02_merge.php

<?php
$jsonPath = __DIR__ . '/geojson';
if(!file_exists($jsonPath)) {
  mkdir($jsonPath, 0777);
}

foreach(glob(__DIR__ . '/raw/*.json') AS $jsonFile) {
  echo "processing {$jsonFile}\n";
  $json = json_decode(file_get_contents($jsonFile), true);
  // if(!isset($json['features'])) {
  //   echo "{$jsonFile}\n";
  //   print_r($json); exit();
  // }
  // continue;
  foreach($json['features'] AS $f) {
    $targetPath = $jsonPath . '/' . substr($f['attributes']['段號'], 0, 6);
    if(!file_exists($targetPath)) {
      mkdir($targetPath, 0777);
    }
    $targetFile = $targetPath . '/' . $f['attributes']['段號'] . '.json';
    $feature = array(
      'type' => 'Feature',
      'properties' => array(
        '段號' => $f['attributes']['段號'],
        '地籍址' => $f['attributes']['地籍址'],
        'PLNInt' => $f['attributes']['PLNInt'],
        '農盤分類' => $f['attributes']['農盤分類'],
        '使用分區' => $f['attributes']['使用分區'],
        '使用類別' => $f['attributes']['使用類別'],
        'Shape_Length' => $f['attributes']['Shape_Length'],
        'Shape_Area' => $f['attributes']['Shape_Area'],
      ),
      'geometry' => array(),
    );

    // if(!isset($f['geometry']['rings'])) {
    //   print_r($json); exit();
    // }
    if(count($f['geometry']['rings']) === 1) {
      $feature['geometry'] = array(
        'type' => 'Polygon',
        'coordinates' => array(),
      );
      foreach($f['geometry']['rings'] AS $k1 => $ring) {
        foreach($ring AS $k2 => $point) {
          $point = twd97_to_latlng($point[0], $point[1]);
          $ring[$k2][0] = floatval($point['lng']);
          $ring[$k2][1] = floatval($point['lat']);
        }
        $feature['geometry']['coordinates'][] = $ring;
      }
    } else {
      $feature['geometry'] = array(
        'type' => 'MultiPolygon',
        'coordinates' => array(),
      );
      foreach($f['geometry']['rings'] AS $k1 => $ring) {
        foreach($ring AS $k2 => $point) {
          $point = twd97_to_latlng($point[0], $point[1]);
          $ring[$k2][0] = floatval($point['lng']);
          $ring[$k2][1] = floatval($point['lat']);
        }
        $feature['geometry']['coordinates'][] = array($ring);
      }
    }
    file_put_contents($targetFile, json_encode($feature));
  }
}

foreach(glob(__DIR__ . '/geojson/*') AS $tmpPath) {
  $fc = array(
    'type' => 'FeatureCollection',
    'features' => array(),
  );
  foreach(glob($tmpPath . '/*.json') AS $jsonFile) {
    $fc['features'][] = json_decode(file_get_contents($jsonFile));
    unlink($jsonFile);
  }
  file_put_contents($tmpPath . '.json', json_encode($fc));
  rmdir($tmpPath);
}

function twd97_to_latlng($x, $y) {
    $a = 6378137.0;
    $b = 6356752.314245;
    $lng0 = 121 * M_PI / 180;
    $k0 = 0.9999;
    $dx = 250000;
    $dy = 0;
    $e = pow((1 - pow($b, 2) / pow($a, 2)), 0.5);
    $x -= $dx;
    $y -= $dy;
    $M = $y / $k0;
    $mu = $M / ($a * (1.0 - pow($e, 2) / 4.0 - 3 * pow($e, 4) / 64.0 - 5 * pow($e, 6) / 256.0));
    $e1 = (1.0 - pow((1.0 - pow($e, 2)), 0.5)) / (1.0 + pow((1.0 - pow($e, 2)), 0.5));
    $J1 = (3 * $e1 / 2 - 27 * pow($e1, 3) / 32.0);
    $J2 = (21 * pow($e1, 2) / 16 - 55 * pow($e1, 4) / 32.0);
    $J3 = (151 * pow($e1, 3) / 96.0);
    $J4 = (1097 * pow($e1, 4) / 512.0);
    $fp = $mu + $J1 * sin(2 * $mu) + $J2 * sin(4 * $mu) + $J3 * sin(6 * $mu) + $J4 * sin(8 * $mu);
    $e2 = pow(($e * $a / $b), 2);
    $C1 = pow($e2 * cos($fp), 2);
    $T1 = pow(tan($fp), 2);
    $R1 = $a * (1 - pow($e, 2)) / pow((1 - pow($e, 2) * pow(sin($fp), 2)), (3.0 / 2.0));
    $N1 = $a / pow((1 - pow($e, 2) * pow(sin($fp), 2)), 0.5);
    $D = $x / ($N1 * $k0);
    $Q1 = $N1 * tan($fp) / $R1;
    $Q2 = (pow($D, 2) / 2.0);
    $Q3 = (5 + 3 * $T1 + 10 * $C1 - 4 * pow($C1, 2) - 9 * $e2) * pow($D, 4) / 24.0;
    $Q4 = (61 + 90 * $T1 + 298 * $C1 + 45 * pow($T1, 2) - 3 * pow($C1, 2) - 252 * $e2) * pow($D, 6) / 720.0;
    $lat = $fp - $Q1 * ($Q2 - $Q3 + $Q4);
    $Q5 = $D;
    $Q6 = (1 + 2 * $T1 + $C1) * pow($D, 3) / 6;
    $Q7 = (5 - 2 * $C1 + 28 * $T1 - 3 * pow($C1, 2) + 8 * $e2 + 24 * pow($T1, 2)) * pow($D, 5) / 120.0;
    $lng = $lng0 + ($Q5 - $Q6 + $Q7) / cos($fp);
    $lat = ($lat * 180) / M_PI;
    $lng = ($lng * 180) / M_PI;
    return array(
        'lat' => round($lat, 7),
        'lng' => round($lng, 7)
    );
}