<?php

namespace App\Filament\Tenant\Pages;

use App\Models\Tenant\Appointment;
use App\Models\Tenant\Client;
use App\Models\Tenant\Post;
use App\Models\Tenant\User;
use App\Models\Tenant\Vehicle;
use Carbon\Carbon;
use Filament\Notifications\Notification;
use Filament\Pages\Page;

class CalendarBoard extends Page
{
    protected static string|\BackedEnum|null $navigationIcon = 'heroicon-o-calendar-days';

    protected static ?string $navigationLabel = 'Calendar vizual';

    protected static string|\UnitEnum|null $navigationGroup = 'CRM';

    protected static ?int $navigationSort = 8;

    protected static ?string $title = 'Calendar vizual';

    protected string $view = 'filament.tenant.pages.calendar';

    public string $weekStart;            // 'Y-m-d' (Monday)
    public string $groupBy = 'post';     // 'post' | 'master'
    public string $viewMode = 'week';    // day | week | month | list
    public string $customStart = '';     // when viewMode='custom'
    public string $customEnd = '';
    public ?int $masterFilter = null;
    public string $statusFilter = 'all'; // all | confirmed | unconfirmed | in_work
    public bool $showNewForm = false;
    public bool $showNewPostForm = false;
    public ?int $openEventId = null;
    public ?int $renamingPostId = null;
    public string $renamingPostName = '';
    public ?int $renamingPostMasterId = null;

    public array $newAppt = [];
    public array $newPost = ['name' => '', 'color' => '#3b82f6', 'hours_per_day' => 10, 'description' => ''];

    public function getMaxContentWidth(): \Filament\Support\Enums\Width
    {
        return \Filament\Support\Enums\Width::Full;
    }

    public function getHeading(): string { return ''; }
    public function getSubheading(): ?string { return null; }

    public function mount(): void
    {
        $this->weekStart = Carbon::now()->startOfWeek()->toDateString();
    }

    public function shiftWeek(int $deltaWeeks): void
    {
        // delta semantic depends on view mode
        $current = Carbon::parse($this->weekStart);
        $this->weekStart = match ($this->viewMode) {
            'day' => $current->addDays($deltaWeeks)->toDateString(),
            'month' => $current->addMonths($deltaWeeks)->startOfMonth()->toDateString(),
            default => $current->addWeeks($deltaWeeks)->toDateString(),
        };
    }

    public function setWeekToday(): void
    {
        $this->weekStart = match ($this->viewMode) {
            'day' => Carbon::today()->toDateString(),
            'month' => Carbon::now()->startOfMonth()->toDateString(),
            default => Carbon::now()->startOfWeek()->toDateString(),
        };
    }

    public function setGroupBy(string $g): void
    {
        $this->groupBy = in_array($g, ['post', 'master'], true) ? $g : 'post';
    }

    public function setViewMode(string $m): void
    {
        if (! in_array($m, ['day', 'week', 'month', 'list', 'custom'], true)) return;
        $this->viewMode = $m;
        // Snap weekStart to a sensible anchor for the new view
        $this->weekStart = match ($m) {
            'day' => Carbon::today()->toDateString(),
            'month' => Carbon::parse($this->weekStart)->startOfMonth()->toDateString(),
            'custom' => $this->customStart ?: Carbon::today()->toDateString(),
            default => Carbon::parse($this->weekStart)->startOfWeek()->toDateString(),
        };
    }

    public function setStatusFilter(string $s): void
    {
        $this->statusFilter = in_array($s, ['all', 'confirmed', 'unconfirmed', 'in_work'], true) ? $s : 'all';
    }

    public function setMasterFilter($id): void
    {
        $this->masterFilter = $id ? (int) $id : null;
    }

    /** Build day headers — count varies by view mode. */
    public function getDays(): array
    {
        $today = Carbon::today()->toDateString();
        $names = ['Luni', 'Marți', 'Miercuri', 'Joi', 'Vineri', 'Sâmbătă', 'Duminică'];
        $start = Carbon::parse($this->weekStart);

