<?php

namespace App\Filament\Pages;

use App\Models\MarkdownImport;
use App\Models\SourcePaper;
use App\Models\Textbook;
use App\Models\TextbookCatalog;
use Filament\Pages\Page;
use Illuminate\Support\Arr;

class MarkdownImportWorkbench extends Page
{
    protected static ?string $navigationLabel = '导入工作台';
    protected static string|\BackedEnum|null $navigationIcon = 'heroicon-o-rectangle-stack';
    protected static string|\UnitEnum|null $navigationGroup = '卷子导入流程';
    protected static ?int $navigationSort = 2;

    protected string $view = 'filament.pages.markdown-import-workbench';

    public ?int $importId = null;
    public ?int $selectedPaperId = null;
    public array $selectedIds = [];
    public string $search = '';
    public string $groupBy = 'bundle';
    public bool $dense = false;
    public bool $filenameValid = true;
    public array $filenameParsed = [];
    public ?string $filenameWarning = null;

    public array $form = [
        'title' => null,
        'edition' => null,
        'grade' => null,
        'term' => null,
        'chapter' => null,
        'source_type' => null,
        'source_year' => null,
        'textbook_id' => null,
        'textbook_series' => null,
        'source_name' => null,
        'source_page' => null,
        'tags' => '',
        'bundle_key' => null,
        'expected_count' => null,
        'catalog_node_id' => null,
    ];

    public array $batch = [
        'edition' => null,
        'grade' => null,
        'term' => null,
        'chapter' => null,
        'source_type' => null,
        'source_year' => null,
        'textbook_id' => null,
        'textbook_series' => null,
        'source_name' => null,
        'source_page' => null,
        'tags' => '',
        'bundle_key' => null,
        'expected_count' => null,
        'catalog_node_id' => null,
    ];

    public function mount(): void
    {
        $this->importId = request()->integer('import_id');

        $parsed = $this->parseImportFilename();
        if (empty($parsed)) {
            $this->filenameValid = false;
            $this->filenameWarning = '文件名不符合规范：系列_年级_学期_学科_名称（例：北师大版_7_1_数学_...）';
        } else {
            $this->filenameParsed = $parsed;
            $this->applyFilenameDefaults();
        }

        $first = $this->papers()->first();
        if ($first) {
            $this->selectPaper($first->id);
        }
    }

    public function importRecord(): ?MarkdownImport
    {
        return $this->importId ? MarkdownImport::query()->find($this->importId) : null;
    }

    public function papers()
    {
        if (!$this->importId) {
            return collect();
        }

        $query = SourcePaper::query()
            ->whereHas('candidates', fn ($q) => $q->where('import_id', $this->importId))
            ->withCount(['candidates', 'parts'])
            ->orderBy('order');

        if ($this->search !== '') {
            $query->where(function ($q) {
                $q->where('title', 'like', '%' . $this->search . '%')
                    ->orWhere('full_title', 'like', '%' . $this->search . '%')
                    ->orWhere('paper_code', 'like', '%' . $this->search . '%');
            });
        }

        return $query->get();
    }

    public function groupedPapers(): array
    {
        $papers = $this->papers();

        if ($this->groupBy === 'paper') {
            return $papers->groupBy(fn ($paper) => $paper->title ?: $paper->full_title ?: '未命名卷子')->toArray();
        }

        if ($this->groupBy === 'grade') {
            return $papers->groupBy(fn ($paper) => $paper->grade ? $paper->grade . '年级' : '未标注年级')->toArray();
        }

        return $papers->groupBy(fn ($paper) => Arr::get($paper->meta ?? [], 'bundle_key', '未归并套卷'))->toArray();
    }

    public function selectedPaper(): ?SourcePaper
    {
        return $this->selectedPaperId
            ? SourcePaper::query()->withCount(['candidates', 'parts'])->find($this->selectedPaperId)
            : null;
    }

    public function selectPaper(int $paperId): void
    {
        $paper = SourcePaper::query()->find($paperId);
        if (!$paper) {
            return;
        }

