package service

import (
	"context"
	"sync"

	"git.x2erp.com/qdy/go-base/logger"
	"git.x2erp.com/qdy/go-svc-code/internal/opencode"
)

// SessionInfo 会话信息
type SessionInfo struct {
	SessionID string
	Title     string
	UserID    string
	CreatedAt string
}

// SessionManager 会话管理器
type SessionManager struct {
	mu           sync.RWMutex
	userSessions map[string][]SessionInfo // userID -> sessions
	client       opencode.OpenCodeClient
}

// NewSessionManager 创建新的会话管理器
func NewSessionManager(client opencode.OpenCodeClient) *SessionManager {
	return &SessionManager{
		userSessions: make(map[string][]SessionInfo),
		client:       client,
	}
}

// CreateSession 为用户创建新会话
func (sm *SessionManager) CreateSession(ctx context.Context, userID, title string) (*SessionInfo, error) {
	// 调用 opencode 创建会话
	session, err := sm.client.CreateSession(ctx, title)
	if err != nil {
		return nil, err
	}

	sessionInfo := &SessionInfo{
		SessionID: session.ID,
		Title:     session.Title,
		UserID:    userID,
		CreatedAt: session.CreatedAt,
	}

	sm.mu.Lock()
	sm.userSessions[userID] = append(sm.userSessions[userID], *sessionInfo)
	sm.mu.Unlock()

	logger.Debug("创建会话", "userID", userID, "sessionID", session.ID)
	return sessionInfo, nil
}

// GetUserSessions 获取用户的所有会话
func (sm *SessionManager) GetUserSessions(userID string) []SessionInfo {
	sm.mu.RLock()
	defer sm.mu.RUnlock()

	sessions, exists := sm.userSessions[userID]
	if !exists {
		return []SessionInfo{}
	}

	// 返回副本
	result := make([]SessionInfo, len(sessions))
	copy(result, sessions)
	return result
}

// GetSession 获取特定会话（检查用户权限）
func (sm *SessionManager) GetSession(userID, sessionID string) (*SessionInfo, bool) {
	sm.mu.RLock()
	defer sm.mu.RUnlock()

	sessions, exists := sm.userSessions[userID]
	if !exists {
		return nil, false
	}

	for _, session := range sessions {
		if session.SessionID == sessionID {
			return &session, true
		}
	}

	return nil, false
}

// DeleteSession 删除用户会话
func (sm *SessionManager) DeleteSession(userID, sessionID string) bool {
	sm.mu.Lock()
	defer sm.mu.Unlock()

	sessions, exists := sm.userSessions[userID]
	if !exists {
		return false
	}

	for i, session := range sessions {
		if session.SessionID == sessionID {
			// 从切片中删除
			sm.userSessions[userID] = append(sessions[:i], sessions[i+1:]...)

			// 如果用户没有会话了，删除用户条目
			if len(sm.userSessions[userID]) == 0 {
				delete(sm.userSessions, userID)
			}

			logger.Debug("删除会话", "userID", userID, "sessionID", sessionID)
			return true
		}
	}

	return false
}

// GetAllSessions 获取所有会话（仅用于调试）
func (sm *SessionManager) GetAllSessions() map[string][]SessionInfo {
	sm.mu.RLock()
	defer sm.mu.RUnlock()

	// 返回深拷贝
	result := make(map[string][]SessionInfo)
	for userID, sessions := range sm.userSessions {
		userSessions := make([]SessionInfo, len(sessions))
		copy(userSessions, sessions)
		result[userID] = userSessions
	}
	return result
}