backend/internal/dto/user_converter.go

package dto

import (
	"carrot_bbs/internal/model"
	"carrot_bbs/internal/pkg/utils"
)

// ==================== User 转换 ====================

// getAvatarOrDefault 获取头像URL，如果为空则返回在线头像生成服务的URL
func getAvatarOrDefault(user *model.User) string {
	return utils.GetAvatarOrDefault(user.Username, user.Nickname, user.Avatar)
}

// ConvertUserToResponse 将User转换为UserResponse（公开信息，不包含敏感数据）
func ConvertUserToResponse(user *model.User) *UserResponse {
	if user == nil {
		return nil
	}
	return &UserResponse{
		ID:             user.ID,
		Username:       user.Username,
		Nickname:       user.Nickname,
		EmailVerified:  user.EmailVerified,
		Avatar:         getAvatarOrDefault(user),
		CoverURL:       user.CoverURL,
		Bio:            user.Bio,
		Website:        user.Website,
		Location:       user.Location,
		PostsCount:     user.PostsCount,
		FollowersCount: user.FollowersCount,
		FollowingCount: user.FollowingCount,
		CreatedAt:      FormatTime(user.CreatedAt),
	}
}

// ConvertUserToSelfResponse 将User转换为UserSelfResponse（本人信息，包含敏感数据）
func ConvertUserToSelfResponse(user *model.User, postsCount int) *UserSelfResponse {
	if user == nil {
		return nil
	}
	return &UserSelfResponse{
		ID:             user.ID,
		Username:       user.Username,
		Nickname:       user.Nickname,
		Email:          user.Email,
		Phone:          user.Phone,
		EmailVerified:  user.EmailVerified,
		Avatar:         getAvatarOrDefault(user),
		CoverURL:       user.CoverURL,
		Bio:            user.Bio,
		Website:        user.Website,
		Location:       user.Location,
		PostsCount:     postsCount,
		FollowersCount: user.FollowersCount,
		FollowingCount: user.FollowingCount,
		IsVerified:     user.IsVerified,
		CreatedAt:      FormatTime(user.CreatedAt),
	}
}

// ConvertUserToResponseWithFollowing 将User转换为UserResponse（包含关注状态，公开信息）
func ConvertUserToResponseWithFollowing(user *model.User, isFollowing bool) *UserResponse {
	if user == nil {
		return nil
	}
	return &UserResponse{
		ID:             user.ID,
		Username:       user.Username,
		Nickname:       user.Nickname,
		EmailVerified:  user.EmailVerified,
		Avatar:         getAvatarOrDefault(user),
		CoverURL:       user.CoverURL,
		Bio:            user.Bio,
		Website:        user.Website,
		Location:       user.Location,
		PostsCount:     user.PostsCount,
		FollowersCount: user.FollowersCount,
		FollowingCount: user.FollowingCount,
		IsFollowing:    isFollowing,
		IsFollowingMe:  false,
		CreatedAt:      FormatTime(user.CreatedAt),
	}
}

// ConvertUserToResponseWithPostsCount 将User转换为UserResponse（使用实时计算的帖子数量，公开信息）
func ConvertUserToResponseWithPostsCount(user *model.User, postsCount int) *UserResponse {
	if user == nil {
		return nil
	}
	return &UserResponse{
		ID:             user.ID,
		Username:       user.Username,
		Nickname:       user.Nickname,
		EmailVerified:  user.EmailVerified,
		Avatar:         getAvatarOrDefault(user),
		CoverURL:       user.CoverURL,
		Bio:            user.Bio,
		Website:        user.Website,
		Location:       user.Location,
		PostsCount:     postsCount,
		FollowersCount: user.FollowersCount,
		FollowingCount: user.FollowingCount,
		CreatedAt:      FormatTime(user.CreatedAt),
	}
}

// ConvertUserToResponseWithMutualFollow 将User转换为UserResponse（包含双向关注状态，公开信息）
func ConvertUserToResponseWithMutualFollow(user *model.User, isFollowing, isFollowingMe bool) *UserResponse {
	if user == nil {
		return nil
	}
	return &UserResponse{
		ID:             user.ID,
		Username:       user.Username,
		Nickname:       user.Nickname,
		EmailVerified:  user.EmailVerified,
		Avatar:         getAvatarOrDefault(user),
		CoverURL:       user.CoverURL,
		Bio:            user.Bio,
		Website:        user.Website,
		Location:       user.Location,
		PostsCount:     user.PostsCount,
		FollowersCount: user.FollowersCount,
		FollowingCount: user.FollowingCount,
		IsFollowing:    isFollowing,
		IsFollowingMe:  isFollowingMe,
		CreatedAt:      FormatTime(user.CreatedAt),
	}
}

