<?php

declare(strict_types=1);

namespace App\Import;

use RuntimeException;

final class ImportJobStore
{
    public function __construct(
        private readonly string $storageDir = '',
    ) {
    }

    public function create(array $state): string
    {
        $token = bin2hex(random_bytes(16));
        $state['token'] = $token;
        $this->write($token, $state);

        return $token;
    }

    public function get(string $token): ?array
    {
        $path = $this->path($token);
        if (!is_file($path)) {
            return null;
        }

        $contents = file_get_contents($path);
        if ($contents === false || $contents === '') {
            return null;
        }

        $state = json_decode($contents, true);
        if (!is_array($state)) {
            throw new RuntimeException('The import job state is corrupt.');
        }

        return $state;
    }

    public function save(string $token, array $state): void
    {
        $state['token'] = $token;
        $this->write($token, $state);
    }

    public function delete(string $token): void
    {
        $path = $this->path($token);
        if (is_file($path)) {
            @unlink($path);
        }
    }

    public function pathForToken(string $token): string
    {
        return $this->path($token);
    }

    private function write(string $token, array $state): void
    {
        $path = $this->path($token);
        $dir = dirname($path);
        if (!is_dir($dir) && !mkdir($dir, 0777, true) && !is_dir($dir)) {
            throw new RuntimeException('Unable to create the import job storage directory.');
        }

        $json = json_encode($state, JSON_THROW_ON_ERROR | JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE);
        $tmpPath = $path . '.' . bin2hex(random_bytes(6)) . '.tmp';
        if (file_put_contents($tmpPath, $json) === false) {
            throw new RuntimeException('Unable to write the import job state.');
        }

        if (!@rename($tmpPath, $path)) {
            @unlink($tmpPath);
            throw new RuntimeException('Unable to persist the import job state.');
        }
    }

    private function path(string $token): string
    {
        $safeToken = preg_replace('/[^a-zA-Z0-9_-]/', '', $token);
        if ($safeToken === '') {
            throw new RuntimeException('Invalid import job token.');
        }

        $storageDir = $this->storageDir !== '' ? $this->storageDir : sys_get_temp_dir() . '/warner-import-jobs';

        return rtrim($storageDir, '/\\') . '/' . $safeToken . '.json';
    }
}