<?php

namespace App\Services\ExerciseDb;

use GuzzleHttp\Client;

class ApiService
{
    public const PER_PAGE = 50;

    public const API_BASE_URL = 'https://www.exercisedb.dev';
    public const EXERCISE_URI = '/api/v1/exercises';

    /**
     * Fetch a page of exercises from ExerciseDB API.
     *
     * @return array<int, array<string, mixed>>
     */
    public function fetch(int $page = 1): array
    {
        $results = $this->call(
            self::EXERCISE_URI,
            $this->pagination($page),
        );

        $decoded = json_decode($results, true);
        return is_array($decoded) ? $decoded : [];
    }

    private function pagination(int $page = 1): array
    {
        return [
            'offset' => ($page - 1) * self::PER_PAGE,
            'limit' => self::PER_PAGE,
        ];
    }

    private function call(
        string $uri,
        array $params = [],
    ): string {
        $client = new Client();

        $url = self::API_BASE_URL . $uri;

        return $client->request('GET', $url, [
            'query' => $params,
        ])->getBody()->getContents();
    }
}