package registry

import (
	"database/sql"
	"fmt"
	"time"
)

// Service represents a service in the registry.
type Service struct {
	Name      string
	Active    bool
	Comment   string
	CreatedAt time.Time
	UpdatedAt time.Time
}

// CreateService creates a new service in the registry.
func CreateService(db *sql.DB, name string, active bool, comment string) error {
	_, err := db.Exec(
		"INSERT INTO services (name, active, comment) VALUES (?, ?, ?)",
		name, active, comment,
	)
	if err != nil {
		return fmt.Errorf("create service %q: %w", name, err)
	}
	return nil
}

// GetService retrieves a service by name.
func GetService(db *sql.DB, name string) (*Service, error) {
	s := &Service{}
	var createdAt, updatedAt string
	err := db.QueryRow(
		"SELECT name, active, comment, created_at, updated_at FROM services WHERE name = ?",
		name,
	).Scan(&s.Name, &s.Active, &s.Comment, &createdAt, &updatedAt)
	if err != nil {
		return nil, fmt.Errorf("get service %q: %w", name, err)
	}
	s.CreatedAt, _ = time.Parse("2006-01-02 15:04:05", createdAt)
	s.UpdatedAt, _ = time.Parse("2006-01-02 15:04:05", updatedAt)
	return s, nil
}

// ListServices returns all services.
func ListServices(db *sql.DB) ([]Service, error) {
	rows, err := db.Query("SELECT name, active, comment, created_at, updated_at FROM services ORDER BY name")
	if err != nil {
		return nil, fmt.Errorf("list services: %w", err)
	}
	defer func() { _ = rows.Close() }()

	var services []Service
	for rows.Next() {
		var s Service
		var createdAt, updatedAt string
		if err := rows.Scan(&s.Name, &s.Active, &s.Comment, &createdAt, &updatedAt); err != nil {
			return nil, fmt.Errorf("scan service: %w", err)
		}
		s.CreatedAt, _ = time.Parse("2006-01-02 15:04:05", createdAt)
		s.UpdatedAt, _ = time.Parse("2006-01-02 15:04:05", updatedAt)
		services = append(services, s)
	}
	return services, rows.Err()
}

// UpdateServiceActive updates a service's active flag and comment. If comment
// is empty, the existing comment is preserved.
func UpdateServiceActive(db *sql.DB, name string, active bool, comment string) error {
	res, err := db.Exec(`
		UPDATE services SET active = ?,
			comment = CASE WHEN ? = '' THEN comment ELSE ? END,
			updated_at = datetime('now')
		WHERE name = ?`,
		active, comment, comment, name,
	)
	if err != nil {
		return fmt.Errorf("update service %q: %w", name, err)
	}
	n, _ := res.RowsAffected()
	if n == 0 {
		return fmt.Errorf("update service %q: %w", name, sql.ErrNoRows)
	}
	return nil
}

// DeleteService removes a service and all its components (via CASCADE).
func DeleteService(db *sql.DB, name string) error {
	res, err := db.Exec("DELETE FROM services WHERE name = ?", name)
	if err != nil {
		return fmt.Errorf("delete service %q: %w", name, err)
	}
	n, _ := res.RowsAffected()
	if n == 0 {
		return fmt.Errorf("delete service %q: %w", name, sql.ErrNoRows)
	}
	return nil
}