<?php

namespace App\Http\Controllers\Miniapp;

use App\Http\Controllers\Miniapp\BaseController;
use App\Models\Course;
use App\Models\CourseSignup;
use App\Models\MiniappUser;
use App\Support\ApiResponse;
use App\Support\Miniapp\MiniappPresenter;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\Request;

class CourseController extends BaseController
{
    use ApiResponse;

    public function index(Request $request): JsonResponse
    {
        $user = $this->optionalUser($request);
        $pageSize = (int) $request->query('page_size', 20);
        $page = max(1, (int) $request->query('page', 1));

        if ($request->filled('progress_status')) {
            $statusFilter = (int) $request->query('progress_status');
            $courses = $this->publishedQuery($request)
                ->orderByDesc('teach_start_date')
                ->orderByDesc('id')
                ->get()
                ->filter(fn (Course $course) => MiniappPresenter::resolveCourseProgressStatus($course) === $statusFilter)
                ->values();

            $total = $courses->count();
            $items = $courses
                ->slice(($page - 1) * $pageSize, $pageSize)
                ->map(fn (Course $course) => MiniappPresenter::serializeCourseList($course, $user))
                ->values()
                ->all();

            return $this->ok([
                'items' => $items,
                'meta' => [
                    'current_page' => $page,
                    'per_page' => $pageSize,
                    'total' => $total,
                    'last_page' => max(1, (int) ceil($total / $pageSize)),
                ],
            ]);
        }

        $paginator = $this->publishedQuery($request)
            ->orderByDesc('teach_start_date')
            ->orderByDesc('id')
            ->paginate($pageSize)
            ->withQueryString();

        $paginator->getCollection()->transform(
            fn (Course $course) => MiniappPresenter::serializeCourseList($course, $user)
        );

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

    public function hot(): JsonResponse
    {
        $items = Course::query()
            ->with(['courseSystemItem', 'coverMedia', 'promoMedia'])
            ->withCount('signups')
            ->where('published', 1)
            ->get()
            ->filter(fn (Course $course) => in_array(
                MiniappPresenter::resolveCourseProgressStatus($course),
                [1, 2],
                true
            ))
            ->sort(function (Course $a, Course $b) {
                $signupDelta = ((int) $b->signups_count) <=> ((int) $a->signups_count);
                if ($signupDelta !== 0) {
                    return $signupDelta;
                }

                return $b->id <=> $a->id;
            })
            ->take(3)
            ->map(fn (Course $course) => MiniappPresenter::serializeCourseList($course))
            ->values()
            ->all();

        return $this->ok(['items' => $items]);
    }

    public function latest(): JsonResponse
    {
        $items = Course::query()
            ->with(['courseSystemItem', 'coverMedia', 'promoMedia'])
            ->withCount('signups')
            ->where('published', 1)
            ->orderByRaw('teach_start_date IS NULL')
            ->orderByDesc('teach_start_date')
            ->orderByDesc('id')
            ->limit(3)
            ->get()
            ->map(fn (Course $course) => MiniappPresenter::serializeCourseList($course))
            ->values()
            ->all();

        return $this->ok(['items' => $items]);
    }

    public function show(Request $request, int $course): JsonResponse
    {
        $user = $this->optionalUser($request);
        $model = Course::query()
            ->with(['courseSystemItem', 'coverMedia', 'promoMedia'])
            ->withCount('signups')
            ->where('published', 1)
            ->findOrFail($course);

        return $this->ok(MiniappPresenter::serializeCourseList($model, $user));
    }

    public function signup(Request $request, int $course): JsonResponse
    {
        /** @var MiniappUser $user */
        $user = $request->user();
        $model = Course::query()->withCount('signups')->where('published', 1)->findOrFail($course);

        if (CourseSignup::query()->where('course_id', $course)->where('miniapp_user_id', $user->id)->exists()) {
            return $this->fail('您已报名该课程', 422);
        }

        if (! MiniappPresenter::canSignupCourse($model, (int) $model->signups_count)) {
            return $this->fail('当前不可报名', 422);
        }

