼓励享受，语气轻松。
- **balance**: 理性建议，温和提醒。
- **poor**: 毒舌劝阻，语气严厉。

用户说：「%s」
财务数据：
%s

请分析消费请求，给出建议。
要求：
1. 不要加前缀，直接回复。
2. **尽情发挥戏剧性**：如果是 rich 模式，就极尽奢华浮夸之能事；如果是 poor 模式，就极尽刻薄毒舌之能事。
3. 可以“顾左右而言他”，不一定非要正面回答买不买，可以吐槽商品、吐槽用户、吐槽世界。
4. 让用户觉得你是一个有独立思想的“杠精”或“捧哏”，而不是一个莫得感情的计算器。`,
		personaMode, healthScore, message, s.formatFinancialContextForLLM(fc))

	messages := []ChatMessage{
		{Role: "user", Content: prompt},
	}

	return s.callLLM(ctx, messages)
}

// mergeParams merges new params into existing params
func (s *AIBookkeepingService) mergeParams(existing, new *AITransactionParams) {
	if new.Amount != nil {
		existing.Amount = new.Amount
	}
	if new.Category != "" {
		existing.Category = new.Category
	}
	if new.CategoryID != nil {
		existing.CategoryID = new.CategoryID
	}
	if new.Account != "" {
		existing.Account = new.Account
	}
	if new.AccountID != nil {
		existing.AccountID = new.AccountID
	}
	if new.Type != "" {
		existing.Type = new.Type
	}
	if new.Date != "" {
		existing.Date = new.Date
	}
	if new.Note != "" {
		existing.Note = new.Note
	}
}

// getDefaultAccount gets the default account based on transaction type
// If no default is set, returns the first available account
func (s *AIBookkeepingService) getDefaultAccount(userID uint, txType string) (*uint, string) {
	// First try to get user's configured default account
	settings, err := s.userSettingsRepo.GetOrCreate(userID)
	if err == nil && settings != nil {
		var accountID *uint
		if txType == "expense" && settings.DefaultExpenseAccountID != nil {
			accountID = settings.DefaultExpenseAccountID
		} else if txType == "income" && settings.DefaultIncomeAccountID != nil {
			accountID = settings.DefaultIncomeAccountID
		}

		if accountID != nil {
			account, err := s.accountRepo.GetByID(userID, *accountID)
			if err == nil && account != nil {
				return accountID, account.Name
			}
		}
	}

	// Fallback: get the first available account
	accounts, err := s.accountRepo.GetAll(userID)
	if err != nil || len(accounts) == 0 {
		return nil, ""
	}

	// Return the first account (usually sorted by sort_order)
	return &accounts[0].ID, accounts[0].Name
}

// getDefaultCategory gets the first category of the given type
func (s *AIBookkeepingService) getDefaultCategory(userID uint, txType string) (*uint, string) {
	categories, err := s.categoryRepo.GetAll(userID)
	if err != nil || len(categories) == 0 {
		return nil, ""
	}

	// Find the first category matching the transaction type
	categoryType := "expense"
	if txType == "income" {
		categoryType = "income"
	}

	for _, cat := range categories {
		if string(cat.Type) == categoryType {
			return &cat.ID, cat.Name
		}
	}

	// If no matching type found, return the first category
	return &categories[0].ID, categories[0].Name
}

// getMissingFields returns list of missing required fields
func (s *AIBookkeepingService) getMissingFields(params *AITransactionParams) []string {
	var missing []string
	if params.Amount == nil || *params.Amount <= 0 {
		missing = append(missing, "amount")
	}
	if params.CategoryID == nil && params.Category == "" {
		missing = append(missing, "category")
	}
	if params.AccountID == nil && params.Account == "" {
		missing = append(missing, "account")
	}
	return missing
}

// generateFollowUpQuestion generates a follow-up question for missing fields using LLM
func (s *AIBookkeepingService) generateFollowUpQuestion(ctx context.Context, missing []string, userMessage string, fc *FinancialContext) string {
	if len(missing) == 0 {
		return ""
	}

	fieldNames := map[string]string{
		"amount":   "金额",
		"category": "分类",
		"account":  "账户",
	}

	var names []string
	for _, field := range missing {
		if name, ok := fieldNames[field]; ok {
			names = append(names, name)
		}
	}
	missingStr := strings.Join(names, "、")