        $meta = $paper->meta ?? [];
        $this->selectedPaperId = $paperId;
        $this->form = [
            'title' => $paper->title,
            'edition' => $paper->edition,
            'grade' => $paper->grade,
            'term' => $paper->term,
            'chapter' => $paper->chapter,
            'source_type' => $paper->source_type,
            'source_year' => $paper->source_year,
            'textbook_id' => $paper->textbook_id,
            'textbook_series' => $paper->textbook_series,
            'source_name' => Arr::get($meta, 'source_name'),
            'source_page' => Arr::get($meta, 'source_page'),
            'tags' => implode(',', Arr::get($meta, 'tags', [])),
            'bundle_key' => Arr::get($meta, 'bundle_key'),
            'expected_count' => Arr::get($meta, 'expected_count'),
            'catalog_node_id' => Arr::get($meta, 'catalog_node_id'),
        ];
    }

    public function seedBatchFromCurrent(): void
    {
        $this->batch = [
            'edition' => $this->form['edition'] ?? null,
            'grade' => $this->form['grade'] ?? null,
            'term' => $this->form['term'] ?? null,
            'chapter' => $this->form['chapter'] ?? null,
            'source_type' => $this->form['source_type'] ?? null,
            'source_year' => $this->form['source_year'] ?? null,
            'textbook_id' => $this->form['textbook_id'] ?? null,
            'textbook_series' => $this->form['textbook_series'] ?? null,
            'source_name' => $this->form['source_name'] ?? null,
            'source_page' => $this->form['source_page'] ?? null,
            'tags' => $this->form['tags'] ?? '',
            'bundle_key' => $this->form['bundle_key'] ?? null,
            'expected_count' => $this->form['expected_count'] ?? null,
            'catalog_node_id' => $this->form['catalog_node_id'] ?? null,
        ];
    }

    public function savePaper(): void
    {
        $paper = $this->selectedPaper();
        if (!$paper) {
            return;
        }

        $meta = $paper->meta ?? [];
        $meta['source_name'] = $this->form['source_name'] ?? null;
        $meta['source_page'] = $this->form['source_page'] ?? null;
        $meta['tags'] = $this->explodeTags($this->form['tags'] ?? '');
        $meta['bundle_key'] = $this->form['bundle_key'] ?? null;
        $meta['expected_count'] = $this->form['expected_count'] ?? null;
        $meta['catalog_node_id'] = $this->form['catalog_node_id'] ?? null;

        $paper->update([
            'title' => $this->form['title'] ?? null,
            'edition' => $this->form['edition'] ?? null,
            'grade' => $this->form['grade'] ?? null,
            'term' => $this->form['term'] ?? null,
            'chapter' => $this->form['chapter'] ?? null,
            'source_type' => $this->form['source_type'] ?? null,
            'source_year' => $this->form['source_year'] ?? null,
            'textbook_id' => $this->form['textbook_id'] ?? null,
            'textbook_series' => $this->form['textbook_series'] ?? null,
            'meta' => $meta,
        ]);
    }

    public function applyBatch(): void
    {
        if (empty($this->selectedIds)) {
            return;
        }

        $updates = array_filter([
            'edition' => $this->batch['edition'] ?? null,
            'grade' => $this->batch['grade'] ?? null,
            'term' => $this->batch['term'] ?? null,
            'chapter' => $this->batch['chapter'] ?? null,
            'source_type' => $this->batch['source_type'] ?? null,
            'source_year' => $this->batch['source_year'] ?? null,
            'textbook_id' => $this->batch['textbook_id'] ?? null,
            'textbook_series' => $this->batch['textbook_series'] ?? null,
        ], fn ($value) => $value !== null && $value !== '');

        foreach (SourcePaper::query()->whereIn('id', $this->selectedIds)->get() as $paper) {
            $meta = $paper->meta ?? [];

            if (!empty($this->batch['source_name'])) {
                $meta['source_name'] = $this->batch['source_name'];
            }
            if (!empty($this->batch['source_page'])) {
                $meta['source_page'] = $this->batch['source_page'];
            }
            if (!empty($this->batch['tags'])) {
                $meta['tags'] = $this->explodeTags($this->batch['tags']);
            }
            if (!empty($this->batch['bundle_key'])) {
                $meta['bundle_key'] = $this->batch['bundle_key'];
            }
            if (!empty($this->batch['expected_count'])) {
                $meta['expected_count'] = $this->batch['expected_count'];
            }
            if (!empty($this->batch['catalog_node_id'])) {
                $meta['catalog_node_id'] = $this->batch['catalog_node_id'];
            }

            $paper->update(array_merge($updates, ['meta' => $meta]));
        }
    }

    public function autoInfer(): void
    {
        $paper = $this->selectedPaper();
        if (!$paper) {
            return;
        }

        $parsed = $this->parseImportFilename();
        if (!empty($parsed)) {
            $this->form['textbook_series'] = $this->form['textbook_series'] ?: $parsed['series'];
            $this->form['grade'] = $this->form['grade'] ?: $parsed['grade'];
            $this->form['term'] = $this->form['term'] ?: $parsed['term'];
            $this->form['source_name'] = $this->form['source_name'] ?: $parsed['name'];
        }