        $data = $request->validate([
            'name' => ['required', 'string', 'max:64'],
            'mobile' => ['required', 'string', 'max:32'],
            'company' => ['nullable', 'string', 'max:128'],
        ]);

        CourseSignup::query()->create([
            'course_id' => $course,
            'miniapp_user_id' => $user->id,
            'name' => $data['name'],
            'mobile' => $data['mobile'],
            'company' => $data['company'] ?? null,
            'signed_up_at' => now(),
            'status' => 1,
        ]);

        if (! $user->name) {
            $user->name = $data['name'];
        }
        if (! $user->mobile) {
            $user->mobile = $data['mobile'];
        }
        if (! $user->company && ! empty($data['company'])) {
            $user->company = $data['company'];
        }
        $user->save();

        return $this->ok(null, '报名成功');
    }

    public function mySignups(Request $request): JsonResponse
    {
        /** @var MiniappUser $user */
        $user = $request->user();

        $courseIds = CourseSignup::query()
            ->where('miniapp_user_id', $user->id)
            ->pluck('course_id');

        $items = Course::query()
            ->with(['courseSystemItem', 'coverMedia', 'promoMedia'])
            ->withCount('signups')
            ->whereIn('id', $courseIds)
            ->orderByDesc('teach_start_date')
            ->orderByDesc('id')
            ->get()
            ->map(fn (Course $course) => MiniappPresenter::serializeCourseList($course, $user))
            ->values()
            ->all();

        return $this->ok(['items' => $items]);
    }

    public function calendar(Request $request): JsonResponse
    {
        /** @var MiniappUser $user */
        $user = $request->user();
        $data = $request->validate([
            'month' => ['required', 'date_format:Y-m'],
        ]);

        $courseIds = CourseSignup::query()
            ->where('miniapp_user_id', $user->id)
            ->pluck('course_id');

        $courses = Course::query()
            ->with(['courseSystemItem'])
            ->withCount('signups')
            ->whereIn('id', $courseIds)
            ->get();

        [$year, $month] = array_map('intval', explode('-', $data['month']));
        $monthStart = sprintf('%04d-%02d-01', $year, $month);
        $monthEnd = date('Y-m-t', strtotime($monthStart));

        $events = $courses->map(function (Course $course) {
            $progressStatus = MiniappPresenter::resolveCourseProgressStatus($course);

            return [
                'id' => $course->id,
                'title' => $course->title,
                'start_date' => $course->teach_start_date?->toDateString(),
                'end_date' => $course->teach_end_date?->toDateString(),
                'time_range' => MiniappPresenter::timeRange(
                    MiniappPresenter::formatTimeValue($course->teach_start_time),
                    MiniappPresenter::formatTimeValue($course->teach_end_time)
                ),
                'location' => $course->location,
                'progress_status' => $progressStatus,
                'progress_status_label' => MiniappPresenter::progressStatusLabel($progressStatus),
            ];
        })->filter(function (array $event) use ($monthStart, $monthEnd) {
            if (! $event['start_date']) {
                return false;
            }
            $start = $event['start_date'];
            $end = $event['end_date'] ?: $start;

            return $start <= $monthEnd && $end >= $monthStart;
        })->values();

        return $this->ok([
            'month' => $data['month'],
            'events' => $events,
        ]);
    }

    protected function publishedQuery(Request $request)
    {
        $query = Course::query()
            ->with(['courseSystemItem', 'coverMedia', 'promoMedia'])
            ->withCount('signups')
            ->where('published', 1);

        if ($kw = $request->query('keyword')) {
            $query->where(function ($q) use ($kw) {
                $q->where('title', 'like', "%{$kw}%")
                    ->orWhere('location', 'like', "%{$kw}%");
            });
        }

        if ($request->filled('course_system_dict_item_id')) {
            $query->where('course_system_dict_item_id', (int) $request->query('course_system_dict_item_id'));
        }

        return $query;
    }
}