package auth

import (
	"context"
	"encoding/json"
	"fmt"
	"time"

	"github.com/break/junhong_cmp_fiber/pkg/constants"
	"github.com/break/junhong_cmp_fiber/pkg/errors"
	"github.com/google/uuid"
	"github.com/redis/go-redis/v9"
)

type TokenManager struct {
	rdb             *redis.Client
	accessTokenTTL  time.Duration
	refreshTokenTTL time.Duration
}

type TokenInfo struct {
	UserID       uint      `json:"user_id"`
	UserType     int       `json:"user_type"`
	ShopID       uint      `json:"shop_id,omitempty"`
	EnterpriseID uint      `json:"enterprise_id,omitempty"`
	Username     string    `json:"username"`
	LoginTime    time.Time `json:"login_time"`
	Device       string    `json:"device"`
	IP           string    `json:"ip"`
}

func NewTokenManager(rdb *redis.Client, accessTTL, refreshTTL time.Duration) *TokenManager {
	return &TokenManager{
		rdb:             rdb,
		accessTokenTTL:  accessTTL,
		refreshTokenTTL: refreshTTL,
	}
}

func (m *TokenManager) GenerateTokenPair(ctx context.Context, info *TokenInfo) (accessToken, refreshToken string, err error) {
	accessToken = uuid.New().String()
	refreshToken = uuid.New().String()

	info.LoginTime = time.Now()

	data, err := json.Marshal(info)
	if err != nil {
		return "", "", fmt.Errorf("failed to marshal token info: %w", err)
	}

	pipe := m.rdb.Pipeline()

	accessKey := constants.RedisAuthTokenKey(accessToken)
	pipe.Set(ctx, accessKey, data, m.accessTokenTTL)

	refreshKey := constants.RedisRefreshTokenKey(refreshToken)
	pipe.Set(ctx, refreshKey, data, m.refreshTokenTTL)

	userTokensKey := constants.RedisUserTokensKey(info.UserID)
	pipe.SAdd(ctx, userTokensKey, accessToken, refreshToken)
	pipe.Expire(ctx, userTokensKey, m.refreshTokenTTL)

	if _, err := pipe.Exec(ctx); err != nil {
		return "", "", errors.New(errors.CodeRedisError, fmt.Sprintf("failed to store tokens: %v", err))
	}

	return accessToken, refreshToken, nil
}

func (m *TokenManager) ValidateAccessToken(ctx context.Context, token string) (*TokenInfo, error) {
	key := constants.RedisAuthTokenKey(token)
	data, err := m.rdb.Get(ctx, key).Result()
	if err == redis.Nil {
		return nil, errors.New(errors.CodeInvalidToken, "无效或过期的令牌")
	}
	if err != nil {
		return nil, errors.New(errors.CodeRedisError, fmt.Sprintf("failed to get token: %v", err))
	}

	var info TokenInfo
	if err := json.Unmarshal([]byte(data), &info); err != nil {
		return nil, fmt.Errorf("failed to unmarshal token info: %w", err)
	}

	return &info, nil
}

func (m *TokenManager) ValidateRefreshToken(ctx context.Context, token string) (*TokenInfo, error) {
	key := constants.RedisRefreshTokenKey(token)
	data, err := m.rdb.Get(ctx, key).Result()
	if err == redis.Nil {
		return nil, errors.New(errors.CodeInvalidToken, "无效或过期的刷新令牌")
	}
	if err != nil {
		return nil, errors.New(errors.CodeRedisError, fmt.Sprintf("failed to get refresh token: %v", err))
	}

	var info TokenInfo
	if err := json.Unmarshal([]byte(data), &info); err != nil {
		return nil, fmt.Errorf("failed to unmarshal token info: %w", err)
	}

	return &info, nil
}

func (m *TokenManager) RefreshAccessToken(ctx context.Context, refreshToken string) (newAccessToken string, err error) {
	info, err := m.ValidateRefreshToken(ctx, refreshToken)
	if err != nil {
		return "", err
	}

	newAccessToken = uuid.New().String()

	data, err := json.Marshal(info)
	if err != nil {
		return "", fmt.Errorf("failed to marshal token info: %w", err)
	}

	pipe := m.rdb.Pipeline()

	newAccessKey := constants.RedisAuthTokenKey(newAccessToken)
	pipe.Set(ctx, newAccessKey, data, m.accessTokenTTL)

	userTokensKey := constants.RedisUserTokensKey(info.UserID)
	pipe.SAdd(ctx, userTokensKey, newAccessToken)

	if _, err := pipe.Exec(ctx); err != nil {
		return "", errors.New(errors.CodeRedisError, fmt.Sprintf("failed to refresh token: %v", err))
	}

	return newAccessToken, nil
}

func (m *TokenManager) RevokeToken(ctx context.Context, token string) error {
	pipe := m.rdb.Pipeline()

	accessKey := constants.RedisAuthTokenKey(token)
	pipe.Del(ctx, accessKey)

	refreshKey := constants.RedisRefreshTokenKey(token)
	pipe.Del(ctx, refreshKey)

	if _, err := pipe.Exec(ctx); err != nil {
		return errors.New(errors.CodeRedisError, fmt.Sprintf("failed to revoke token: %v", err))
	}

	return nil
}

func (m *TokenManager) RevokeAllUserTokens(ctx context.Context, userID uint) error {
	userTokensKey := constants.RedisUserTokensKey(userID)

	tokens, err := m.rdb.SMembers(ctx, userTokensKey).Result()
	if err != nil && err != redis.Nil {
		return errors.New(errors.CodeRedisError, fmt.Sprintf("failed to get user tokens: %v", err))
	}

	if len(tokens) == 0 {
		return nil
	}

	pipe := m.rdb.Pipeline()

	for _, token := range tokens {
		accessKey := constants.RedisAuthTokenKey(token)
		pipe.Del(ctx, accessKey)

		refreshKey := constants.RedisRefreshTokenKey(token)
		pipe.Del(ctx, refreshKey)
	}

	pipe.Del(ctx, userTokensKey)

	if _, err := pipe.Exec(ctx); err != nil {
		return errors.New(errors.CodeRedisError, fmt.Sprintf("failed to revoke user tokens: %v", err))
	}

	return nil
}