<?php
// ============================================================
// api/roads.php — CRUD for road polylines
// Road types: national (red), provincial (orange), district (blue)
// ============================================================

require_once __DIR__ . '/../config/db.php';
require_once __DIR__ . '/../config/helpers.php';

session_start();
if (!isset($_SESSION['user_id'])) {
    jsonResponse(['error' => 'Unauthorized'], 401);
}

handlePreflight();

$method = getMethod();
if ($method !== 'GET') {
    if (!isset($_SESSION['role']) || $_SESSION['role'] !== 'admin') {
        jsonResponse(['error' => 'Forbidden: Admin access required'], 403);
    }
}

$db     = getDB();

switch ($method) {

    // ----------------------------------------------------------
    // GET /api/roads.php           → all roads as GeoJSON
    // GET /api/roads.php?id=N      → single road
    // GET /api/roads.php?type=national → filter by type
    // ----------------------------------------------------------
    case 'GET':
        if (isset($_GET['id'])) {
            $stmt = $db->prepare('SELECT * FROM roads WHERE id = ?');
            $stmt->execute([(int)$_GET['id']]);
            $row = $stmt->fetch();
            if (!$row) jsonResponse(['error' => 'Road not found'], 404);
            $row['geojson'] = json_decode($row['geojson'], true);
            jsonResponse($row);
        }

        $where  = '';
        $params = [];
        if (!empty($_GET['type'])) {
            $where  = 'WHERE road_type = ?';
            $params = [$_GET['type']];
        }

        $stmt = $db->prepare("SELECT * FROM roads $where ORDER BY created_at DESC");
        $stmt->execute($params);
        $rows = $stmt->fetchAll();

        $features = [];
        foreach ($rows as $row) {
            $geo = json_decode($row['geojson'], true);
            $features[] = [
                'type'       => 'Feature',
                'geometry'   => $geo,
                'properties' => [
                    'id'          => $row['id'],
                    'name'        => $row['name'],
                    'road_type'   => $row['road_type'],
                    'length_m'    => (float)$row['length_m'],
                    'description' => $row['description'],
                    'created_at'  => $row['created_at'],
                ],
            ];
        }
        jsonResponse(['type' => 'FeatureCollection', 'features' => $features]);
        break;

    // ----------------------------------------------------------
    // POST /api/roads.php
    // Body: { name, road_type, length_m, geojson, description }
    // ----------------------------------------------------------
    case 'POST':
        $body = getRequestBody();

        foreach (['name', 'road_type', 'geojson'] as $f) {
            if (empty($body[$f])) jsonResponse(['error' => "Field '$f' is required"], 422);
        }

        $allowed = ['national', 'provincial', 'district'];
        if (!in_array($body['road_type'], $allowed, true)) {
            jsonResponse(['error' => 'Invalid road_type'], 422);
        }

        $geojson = is_array($body['geojson'])
            ? json_encode($body['geojson'])
            : $body['geojson'];

        $stmt = $db->prepare(
            'INSERT INTO roads (name, road_type, length_m, geojson, description)
             VALUES (?, ?, ?, ?, ?)'
        );
        $stmt->execute([
            $body['name'],
            $body['road_type'],
            (float)($body['length_m'] ?? 0),
            $geojson,
            $body['description'] ?? null,
        ]);

        $id   = (int)$db->lastInsertId();
        $stmt2 = $db->prepare('SELECT * FROM roads WHERE id = ?');
        $stmt2->execute([$id]);
        $row = $stmt2->fetch();
        $row['geojson'] = json_decode($row['geojson'], true);
        jsonResponse($row, 201);
        break;

    // ----------------------------------------------------------
    // PUT /api/roads.php?id=N
    // ----------------------------------------------------------
    case 'PUT':
        if (empty($_GET['id'])) jsonResponse(['error' => 'id required'], 400);
        $body = getRequestBody();
        $id   = (int)$_GET['id'];

        $check = $db->prepare('SELECT id FROM roads WHERE id = ?');
        $check->execute([$id]);
        if (!$check->fetch()) jsonResponse(['error' => 'Road not found'], 404);

        $geojson = is_array($body['geojson'] ?? null)
            ? json_encode($body['geojson'])
            : ($body['geojson'] ?? '{}');

        $stmt = $db->prepare(
            'UPDATE roads SET name=?, road_type=?, length_m=?, geojson=?, description=? WHERE id=?'
        );
        $stmt->execute([
            $body['name']        ?? '',
            $body['road_type']   ?? 'national',
            (float)($body['length_m'] ?? 0),
            $geojson,
            $body['description'] ?? null,
            $id,
        ]);

        $stmt2 = $db->prepare('SELECT * FROM roads WHERE id = ?');
        $stmt2->execute([$id]);
        $row = $stmt2->fetch();
        $row['geojson'] = json_decode($row['geojson'], true);
        jsonResponse($row);
        break;

    // ----------------------------------------------------------
    // DELETE /api/roads.php?id=N
    // ----------------------------------------------------------
    case 'DELETE':
        if (empty($_GET['id'])) jsonResponse(['error' => 'id required'], 400);
        $id   = (int)$_GET['id'];
        $stmt = $db->prepare('DELETE FROM roads WHERE id = ?');
        $stmt->execute([$id]);
        if ($stmt->rowCount() === 0) jsonResponse(['error' => 'Road not found'], 404);
        jsonResponse(['message' => 'Road deleted', 'id' => $id]);
        break;

    default:
        jsonResponse(['error' => 'Method not allowed'], 405);
}