@Blog

<?php

class JapanPostAPIClient
{
    private string $clientId;
    private string $secretKey;
    private string $clientIp;
    private ?string $accessToken = null;
    private ?array $lastResponse = null;

    public function __construct(string $clientId, string $secretKey, string $clientIp)
    {
        $this->clientId = $clientId;
        $this->secretKey = $secretKey;
        $this->clientIp = $clientIp;
    }

    public function authenticate(): self
    {
        $url = 'https://api.da.pf.japanpost.jp/api/v1/j/token';
        $data = json_encode([
            'grant_type' => 'client_credentials',
            'client_id' => $this->clientId,
            'secret_key' => $this->secretKey
        ]);

        $headers = [
            "Content-Type: application/json",
            "x-forwarded-for: {$this->clientIp}"
        ];

        $ch = curl_init($url);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_POST, true);
        curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
        curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);

        $response = curl_exec($ch);
        $httpcode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        curl_close($ch);

        if ($httpcode !== 200) {
            throw new Exception("Token request failed with status {$httpcode}: {$response}");
        }

        $responseData = json_decode($response, true);
        $this->accessToken = $responseData['token'] ?? null;
        $this->lastResponse = $responseData;

        return $this;
    }

    public function searchCode(string $searchCode, array $params = []): self
    {
        if (!$this->accessToken) {
            throw new Exception("Access token is not set. Please call authenticate() first.");
        }

        $defaultParams = [
            'page' => 1,
            'limit' => 10,
            'choikitype' => 1,
            'searchtype' => 1
        ];

        $queryParams = http_build_query(array_merge($defaultParams, $params));
        $url = "https://api.da.pf.japanpost.jp/api/v1/searchcode/{$searchCode}?{$queryParams}";

        $headers = [
            "Authorization: Bearer {$this->accessToken}",
            "Accept: application/json"
        ];

        $ch = curl_init($url);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);

        $response = curl_exec($ch);
        $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        curl_close($ch);

        if ($httpCode !== 200) {
            throw new Exception("Search request failed with status {$httpCode}: {$response}");
        }

        $this->lastResponse = json_decode($response, true);
        return $this;
    }

    public function getJson(): string
    {
        return json_encode($this->lastResponse, JSON_UNESCAPED_UNICODE | JSON_PRETTY_PRINT);
    }

    public function getArray(): ?array
    {
        return $this->lastResponse;
    }
}

// 使い方の例：
// $client = new JapanPostAPIClient('YOUR_CLIENT_ID', 'YOUR_SECRET_KEY', 'IPアドレス.xxx.xxx.xxx');
// echo $client->authenticate()->searchCode('1000001')->getJson();