<?php

namespace App\Libraries;

class ApiConnector
{
    /**
     * @param array<string, mixed> $headers
     * @return array<int, array<string, mixed>>
     */
    public function fetch(string $endpoint, array $headers = [], ?string $jsonPath = null): array
    {
        if (! filter_var($endpoint, FILTER_VALIDATE_URL)) {
            throw new \InvalidArgumentException('Invalid API endpoint URL.');
        }

        $curlHeaders = ['Accept: application/json'];
        foreach ($headers as $key => $value) {
            $k = trim((string) $key);
            if ($k === '') {
                continue;
            }
            $curlHeaders[] = $k . ': ' . (string) $value;
        }

        $ch = curl_init($endpoint);
        curl_setopt_array($ch, [
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_TIMEOUT => 10,
            CURLOPT_HTTPHEADER => $curlHeaders,
        ]);
        $raw = (string) curl_exec($ch);
        $httpCode = (int) curl_getinfo($ch, CURLINFO_HTTP_CODE);
        $error = curl_error($ch);
        curl_close($ch);

        if ($error !== '') {
            throw new \RuntimeException('API request failed: ' . $error);
        }
        if ($httpCode < 200 || $httpCode >= 400) {
            throw new \RuntimeException('API request failed with HTTP ' . $httpCode . '.');
        }

        $decoded = json_decode($raw, true);
        if (! is_array($decoded)) {
            return [];
        }

        $data = $decoded;
        if ($jsonPath !== null && trim($jsonPath) !== '') {
            foreach (explode('.', $jsonPath) as $segment) {
                $segment = trim($segment);
                if ($segment === '' || ! is_array($data) || ! array_key_exists($segment, $data)) {
                    return [];
                }
                $data = $data[$segment];
            }
        }

        if (! is_array($data)) {
            return [];
        }

        // Normalize to list of rows.
        if ($data !== [] && array_keys($data) !== range(0, count($data) - 1)) {
            return [$data];
        }

        $rows = [];
        foreach ($data as $row) {
            if (is_array($row)) {
                $rows[] = $row;
            }
        }

        return $rows;
    }
}