<?php

namespace NoccyLabs\Hotfix\Hotfix;

use Symfony\Component\Yaml\Yaml;

class Signature
{
    /** @var bool Whether the signature is valid  */
    protected $valid;

    /** @var string|null The name of the key used to sign */
    protected $signer;

    /** @var string|null The ID of the key used to sign */
    protected $keyId;

    protected $error;

    protected $body;

    protected $signature;

    /**
     * Constructor
     *
     * @param bool $valid Whether the signature is valid
     * @param string $signer For a valid signature, the name of the signer
     * @param string $keyId For a valid signature, the key ID
     */
    public function __construct($body, $signature)
    {
        $this->body = $body;
        $this->signature = $signature;
        $this->verify();
    }

    public function verify()
    {
        if (!$this->signature) {
            $this->error = "Hotfix is not signed!";
            return;
        }

        $gpg = gnupg_init();

        $sigInfo = gnupg_verify($gpg, $this->body, $this->signature);

        if ($sigInfo === false) {
            $this->error = "Invalid signature";
            return;
        }

        $fingerprint = $sigInfo[0]['fingerprint'];
        $keyInfo = gnupg_keyinfo($gpg, $fingerprint);

        if (empty($keyInfo)) {
            $this->error = "Unknown signer (key id {$sigInfo[0]['fingerprint']})";
            return;
        }

        $subKeys = $keyInfo[0]['subkeys'];
        $keyId = null;
        foreach ($subKeys as $subKey) {
            if ($subKey['fingerprint'] == $fingerprint) {
                $keyId = $subKey['keyid'];
                break;
            }
        }

        $signerInfo = sprintf("%s (%s)", $keyInfo[0]['uids'][0]['name'], $keyInfo[0]['uids'][0]['email']);

        $this->valid = true;
        $this->signer = $signerInfo;
        $this->keyId = $keyId;
    }

    public function isValid()
    {
        return ($this->valid === true);
    }

    public function getSigner()
    {
        return $this->signer;
    }

    public function getKeyId()
    {
        return $this->keyId;
    }

    public function getError()
    {
        return $this->error;
    }

}