        $count = match ($this->viewMode) {
            'day' => 1,
            'month' => $start->daysInMonth,
            'custom' => $this->customStart && $this->customEnd
                ? max(1, min(31, Carbon::parse($this->customStart)->diffInDays(Carbon::parse($this->customEnd)) + 1))
                : 7,
            default => 7,
        };

        if ($this->viewMode === 'month') {
            $start = Carbon::parse($this->weekStart)->startOfMonth();
        }
        if ($this->viewMode === 'custom' && $this->customStart) {
            $start = Carbon::parse($this->customStart);
        }

        $days = [];
        for ($i = 0; $i < $count; $i++) {
            $d = $start->copy()->addDays($i);
            $dow = (int) $d->dayOfWeek;     // 0=Sunday, 6=Saturday in Carbon
            $isoDow = (int) $d->isoWeekday();   // 1=Mon..7=Sun
            $days[] = [
                'date' => $d->toDateString(),
                'label' => $d->format('d.m'),
                'name' => $names[($isoDow - 1) % 7],
                'is_today' => $d->toDateString() === $today,
                'is_weekend' => $isoDow >= 6,
                'is_closed' => $isoDow === 7, // Sunday default
            ];
        }
        return $days;
    }

    /** Rows: either Posts or active Masters depending on $groupBy. */
    public function getRows(): array
    {
        if ($this->groupBy === 'master') {
            $rows = User::query()
                ->where('status', 'active')
                ->whereNotNull('role')
                ->where(function ($q) { $q->where('role', 'master')->orWhere('role', 'mecanic')->orWhereNull('role'); })
                ->orderBy('name')
                ->get(['id', 'name', 'color', 'specialization'])
                ->map(fn ($u) => [
                    'kind' => 'master',
                    'id' => $u->id,
                    'name' => $u->name,
                    'color' => $u->color ?: '#3b82f6',
                    'meta' => $u->specialization ?: '8h/zi',
                    'capacity_hours' => 8.0,
                ])->all();
            // Always include "Fără maistru" row at the bottom
            $rows[] = ['kind' => 'master', 'id' => 0, 'name' => 'Fără maistru', 'color' => '#94a3b8', 'meta' => '—', 'capacity_hours' => 0];
            return $rows;
        }

        $posts = Post::where('is_active', true)->orderBy('sort_order')->orderBy('name')->get();
        // Fallback: synthesize a default post if none configured yet
        if ($posts->isEmpty()) {
            return [
                ['kind' => 'post', 'id' => 0, 'name' => 'Pod 1 (default)', 'color' => '#3b82f6', 'meta' => '10h/zi', 'capacity_hours' => 10.0],
            ];
        }
        return $posts->map(fn ($p) => [
            'kind' => 'post',
            'id' => $p->id,
            'name' => $p->name,
            'color' => $p->color ?: '#3b82f6',
            'meta' => ($p->hours_per_day ? $p->hours_per_day . 'h/zi' : '10h/zi') . ($p->description ? ' · ' . $p->description : ''),
            'capacity_hours' => (float) ($p->hours_per_day ?: 10),
        ])->all();
    }

    /** Returns map [rowId][date] => ['events'=>[], 'load_hours'=>float, 'capacity'=>float] */
    public function getMatrix(): array
    {
        $start = $this->weekStart;
        $end = Carbon::parse($this->weekStart)->addDays(6)->toDateString();

        $q = Appointment::with(['client:id,name', 'vehicle:id,plate,make,model', 'master:id,name,color', 'post:id,name,color'])
            ->whereBetween('date', [$start, $end]);

        if ($this->masterFilter) {
            $q->where('master_id', $this->masterFilter);
        }
        if ($this->statusFilter === 'confirmed') {
            $q->where('status', 'arrived');
        } elseif ($this->statusFilter === 'unconfirmed') {
            $q->where('status', 'scheduled');
        } elseif ($this->statusFilter === 'in_work') {
            $q->where('status', 'in_work');
        }

        $events = $q->get();
        $rows = $this->getRows();
        $days = $this->getDays();

