mygo/internal/repository/user.go

package repository

import (
	"context"
	"errors"
	"strings"

	"gorm.io/gorm"

	"github.com/dhao2001/mygo/internal/model"
)

// isDuplicateKeyError checks if the error indicates a unique constraint violation.
func isDuplicateKeyError(err error) bool {
	return errors.Is(err, gorm.ErrDuplicatedKey) || strings.Contains(strings.ToLower(err.Error()), "unique constraint failed")
}

// RegisteredUserParams contains the fields accepted when registering a user.
// Administrative and lifecycle fields are intentionally excluded.
type RegisteredUserParams struct {
	ID           string
	Username     string
	Email        string
	PasswordHash string
}

// AuthUserRepository exposes only user operations required by authentication.
type AuthUserRepository interface {
	CreateRegisteredUser(ctx context.Context, params RegisteredUserParams) (*model.User, error)
	FindByID(ctx context.Context, id string) (*model.User, error)
	FindByEmail(ctx context.Context, email string) (*model.User, error)
}

// AdminUserRepository exposes only user operations required by administration.
type AdminUserRepository interface {
	FindByIDIncludeDeleted(ctx context.Context, id string) (*model.User, error)
	MarkAdminDeleted(ctx context.Context, id string) error
	ListIncludeDeleted(ctx context.Context, offset, limit int) ([]model.User, int64, error)
}

// UserRepository is the composition-time union of user capabilities.
type UserRepository interface {
	AuthUserRepository
	AdminUserRepository
	FindByUsername(ctx context.Context, username string) (*model.User, error)
	List(ctx context.Context, offset, limit int) ([]model.User, int64, error)
}

type userRepository struct {
	db *gorm.DB
}

// NewUserRepository creates a UserRepository backed by GORM.
func NewUserRepository(db *gorm.DB) UserRepository {
	return &userRepository{db: db}
}

func (r *userRepository) CreateRegisteredUser(ctx context.Context, params RegisteredUserParams) (*model.User, error) {
	user := &model.User{
		ID:           params.ID,
		Username:     params.Username,
		Email:        params.Email,
		PasswordHash: params.PasswordHash,
		IsAdmin:      false,
		Status:       model.StatusActive,
	}
	result := r.db.WithContext(ctx).Create(user)
	if result.Error != nil {
		if isDuplicateKeyError(result.Error) {
			return nil, model.ErrDuplicate
		}
		return nil, result.Error
	}
	return user, nil
}

func (r *userRepository) FindByID(ctx context.Context, id string) (*model.User, error) {
	var user model.User
	result := r.db.WithContext(ctx).First(&user, "id = ? AND status = ?", id, model.StatusActive)
	if errors.Is(result.Error, gorm.ErrRecordNotFound) {
		return nil, model.ErrNotFound
	}
	if result.Error != nil {
		return nil, result.Error
	}
	return &user, nil
}

// FindByIDIncludeDeleted finds a user by ID regardless of status.
func (r *userRepository) FindByIDIncludeDeleted(ctx context.Context, id string) (*model.User, error) {
	var user model.User
	result := r.db.WithContext(ctx).First(&user, "id = ?", id)
	if errors.Is(result.Error, gorm.ErrRecordNotFound) {
		return nil, model.ErrNotFound
	}
	if result.Error != nil {
		return nil, result.Error
	}
	return &user, nil
}

func (r *userRepository) FindByEmail(ctx context.Context, email string) (*model.User, error) {
	var user model.User
	result := r.db.WithContext(ctx).First(&user, "email = ? AND status = ?", email, model.StatusActive)
	if errors.Is(result.Error, gorm.ErrRecordNotFound) {
		return nil, model.ErrNotFound
	}
	if result.Error != nil {
		return nil, result.Error
	}
	return &user, nil
}

func (r *userRepository) FindByUsername(ctx context.Context, username string) (*model.User, error) {
	var user model.User
	result := r.db.WithContext(ctx).First(&user, "username = ? AND status = ?", username, model.StatusActive)
	if errors.Is(result.Error, gorm.ErrRecordNotFound) {
		return nil, model.ErrNotFound
	}
	if result.Error != nil {
		return nil, result.Error
	}
	return &user, nil
}

func (r *userRepository) MarkAdminDeleted(ctx context.Context, id string) error {
	result := r.db.WithContext(ctx).Model(&model.User{}).Where("id = ?", id).Update("status", model.StatusAdminDeleted)
	if result.Error != nil {
		return result.Error
	}
	return nil
}

func (r *userRepository) List(ctx context.Context, offset, limit int) ([]model.User, int64, error) {
	var users []model.User
	var total int64

	if err := r.db.WithContext(ctx).Model(&model.User{}).Where("status = ?", model.StatusActive).Count(&total).Error; err != nil {
		return nil, 0, err
	}

	result := r.db.WithContext(ctx).Where("status = ?", model.StatusActive).Offset(offset).Limit(limit).Find(&users)
	if result.Error != nil {
		return nil, 0, result.Error
	}

	return users, total, nil
}

// ListIncludeDeleted returns all users (including soft-deleted), paginated.
func (r *userRepository) ListIncludeDeleted(ctx context.Context, offset, limit int) ([]model.User, int64, error) {
	var users []model.User
	var total int64

	if err := r.db.WithContext(ctx).Model(&model.User{}).Count(&total).Error; err != nil {
		return nil, 0, err
	}

	result := r.db.WithContext(ctx).Offset(offset).Limit(limit).Find(&users)
	if result.Error != nil {
		return nil, 0, result.Error
	}

	return users, total, nil
}