package db

import "fmt"

// L7Policy is a database L7 policy record.
type L7Policy struct {
	ID      int64
	RouteID int64
	Type    string // "block_user_agent" or "require_header"
	Value   string
}

// ListL7Policies returns all L7 policies for a route.
func (s *Store) ListL7Policies(routeID int64) ([]L7Policy, error) {
	rows, err := s.db.Query(
		"SELECT id, route_id, type, value FROM l7_policies WHERE route_id = ? ORDER BY id",
		routeID,
	)
	if err != nil {
		return nil, fmt.Errorf("querying l7 policies: %w", err)
	}
	defer rows.Close()

	var policies []L7Policy
	for rows.Next() {
		var p L7Policy
		if err := rows.Scan(&p.ID, &p.RouteID, &p.Type, &p.Value); err != nil {
			return nil, fmt.Errorf("scanning l7 policy: %w", err)
		}
		policies = append(policies, p)
	}
	return policies, rows.Err()
}

// CreateL7Policy inserts an L7 policy and returns its ID.
func (s *Store) CreateL7Policy(routeID int64, policyType, value string) (int64, error) {
	result, err := s.db.Exec(
		"INSERT INTO l7_policies (route_id, type, value) VALUES (?, ?, ?)",
		routeID, policyType, value,
	)
	if err != nil {
		return 0, fmt.Errorf("inserting l7 policy: %w", err)
	}
	return result.LastInsertId()
}

// DeleteL7Policy deletes an L7 policy by route ID, type, and value.
func (s *Store) DeleteL7Policy(routeID int64, policyType, value string) error {
	result, err := s.db.Exec(
		"DELETE FROM l7_policies WHERE route_id = ? AND type = ? AND value = ?",
		routeID, policyType, value,
	)
	if err != nil {
		return fmt.Errorf("deleting l7 policy: %w", err)
	}
	n, _ := result.RowsAffected()
	if n == 0 {
		return fmt.Errorf("l7 policy not found (route %d, type %q, value %q)", routeID, policyType, value)
	}
	return nil
}

// GetRouteID returns the route ID for a listener/hostname pair.
func (s *Store) GetRouteID(listenerID int64, hostname string) (int64, error) {
	var id int64
	err := s.db.QueryRow(
		"SELECT id FROM routes WHERE listener_id = ? AND hostname = ?",
		listenerID, hostname,
	).Scan(&id)
	if err != nil {
		return 0, fmt.Errorf("looking up route %q on listener %d: %w", hostname, listenerID, err)
	}
	return id, nil
}