fix bugs

app/Services/PolylineEncoder.php

@@ -0,0 +1,88 @@
+<?php
+
+namespace App\Services;
+
+/**
+ * Class PolylineEncoder
+ *
+ * Encodes a list of latitude/longitude coordinates into an encoded polyline string.
+ *
+ * This implementation is compatible with Google's Polyline Algorithm Format:
+ * https://developers.google.com/maps/documentation/utilities/polylinealgorithm
+ *
+ * Example input:
+ * [
+ *   [lat, lng],
+ *   [lat, lng]
+ * ]
+ *
+ * or if `$lng_lat_format = true`:
+ * [
+ *   [lng, lat],
+ *   [lng, lat]
+ * ]
+ *
+ * @package App\Services
+ */
+class PolylineEncoder
+{
+    /**
+     * Encode an array of coordinates into a polyline string.
+     *
+     * Each coordinate is encoded as a delta from the previous point,
+     * scaled by the given precision factor.
+     *
+     * @param array $coords Array of coordinate pairs:
+     *                      - default: [lat, lng]
+     *                      - if $lng_lat_format = true: [lng, lat]
+     * @param int $precision Number of decimal places to preserve (default: 6)
+     * @param bool $lng_lat_format If true, input is treated as [lng, lat] instead of [lat, lng]
+     *
+     * @return string Encoded polyline string
+     */
+    public function encodePolyline(array $coords, int $precision = 6, bool $lng_lat_format = false): string
+    {
+        $factor = 10 ** $precision;
+        $output = '';
+        $prevLat = 0;
+        $prevLng = 0;
+
+        foreach ($coords as [$a, $b]) {
+            [$lat, $lng] = $lng_lat_format ? [$b, $a] : [$a, $b];
+
+            $output .= $this->encodeValue((int)round($lat * $factor) - $prevLat);
+            $output .= $this->encodeValue((int)round($lng * $factor) - $prevLng);
+
+            $prevLat = (int)round($lat * $factor);
+            $prevLng = (int)round($lng * $factor);
+        }
+
+        return $output;
+    }
+
+    /**
+     * Encodes a single integer value using Google's polyline encoding algorithm.
+     *
+     * Steps:
+     * - Left shift the value
+     * - Invert bits if negative
+     * - Split into 5-bit chunks
+     * - Convert to ASCII characters
+     *
+     * @param int $value Signed integer delta to encode
+     *
+     * @return string Encoded character sequence
+     */
+    public function encodeValue(int $value): string
+    {
+        $value = $value < 0 ? ~($value << 1) : ($value << 1);
+        $result = '';
+
+        while ($value >= 0x20) {
+            $result .= chr((0x20 | ($value & 0x1f)) + 63);
+            $value >>= 5;
+        }
+
+        return $result . chr($value + 63);
+    }
+}