package redisdao

import (
	"context"
	"fmt"
	"time"

	"git.lzcwy.cn/zhengchiliu/zt-closet-backend/global"
	"git.lzcwy.cn/zhengchiliu/zt-closet-backend/internal/redismodel"
	"github.com/redis/go-redis/v9"
)

// authTokenSAddScript 向用户 token 集合加入 refresh_token，仅在集合由空变为非空时设置 TTL，
// 避免每次登录都刷新集合 TTL 导致旧 token 条目长期驻留。
const authTokenSAddScript = `
local added = redis.call('SADD', KEYS[1], ARGV[1])
if added == 1 and redis.call('SCARD', KEYS[1]) == 1 then
  redis.call('EXPIRE', KEYS[1], ARGV[2])
end
return added
`

// AuthTokenSet 登录成功后写入会话：
//   - access_token -> user_id
//   - refresh_token -> user_id
//   - user_id 的 token 集合加入 refresh_token（用于多端管理 / 登出）
func AuthTokenSet(ctx context.Context, userID int64, accessToken, refreshToken string) error {
	ctx, span := global.Tracer.Start(ctx, "redisdao.AuthTokenSet")
	defer span.End()

	accessKey := fmt.Sprintf(redismodel.KeyAuthAccess, accessToken)
	refreshKey := fmt.Sprintf(redismodel.KeyAuthRefresh, refreshToken)
	userTokensKey := fmt.Sprintf(redismodel.KeyAuthUserTokens, userID)

	accessTTL := time.Duration(global.JWTSetting.AccessTokenExpire) * time.Second
	refreshTTL := time.Duration(global.JWTSetting.RefreshTokenExpire) * time.Second

	pipe := global.RedisEngine.TxPipeline()
	pipe.Set(ctx, accessKey, userID, accessTTL)
	pipe.Set(ctx, refreshKey, userID, refreshTTL)
	pipe.Eval(ctx, authTokenSAddScript, []string{userTokensKey}, refreshToken, int(refreshTTL.Seconds()))
	if _, err := pipe.Exec(ctx); err != nil {
		span.RecordError(err)
		return err
	}
	return nil
}

// AuthTokenDel 登出/失效：删除 access、refresh 映射，并从用户 token 集合移除 refresh_token
func AuthTokenDel(ctx context.Context, userID int64, accessToken, refreshToken string) error {
	ctx, span := global.Tracer.Start(ctx, "redisdao.AuthTokenDel")
	defer span.End()

	accessKey := fmt.Sprintf(redismodel.KeyAuthAccess, accessToken)
	refreshKey := fmt.Sprintf(redismodel.KeyAuthRefresh, refreshToken)
	userTokensKey := fmt.Sprintf(redismodel.KeyAuthUserTokens, userID)

	pipe := global.RedisEngine.TxPipeline()
	pipe.Del(ctx, accessKey)
	pipe.Del(ctx, refreshKey)
	pipe.SRem(ctx, userTokensKey, refreshToken)
	if _, err := pipe.Exec(ctx); err != nil {
		span.RecordError(err)
		return err
	}
	return nil
}

// AuthUserIDByAccess 通过 access token 查询 user_id，token 不存在或已过期返回 redis.Nil
func AuthUserIDByAccess(ctx context.Context, accessToken string) (int64, error) {
	ctx, span := global.Tracer.Start(ctx, "redisdao.AuthUserIDByAccess")
	defer span.End()

	key := fmt.Sprintf(redismodel.KeyAuthAccess, accessToken)
	userID, err := global.RedisEngine.Get(ctx, key).Int64()
	if err != nil && err != redis.Nil {
		span.RecordError(err)
	}
	return userID, err
}

// AuthUserIDByRefresh 通过 refresh token 查询 user_id，token 不存在或已过期返回 redis.Nil
func AuthUserIDByRefresh(ctx context.Context, refreshToken string) (int64, error) {
	ctx, span := global.Tracer.Start(ctx, "redisdao.AuthUserIDByRefresh")
	defer span.End()

	key := fmt.Sprintf(redismodel.KeyAuthRefresh, refreshToken)
	userID, err := global.RedisEngine.Get(ctx, key).Int64()
	if err != nil && err != redis.Nil {
		span.RecordError(err)
	}
	return userID, err
}

// sessionKeyTTL session_key 缓存时长（30 天，与微信 session_key 有效期对齐）。
const sessionKeyTTL = 30 * 24 * time.Hour

// AuthSessionKeySet 写入用户的 session_key（登录时 code2session 返回，用于虚拟支付 signature 计算）。
func AuthSessionKeySet(ctx context.Context, userID int64, sessionKey string) error {
	ctx, span := global.Tracer.Start(ctx, "redisdao.AuthSessionKeySet")
	defer span.End()

	key := fmt.Sprintf(redismodel.KeyAuthSessionKey, userID)
	if err := global.RedisEngine.Set(ctx, key, sessionKey, sessionKeyTTL).Err(); err != nil {
		span.RecordError(err)
		return err
	}
	return nil
}

// AuthSessionKeyGet 读取用户的 session_key，不存在返回 redis.Nil。
func AuthSessionKeyGet(ctx context.Context, userID int64) (string, error) {
	ctx, span := global.Tracer.Start(ctx, "redisdao.AuthSessionKeyGet")
	defer span.End()

	key := fmt.Sprintf(redismodel.KeyAuthSessionKey, userID)
	sessionKey, err := global.RedisEngine.Get(ctx, key).Result()
	if err != nil && err != redis.Nil {
		span.RecordError(err)
	}
	return sessionKey, err
}