<?php

use GuzzleHttp\Client;

class SlackFileDeleter
{
    /**
     * Slack API token.
     *
     * @var string
     */
    protected $token = 'your api token';

    /**
     * Slack domain.
     *
     * @var string
     */
    protected $domain = 'your Slack domain';

    /**
     * Start time for delete. For example, if set to '-60 days' all files older
     * than 60 days will be deleted.
     *
     * @var string Valid strtotime string.
     */
    protected $time = '-60 days';

    /**
     * Clear the slack file backlog.
     */
    public function cleanAction(array $params)
    {
        $data = [
            'token' => $this->token,
            'ts_to' => strtotime($this->time),
        ];

        $client = new Client();

        $response = $client->request(
            'post',
            'https://slack.com/api/files.list',
            ['form_params' => $data]
        );
        
        $files = json_decode($response->getBody(), true)['files'];
        
        if ($files != 0) {
            foreach ($files as $file) {
                echo "Deleting file {$file['name']} ..." . PHP_EOL;

                $timestamp = strtotime(time());

                $delete_data = [
                    'token' => $this->token,
                    'file' => $file['id'],
                    'set_active' => 'true',
                    '_attempts' => 1,
                ];

                $client = new Client();

                $response = $client->request(
                    'post',
                    "https://{$this->domain}.slack.com/api/files.delete?t={$timestamp}",
                    ['form_params' => $delete_data]
                );
            }

            echo "Done!" . PHP_EOL;
        }
    }
}