        $title = (string) ($paper->title ?? $paper->full_title ?? '');
        $raw = (string) ($paper->raw_markdown ?? '');
        $context = $title . ' ' . $raw;

        $this->form['term'] = $this->inferTerm($context) ?? $this->form['term'];
        $this->form['grade'] = $this->inferGrade($context) ?? $this->form['grade'];
        $this->form['chapter'] = $this->inferChapter($context) ?? $this->form['chapter'];
    }

    public function autoBundleKey(): void
    {
        $paper = $this->selectedPaper();
        if (!$paper) {
            return;
        }

        $this->form['bundle_key'] = $this->buildBundleKey($paper);
    }

    public function autoBundleKeySelected(): void
    {
        if (empty($this->selectedIds)) {
            return;
        }

        foreach (SourcePaper::query()->whereIn('id', $this->selectedIds)->get() as $paper) {
            $meta = $paper->meta ?? [];
            $meta['bundle_key'] = $this->buildBundleKey($paper);
            $paper->update(['meta' => $meta]);
        }
    }

    public function autoInferSelected(): void
    {
        if (empty($this->selectedIds)) {
            return;
        }

        $parsed = $this->parseImportFilename();
        foreach (SourcePaper::query()->whereIn('id', $this->selectedIds)->get() as $paper) {
            $context = (string) ($paper->title ?? $paper->full_title ?? '') . ' ' . (string) ($paper->raw_markdown ?? '');
            $updates = array_filter([
                'term' => $this->inferTerm($context),
                'grade' => $this->inferGrade($context),
                'chapter' => $this->inferChapter($context),
            ], fn ($value) => $value !== null && $value !== '');

            if (!empty($parsed)) {
                if (empty($paper->textbook_series) && !empty($parsed['series'])) {
                    $updates['textbook_series'] = $parsed['series'];
                }
                if (empty($paper->grade) && !empty($parsed['grade'])) {
                    $updates['grade'] = $parsed['grade'];
                }
                if (empty($paper->term) && !empty($parsed['term'])) {
                    $updates['term'] = $parsed['term'];
                }
            }

            $meta = $paper->meta ?? [];
            if (!empty($parsed['name']) && empty($meta['source_name'])) {
                $meta['source_name'] = $parsed['name'];
            }

            if (!empty($updates)) {
                $updates['meta'] = $meta;
                $paper->update($updates);
            } elseif (!empty($meta)) {
                $paper->update(['meta' => $meta]);
            }
        }
    }

    public function selectAllVisible(): void
    {
        $this->selectedIds = $this->papers()->pluck('id')->toArray();
    }

    public function clearSelection(): void
    {
        $this->selectedIds = [];
    }

    public function gradeOptions(): array
    {
        return collect(range(1, 12))->mapWithKeys(fn ($grade) => [$grade => $grade . '年级'])->toArray();
    }

    public function termOptions(): array
    {
        return [
            '上册' => '上册',
            '下册' => '下册',
            '上学期' => '上学期',
            '下学期' => '下学期',
        ];
    }

    public function sourceTypeOptions(): array
    {
        return [
            '期中' => '期中卷',
            '期末' => '期末卷',
            '单元卷' => '单元卷',
            '专项卷' => '专项卷',
            '教材' => '教材',
            '其他' => '其他',
        ];
    }

    public function textbookOptions(): array
    {
        return Textbook::query()
            ->orderBy('id')
            ->get(['id', 'official_title'])
            ->mapWithKeys(function ($textbook) {
                $title = $textbook->official_title ?: '未命名教材';
                return [$textbook->id => $title];
            })
            ->toArray();
    }

    public function catalogOptions(): array
    {
        if (empty($this->form['textbook_id']) && empty($this->batch['textbook_id'])) {
            return [];
        }

        $textbookId = $this->form['textbook_id'] ?: $this->batch['textbook_id'];
        $nodes = TextbookCatalog::query()
            ->where('textbook_id', $textbookId)
            ->orderBy('sort_order')
            ->get(['id', 'title', 'parent_id']);

        $grouped = $nodes->groupBy('parent_id');
        $walk = function ($parent, int $depth) use (&$walk, $grouped): array {
            $items = [];
            foreach ($grouped->get($parent, collect()) as $node) {
                $title = $node->title ?: '未命名目录';
                $indent = str_repeat('—', $depth);
                $items[$node->id] = trim($indent . ' ' . $title);
                $items += $walk($node->id, $depth + 1);
            }
            return $items;
        };

        return $walk(null, 0);
    }

    public function catalogCoverageSummary(): array
    {
        $textbookId = $this->selectedTextbookId();
        if (!$textbookId) {
            return [];
        }