// ConvertUserToResponseWithMutualFollowAndPostsCount 将User转换为UserResponse（包含双向关注状态和实时计算的帖子数量，公开信息）
func ConvertUserToResponseWithMutualFollowAndPostsCount(user *model.User, isFollowing, isFollowingMe bool, postsCount int) *UserResponse {
	if user == nil {
		return nil
	}
	return &UserResponse{
		ID:             user.ID,
		Username:       user.Username,
		Nickname:       user.Nickname,
		EmailVerified:  user.EmailVerified,
		Avatar:         getAvatarOrDefault(user),
		CoverURL:       user.CoverURL,
		Bio:            user.Bio,
		Website:        user.Website,
		Location:       user.Location,
		PostsCount:     postsCount,
		FollowersCount: user.FollowersCount,
		FollowingCount: user.FollowingCount,
		IsFollowing:    isFollowing,
		IsFollowingMe:  isFollowingMe,
		CreatedAt:      FormatTime(user.CreatedAt),
	}
}

// ConvertUserToDetailResponse 将User转换为UserDetailResponse（仅本人可见，包含敏感信息）
func ConvertUserToDetailResponse(user *model.User) *UserDetailResponse {
	if user == nil {
		return nil
	}
	return &UserDetailResponse{
		ID:             user.ID,
		Username:       user.Username,
		Nickname:       user.Nickname,
		Email:          user.Email,
		EmailVerified:  user.EmailVerified,
		Avatar:         getAvatarOrDefault(user),
		CoverURL:       user.CoverURL,
		Bio:            user.Bio,
		Website:        user.Website,
		Location:       user.Location,
		PostsCount:     user.PostsCount,
		FollowersCount: user.FollowersCount,
		FollowingCount: user.FollowingCount,
		IsVerified:     user.IsVerified,
		CreatedAt:      FormatTime(user.CreatedAt),
	}
}

// ConvertUserToDetailResponseWithPostsCount 将User转换为UserDetailResponse（使用实时计算的帖子数量，仅本人可见）
func ConvertUserToDetailResponseWithPostsCount(user *model.User, postsCount int) *UserDetailResponse {
	if user == nil {
		return nil
	}
	return &UserDetailResponse{
		ID:             user.ID,
		Username:       user.Username,
		Nickname:       user.Nickname,
		Email:          user.Email,
		EmailVerified:  user.EmailVerified,
		Phone:          user.Phone,
		Avatar:         getAvatarOrDefault(user),
		CoverURL:       user.CoverURL,
		Bio:            user.Bio,
		Website:        user.Website,
		Location:       user.Location,
		PostsCount:     postsCount,
		FollowersCount: user.FollowersCount,
		FollowingCount: user.FollowingCount,
		IsVerified:     user.IsVerified,
		CreatedAt:      FormatTime(user.CreatedAt),
	}
}

// ConvertUsersToResponse 将User列表转换为响应列表
func ConvertUsersToResponse(users []*model.User) []*UserResponse {
	result := make([]*UserResponse, 0, len(users))
	for _, user := range users {
		result = append(result, ConvertUserToResponse(user))
	}
	return result
}

// ConvertUsersToResponseWithMutualFollow 将User列表转换为响应列表（包含双向关注状态）
// followingStatusMap: key是用户ID，value是[isFollowing, isFollowingMe]
func ConvertUsersToResponseWithMutualFollow(users []*model.User, followingStatusMap map[string][2]bool) []*UserResponse {
	result := make([]*UserResponse, 0, len(users))
	for _, user := range users {
		status, ok := followingStatusMap[user.ID]
		if ok {
			result = append(result, ConvertUserToResponseWithMutualFollow(user, status[0], status[1]))
		} else {
			result = append(result, ConvertUserToResponse(user))
		}
	}
	return result
}

// ConvertUsersToResponseWithMutualFollowAndPostsCount 将User列表转换为响应列表（包含双向关注状态和实时计算的帖子数量）
// followingStatusMap: key是用户ID，value是[isFollowing, isFollowingMe]
// postsCountMap: key是用户ID，value是帖子数量
func ConvertUsersToResponseWithMutualFollowAndPostsCount(users []*model.User, followingStatusMap map[string][2]bool, postsCountMap map[string]int64) []*UserResponse {
	result := make([]*UserResponse, 0, len(users))
	for _, user := range users {
		status, hasStatus := followingStatusMap[user.ID]
		postsCount, hasPostsCount := postsCountMap[user.ID]

		// 如果没有帖子数量，使用数据库中的值
		if !hasPostsCount {
			postsCount = int64(user.PostsCount)
		}

		if hasStatus {
			result = append(result, ConvertUserToResponseWithMutualFollowAndPostsCount(user, status[0], status[1], int(postsCount)))
		} else {
			result = append(result, ConvertUserToResponseWithPostsCount(user, int(postsCount)))
		}
	}
	return result
}