package memory

import (
	"encoding/json"
	"fmt"
	"os"
	"path/filepath"
	"time"

	"github.com/hxclaw/hxclaw/cmd/hxclaw/internal"
)

type ExportDocument struct {
	Version    int           `json:"version"`
	ExportedAt string        `json:"exported_at"`
	Sessions   []*SessionData `json:"sessions"`
}

type SessionData struct {
	ID         int64    `json:"id"`
	UUID       string  `json:"uuid"`
	Summary    string  `json:"summary"`
	ChatIDs    []int64 `json:"chat_ids"`
	CreatedAt  int64   `json:"created_at"`
	UpdatedAt int64   `json:"updated_at"`
	Chats      []*Chat `json:"chats"`
}

func ExportIfNeeded() {
	memoryCfg := internal.GetProjectConfig().Memory
	if !memoryCfg.Enabled || !memoryCfg.AutoExport {
		return
	}

	db := GetDB()
	if db == nil {
		return
	}

	exportPath := filepath.Join(internal.GetConfigDir(), "export-data.json")
	if err := ExportToFile(exportPath); err != nil {
		fmt.Printf("警告：导出数据失败: %v\n", err)
		return
	}
	fmt.Printf("数据已导出: %s\n", exportPath)
}

func ExportToFile(filename string) error {
	db := GetDB()
	if db == nil {
		return fmt.Errorf("数据库未初始化")
	}

	sessions, err := db.GetAllSessions()
	if err != nil {
		return fmt.Errorf("查询会话失败: %w", err)
	}

	var doc ExportDocument
	doc.Version = 1
	doc.ExportedAt = time.Now().Format(time.RFC3339)

	if _, err := os.Stat(filename); err == nil {
		data, readErr := os.ReadFile(filename)
		if readErr == nil {
			json.Unmarshal(data, &doc)
		}
	}

	sessionMap := make(map[string]*SessionData)
	for i := range doc.Sessions {
		sessionMap[doc.Sessions[i].UUID] = doc.Sessions[i]
	}

	for _, s := range sessions {
		if existing, ok := sessionMap[s.UUID]; ok {
			existing.Summary = s.Summary
			existing.ChatIDs = s.ChatIDs
			existing.UpdatedAt = s.UpdatedAt
		} else {
			sessionData := &SessionData{
				ID:         s.ID,
				UUID:       s.UUID,
				Summary:    s.Summary,
				ChatIDs:    s.ChatIDs,
				CreatedAt:  s.CreatedAt,
				UpdatedAt:  s.UpdatedAt,
				Chats:      []*Chat{},
			}
			doc.Sessions = append(doc.Sessions, sessionData)
			sessionMap[s.UUID] = sessionData
		}

		chats, err := db.GetChatsBySessionID(s.ID)
		if err != nil {
			continue
		}
		sessionMap[s.UUID].Chats = append(sessionMap[s.UUID].Chats, chats...)
	}

	file, err := os.Create(filename)
	if err != nil {
		return fmt.Errorf("创建文件失败: %w", err)
	}
	defer file.Close()

	encoder := json.NewEncoder(file)
	encoder.SetIndent("", "  ")
	return encoder.Encode(doc)
}