        $nodes = TextbookCatalog::query()
            ->where('textbook_id', $textbookId)
            ->whereDoesntHave('children')
            ->get(['id']);

        $coverage = [];
        SourcePaper::query()
            ->where('textbook_id', $textbookId)
            ->get(['meta'])
            ->each(function ($paper) use (&$coverage) {
                $catalogId = $paper->meta['catalog_node_id'] ?? null;
                if ($catalogId) {
                    $coverage[$catalogId] = ($coverage[$catalogId] ?? 0) + 1;
                }
            });

        $linked = count($coverage);
        $missing = max(0, $nodes->count() - count($coverage));

        return [
            'total' => $nodes->count(),
            'linked' => $linked,
            'missing' => $missing,
        ];
    }

    public function missingCatalogNodes(): array
    {
        $textbookId = $this->selectedTextbookId();
        if (!$textbookId) {
            return [];
        }

        $nodes = TextbookCatalog::query()
            ->where('textbook_id', $textbookId)
            ->whereDoesntHave('children')
            ->orderBy('sort_order')
            ->get(['id', 'title']);

        $coverage = [];
        SourcePaper::query()
            ->where('textbook_id', $textbookId)
            ->get(['meta'])
            ->each(function ($paper) use (&$coverage) {
                $catalogId = $paper->meta['catalog_node_id'] ?? null;
                if ($catalogId) {
                    $coverage[$catalogId] = ($coverage[$catalogId] ?? 0) + 1;
                }
            });

        $missing = [];
        foreach ($nodes as $node) {
            if (!isset($coverage[$node->id])) {
                $missing[] = [
                    'id' => $node->id,
                    'title' => $node->title,
                ];
            }
        }

        return array_slice($missing, 0, 8);
    }

    public function textbookSuggestions(): array
    {
        $paper = $this->selectedPaper();
        if (!$paper) {
            return [];
        }

        $title = (string) ($paper->title ?? $paper->full_title ?? '');
        $context = mb_strtolower($title);
        $parsed = $this->parseImportFilename();
        $grade = $paper->grade ? (int) $paper->grade : ($parsed['grade'] ?? null);
        $semester = $this->termToSemester($paper->term) ?? $this->termToSemester($parsed['term'] ?? null);
        $seriesHint = $paper->textbook_series ?: ($parsed['series'] ?? null);
        $subjectHint = $parsed['subject'] ?? null;

        $suggestions = [];
        $textbooks = Textbook::query()->with('series')->get();
        foreach ($textbooks as $textbook) {
            $score = 0;

            if ($grade && (int) $textbook->grade === $grade) {
                $score += 3;
            }
            if ($semester && (int) $textbook->semester === $semester) {
                $score += 3;
            }

            $official = mb_strtolower((string) $textbook->official_title);
            if ($official !== '' && str_contains($context, $official)) {
                $score += 4;
            }

            $aliases = $textbook->aliases ?? [];
            foreach ($aliases as $alias) {
                $alias = mb_strtolower((string) $alias);
                if ($alias !== '' && str_contains($context, $alias)) {
                    $score += 2;
                }
            }

            $seriesName = $textbook->series?->name ?? null;
            if ($seriesHint && $seriesName && str_contains((string) $seriesHint, (string) $seriesName)) {
                $score += 5;
            }

            if ($subjectHint) {
                $subjectHint = mb_strtolower((string) $subjectHint);
                $official = mb_strtolower((string) $textbook->official_title);
                if ($official !== '' && str_contains($official, $subjectHint)) {
                    $score += 1;
                }
            }

            if ($score > 0) {
                $suggestions[] = [
                    'id' => $textbook->id,
                    'title' => $textbook->official_title,
                    'series' => $textbook->series?->name ?? '未归类系列',
                    'grade' => $textbook->grade,
                    'semester' => $textbook->semester,
                    'score' => $score,
                ];
            }
        }

        usort($suggestions, fn ($a, $b) => $b['score'] <=> $a['score']);
        return array_slice($suggestions, 0, 5);
    }

    public function catalogSuggestions(): array
    {
        $paper = $this->selectedPaper();
        $textbookId = $paper?->textbook_id ?? $this->form['textbook_id'];
        if (!$paper || !$textbookId) {
            return [];
        }

        $needle = trim((string) ($paper->chapter ?? $paper->title ?? ''));
        if ($needle === '') {
            return [];
        }

