<?php

declare(strict_types=1);

namespace App\Services\AdditionalProcessing;

use App\Services\AdditionalProcessing\Config\ProcessingConfiguration;
use App\Services\AdditionalProcessing\DTO\AdditionalWorkPlan;
use App\Services\AdditionalProcessing\DTO\ArchiveCandidate;
use Illuminate\Support\Facades\Log;

final readonly class AdditionalWorkPlanner
{
    private const string ARCHIVE_PATTERN = '/(\.(part\d+|[rz]\d+|rar|0+|0*10?|zipr\d{2,3}|zipx?)("|\s*\.rar)*($|[ ")]|-])|"[a-f0-9]{32}\.[1-9]\d{1,2}".*\(\d+\/\d{2,}\)$)/i';

    public function __construct(private ProcessingConfiguration $config) {}

    /**
     * @param  array<int|string, mixed>  $nzbContents
     */
    public function plan(array $nzbContents, string $groupName): AdditionalWorkPlan
    {
        $sampleMessageIds = [];
        $jpgMessageIds = [];
        $mediaInfoMessageId = '';
        $audioInfoMessageId = '';
        $audioInfoExtension = '';
        $archiveCandidates = [];
        $bookFileCount = 0;
        $duplicateMessageIdCount = 0;
        $seenMessageIds = [];

        foreach (array_values($nzbContents) as $sourceIndex => $file) {
            if (! is_array($file)) {
                continue;
            }

            try {
                $title = (string) ($file['title'] ?? '');
                $segments = is_array($file['segments'] ?? null) ? $file['segments'] : [];

                if (preg_match($this->config->ignoreBookRegex, $title) === 1) {
                    $bookFileCount++;
                }

                if (preg_match(self::ARCHIVE_PATTERN, $title) === 1) {
                    $archiveMessageIds = $this->extractSegments(
                        $segments,
                        $this->config->maximumRarSegments,
                        $seenMessageIds,
                        $duplicateMessageIdCount,
                    );
                    if ($archiveMessageIds !== []) {
                        $archiveCandidates[] = new ArchiveCandidate(
                            title: $title,
                            messageIds: $archiveMessageIds,
                            likelyFirstVolume: $this->isLikelyFirstVolume($title),
                            sourceIndex: $sourceIndex,
                        );
                    }
                }

                if ($this->isSupportFile($title)) {
                    continue;
                }

                if ($this->config->processThumbnails && $sampleMessageIds === [] && $segments !== []
                    && stripos($title, 'sample') !== false
                    && preg_match('/\.(?:jpe?g|png|webp)$/i', $title) !== 1
                ) {
                    $sampleMessageIds = $this->extractSegments(
                        $segments,
                        $this->config->segmentsToDownload,
                        $seenMessageIds,
                        $duplicateMessageIdCount,
                    );
                }

                if ($this->config->processJPGSample && $jpgMessageIds === [] && $segments !== []
                    && preg_match('/flac|lossless|mp3|music|inner-sanctum|sound/i', $groupName) !== 1
                    && preg_match('/\.(?:jpe?g|png|webp)[. ")\]]/i', $title) === 1
                ) {
                    $jpgMessageIds = $this->extractSegments(
                        $segments,
                        $this->config->segmentsToDownload,
                        $seenMessageIds,
                        $duplicateMessageIdCount,
                    );
                }

                if ($this->config->processMediaInfo && $mediaInfoMessageId === '' && isset($segments[0])
                    && stripos($title, 'sample') !== false
                    && preg_match('/'.$this->config->videoFileRegex.'[. ")\]]/i', $title) === 1
                ) {
                    $mediaInfoMessageId = (string) $segments[0];
                    $this->recordMessageId($mediaInfoMessageId, $seenMessageIds, $duplicateMessageIdCount);
                }

                if ($this->config->processAudioInfo && $audioInfoMessageId === '' && isset($segments[0])
                    && preg_match('/'.$this->config->audioFileRegex.'[. ")\]]/i', $title, $type) === 1
                ) {
                    $audioInfoExtension = (string) ($type[1] ?? '');
                    $audioInfoMessageId = (string) $segments[0];
                    $this->recordMessageId($audioInfoMessageId, $seenMessageIds, $duplicateMessageIdCount);
                }
            } catch (\ErrorException $e) {
                Log::debug($e->getTraceAsString());
            }
        }

        $bookFlood = $bookFileCount > 80 && ($bookFileCount * 2) >= count($nzbContents);
        $unsupportedReasons = [];
        if ($bookFlood) {
            $unsupportedReasons[] = 'book-flood';
        }
        if ($archiveCandidates === []
            && $sampleMessageIds === []
            && $jpgMessageIds === []
            && $mediaInfoMessageId === ''
            && $audioInfoMessageId === ''
        ) {
            $unsupportedReasons[] = 'no-supported-candidates';
        }

        return new AdditionalWorkPlan(
            sampleMessageIds: $sampleMessageIds,
            jpgMessageIds: $jpgMessageIds,
            mediaInfoMessageId: $mediaInfoMessageId,
            audioInfoMessageId: $audioInfoMessageId,
            audioInfoExtension: $audioInfoExtension,
            archiveCandidates: $archiveCandidates,
            bookFileCount: $bookFileCount,
            bookFlood: $bookFlood,
            duplicateMessageIdCount: $duplicateMessageIdCount,
            unsupportedReasons: $unsupportedReasons,
        );
    }

    private function isSupportFile(string $title): bool
    {
        return preg_match(
            '/(?:'.$this->config->supportFileRegex.'|nfo\b|inf\b|ofn\b)($|[ ")]|-])(?!.{20,})/i',
            $title,
        ) === 1;
    }

    private function isLikelyFirstVolume(string $title): bool
    {
        if (preg_match('/\.part0*(\d+)/i', $title, $part) === 1) {
            return (int) $part[1] === 1;
        }

        if (preg_match('/"[a-f0-9]{32}\.[1-9]\d{1,2}".*\((\d+)\/\d{2,}\)$/i', $title, $position) === 1) {
            return (int) $position[1] === 1;
        }

        return preg_match('/\.(rar|zip)($|[ ")]|-])/i', $title) === 1;
    }

    /**
     * @param  array<int|string, mixed>  $segments
     * @param  array<string, true>  $seenMessageIds
     * @return list<string>
     */
    private function extractSegments(
        array $segments,
        int $limit,
        array &$seenMessageIds,
        int &$duplicateMessageIdCount,
    ): array {
        $messageIds = [];
        $requestMessageIds = [];

        foreach (array_slice($segments, 0, max($limit, 0)) as $segment) {
            $messageId = (string) $segment;
            if ($messageId === '' || isset($requestMessageIds[$messageId])) {
                if ($messageId !== '') {
                    $duplicateMessageIdCount++;
                }

                continue;
            }

            $requestMessageIds[$messageId] = true;
            $messageIds[] = $messageId;
            $this->recordMessageId($messageId, $seenMessageIds, $duplicateMessageIdCount);
        }

        return $messageIds;
    }

    /**
     * @param  array<string, true>  $seenMessageIds
     */
    private function recordMessageId(string $messageId, array &$seenMessageIds, int &$duplicateMessageIdCount): void
    {
        if (isset($seenMessageIds[$messageId])) {
            $duplicateMessageIdCount++;

            return;
        }

        $seenMessageIds[$messageId] = true;
    }
}