<?php

namespace App\Filament\Pages;

use App\Models\Student;
use App\Services\KnowledgeServiceApi;
use App\Services\MistakeBookService;
use App\Services\QuestionBankService;
use BackedEnum;
use Filament\Pages\Page;
use Illuminate\Http\Request;
use Illuminate\Support\Arr;
use Illuminate\Support\Facades\Log;
use UnitEnum;
use Livewire\Attributes\On;
use Livewire\Attributes\Computed;
use App\Models\Teacher;

class MistakeBook extends Page
{
    protected static ?string $title = '错题本';

    protected static string|BackedEnum|null $navigationIcon = 'heroicon-o-bookmark';

    protected static ?string $navigationLabel = '错题本';

    protected static string|UnitEnum|null $navigationGroup = '资源';

    protected static ?int $navigationSort = 6;

    protected static ?string $slug = 'mistake-book';

    protected string $view = 'filament.pages.mistake-book';

    public string $teacherId = '';
    public string $studentId = '';

    public array $filters = [
        'kp_ids' => [],
        'skill_ids' => [],
        'error_types' => [],
        'time_range' => 'last_30',
        'start_date' => null,
        'end_date' => null,
    ];

    public array $filterOptions = [
        'knowledge_points' => [],
        'skills' => [],
    ];

    public array $mistakes = [];

    public array $patterns = [];

    public array $summary = [];

    public array $recommendations = [];

    public array $relatedQuestions = [];

    public array $selectedMistakeIds = [];

    public bool $isLoading = false;

    public string $errorMessage = '';

    public string $actionMessage = '';

    public string $actionMessageType = 'success';

    public function mount(Request $request): void
    {
        $this->teacherId = (string) ($request->input('teacher_id') ?? '');
        $this->studentId = (string) ($request->input('student_id') ?? '');
        $this->filters['time_range'] = (string) ($request->input('range') ?? 'last_30');

        if ($this->studentId && empty($this->teacherId)) {
            $student = Student::find($this->studentId);
            if ($student && $student->teacher_id) {
                $this->teacherId = (string) $student->teacher_id;
            }
        }

        $this->loadFilterOptions();

        if ($this->studentId) {
            $this->loadMistakeData();
        }
    }

    public function updatedStudentId(): void
    {
        if ($this->studentId) {
            $this->loadMistakeData();
        } else {
            $this->resetPageState();
        }
    }

    public function loadMistakeData(): void
    {
        if (empty($this->studentId)) {
            $this->errorMessage = '请先选择学生';
            return;
        }

        $this->isLoading = true;
        $this->errorMessage = '';
        $this->actionMessage = '';

        try {
            $service = app(MistakeBookService::class);

            $list = $service->listMistakes([
                ...$this->filters,
                'student_id' => $this->studentId,
            ]);
            $this->mistakes = $list['data'] ?? [];

            $this->summary = $service->summarize($this->studentId);
            $this->patterns = $service->getMistakePatterns($this->studentId);

            // 清理无效的选中项
            $validIds = collect($this->mistakes)->pluck('id')->filter()->all();
            $this->selectedMistakeIds = array_values(
                array_intersect($this->selectedMistakeIds, $validIds)
            );
        } catch (\Throwable $e) {
            $this->errorMessage = '加载错题本数据失败：' . $e->getMessage();
            Log::error('Load mistake book failed', [
                'student_id' => $this->studentId,
                'error' => $e->getMessage(),
            ]);
        } finally {
            $this->isLoading = false;
        }
    }

    public function refreshPatterns(): void
    {
        if (!$this->studentId) {
            return;
        }

        try {
            $service = app(MistakeBookService::class);
            $this->patterns = $service->getMistakePatterns($this->studentId);
        } catch (\Throwable $e) {
            Log::error('Refresh mistake patterns failed', [
                'student_id' => $this->studentId,
                'error' => $e->getMessage(),
            ]);
        }
    }

    public function toggleFavorite(string $mistakeId): void
    {
        $service = app(MistakeBookService::class);