	// 如果没有 API Key，降级到模板回复
	if s.config.OpenAIAPIKey == "" {
		if len(names) == 1 {
			return fmt.Sprintf("请问%s是多少？", names[0])
		}
		return fmt.Sprintf("请补充以下信息：%s", missingStr)
	}

	// 动态人设逻辑
	personaMode := "balance"
	healthScore := 60
	if fc != nil && fc.TotalAssets > 0 {
		ratio := (fc.TotalAssets - fc.TotalLiabilities) / fc.TotalAssets
		healthScore = 40 + int(ratio*50)
	}
	if healthScore > 80 {
		personaMode = "rich"
	} else if healthScore <= 40 {
		personaMode = "poor"
	}

	prompt := fmt.Sprintf(`你是「小金」，一个贱萌、毒舌、幽默的 AI 记账助手。
当前模式：%s
缺失信息：%s
用户说：「%s」

请用你的风格追问用户缺失的信息。
要求：
1. 针对缺失的 "%s"，用幽默、调侃、甚至一点点“攻击性”的方式追问。
2. **拒绝机械模板**：不要每次都问一样的话，要根据心情随机应变。
3. 比如缺失金额，可以问"是白嫖的吗？"、"价格是国家机密吗？"、"快说花了多少，让我死心"。
4. 比如缺失分类，可以猜"这属于吃喝玩乐哪一类？"、"是用来填饱肚子的还是填补空虚的？"。
5. 字数不限，关键是要**有灵魂**，像个真人在聊天。`,
		personaMode, missingStr, userMessage, missingStr)

	messages := []ChatMessage{
		{Role: "user", Content: prompt},
	}

	answer := s.callLLM(ctx, messages)
	if answer == "" || answer == "..." {
		return fmt.Sprintf("那个...你能告诉我%s吗？", missingStr)
	}
	return answer
}

// getTypeLabel returns Chinese label for transaction type
func (s *AIBookkeepingService) getTypeLabel(txType string) string {
	if txType == "income" {
		return "收入"
	}
	return "支出"
}

// GenerateConfirmationCard creates a confirmation card from session params
func (s *AIBookkeepingService) GenerateConfirmationCard(session *AISession) *ConfirmationCard {
	params := session.Params

	card := &ConfirmationCard{
		SessionID:  session.ID,
		Type:       params.Type,
		Note:       params.Note,
		IsComplete: true,
	}

	if params.Amount != nil {
		card.Amount = *params.Amount
	}
	if params.CategoryID != nil {
		card.CategoryID = *params.CategoryID
	}
	card.Category = params.Category
	if params.AccountID != nil {
		card.AccountID = *params.AccountID
	}
	card.Account = params.Account

	// Set date
	if params.Date != "" {
		card.Date = params.Date
	} else {
		card.Date = time.Now().Format("2006-01-02")
	}

	// Check for budget warnings
	if params.Amount != nil && *params.Amount > 0 && params.Type == "expense" {
		card.Warning = s.checkBudgetWarning(session.UserID, params.CategoryID, *params.Amount)
	}

	return card
}

// checkBudgetWarning checks if the transaction exceeds any budget
func (s *AIBookkeepingService) checkBudgetWarning(userID uint, categoryID *uint, amount float64) string {
	now := time.Now()
	var budgets []models.Budget

	// Find active budgets
	// We check:
	// 1. Budgets specifically for this category
	// 2. Global budgets (CategoryID is NULL)
	query := s.db.Where("user_id = ?", userID).
		Where("start_date <= ?", now).
		Where("end_date IS NULL OR end_date >= ?", now)

	if categoryID != nil {
		query = query.Where("category_id = ? OR category_id IS NULL", *categoryID)
	} else {
		query = query.Where("category_id IS NULL")
	}

	if err := query.Find(&budgets).Error; err != nil {
		return ""
	}

	for _, budget := range budgets {
		// Calculate current period
		start, end := s.calculateBudgetPeriod(&budget, now)

		// Query spent amount
		var totalSpent float64
		q := s.db.Model(&models.Transaction{}).
			Where("user_id = ? AND type = ? AND transaction_date BETWEEN ? AND ?",
				userID, models.TransactionTypeExpense, start, end)

		if budget.CategoryID != nil {
			// Get sub-categories
			var subCategoryIDs []uint
			s.db.Model(&models.Category{}).Where("parent_id = ?", *budget.CategoryID).Pluck("id", &subCategoryIDs)
			categoryIDs := append(subCategoryIDs, *budget.CategoryID)
			q = q.Where("category_id IN ?", categoryIDs)
		}
		// If budget has account restriction, we should ideally check that too,
		// but we don't always have accountID resolved here perfectly or it might be complex.
		// For now, focusing on category budgets which are most common.