        $nodes = TextbookCatalog::query()
            ->where('textbook_id', $textbookId)
            ->orderBy('sort_order')
            ->get(['id', 'title']);

        $matches = [];
        foreach ($nodes as $node) {
            $title = (string) $node->title;
            if ($title !== '' && str_contains($needle, $title)) {
                $matches[] = ['id' => $node->id, 'title' => $title];
            }
        }

        return array_slice($matches, 0, 5);
    }

    public function applyTextbookSuggestion(int $textbookId): void
    {
        $textbook = Textbook::query()->with('series')->find($textbookId);
        if (!$textbook) {
            return;
        }

        $this->form['textbook_id'] = $textbook->id;
        $this->form['textbook_series'] = $textbook->series?->name ?? $this->form['textbook_series'];
    }

    public function applyCatalogSuggestion(int $catalogId): void
    {
        $this->form['catalog_node_id'] = $catalogId;
    }

    public function candidateCountFor(SourcePaper $paper): int
    {
        return (int) ($paper->candidates_count ?? 0);
    }

    private function inferTerm(string $context): ?string
    {
        if (str_contains($context, '上册') || str_contains($context, '上学期')) {
            return '上册';
        }
        if (str_contains($context, '下册') || str_contains($context, '下学期')) {
            return '下册';
        }
        return null;
    }

    private function inferGrade(string $context): ?string
    {
        foreach (['七年级' => '7', '八年级' => '8', '九年级' => '9', '高一' => '10', '高二' => '11', '高三' => '12'] as $label => $value) {
            if (str_contains($context, $label)) {
                return $value;
            }
        }
        return null;
    }

    private function inferChapter(string $context): ?string
    {
        if (preg_match('/第[一二三四五六七八九十]+章[^\\n]*/u', $context, $match)) {
            return $match[0];
        }
        return null;
    }

    private function explodeTags(string $tags): array
    {
        return array_values(array_filter(array_map('trim', explode(',', $tags))));
    }

    private function termToSemester(?string $term): ?int
    {
        if (!$term) {
            return null;
        }
        if (str_contains($term, '上')) {
            return 1;
        }
        if (str_contains($term, '下')) {
            return 2;
        }
        return null;
    }

    private function buildBundleKey(SourcePaper $paper): string
    {
        $import = $this->importRecord();
        $base = $import?->file_name
            ? pathinfo($import->file_name, PATHINFO_FILENAME)
            : ($paper->title ?: $paper->full_title ?: '卷子');

        $grade = $paper->grade ? $this->gradeToLabel((int) $paper->grade) : null;
        $term = $paper->term ? $paper->term : null;
        $sourceType = $paper->source_type ?: null;

        $parts = array_filter([$grade, $term, $sourceType, $base]);
        return implode('·', $parts);
    }

    private function gradeToLabel(int $grade): string
    {
        $map = [
            7 => '七年级',
            8 => '八年级',
            9 => '九年级',
            10 => '高一',
            11 => '高二',
            12 => '高三',
        ];

        return $map[$grade] ?? $grade . '年级';
    }

    private function selectedTextbookId(): ?int
    {
        return $this->form['textbook_id'] ?: $this->batch['textbook_id'];
    }

    private function applyFilenameDefaults(): void
    {
        if (!$this->importId || empty($this->filenameParsed)) {
            return;
        }

        $parsed = $this->filenameParsed;
        $papers = SourcePaper::query()
            ->whereHas('candidates', fn ($q) => $q->where('import_id', $this->importId))
            ->get();

        foreach ($papers as $paper) {
            $meta = $paper->meta ?? [];
            if (!empty($meta['filename_defaults_applied'])) {
                continue;
            }

            $updates = [];

            if (empty($paper->textbook_series) && !empty($parsed['series'])) {
                $updates['textbook_series'] = $parsed['series'];
            }
            if (empty($paper->grade) && !empty($parsed['grade'])) {
                $updates['grade'] = $parsed['grade'];
            }
            if (empty($paper->term) && !empty($parsed['term'])) {
                $updates['term'] = $parsed['term'];
            }

            if (empty($meta['source_name']) && !empty($parsed['name'])) {
                $meta['source_name'] = $parsed['name'];
            }

            if (!empty($updates)) {
                $meta['filename_defaults_applied'] = true;
                $updates['meta'] = $meta;
                $paper->update($updates);
            } elseif (!empty($meta)) {
                $meta['filename_defaults_applied'] = true;
                $paper->update(['meta' => $meta]);
            }
        }
    }

    private function parseImportFilename(): array
    {
        $import = $this->importRecord();
        return $import?->parseFilename() ?? [];
    }
}