        $matrix = [];
        foreach ($rows as $row) {
            foreach ($days as $day) {
                $matrix[$row['id']][$day['date']] = ['events' => [], 'load_hours' => 0, 'capacity' => $row['capacity_hours']];
            }
        }

        foreach ($events as $a) {
            $rowId = $this->groupBy === 'post' ? ($a->post_id ?: ($rows[0]['id'] ?? 0)) : ($a->master_id ?: 0);
            if (! isset($matrix[$rowId])) continue;
            $date = $a->date->toDateString();
            if (! isset($matrix[$rowId][$date])) continue;

            $hours = $this->calcHours($a->time_start, $a->time_end);
            $matrix[$rowId][$date]['load_hours'] += $hours;
            $matrix[$rowId][$date]['events'][] = [
                'id' => $a->id,
                'title' => $a->title ?: ($a->client?->name ?? '—'),
                'client_name' => $a->client?->name,
                'vehicle' => trim(($a->vehicle?->make ?? '') . ' ' . ($a->vehicle?->model ?? '')),
                'plate' => $a->vehicle?->plate,
                'master_name' => $a->master?->name,
                'master_initial' => $a->master ? strtoupper(mb_substr($a->master->name, 0, 1)) . '.' : '',
                'time' => substr($a->time_start ?? '', 0, 5) . '–' . substr($a->time_end ?? '', 0, 5),
                'color' => $a->color ?: ($a->master?->color ?? '#3b82f6'),
                'status' => $a->status,
            ];
        }

        return $matrix;
    }

    public function getStats(): array
    {
        $start = $this->weekStart;
        $end = Carbon::parse($this->weekStart)->addDays(6)->toDateString();
        $events = Appointment::whereBetween('date', [$start, $end])->get();
        $rows = $this->getRows();
        // Capacity = sum(rows.capacity_hours) * 6 working days
        $capacity = 0;
        foreach ($rows as $r) { $capacity += $r['capacity_hours'] * 6; }
        $scheduled = 0;
        foreach ($events as $a) {
            $scheduled += $this->calcHours($a->time_start, $a->time_end);
        }
        $open = $events->whereNotIn('status', ['done', 'cancelled', 'no_show'])->count();
        $confirmed = $events->whereIn('status', ['arrived', 'in_work', 'done'])->count();
        $noShowAlert = $events
            ->where('status', 'scheduled')
            ->filter(fn ($a) => Carbon::parse($a->date->toDateString() . ' ' . ($a->time_start ?? '08:00'))->diffInHours(now(), false) > -24)
            ->count();

        return [
            'scheduled_hours' => round($scheduled, 1),
            'capacity_hours' => round($capacity, 1),
            'utilization_pct' => $capacity > 0 ? (int) round(100 * $scheduled / $capacity) : 0,
            'open_count' => $open,
            'confirmed_count' => $confirmed,
            'total_count' => $events->count(),
            'confirmation_rate_pct' => $events->count() > 0 ? (int) round(100 * $confirmed / $events->count()) : 0,
            'no_show_alert' => $noShowAlert,
        ];
    }

    // ============== mutations ==============

    public function moveEvent(int $id, int $toRowId, string $toDate): void
    {
        $a = Appointment::find($id);
        if (! $a) return;
        if ($this->groupBy === 'post') {
            $a->post_id = $toRowId ?: null;
        } else {
            $a->master_id = $toRowId ?: null;
        }
        $a->date = $toDate;
        $a->save();
        Notification::make()->title('Programare mutată')->body($a->title . ' → ' . $toDate)->success()->send();
    }

    public function openEvent(int $id): void
    {
        $this->openEventId = $id;
        $this->showNewForm = false;
    }