		q.Select("COALESCE(SUM(amount), 0)").Scan(&totalSpent)

		if totalSpent+amount > budget.Amount {
			remaining := budget.Amount - totalSpent
			if remaining < 0 {
				remaining = 0
			}
			return fmt.Sprintf("⚠️ 预算预警：此交易将使【%s】预算超支 (当前剩余 %.2f)", budget.Name, remaining)
		}
	}
	return ""
}

// TranscribeAudio transcribes audio and returns text
func (s *AIBookkeepingService) TranscribeAudio(ctx context.Context, audioData io.Reader, filename string) (*TranscriptionResult, error) {
	return s.whisperService.TranscribeAudio(ctx, audioData, filename)
}

// ConfirmTransaction creates a transaction from confirmed card
// Requirements: 7.10
func (s *AIBookkeepingService) ConfirmTransaction(ctx context.Context, sessionID string, userID uint) (*models.Transaction, error) {
	s.sessionMutex.RLock()
	session, ok := s.sessions[sessionID]
	s.sessionMutex.RUnlock()

	if !ok {
		return nil, errors.New("session not found or expired")
	}

	params := session.Params

	// Validate required fields
	if params.Amount == nil || *params.Amount <= 0 {
		return nil, errors.New("无效的金额")
	}
	if params.CategoryID == nil {
		return nil, errors.New("未指定分类")
	}
	if params.AccountID == nil {
		return nil, errors.New("未指定账户")
	}

	// Parse date
	var txDate time.Time
	if params.Date != "" {
		var err error
		txDate, err = time.Parse("2006-01-02", params.Date)
		if err != nil {
			txDate = time.Now()
		}
	} else {
		txDate = time.Now()
	}

	// Determine transaction type
	txType := models.TransactionTypeExpense
	if params.Type == "income" {
		txType = models.TransactionTypeIncome
	}

	var transaction *models.Transaction

	// Execute within a database transaction to ensure atomicity
	err := s.db.Transaction(func(tx *gorm.DB) error {
		txAccountRepo := repository.NewAccountRepository(tx)
		txTransactionRepo := repository.NewTransactionRepository(tx)

		// Get account first to check balance
		account, err := txAccountRepo.GetByID(userID, *params.AccountID)
		if err != nil {
			return fmt.Errorf("failed to find account: %w", err)
		}

		// Calculate new balance
		newBalance := account.Balance
		if txType == models.TransactionTypeExpense {
			newBalance -= *params.Amount
		} else {
			newBalance += *params.Amount
		}

		// Critical Check: Prevent negative balance for non-credit accounts
		if !account.IsCredit && newBalance < 0 {
			return fmt.Errorf("余额不足：账户“%s”不支持负余额 (当前: %.2f, 尝试扣款: %.2f)",
				account.Name, account.Balance, *params.Amount)
		}

		// Create transaction model
		transaction = &models.Transaction{
			UserID:          userID,
			Amount:          *params.Amount,
			Type:            txType,
			CategoryID:      *params.CategoryID,
			AccountID:       *params.AccountID,
			TransactionDate: txDate,
			Note:            params.Note,
			Currency:        models.Currency(account.Currency), // Use account currency
		}
		if transaction.Currency == "" {
			transaction.Currency = "CNY"
		}

		// Save transaction
		if err := txTransactionRepo.Create(transaction); err != nil {
			return fmt.Errorf("failed to create transaction: %w", err)
		}

		// Update account balance
		account.Balance = newBalance
		if err := txAccountRepo.Update(account); err != nil {
			return fmt.Errorf("failed to update account balance: %w", err)
		}

		return nil
	})

	if err != nil {
		return nil, err
	}

	// Clean up session only on success
	s.sessionMutex.Lock()
	delete(s.sessions, sessionID)
	s.sessionMutex.Unlock()

	return transaction, nil
}

// GetSession returns session by ID
func (s *AIBookkeepingService) GetSession(sessionID string) (*AISession, bool) {
	s.sessionMutex.RLock()
	defer s.sessionMutex.RUnlock()

	session, ok := s.sessions[sessionID]
	if !ok || time.Now().After(session.ExpiresAt) {
		return nil, false
	}
	return session, true
}

