<?php

namespace App\Http\Controllers\Admin;

use App\Http\Controllers\Controller;
use App\Models\Paper;
use App\Models\ResearchDirection;
use App\Models\Teacher;
use App\Services\GridMemberScopeService;
use App\Support\ApiResponse;
use Carbon\Carbon;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\Request;

class PaperController extends Controller
{
    use ApiResponse;

    public function __construct(
        protected GridMemberScopeService $gridScope,
    ) {}

    public function index(Request $request): JsonResponse
    {
        $query = Paper::query()->withCount('teachers');

        if ($kw = $request->query('keyword')) {
            $query->where(function ($q) use ($kw) {
                $q->where('title', 'like', "%{$kw}%")
                    ->orWhere('authors', 'like', "%{$kw}%")
                    ->orWhere('school_name', 'like', "%{$kw}%")
                    ->orWhere('summary', 'like', "%{$kw}%");
            });
        }
        if ($request->filled('school_name')) {
            $query->where('school_name', $request->query('school_name'));
        }
        if ($request->filled('university_id')) {
            $query->where('university_id', (int) $request->query('university_id'));
        }
        if ($request->filled('research_direction_id')) {
            $dirId = (int) $request->query('research_direction_id');
            $query->whereHas('teachers.researchDirections', fn ($q) => $q->where('research_directions.id', $dirId));
        } elseif ($request->filled('research_direction')) {
            $dir = $request->query('research_direction');
            $query->whereHas('teachers.researchDirections', fn ($q) => $q->where('research_directions.name', 'like', "%{$dir}%"));
        }
        if ($request->query('link_status') === 'linked') {
            $query->has('teachers');
        } elseif ($request->query('link_status') === 'unlinked') {
            $query->doesntHave('teachers');
        }
        if ($request->filled('source')) {
            $query->where('source', $request->query('source'));
        }
        if ($request->filled('crawl_job_id')) {
            $query->where('crawl_job_id', (int) $request->query('crawl_job_id'));
        }

        $paginator = $query
            ->orderByDesc('published_at')
            ->orderByDesc('id')
            ->paginate((int) $request->query('page_size', 20))
            ->withQueryString();

        $paginator->getCollection()->transform(fn (Paper $p) => $this->serializeList($p));

        return $this->paginated($paginator);
    }

    public function filterOptions(): JsonResponse
    {
        $schools = Paper::query()
            ->whereNotNull('school_name')
            ->distinct()
            ->orderBy('school_name')
            ->pluck('school_name')
            ->filter()
            ->values();

        $directions = ResearchDirection::query()
            ->where('status', 1)
            ->whereHas('teachers')
            ->orderBy('sort')
            ->orderBy('name')
            ->pluck('name')
            ->values();

        return $this->ok([
            'school_names' => $schools,
            'research_directions' => $directions,
        ]);
    }

    public function show(int $paper): JsonResponse
    {
        $model = Paper::query()->with(['teachers.university'])->findOrFail($paper);

        return $this->ok($this->serializeDetail($model));
    }

    public function attachTeachers(Request $request, int $paper): JsonResponse
    {
        $data = $request->validate([
            'teacher_ids' => ['required', 'array', 'min:1'],
            'teacher_ids.*' => ['integer', 'exists:teachers,id'],
        ]);

        $model = Paper::query()->findOrFail($paper);
        $user = $this->gridScope->userFromRequest($request);
        $teacherIds = array_values(array_unique(array_map('intval', $data['teacher_ids'])));

        $teachers = Teacher::query()->whereIn('id', $teacherIds)->get();
        foreach ($teachers as $teacher) {
            $this->gridScope->assertTeacherAccessible($user, $teacher);
        }

        $model->teachers()->syncWithoutDetaching($teacherIds);

        return $this->ok(null, '已关联老师');
    }

    public function destroy(int $paper): JsonResponse
    {
        $model = Paper::query()->findOrFail($paper);
        $model->teachers()->detach();
        $model->delete();

        return $this->ok(null, '已删除');
    }

    /**
     * @return array<string, mixed>
     */
    protected function serializeList(Paper $p): array
    {
        $isNew = $p->source === 'crawl'
            && $p->created_at
            && $p->created_at->gte(Carbon::now()->subDay());

        return [
            'id' => $p->id,
            'title' => $p->title,
            'authors' => $p->authors,
            'school_name' => $p->school_name,
            'published_at' => $p->published_at?->format('Y-m'),
            'imported_at' => $p->created_at?->format('Y-m-d'),
            'url' => $p->url,
            'summary' => $p->summary,
            'source' => $p->source,
            'is_new' => $isNew,
            'teachers_count' => (int) ($p->teachers_count ?? 0),
            'is_linked' => (int) ($p->teachers_count ?? 0) > 0,
        ];
    }

    /**
     * @return array<string, mixed>
     */
    protected function serializeDetail(Paper $p): array
    {
        $row = $this->serializeList($p);
        $row['published_at'] = $p->published_at?->toDateString();
        $row['teachers'] = $p->teachers->map(fn ($t) => [
            'id' => $t->id,
            'name' => $t->name,
            'university_name' => $t->university?->name,
        ])->values();

        return $row;
    }
}