<?php

declare(strict_types=1);

namespace App\Controllers\Api;

use App\Controllers\BaseController;
use App\Libraries\Pipeline;
use App\Libraries\Pipeline\Youtube as YoutubeLib;
use App\Models\JobModel;

/**
 * Job lifecycle API used by tool pages and the v1 developer API.
 * POST /api/jobs  — enqueue (URL-based tools)
 * GET  /api/jobs/{id} — poll status/progress
 * DELETE /api/jobs/{id} — cancel queued job / delete result
 */
final class Jobs extends BaseController
{
    public function create(): \CodeIgniter\HTTP\ResponseInterface
    {
        $isApiV1 = uri_string() === 'api/v1/convert';
        $payload = $this->request->getJSON(true) ?: $this->request->getPost();

        $slug = (string) ($payload['tool'] ?? '');
        $tool = service('finder')->tool($slug);
        if ($tool === null) {
            return response()->setStatusCode(400)->setJSON(['ok' => false, 'error' => 'unknown_tool', 'message' => 'Unknown tool slug.']);
        }

        // URL-kind tools fetch their input server-side (SSRF-guarded).
        $params = array_intersect_key($payload, array_flip([
            'url', 'format', 'bitrate', 'quality', 'width', 'height',
            'start', 'end', 'x', 'y', 'crop_width', 'crop_height',
            'degrees', 'direction', 'factor', 'fps', 'gain_db', 'level',
            'preset', 'pages', '_operation',
        ]));
        $params['_operation'] = $params['_operation'] ?? $tool['operation'];

        if ($tool['kind'] === 'upload') {
            return response()->setStatusCode(400)->setJSON(['ok' => false, 'error' => 'upload_required', 'message' => 'This tool requires a file upload via POST /upload first.']);
        }

        if ($tool['kind'] === 'url') {
            $videoId = YoutubeLib::extractId((string) ($params['url'] ?? ''));
            if ($videoId === null) {
                service('analytics')->track('error', ['tool' => $slug]);
                return response()->setStatusCode(422)->setJSON(['ok' => false, 'error' => 'invalid_url', 'message' => 'Invalid YouTube URL.']);
            }
            // canonicalize to a plain watch URL
            $params['url'] = 'https://www.youtube.com/watch?v=' . $videoId;
        }

        try {
            $jobId = service('pipeline')->enqueue($tool, $params, $isApiV1 ? 'api' : 'web');
        } catch (\RuntimeException $e) {
            return response()->setStatusCode(429)->setJSON(['ok' => false, 'error' => 'limit_reached', 'message' => $e->getMessage()]);
        }

        model(\App\Models\ToolModel::class)->bumpUseCount((int) $tool['id']);
        service('analytics')->track('tool_start', ['tool' => $slug]);

        return response()->setStatusCode(202)->setJSON([
            'ok'       => true,
            'job_id'   => $jobId,
            'status'   => 'queued',
            'poll_url' => base_url('/api/jobs/' . $jobId),
        ]);
    }

    public function show(string $id): \CodeIgniter\HTTP\ResponseInterface
    {
        $job = model(JobModel::class)->find($id);
        if ($job === null || ! $this->owns($job)) {
            return response()->setStatusCode(404)->setJSON(['ok' => false, 'error' => 'not_found']);
        }

        $body = [
            'job_id'     => $job['id'],
            'status'     => $job['status'],
            'stage'      => $job['stage'],
            'progress'   => (int) $job['progress'],
            'created_at' => $job['created_at'],
            'expires_at' => $job['expires_at'],
        ];
        if ($job['status'] === 'completed') {
            $body['download_url'] = '/download/' . $job['id'];
            $body['preview_url']  = '/preview/' . $job['id'] . '.' . pathinfo((string) $job['output_file'], PATHINFO_EXTENSION);
            $body['output_name']  = $job['output_name'];
            $body['output_size']  = (int) $job['output_size'];
        }
        if ($job['status'] === 'failed') {
            $body['message'] = self::friendlyError((string) ($job['error'] ?? 'Processing failed.'));
        }

        return response()->setJSON(['ok' => true] + $body);
    }

    public function delete(string $id): \CodeIgniter\HTTP\ResponseInterface
    {
        $jobs = model(JobModel::class);
        $job  = $jobs->find($id);

        if ($job === null || ! $this->owns($job)) {
            return response()->setStatusCode(404)->setJSON(['ok' => false, 'error' => 'not_found']);
        }

        foreach (['input_file', 'output_file'] as $field) {
            if (! empty($job[$field])) {
                @unlink(Pipeline::storageDir() . '/' . $job[$field]);
                @unlink(Pipeline::incomingDir() . '/' . $job[$field]);
            }
        }

        if (in_array($job['status'], ['queued'], true)) {
            $jobs->update($id, ['status' => 'cancelled', 'completed_at' => gmdate('Y-m-d H:i:s')]);
        } else {
            $jobs->delete($id);
        }

        return response()->setJSON(['ok' => true, 'deleted' => true]);
    }

    /** Session ownership for web callers; API-token jobs are keyed by session hash too. */
    private function owns(array $job): bool
    {
        return $job['session_id'] === service('analytics')->sessionHash();
    }

    private static function friendlyError(string $raw): string
    {
        $known = [
            'Invalid YouTube URL.'          => 'That does not look like a valid YouTube link. Paste the full URL.',
            'disabled on this server'       => 'This capability is currently disabled on this server.',
            'exceeds'                       => 'The file is too large for this tool.',
        ];
        foreach ($known as $needle => $friendly) {
            if (str_contains($raw, $needle)) {
                return $friendly;
            }
        }

        return 'This file could not be processed. Please check the format and try again.';
    }
}