// FinancialContext 用户财务上下文，供 AI 综合分析
type FinancialContext struct {
	// 账户信息
	TotalBalance     float64        `json:"total_balance"`     // 净资产 (资产 - 负债)
	TotalAssets      float64        `json:"total_assets"`      // 总资产
	TotalLiabilities float64        `json:"total_liabilities"` // 总负债
	DebtRatio        float64        `json:"debt_ratio"`        // 负债率 (0-1)
	AccountSummary   []AccountBrief `json:"account_summary"`   // 账户摘要

	// 最近消费
	Last30DaysSpend    float64            `json:"last_30_days_spend"`  // 近30天支出
	Last7DaysSpend     float64            `json:"last_7_days_spend"`   // 近7天支出
	TodaySpend         float64            `json:"today_spend"`         // 今日支出
	MaxSingleSpend     *TransactionBrief  `json:"max_single_spend"`    // 本月最大单笔支出
	TopCategories      []CategorySpend    `json:"top_categories"`      // 消费大类TOP3
	RecentTransactions []TransactionBrief `json:"recent_transactions"` // 最近5笔交易
	UpcomingRecurring  []string           `json:"upcoming_recurring"`  // 未来7天固定支出提醒

	// 预算与目标
	ActiveBudgets   []BudgetBrief `json:"active_budgets"`   // 活跃预算
	BudgetWarnings  []string      `json:"budget_warnings"`  // 预算警告
	SavingsProgress []string      `json:"savings_progress"` // 存钱进度摘要

	// 历史对比
	LastMonthSpend float64 `json:"last_month_spend"` // 上月同期支出
	SpendTrend     string  `json:"spend_trend"`      // 消费趋势: up/down/stable
}

// AccountBrief 账户摘要
type AccountBrief struct {
	Name    string  `json:"name"`
	Balance float64 `json:"balance"`
	Type    string  `json:"type"`
}

// CategorySpend 分类消费
type CategorySpend struct {
	Category string  `json:"category"`
	Amount   float64 `json:"amount"`
	Percent  float64 `json:"percent"`
}

// TransactionBrief 交易摘要
type TransactionBrief struct {
	Amount   float64 `json:"amount"`
	Category string  `json:"category"`
	Note     string  `json:"note"`
	Date     string  `json:"date"`
	Type     string  `json:"type"`
}

// BudgetBrief 预算摘要
type BudgetBrief struct {
	Name        string  `json:"name"`
	Amount      float64 `json:"amount"`
	Spent       float64 `json:"spent"`
	Remaining   float64 `json:"remaining"`
	Progress    float64 `json:"progress"` // 0-100
	IsNearLimit bool    `json:"is_near_limit"`
	Category    string  `json:"category,omitempty"`
}

// GetUserFinancialContext 获取用户财务上下文
func (s *AIBookkeepingService) GetUserFinancialContext(ctx context.Context, userID uint) (*FinancialContext, error) {
	fc := &FinancialContext{}

	// 1. 获取账户信息
	accounts, err := s.accountRepo.GetAll(userID)
	if err == nil {
		for _, acc := range accounts {
			fc.TotalBalance += acc.Balance

			// 根据余额正负判断资产/负债
			// 余额 >= 0 计入资产
			// 余额 < 0 计入负债（取绝对值）
			if acc.Balance >= 0 {
				fc.TotalAssets += acc.Balance
			} else {
				fc.TotalLiabilities += -acc.Balance
			}

			fc.AccountSummary = append(fc.AccountSummary, AccountBrief{
				Name:    acc.Name,
				Balance: acc.Balance,
				Type:    string(acc.Type),
			})
		}
	}

	// 2. 获取最近交易统计
	now := time.Now()
	today := time.Date(now.Year(), now.Month(), now.Day(), 0, 0, 0, 0, now.Location())
	last7Days := today.AddDate(0, 0, -7)
	last30Days := today.AddDate(0, 0, -30)
	lastMonthStart := today.AddDate(0, -1, -today.Day()+1)
	lastMonthEnd := today.AddDate(0, 0, -today.Day())

	// 获取近30天交易
	transactions, err := s.transactionRepo.GetByDateRange(userID, last30Days, now)
	if err == nil {
		categorySpend := make(map[string]float64)

		for _, tx := range transactions {
			if tx.Type == models.TransactionTypeExpense {
				fc.Last30DaysSpend += tx.Amount

				if tx.TransactionDate.After(last7Days) || tx.TransactionDate.Equal(last7Days) {
					fc.Last7DaysSpend += tx.Amount
				}
				if tx.TransactionDate.After(today) || tx.TransactionDate.Equal(today) {
					fc.TodaySpend += tx.Amount
				}