    public function getOpenEvent(): ?array
    {
        if (! $this->openEventId) return null;
        $a = Appointment::with(['client', 'vehicle', 'master', 'post'])->find($this->openEventId);
        if (! $a) return null;
        return [
            'id' => $a->id,
            'title' => $a->title,
            'status' => $a->status,
            'date' => $a->date->format('d.m.Y'),
            'time' => substr($a->time_start ?? '', 0, 5) . '–' . substr($a->time_end ?? '', 0, 5),
            'client_name' => $a->client?->name,
            'client_phone' => $a->client?->phone,
            'vehicle' => trim(($a->vehicle?->make ?? '') . ' ' . ($a->vehicle?->model ?? '')),
            'plate' => $a->vehicle?->plate,
            'master_name' => $a->master?->name,
            'post_name' => $a->post?->name,
            'notes' => $a->notes,
            'deal_id' => $a->deal_id,
        ];
    }

    public function closeEvent(): void
    {
        $this->openEventId = null;
    }

    public function deleteEvent(int $id): void
    {
        Appointment::where('id', $id)->delete();
        $this->openEventId = null;
        Notification::make()->title('Programare ștearsă')->success()->send();
    }

    public function openNewForm(int $rowId = 0, string $date = ''): void
    {
        $masterId = $this->groupBy === 'master' && $rowId ? $rowId : null;
        $postId = $this->groupBy === 'post' && $rowId ? $rowId : null;

        // Auto-fill default master from post if one is set
        if ($postId && ! $masterId) {
            $post = Post::find($postId);
            if ($post && $post->default_master_id) {
                $masterId = $post->default_master_id;
            }
        }

        $this->newAppt = [
            'date' => $date ?: today()->toDateString(),
            'time_start' => '09:00',
            'time_end' => '10:00',
            'title' => '',
            'client_id' => null,
            'vehicle_id' => null,
            'master_id' => $masterId,
            'post_id' => $postId,
            'notes' => '',
        ];
        $this->showNewForm = true;
        $this->openEventId = null;
    }

    /** Quick-add post from calendar toolbar. */
    public function openNewPostForm(): void
    {
        $this->showNewPostForm = true;
        $this->newPost = ['name' => '', 'color' => '#3b82f6', 'hours_per_day' => 10, 'description' => ''];
    }

    public function createPost(): void
    {
        $name = trim($this->newPost['name'] ?? '');
        if ($name === '') {
            Notification::make()->title('Numele este obligatoriu')->danger()->send();
            return;
        }
        Post::create([
            'name' => $name,
            'color' => $this->newPost['color'] ?? '#3b82f6',
            'hours_per_day' => (float) ($this->newPost['hours_per_day'] ?? 10),
            'description' => trim($this->newPost['description'] ?? '') ?: null,
            'is_active' => true,
            'sort_order' => 100,
        ]);
        $this->showNewPostForm = false;
        Notification::make()->title('Spațiu de lucru adăugat')->success()->send();
    }

    /** Inline rename + reassign default master from row label click. */
    public function openRenamePost(int $postId): void
    {
        $post = Post::find($postId);
        if (! $post) return;
        $this->renamingPostId = $postId;
        $this->renamingPostName = $post->name;
        $this->renamingPostMasterId = $post->default_master_id;
    }

    public function saveRenamePost(): void
    {
        if (! $this->renamingPostId) return;
        $post = Post::find($this->renamingPostId);
        if (! $post) return;
        $name = trim($this->renamingPostName);
        if ($name === '') return;
        $post->update([
            'name' => $name,
            'default_master_id' => $this->renamingPostMasterId ?: null,
        ]);
        $this->renamingPostId = null;
        Notification::make()->title('Post actualizat')->success()->send();
    }

    /** Generate PDF for all appointments in the visible period. */
    public function exportPdf()
    {
        $days = $this->getDays();
        $firstDate = $days[0]['date'] ?? today()->toDateString();
        $lastDate = end($days)['date'] ?? today()->toDateString();
        $appointments = \App\Models\Tenant\Appointment::with(['client:id,name', 'vehicle:id,plate,make,model', 'master:id,name', 'post:id,name'])
            ->whereBetween('date', [$firstDate, $lastDate])
            ->orderBy('date')
            ->orderBy('time_start')
            ->get();

