backend/internal/dto/user_converter.go

package dto

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

type UserResponseOption func(*UserResponse)

func WithFollowing(isFollowing, isFollowingMe bool) UserResponseOption {
	return func(r *UserResponse) {
		r.IsFollowing = isFollowing
		r.IsFollowingMe = isFollowingMe
	}
}

func WithPostsCount(count int) UserResponseOption {
	return func(r *UserResponse) {
		r.PostsCount = count
	}
}

// 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)
}

// publicVerificationFields 返回认证信息：
// - approved 时返回真实身份和状态
// - 其他状态统一返回 general + none，不暴露具体审核状态
func publicVerificationFields(user *model.User) (model.UserIdentity, model.VerificationStatus) {
	if user.VerificationStatus == model.VerificationStatusApproved {
		return user.Identity, user.VerificationStatus
	}
	return model.UserIdentityGeneral, model.VerificationStatusNone
}

func baseUserResponse(user *model.User) *UserResponse {
	if user == nil {
		return nil
	}
	identity, vs := publicVerificationFields(user)
	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),
		Identity:           identity,
		VerificationStatus: vs,
	}
}

// ConvertUserToResponse 将User转换为UserResponse（公开信息，不包含敏感数据）
func ConvertUserToResponse(user *model.User, opts ...UserResponseOption) *UserResponse {
	r := baseUserResponse(user)
	if r == nil {
		return nil
	}
	for _, opt := range opts {
		opt(r)
	}
	return r
}

// 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),
		PrivacySettings:    convertPrivacySettingsToResponse(&user.PrivacySettings),
		Identity:           user.Identity,
		VerificationStatus: user.VerificationStatus,
	}
}

// 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),
		PrivacySettings:    convertPrivacySettingsToResponse(&user.PrivacySettings),
		Identity:           user.Identity,
		VerificationStatus: user.VerificationStatus,
	}
}

func convertPrivacySettingsToResponse(ps *model.PrivacySettings) *PrivacySettingsResponse {
	if ps == nil {
		return nil
	}
	return &PrivacySettingsResponse{
		FollowersVisibility: string(ps.FollowersVisibility),
		FollowingVisibility: string(ps.FollowingVisibility),
		PostsVisibility:     string(ps.PostsVisibility),
		FavoritesVisibility: string(ps.FavoritesVisibility),
	}
}

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

// ConvertUsersToResponseWithMutualFollowAndPostsCount 将User列表转换为响应列表（包含双向关注状态和帖子数量）
// 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]
		if !hasPostsCount {
			postsCount = int64(user.PostsCount)
		}
		var opts []UserResponseOption
		if hasStatus {
			opts = append(opts, WithFollowing(status[0], status[1]))
		}
		opts = append(opts, WithPostsCount(int(postsCount)))
		result = append(result, ConvertUserToResponse(user, opts...))
	}
	return result
}