<?php

namespace App\Services;

use App\Domain\Import\ImportPipeline;
use App\Domain\Import\ImportResult;
use App\Models\MarkdownImport;
use App\Models\PreQuestionCandidate;
use App\Models\SourceFile;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Log;
use Illuminate\Support\Str;

class QuestionImportService
{
    public function __construct(private readonly ImportPipeline $pipeline)
    {
    }

    public function importMarkdown(string $path, array $meta = []): ImportResult
    {
        $markdown = (string) file_get_contents($path);

        return $this->importMarkdownContent($markdown, [
            'path' => $path,
            'meta' => $meta,
        ]);
    }

    public function importMarkdownContent(string $markdown, array $context = []): ImportResult
    {
        return DB::transaction(function () use ($markdown, $context) {
            $sourceFile = SourceFile::create([
                'uuid' => (string) Str::uuid(),
                'original_filename' => basename((string) ($context['path'] ?? '')),
                'normalized_filename' => basename((string) ($context['path'] ?? '')),
                'extension' => 'md',
                'storage_path' => $context['path'] ?? null,
                'raw_markdown' => $markdown,
                'file_metadata' => $context['meta'] ?? [],
                'source_type' => 'markdown',
                'filename' => basename((string) ($context['path'] ?? '')),
                'path' => $context['path'] ?? null,
                'meta' => $context['meta'] ?? [],
                'status' => 'pending',
            ]);

            $import = MarkdownImport::create([
                'file_name' => $sourceFile->original_filename ?: $sourceFile->filename ?: 'markdown',
                'original_markdown' => $markdown,
                'source_type' => 'markdown',
                'source_name' => $context['path'] ?? 'markdown',
                'status' => MarkdownImport::STATUS_PROCESSING,
                'progress_stage' => MarkdownImport::STAGE_SPLITTING,
            ]);

            return new ImportResult($sourceFile->id, $import->id, 0);
        });
    }

    public function processMarkdownImport(int $importId, int $sourceFileId, string $markdown): int
    {
        $payload = $this->pipeline->run('markdown', [
            'markdown' => $markdown,
        ]);

        $blocks = $payload['blocks'] ?? [];

        MarkdownImport::where('id', $importId)->update([
            'progress_stage' => MarkdownImport::STAGE_AI_PARSING,
            'progress_total' => count($blocks),
            'progress_current' => 0,
        ]);

        $parser = app(MarkdownQuestionParser::class);
        $created = 0;

            foreach ($blocks as $block) {
                $candidate = $parser->parseRawMarkdown((string) ($block['raw_markdown'] ?? ''), (int) ($block['index'] ?? 0));
                $raw = (string) ($candidate['raw_markdown'] ?? '');
                $clean = trim(str_replace("\r", '', $raw));

            PreQuestionCandidate::create([
                'import_id' => $importId,
                'source_file_id' => $sourceFileId,
                'order_index' => (int) ($block['sequence'] ?? 0),
                'index' => (int) ($block['index'] ?? 0),
                'raw_markdown' => $raw,
                'raw_hash' => $this->hashContent($raw),
                'raw_text' => strip_tags($raw),
                'clean_markdown' => $clean,
                'clean_hash' => $this->hashContent($clean),
                'stem' => $candidate['stem'] ?? null,
                'options' => $candidate['options'] ?? null,
                'images' => $candidate['images'] ?? [],
                'tables' => $candidate['tables'] ?? [],
                'is_question_candidate' => (bool) ($candidate['is_question_candidate'] ?? false),
                'ai_confidence' => $candidate['ai_confidence'] ?? null,
                'status' => PreQuestionCandidate::STATUS_PENDING,
                'meta' => [
                    'split_meta' => $block,
                ],
            ]);

            $created++;

            MarkdownImport::where('id', $importId)->update([
                'progress_current' => $created,
            ]);
        }

        MarkdownImport::where('id', $importId)->update([
            'status' => MarkdownImport::STATUS_PARSED,
            'progress_stage' => MarkdownImport::STAGE_PARSED,
        ]);

        Log::info('Markdown import parsed', [
            'import_id' => $importId,
            'source_file_id' => $sourceFileId,
            'candidates' => $created,
        ]);

        return $created;
    }

    private function hashContent(?string $content): ?string
    {
        $content = trim((string) $content);
        if ($content === '') {
            return null;
        }

        return hash('sha1', $content);
    }
}