package session

import (
	"context"
	"fmt"

	"gitea.com/red-future/common/beans"
	"gitea.com/red-future/common/utils"
	"github.com/gogf/gf/v2/frame/g"
	"github.com/gogf/gf/v2/util/gconv"

	"prompts-core/common/util"
	"prompts-core/dao"
	"prompts-core/model/dto"
	"prompts-core/model/entity"
)

// ============================================
// 回调存储
// ============================================

// Callback 会话回调
func Callback(ctx context.Context, req *dto.SessionCallbackReq) (*dto.SessionCallbackRes, error) {
	fmt.Println("打印会话回调", req)
	req.Messages["role"] = "assistant"
	// 1) 更新 DB
	_, err := dao.ComposeSession.Update(ctx, &entity.ComposeSession{
		SQLBaseDO:       beans.SQLBaseDO{Id: req.EpicycleId},
		ResponseContent: req.Messages,
	})
	if err != nil {
		g.Log().Errorf(ctx, "[会话回调] 更新数据库失败 epicycleId=%d err=%v", req.EpicycleId, err)
		return nil, fmt.Errorf("更新数据库失败: %w", err)
	}

	// 2) 查询完整记录
	session, err := dao.ComposeSession.Get(ctx, &entity.ComposeSession{
		SQLBaseDO: beans.SQLBaseDO{Id: req.EpicycleId},
	})
	if err != nil || session == nil {
		return nil, fmt.Errorf("会话不存在: epicycleId=%d", req.EpicycleId)
	}

	// 3) entity → HistoryRound → 写入 Redis
	round := entityToHistoryRound(session)
	round.Assistant = req.Messages
	if err = SaveToRedis(ctx, session.TenantId, session.SessionId, round); err != nil {
		return nil, fmt.Errorf("redis存储失败: %w", err)
	}

	g.Log().Infof(ctx, "[会话回调] 存储成功 sessionId=%s id=%d", session.SessionId, session.Id)
	return &dto.SessionCallbackRes{Status: true, SessionId: session.SessionId}, nil
}

// ============================================
// 场景1：前端历史列表（按 creator）
// ============================================

// GetHistoryList 获取历史列表
func GetHistoryList(ctx context.Context, req *dto.GetHistoryListReq) (*dto.GetHistoryListRes, error) {
	user, err := utils.GetUserInfo(ctx)
	if err != nil {
		return nil, err
	}
	sessions, total, err := dao.ComposeSession.List(ctx, &entity.ComposeSession{
		SQLBaseDO: beans.SQLBaseDO{Creator: user.UserName},
	}, req.Page, req.Size)
	if err != nil {
		return nil, fmt.Errorf("DB获取历史列表失败: %w", err)
	}
	rounds := sessionsToHistoryRounds(sessions)
	return &dto.GetHistoryListRes{List: rounds, Total: total}, nil
}

// ============================================
// 场景2：提示词拼接（按 sessionId + nodeId）
// ============================================

// GetHistoryMessages 获取历史消息（Redis → DB → 异步回种）
func GetHistoryMessages(ctx context.Context, req *dto.GetHistoryMessagesReq) (*dto.GetHistoryMessagesRes, error) {
	user, err := utils.GetUserInfo(ctx)
	if err != nil {
		return nil, err
	}

	// 1) Redis
	if rounds, err := GetFromRedis(ctx, user.TenantId, req.SessionId); err == nil && len(rounds) > 0 {
		g.Log().Debugf(ctx, "[历史消息] Redis命中 sessionId=%s count=%d", req.SessionId, len(rounds))
		return &dto.GetHistoryMessagesRes{Messages: flattenRounds(rounds)}, nil
	}

	// 2) DB
	maxRounds := util.GetMaxRounds(ctx)
	sessions, _, err := dao.ComposeSession.List(ctx, &entity.ComposeSession{
		SQLBaseDO: beans.SQLBaseDO{Creator: user.UserName},
		SessionId: req.SessionId,
		NodeId:    req.NodeId,
	}, 1, maxRounds)
	if err != nil {
		return nil, fmt.Errorf("DB获取历史失败: %w", err)
	}
	if len(sessions) == 0 {
		return &dto.GetHistoryMessagesRes{Messages: []dto.FlatMessage{}}, nil
	}

	// 3) 转换 + 异步回种
	rounds := sessionsToHistoryRounds(sessions)
	go asyncCacheToRedis(context.WithoutCancel(ctx), user.TenantId, req.SessionId, rounds)

	return &dto.GetHistoryMessagesRes{Messages: flattenRounds(rounds)}, nil
}

// ============================================
// 删除
// ============================================

// DeleteMessages 批量删除消息
func DeleteMessages(ctx context.Context, req *dto.DeleteMessagesReq) (*dto.DeleteMessagesRes, error) {
	if len(req.MsgIds) == 0 {
		return &dto.DeleteMessagesRes{Ok: false}, fmt.Errorf("msgIds不能为空")
	}

	// 1) 删 DB
	for _, id := range req.MsgIds {
		_, _ = dao.ComposeSession.Delete(ctx, &entity.ComposeSession{
			SQLBaseDO: beans.SQLBaseDO{Id: id},
		})
	}
	user, err := utils.GetUserInfo(ctx)
	if err != nil {
		return nil, err
	}
	// 2) 删 Redis
	_ = DeleteRedisMessages(ctx, user.TenantId, req.SessionId, req.MsgIds)

	return &dto.DeleteMessagesRes{Ok: true}, nil
}

// DeleteSession 删除整个会话
func DeleteSession(ctx context.Context, req *dto.DeleteSessionReq) (*dto.DeleteSessionRes, error) {
	// 1) 删 DB
	if _, err := dao.ComposeSession.Delete(ctx, &entity.ComposeSession{
		SessionId: req.SessionId,
	}); err != nil {
		return nil, fmt.Errorf("DB删除失败: %w", err)
	}

	user, err := utils.GetUserInfo(ctx)
	if err != nil {
		return nil, err
	}
	// 2) 删 Redis
	if err := DeleteSessionHistory(ctx, user.TenantId, req.SessionId); err != nil {
		g.Log().Warningf(ctx, "[删除会话] Redis删除失败 sessionId=%s err=%v", req.SessionId, err)
	}

	return &dto.DeleteSessionRes{Ok: true}, nil
}

// ============================================
// 转换方法（entity ↔ dto，集中管理）
// ============================================

// entityToHistoryRound entity → HistoryRound
func entityToHistoryRound(s *entity.ComposeSession) *dto.HistoryRound {
	return &dto.HistoryRound{
		Id:        s.Id,
		SessionId: s.SessionId,
		NodeId:    s.NodeId,
		CreatedAt: gconv.String(s.CreatedAt),
		UpdatedAt: gconv.String(s.UpdatedAt),
		User:      s.RequestContent,
		Assistant: s.ResponseContent,
	}
}

// sessionsToHistoryRounds 批量转换
func sessionsToHistoryRounds(sessions []*entity.ComposeSession) []dto.HistoryRound {
	rounds := make([]dto.HistoryRound, 0, len(sessions))
	for _, s := range sessions {
		rounds = append(rounds, *entityToHistoryRound(s))
	}
	return rounds
}

// asyncCacheToRedis 异步缓存到 Redis
func asyncCacheToRedis(ctx context.Context, tenantID uint64, sessionID string, rounds []dto.HistoryRound) {
	for i := range rounds {
		if rounds[i].User != nil || rounds[i].Assistant != nil {
			_ = SaveToRedis(ctx, tenantID, sessionID, &rounds[i])
		}
	}
}