        $current = $this->findMistakeById($mistakeId);
        $willFavorite = !($current['favorite'] ?? false);

        if ($service->toggleFavorite($mistakeId, $willFavorite)) {
            $this->updateMistakeField($mistakeId, 'favorite', $willFavorite);
            $this->notify('已更新收藏状态');
        } else {
            $this->notify('收藏操作失败，请稍后再试', 'danger');
        }
    }

    public function markReviewed(string $mistakeId): void
    {
        $service = app(MistakeBookService::class);

        if ($service->markReviewed($mistakeId)) {
            $this->updateMistakeField($mistakeId, 'reviewed', true);
            $this->notify('已标记为已复习');
        } else {
            $this->notify('标记失败，请稍后再试', 'danger');
        }
    }

    public function addToRetryList(string $mistakeId): void
    {
        $service = app(MistakeBookService::class);

        if ($service->addToRetryList($mistakeId)) {
            $this->notify('已加入重练清单');
        } else {
            $this->notify('加入清单失败，请稍后再试', 'danger');
        }
    }

    public function loadRelatedQuestions(string $mistakeId): void
    {
        $mistake = $this->findMistakeById($mistakeId);
        if (empty($mistake)) {
            return;
        }

        $questionBank = app(QuestionBankService::class);
        $kpIds = Arr::wrap($mistake['kp_ids'] ?? []);
        $skills = Arr::wrap($mistake['skill_ids'] ?? $mistake['skills'] ?? []);

        $response = $questionBank->filterQuestions(array_filter([
            'kp_codes' => !empty($kpIds) ? implode(',', $kpIds) : null,
            'skills' => !empty($skills) ? implode(',', $skills) : null,
            'limit' => 5,
        ]));

        $this->relatedQuestions[$mistakeId] = $response['data'] ?? [];
    }

    public function toggleSelection(string $mistakeId): void
    {
        if (in_array($mistakeId, $this->selectedMistakeIds, true)) {
            $this->selectedMistakeIds = array_values(array_diff($this->selectedMistakeIds, [$mistakeId]));
        } else {
            $this->selectedMistakeIds[] = $mistakeId;
        }
    }

    public function generatePracticeFromSelection(): void
    {
        if (empty($this->selectedMistakeIds)) {
            $this->notify('请先选择至少一道错题', 'warning');
            return;
        }

        $selected = array_filter($this->mistakes, fn ($item) => in_array($item['id'] ?? '', $this->selectedMistakeIds, true));

        $kpIds = collect($selected)
            ->pluck('kp_ids')
            ->flatten()
            ->filter()
            ->unique()
            ->values()
            ->all();

        $skillIds = collect($selected)
            ->pluck('skill_ids')
            ->flatten()
            ->filter()
            ->unique()
            ->values()
            ->all();

        $service = app(MistakeBookService::class);
        $result = $service->recommendPractice($this->studentId, $kpIds, $skillIds);

        $this->recommendations = $result['data'] ?? ($result['questions'] ?? []);

        if (!empty($this->recommendations)) {
            $this->notify('已生成重练题单');
        } else {
            $this->notify('未能生成题单，请稍后再试', 'warning');
        }
    }

    public function applyFilters(): void
    {
        $this->loadMistakeData();
    }

    public function clearCustomRange(): void
    {
        $this->filters['start_date'] = null;
        $this->filters['end_date'] = null;
    }

    #[Computed]
    public function teachers(): array
    {
        try {
            $teachers = Teacher::query()
                ->leftJoin('users as u', 'teachers.teacher_id', '=', 'u.user_id')
                ->select(
                    'teachers.teacher_id',
                    'teachers.name',
                    'teachers.subject',
                    'u.username',
                    'u.email'
                )
                ->orderBy('teachers.name')
                ->get();

            $teacherIds = $teachers->pluck('teacher_id')->toArray();
            $missingTeacherIds = Student::query()
                ->distinct()
                ->whereNotIn('teacher_id', $teacherIds)
                ->pluck('teacher_id')
                ->toArray();

            $teachersArray = $teachers->all();

            if (!empty($missingTeacherIds)) {
                foreach ($missingTeacherIds as $missingId) {
                    $teachersArray[] = (object) [
                        'teacher_id' => $missingId,
                        'name' => '未知老师 (' . $missingId . ')',
                        'subject' => '未知',
                        'username' => null,
                        'email' => null
                    ];
                }

                usort($teachersArray, function($a, $b) {
                    return strcmp($a->name, $b->name);
                });
            }

            return $teachersArray;
        } catch (\Exception $e) {
            Log::error('加载老师列表失败', [
                'error' => $e->getMessage()
            ]);
            return [];
        }
    }