				// 分类统计
				catName := "其他"
				if tx.Category.ID != 0 {
					catName = tx.Category.Name
				}
				categorySpend[catName] += tx.Amount
			}
		}

		// 计算 TOP3 分类
		type catAmount struct {
			name   string
			amount float64
		}
		var cats []catAmount
		for name, amount := range categorySpend {
			cats = append(cats, catAmount{name, amount})
		}
		// 简单排序取 TOP3
		for i := 0; i < len(cats)-1; i++ {
			for j := i + 1; j < len(cats); j++ {
				if cats[j].amount > cats[i].amount {
					cats[i], cats[j] = cats[j], cats[i]
				}
			}
		}
		for i := 0; i < len(cats) && i < 3; i++ {
			percent := 0.0
			if fc.Last30DaysSpend > 0 {
				percent = cats[i].amount / fc.Last30DaysSpend * 100
			}
			fc.TopCategories = append(fc.TopCategories, CategorySpend{
				Category: cats[i].name,
				Amount:   cats[i].amount,
				Percent:  percent,
			})
		}

		// 最近5笔交易
		count := 0
		for i := len(transactions) - 1; i >= 0 && count < 5; i-- {
			tx := transactions[i]
			catName := "其他"
			if tx.Category.ID != 0 {
				catName = tx.Category.Name
			}
			fc.RecentTransactions = append(fc.RecentTransactions, TransactionBrief{
				Amount:   tx.Amount,
				Category: catName,
				Note:     tx.Note,
				Date:     tx.TransactionDate.Format("01-02"),
				Type:     string(tx.Type),
			})
			count++
		}
	}

	// 3. 获取上月同期支出用于对比
	lastMonthTx, err := s.transactionRepo.GetByDateRange(userID, lastMonthStart, lastMonthEnd)
	if err == nil {
		for _, tx := range lastMonthTx {
			if tx.Type == models.TransactionTypeExpense {
				fc.LastMonthSpend += tx.Amount
			}
		}
	}

	// 计算消费趋势
	if fc.LastMonthSpend > 0 {
		ratio := fc.Last30DaysSpend / fc.LastMonthSpend
		if ratio > 1.1 {
			fc.SpendTrend = "up"
		} else if ratio < 0.9 {
			fc.SpendTrend = "down"
		} else {
			fc.SpendTrend = "stable"
		}
	} else {
		fc.SpendTrend = "stable"
	}

	// 4. 获取预算信息（通过直接查询数据库）
	var budgets []models.Budget
	if err := s.db.Where("user_id = ?", userID).
		Where("start_date <= ?", now).
		Where("end_date IS NULL OR end_date >= ?", now).
		Preload("Category").
		Find(&budgets).Error; err == nil {

		for _, budget := range budgets {
			// 计算当期支出
			periodStart, periodEnd := s.calculateBudgetPeriod(&budget, now)
			spent := 0.0

			// 查询当期支出
			var totalSpent float64
			query := s.db.Model(&models.Transaction{}).
				Where("user_id = ?", userID).
				Where("type = ?", models.TransactionTypeExpense).
				Where("transaction_date >= ? AND transaction_date <= ?", periodStart, periodEnd)

			if budget.CategoryID != nil {
				query = query.Where("category_id = ?", *budget.CategoryID)
			}
			if budget.AccountID != nil {
				query = query.Where("account_id = ?", *budget.AccountID)
			}
			query.Select("COALESCE(SUM(amount), 0)").Scan(&totalSpent)
			spent = totalSpent

			progress := 0.0
			if budget.Amount > 0 {
				progress = spent / budget.Amount * 100
			}

			isNearLimit := progress >= 80.0

			catName := ""
			if budget.Category != nil {
				catName = budget.Category.Name
			}

			fc.ActiveBudgets = append(fc.ActiveBudgets, BudgetBrief{
				Name:        budget.Name,
				Amount:      budget.Amount,
				Spent:       spent,
				Remaining:   budget.Amount - spent,
				Progress:    progress,
				IsNearLimit: isNearLimit,
				Category:    catName,
			})

			// 生成预算警告
			if progress >= 100 {
				fc.BudgetWarnings = append(fc.BudgetWarnings,
					fmt.Sprintf("【%s】预算已超支！", budget.Name))
			} else if isNearLimit {
				fc.BudgetWarnings = append(fc.BudgetWarnings,
					fmt.Sprintf("【%s】预算已用%.0f%%，请注意控制", budget.Name, progress))
			}
		}
	}

