<?php

namespace App\Services\Geo;

use App\Models\Barangay;
use Illuminate\Support\Facades\Cache;
use Illuminate\Support\Facades\DB;

class GeoLocationService
{
    public function __construct(private readonly int $cacheTtlSeconds = 300) {}

    /**
     * Resolve a (latitude, longitude) pair to the containing barangay using
     * MySQL ST_Contains. Returns null if no barangay polygon contains the point
     * or if the input is outside the Philippines bounding box.
     */
    public function findBarangayByCoordinates(float $latitude, float $longitude): ?Barangay
    {
        if (! $this->insidePhilippinesBoundingBox($latitude, $longitude)) {
            return null;
        }

        $key = sprintf('geo:resolve:%.6f:%.6f', $latitude, $longitude);

        $barangayId = Cache::remember($key, $this->cacheTtlSeconds, function () use ($latitude, $longitude) {
            $row = DB::table('barangays')
                ->whereNull('deleted_at')
                ->whereNotNull('boundary')
                ->whereRaw(
                    'ST_Contains(boundary, ST_SRID(POINT(?, ?), 4326))',
                    [$longitude, $latitude],
                )
                ->select('id')
                ->first();

            return $row?->id;
        });

        if (! $barangayId) {
            return null;
        }

        return Barangay::with('cityMunicipality.province.region')->find($barangayId);
    }

    private function insidePhilippinesBoundingBox(float $latitude, float $longitude): bool
    {
        // Rough bounds for the Philippines archipelago.
        return $latitude >= 4.5 && $latitude <= 21.5
            && $longitude >= 116.0 && $longitude <= 127.0;
    }
}