package repositories

import (
	"database/sql"
	"log"

	"github.com/niangaodev/art-code/config"
	"github.com/niangaodev/art-code/models"
)

// GetUserByUsername 根据用户名获取用户
func GetUserByUsername(username string) (*models.User, error) {
	query := `
		SELECT u.id, u.username, u.email, u.password_hash, u.role_id, COALESCE(r.name, u.role), u.is_active, u.created_at, u.updated_at 
		FROM users u 
		LEFT JOIN roles r ON u.role_id = r.id
		WHERE u.username = ?
	`
	row := config.DB.QueryRow(query, username)

	var user models.User
	var roleID sql.NullInt64    // Handle nullable role_id
	var roleName sql.NullString // Handle nullable role name

	if err := row.Scan(
		&user.ID,
		&user.Username,
		&user.Email,
		&user.PasswordHash,
		&roleID,
		&roleName,
		&user.IsActive,
		&user.CreatedAt,
		&user.UpdatedAt,
	); err != nil {
		if err == sql.ErrNoRows {
			return nil, nil
		}
		log.Printf("Error scanning user by username: %v", err)
		return nil, err
	}

	if roleID.Valid {
		user.RoleID = uint(roleID.Int64)
	}
	if roleName.Valid {
		user.Role = roleName.String
	}

	return &user, nil
}

// GetUserByID 根据ID获取用户
func GetUserByID(id uint) (*models.User, error) {
	query := `
		SELECT u.id, u.username, u.email, u.password_hash, u.role_id, COALESCE(r.name, u.role), u.is_active, u.created_at, u.updated_at 
		FROM users u 
		LEFT JOIN roles r ON u.role_id = r.id
		WHERE u.id = ?
	`
	row := config.DB.QueryRow(query, id)

	var user models.User
	var roleID sql.NullInt64
	var roleName sql.NullString

	if err := row.Scan(
		&user.ID,
		&user.Username,
		&user.Email,
		&user.PasswordHash,
		&roleID,
		&roleName,
		&user.IsActive,
		&user.CreatedAt,
		&user.UpdatedAt,
	); err != nil {
		if err == sql.ErrNoRows {
			return nil, nil
		}
		log.Printf("Error scanning user by ID: %v", err)
		return nil, err
	}

	if roleID.Valid {
		user.RoleID = uint(roleID.Int64)
	}
	if roleName.Valid {
		user.Role = roleName.String
	}

	return &user, nil
}

// GetUsers 获取所有用户
func GetUsers() ([]models.User, error) {
	query := `
		SELECT u.id, u.username, u.email, u.password_hash, u.role_id, COALESCE(r.name, u.role), u.is_active, u.created_at, u.updated_at 
		FROM users u 
		LEFT JOIN roles r ON u.role_id = r.id
		ORDER BY u.created_at DESC
	`
	rows, err := config.DB.Query(query)
	if err != nil {
		log.Printf("Error querying users: %v", err)
		return nil, err
	}
	defer rows.Close()

	var users []models.User
	for rows.Next() {
		var user models.User
		var roleID sql.NullInt64
		var roleName sql.NullString

		if err := rows.Scan(
			&user.ID,
			&user.Username,
			&user.Email,
			&user.PasswordHash,
			&roleID,
			&roleName,
			&user.IsActive,
			&user.CreatedAt,
			&user.UpdatedAt,
		); err != nil {
			log.Printf("Error scanning user: %v", err)
			continue
		}

		if roleID.Valid {
			user.RoleID = uint(roleID.Int64)
		}
		if roleName.Valid {
			user.Role = roleName.String
		}

		users = append(users, user)
	}

	return users, nil
}

// CreateUser 创建用户
func CreateUser(user *models.User) error {
	// 如果提供了RoleID，确保它有效。如果没有RoleID但有Role name，尝试查找RoleID
	if user.RoleID == 0 && user.Role != "" {
		role, err := GetRoleByName(user.Role)
		if err == nil && role != nil {
			user.RoleID = role.ID
		}
	}

	query := `
		INSERT INTO users (username, email, password_hash, role_id, role, is_active, created_at, updated_at)
		VALUES (?, ?, ?, ?, ?, ?, NOW(), NOW())
	`

	var roleID interface{}
	if user.RoleID != 0 {
		roleID = user.RoleID
	} else {
		roleID = nil
	}

	result, err := config.DB.Exec(
		query,
		user.Username,
		user.Email,
		user.PasswordHash,
		roleID,
		user.Role, // Fallback legacy column
		user.IsActive,
	)
	if err != nil {
		log.Printf("Error creating user: %v", err)
		return err
	}

	// 获取自增ID
	id, err := result.LastInsertId()
	if err != nil {
		log.Printf("Error getting last insert ID: %v", err)
		return err
	}
	user.ID = uint(id)

	return nil
}

// UpdateUser 更新用户
func UpdateUser(user *models.User) error {
	// 同样尝试解析RoleID
	if user.RoleID == 0 && user.Role != "" {
		role, err := GetRoleByName(user.Role)
		if err == nil && role != nil {
			user.RoleID = role.ID
		}
	}

	query := `
		UPDATE users SET username = ?, email = ?, role_id = ?, role = ?, is_active = ?, updated_at = NOW()
		WHERE id = ?
	`

	var roleID interface{}
	if user.RoleID != 0 {
		roleID = user.RoleID
	} else {
		roleID = nil
	}

	_, err := config.DB.Exec(
		query,
		user.Username,
		user.Email,
		roleID,
		user.Role,
		user.IsActive,
		user.ID,
	)
	if err != nil {
		log.Printf("Error updating user: %v", err)
		return err
	}

	return nil
}

// UpdateUserPassword 更新用户密码
func UpdateUserPassword(id uint, passwordHash string) error {
	query := `
		UPDATE users SET password_hash = ?, updated_at = NOW()
		WHERE id = ?
	`
	_, err := config.DB.Exec(query, passwordHash, id)
	if err != nil {
		log.Printf("Error updating user password: %v", err)
		return err
	}

	return nil
}

// DeleteUser 删除用户
func DeleteUser(id uint) error {
	query := "DELETE FROM users WHERE id = ?"
	_, err := config.DB.Exec(query, id)
	if err != nil {
		log.Printf("Error deleting user: %v", err)
		return err
	}

	return nil
}

// GetUserCount 获取用户总数
func GetUserCount() (int, error) {
	var count int
	query := "SELECT COUNT(*) FROM users"
	row := config.DB.QueryRow(query)

	err := row.Scan(&count)
	if err != nil {
		log.Printf("Error getting user count: %v", err)
		return 0, err
	}

	return count, nil
}

// BuildUserResponse 构建用户响应
func BuildUserResponse(user *models.User) *models.UserResponse {
	return &models.UserResponse{
		ID:        user.ID,
		Username:  user.Username,
		Email:     user.Email,
		RoleID:    user.RoleID,
		Role:      user.Role,
		IsActive:  user.IsActive,
		CreatedAt: user.CreatedAt.Format("2006-01-02 15:04:05"),
		UpdatedAt: user.UpdatedAt.Format("2006-01-02 15:04:05"),
	}
}

// BuildUsersResponse 构建用户列表响应
func BuildUsersResponse(users []models.User) []models.UserResponse {
	var responses []models.UserResponse
	for _, user := range users {
		responses = append(responses, *BuildUserResponse(&user))
	}
	return responses
}