	// 计算负债率
	if fc.TotalAssets+fc.TotalLiabilities > 0 {
		fc.DebtRatio = fc.TotalLiabilities / (fc.TotalAssets + fc.TotalLiabilities)
	}

	// 5. 获取存钱罐进度 (PiggyBank)
	var piggyBanks []models.PiggyBank
	if err := s.db.Where("user_id = ?", userID).Find(&piggyBanks).Error; err == nil {
		for _, pb := range piggyBanks {
			progress := 0.0
			if pb.TargetAmount > 0 {
				progress = pb.CurrentAmount / pb.TargetAmount * 100
			}
			status := "进行中"
			if progress >= 100 {
				status = "已达成"
			}
			fc.SavingsProgress = append(fc.SavingsProgress, fmt.Sprintf("%s: %.0f/%.0f (%.1f%%) - %s", pb.Name, pb.CurrentAmount, pb.TargetAmount, progress, status))
		}
	}

	// 6. 获取未来7天即将到期的定期事务 (RecurringTransaction)
	var recurrings []models.RecurringTransaction
	next7Days := now.AddDate(0, 0, 7)
	if err := s.db.Where("user_id = ? AND is_active = ? AND type = ?", userID, true, models.TransactionTypeExpense).
		Where("next_occurrence BETWEEN ? AND ?", now, next7Days).
		Find(&recurrings).Error; err == nil {
		for _, r := range recurrings {
			days := int(r.NextOccurrence.Sub(now).Hours() / 24)
			msg := fmt.Sprintf("%s 还有 %d 天扣款 %.2f元", r.Note, days, r.Amount)
			if r.Note == "" {
				// 获取分类名
				var cat models.Category
				s.db.First(&cat, r.CategoryID)
				msg = fmt.Sprintf("%s 还有 %d 天扣款 %.2f元", cat.Name, days, r.Amount)
			}
			fc.UpcomingRecurring = append(fc.UpcomingRecurring, msg)
		}
	}

	// 7. 计算本月最大单笔支出
	if len(transactions) > 0 {
		var maxTx *models.Transaction
		for _, tx := range transactions {
			if tx.Type == models.TransactionTypeExpense {
				if maxTx == nil || tx.Amount > maxTx.Amount {
					currentTx := tx // 创建副本以避免取地址问题
					maxTx = &currentTx
				}
			}
		}
		if maxTx != nil {
			catName := "其他"
			if maxTx.Category.ID != 0 {
				catName = maxTx.Category.Name
			}
			fc.MaxSingleSpend = &TransactionBrief{
				Amount:   maxTx.Amount,
				Category: catName,
				Note:     maxTx.Note,
				Date:     maxTx.TransactionDate.Format("01-02"),
				Type:     string(maxTx.Type),
			}
		}
	}

	return fc, nil
}

// calculateBudgetPeriod 计算预算当前周期
func (s *AIBookkeepingService) calculateBudgetPeriod(budget *models.Budget, now time.Time) (time.Time, time.Time) {
	switch budget.PeriodType {
	case models.PeriodTypeDaily:
		start := time.Date(now.Year(), now.Month(), now.Day(), 0, 0, 0, 0, now.Location())
		end := start.AddDate(0, 0, 1).Add(-time.Second)
		return start, end
	case models.PeriodTypeWeekly:
		weekday := int(now.Weekday())
		if weekday == 0 {
			weekday = 7
		}
		start := time.Date(now.Year(), now.Month(), now.Day()-weekday+1, 0, 0, 0, 0, now.Location())
		end := start.AddDate(0, 0, 7).Add(-time.Second)
		return start, end
	case models.PeriodTypeMonthly:
		start := time.Date(now.Year(), now.Month(), 1, 0, 0, 0, 0, now.Location())
		end := start.AddDate(0, 1, 0).Add(-time.Second)
		return start, end
	case models.PeriodTypeYearly:
		start := time.Date(now.Year(), 1, 1, 0, 0, 0, 0, now.Location())
		end := start.AddDate(1, 0, 0).Add(-time.Second)
		return start, end
	default:
		start := time.Date(now.Year(), now.Month(), 1, 0, 0, 0, 0, now.Location())
		end := start.AddDate(0, 1, 0).Add(-time.Second)
		return start, end
	}
}