package repositories

import (
	"context"
	"errors"
	"fmt"
	"time"

	"go.uber.org/zap"
	"gorm.io/gorm"

	"tyapi-server/internal/domains/user/entities"
	"tyapi-server/internal/shared/interfaces"
)

// 定义错误常量
var (
	// ErrUserNotFound 用户不存在错误
	ErrUserNotFound = errors.New("用户不存在")
)

// UserRepository 用户仓储实现
type UserRepository struct {
	db     *gorm.DB
	cache  interfaces.CacheService
	logger *zap.Logger
}

// NewUserRepository 创建用户仓储
func NewUserRepository(db *gorm.DB, cache interfaces.CacheService, logger *zap.Logger) *UserRepository {
	return &UserRepository{
		db:     db,
		cache:  cache,
		logger: logger,
	}
}

// Create 创建用户
func (r *UserRepository) Create(ctx context.Context, user *entities.User) error {
	if err := r.db.WithContext(ctx).Create(user).Error; err != nil {
		r.logger.Error("创建用户失败", zap.Error(err))
		return err
	}

	// 清除相关缓存
	r.deleteCacheByPhone(ctx, user.Phone)

	r.logger.Info("用户创建成功", zap.String("user_id", user.ID))
	return nil
}

// GetByID 根据ID获取用户
func (r *UserRepository) GetByID(ctx context.Context, id string) (*entities.User, error) {
	// 尝试从缓存获取
	cacheKey := fmt.Sprintf("user:id:%s", id)
	var user entities.User
	if err := r.cache.Get(ctx, cacheKey, &user); err == nil {
		return &user, nil
	}

	// 从数据库查询
	if err := r.db.WithContext(ctx).Where("id = ?", id).First(&user).Error; err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return nil, ErrUserNotFound
		}
		r.logger.Error("根据ID查询用户失败", zap.Error(err))
		return nil, err
	}

	// 缓存结果
	r.cache.Set(ctx, cacheKey, &user, 10*time.Minute)

	return &user, nil
}

// FindByPhone 根据手机号查找用户
func (r *UserRepository) FindByPhone(ctx context.Context, phone string) (*entities.User, error) {
	// 尝试从缓存获取
	cacheKey := fmt.Sprintf("user:phone:%s", phone)
	var user entities.User
	if err := r.cache.Get(ctx, cacheKey, &user); err == nil {
		return &user, nil
	}

	// 从数据库查询
	if err := r.db.WithContext(ctx).Where("phone = ?", phone).First(&user).Error; err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return nil, ErrUserNotFound
		}
		r.logger.Error("根据手机号查询用户失败", zap.Error(err))
		return nil, err
	}

	// 缓存结果
	r.cache.Set(ctx, cacheKey, &user, 10*time.Minute)

	return &user, nil
}

// Update 更新用户
func (r *UserRepository) Update(ctx context.Context, user *entities.User) error {
	if err := r.db.WithContext(ctx).Save(user).Error; err != nil {
		r.logger.Error("更新用户失败", zap.Error(err))
		return err
	}

	// 清除相关缓存
	r.deleteCacheByID(ctx, user.ID)
	r.deleteCacheByPhone(ctx, user.Phone)

	r.logger.Info("用户更新成功", zap.String("user_id", user.ID))
	return nil
}

// Delete 删除用户
func (r *UserRepository) Delete(ctx context.Context, id string) error {
	// 先获取用户信息用于清除缓存
	user, err := r.GetByID(ctx, id)
	if err != nil {
		return err
	}

	if err := r.db.WithContext(ctx).Delete(&entities.User{}, "id = ?", id).Error; err != nil {
		r.logger.Error("删除用户失败", zap.Error(err))
		return err
	}

	// 清除相关缓存
	r.deleteCacheByID(ctx, id)
	r.deleteCacheByPhone(ctx, user.Phone)

	r.logger.Info("用户删除成功", zap.String("user_id", id))
	return nil
}

// List 分页获取用户列表
func (r *UserRepository) List(ctx context.Context, offset, limit int) ([]*entities.User, error) {
	var users []*entities.User
	if err := r.db.WithContext(ctx).Offset(offset).Limit(limit).Find(&users).Error; err != nil {
		r.logger.Error("查询用户列表失败", zap.Error(err))
		return nil, err
	}

	return users, nil
}

// Count 获取用户总数
func (r *UserRepository) Count(ctx context.Context) (int64, error) {
	var count int64
	if err := r.db.WithContext(ctx).Model(&entities.User{}).Count(&count).Error; err != nil {
		r.logger.Error("统计用户数量失败", zap.Error(err))
		return 0, err
	}

	return count, nil
}

// ExistsByPhone 检查手机号是否存在
func (r *UserRepository) ExistsByPhone(ctx context.Context, phone string) (bool, error) {
	var count int64
	if err := r.db.WithContext(ctx).Model(&entities.User{}).Where("phone = ?", phone).Count(&count).Error; err != nil {
		r.logger.Error("检查手机号是否存在失败", zap.Error(err))
		return false, err
	}

	return count > 0, nil
}

// 私有辅助方法

// deleteCacheByID 根据ID删除缓存
func (r *UserRepository) deleteCacheByID(ctx context.Context, id string) {
	cacheKey := fmt.Sprintf("user:id:%s", id)
	if err := r.cache.Delete(ctx, cacheKey); err != nil {
		r.logger.Warn("删除用户ID缓存失败", zap.String("cache_key", cacheKey), zap.Error(err))
	}
}

// deleteCacheByPhone 根据手机号删除缓存
func (r *UserRepository) deleteCacheByPhone(ctx context.Context, phone string) {
	cacheKey := fmt.Sprintf("user:phone:%s", phone)
	if err := r.cache.Delete(ctx, cacheKey); err != nil {
		r.logger.Warn("删除用户手机号缓存失败", zap.String("cache_key", cacheKey), zap.Error(err))
	}
}