    #[Computed]
    public function students(): array
    {
        if (empty($this->teacherId)) {
            return [];
        }

        try {
            return Student::query()
                ->leftJoin('users as u', 'students.student_id', '=', 'u.user_id')
                ->where('students.teacher_id', $this->teacherId)
                ->select(
                    'students.student_id',
                    'students.name',
                    'students.grade',
                    'students.class_name',
                    'u.username',
                    'u.email'
                )
                ->orderBy('students.grade')
                ->orderBy('students.class_name')
                ->orderBy('students.name')
                ->get()
                ->all();
        } catch (\Exception $e) {
            Log::error('加载学生列表失败', [
                'teacher_id' => $this->teacherId,
                'error' => $e->getMessage()
            ]);
            return [];
        }
    }

    public function getStudents(): array
    {
        return Student::query()
            ->select(['student_id', 'name', 'grade', 'class_name'])
            ->orderBy('grade')
            ->orderBy('class_name')
            ->orderBy('name')
            ->get()
            ->toArray();
    }

    #[On('teacherChanged')]
    public function onTeacherChanged(string $teacherId): void
    {
        $this->teacherId = $teacherId;
        $this->studentId = '';
        $this->resetPageState();
    }

    #[On('studentChanged')]
    public function onStudentChanged(?string $teacherId, ?string $studentId): void
    {
        $this->teacherId = (string) ($teacherId ?? '');
        $this->studentId = (string) ($studentId ?? '');

        if ($this->studentId) {
            $this->loadMistakeData();
        } else {
            $this->resetPageState();
        }
    }

    protected function loadFilterOptions(): void
    {
        try {
            $knowledgeService = app(KnowledgeServiceApi::class);
            $knowledge = $knowledgeService->listKnowledgePoints(150);

            $this->filterOptions['knowledge_points'] = $knowledge
                ->map(function ($item) {
                    $code = $item['kp_code'] ?? $item['code'] ?? null;
                    if (!$code) {
                        return null;
                    }
                    return [
                        'code' => $code,
                        'name' => $item['cn_name'] ?? $item['name'] ?? $code,
                    ];
                })
                ->filter()
                ->take(200)
                ->values()
                ->toArray();

            $skills = $knowledgeService->listSkills(null, 200);
            $this->filterOptions['skills'] = $skills
                ->map(function ($item) {
                    return [
                        'id' => $item['skill_id'] ?? $item['id'] ?? ($item['code'] ?? ''),
                        'name' => $item['name'] ?? $item['skill_name'] ?? ($item['code'] ?? ''),
                        'kp_code' => $item['kp_code'] ?? $item['knowledge_point_code'] ?? null,
                    ];
                })
                ->filter(fn ($item) => filled($item['id']))
                ->values()
                ->toArray();
        } catch (\Throwable $e) {
            Log::error('Load filter options failed', [
                'error' => $e->getMessage(),
            ]);
            $this->filterOptions = ['knowledge_points' => [], 'skills' => []];
        }
    }

    protected function updateMistakeField(string $mistakeId, string $field, $value): void
    {
        foreach ($this->mistakes as &$mistake) {
            if (($mistake['id'] ?? null) === $mistakeId) {
                $mistake[$field] = $value;
                break;
            }
        }
    }

    protected function findMistakeById(string $mistakeId): array
    {
        foreach ($this->mistakes as $mistake) {
            if (($mistake['id'] ?? null) === $mistakeId) {
                return $mistake;
            }
        }

        return [];
    }

    protected function resetPageState(): void
    {
        $this->mistakes = [];
        $this->patterns = [];
        $this->summary = [];
        $this->selectedMistakeIds = [];
        $this->recommendations = [];
        $this->relatedQuestions = [];
        $this->actionMessage = '';
        $this->errorMessage = '';
    }

    protected function notify(string $message, string $type = 'success'): void
    {
        $this->actionMessage = $message;
        $this->actionMessageType = $type;
    }
}