        $pdf = \Barryvdh\DomPDF\Facade\Pdf::loadView('pdf.appointments', [
            'appointments' => $appointments->groupBy(fn ($a) => $a->date->toDateString()),
            'periodLabel' => Carbon::parse($firstDate)->format('d.m.Y') . ' — ' . Carbon::parse($lastDate)->format('d.m.Y'),
            'generatedAt' => now()->format('d.m.Y H:i'),
        ])->setPaper('a4', 'portrait');

        return response()->streamDownload(
            fn () => print $pdf->output(),
            'programari_' . $firstDate . '_' . $lastDate . '.pdf',
            ['Content-Type' => 'application/pdf']
        );
    }

    /** Flat list of appointments for the visible period — used by list view. */
    public function getListAppointments(): array
    {
        $days = $this->getDays();
        $firstDate = $days[0]['date'] ?? today()->toDateString();
        $lastDate = end($days)['date'] ?? today()->toDateString();
        return \App\Models\Tenant\Appointment::with(['client:id,name,phone', 'vehicle:id,plate,make,model', 'master:id,name', 'post:id,name'])
            ->whereBetween('date', [$firstDate, $lastDate])
            ->when($this->masterFilter, fn ($q) => $q->where('master_id', $this->masterFilter))
            ->orderBy('date')
            ->orderBy('time_start')
            ->get()
            ->map(fn ($a) => [
                'id' => $a->id,
                'date' => $a->date->format('d.m.Y'),
                'time' => substr($a->time_start ?? '', 0, 5) . '–' . substr($a->time_end ?? '', 0, 5),
                'title' => $a->title,
                'client_name' => $a->client?->name,
                'client_phone' => $a->client?->phone,
                'vehicle' => trim(($a->vehicle?->make ?? '') . ' ' . ($a->vehicle?->model ?? '')) . ' · ' . ($a->vehicle?->plate ?? '—'),
                'master_name' => $a->master?->name ?? '—',
                'post_name' => $a->post?->name ?? '—',
                'status' => $a->status,
            ])->all();
    }

    public function createAppt(): void
    {
        $d = $this->newAppt;
        if (empty($d['title']) || empty($d['date'])) {
            Notification::make()->title('Subiect și data sunt obligatorii')->danger()->send();
            return;
        }
        Appointment::create([
            'date' => $d['date'],
            'time_start' => $d['time_start'] ?: '09:00',
            'time_end' => $d['time_end'] ?: '10:00',
            'title' => $d['title'],
            'client_id' => $d['client_id'] ?: null,
            'vehicle_id' => $d['vehicle_id'] ?: null,
            'master_id' => $d['master_id'] ?: null,
            'post_id' => $d['post_id'] ?: null,
            'notes' => $d['notes'] ?: null,
            'status' => 'scheduled',
        ]);
        $this->showNewForm = false;
        Notification::make()->title('Programare adăugată')->success()->send();
    }

    public function getMasterOptions(): array
    {
        return User::where('status', 'active')->pluck('name', 'id')->toArray();
    }

    public function getPostOptions(): array
    {
        return Post::where('is_active', true)->pluck('name', 'id')->toArray();
    }

    public function getClientOptions(): array
    {
        return Client::orderBy('name')->limit(50)->pluck('name', 'id')->toArray();
    }

    public function getVehicleOptions(?int $clientId): array
    {
        if (! $clientId) return [];
        return Vehicle::where('client_id', $clientId)->pluck('plate', 'id')->toArray();
    }

    private function calcHours(?string $start, ?string $end): float
    {
        if (! $start || ! $end) return 1.0;
        try {
            $s = Carbon::createFromTimeString($start);
            $e = Carbon::createFromTimeString($end);
            $h = $e->floatDiffInHours($s);
            return max(0, abs($h));
        } catch (\Throwable $e) {
            return 1.0;
        }
    }

    public function getWeekLabel(): string
    {
        $s = Carbon::parse($this->weekStart);
        $e = $s->copy()->addDays(6);
        return $s->format('d.m') . ' — ' . $e->format('d.m.Y');
    }
}