<?php

namespace App\Http\Controllers;

use App\Http\Requests\StoreRequisitionRequest;
use App\Models\AuditLog;
use App\Models\CostCenter;
use App\Models\Equipment;
use App\Models\EquipmentSparePart;
use App\Models\Requisition;
use App\Models\SparePart;
use App\Models\StockItem;
use App\Models\TechnicalReview;
use App\Models\Tenant;
use App\Services\ConflictGuard;
use App\Services\EquipmentWorkflow;
use App\Services\RequisitionWorkflow;
use Illuminate\Http\RedirectResponse;
use Illuminate\Http\Request;
use Illuminate\Validation\Rule;
use Inertia\Inertia;
use Inertia\Response;

class RequisitionController extends Controller
{
    public function index(Request $request): Response
    {
        $filters = $request->validate(['search' => 'nullable|string|max:100', 'status' => ['nullable', Rule::in(['draft', 'pending', 'approved', 'rejected'])]]);
        $query = Requisition::query()->visibleTo($request->user())->with(['requester:id,name', 'department:id,name', 'steps']);
        if (! empty($filters['search'])) {
            $query->where('number', 'like', '%'.$filters['search'].'%');
        }
        if (! empty($filters['status'])) {
            $query->where('status', $filters['status']);
        }

        return Inertia::render('requisitions/index', [
            'requisitions' => $query->latest()->paginate(15)->withQueryString(),
            'filters' => $filters,
        ]);
    }

    public function create(Request $request): Response
    {
        return Inertia::render('requisitions/form', [
            'costCenters' => CostCenter::query()->where('department_id', $request->user()->department_id)->orderBy('code')->get(),
            'requisition' => null,
            ...$this->equipmentOptions($request),
        ]);
    }

    public function store(StoreRequisitionRequest $request, RequisitionWorkflow $workflow): RedirectResponse
    {
        $requisition = $workflow->save($request->user(), $request->validated());

        return to_route('requisitions.show', $requisition);
    }

    public function show(Request $request, Requisition $requisition): Response
    {
        Requisition::query()->visibleTo($request->user())->findOrFail($requisition->id);
        $requisition->load(['items', 'steps', 'requester:id,name', 'department:id,name', 'costCenter']);

        return Inertia::render('requisitions/show', [
            'requisition' => $requisition,
            'canEdit' => $requisition->requester_id === $request->user()->id && $requisition->status === 'draft',
            'canDecide' => $requisition->canDecide($request->user()),
            'conflictBlocked' => app(ConflictGuard::class)->participationBlocked($request->user(), $requisition),
            'audit' => AuditLog::query()->where('requisition_id', $requisition->id)->orderBy('id')->get(['id', 'action', 'user_id', 'created_at']),
            'technical' => [
                'canReview' => app(EquipmentWorkflow::class)->canReview($request->user(), $requisition),
                'basis_hash' => app(EquipmentWorkflow::class)->basis($requisition),
                'reviews' => TechnicalReview::query()->where('requisition_id', $requisition->id)->orderBy('id')->get(),
            ],
        ]);
    }

    public function edit(Request $request, Requisition $requisition): Response
    {
        abort_unless($requisition->requester_id === $request->user()->id && $requisition->status === 'draft', 403);

        return Inertia::render('requisitions/form', [
            'requisition' => $requisition->load('items'),
            'costCenters' => CostCenter::query()->where('department_id', $request->user()->department_id)->orderBy('code')->get(),
            ...$this->equipmentOptions($request),
        ]);
    }

    /** @return array<string,mixed> */
    private function equipmentOptions(Request $request): array
    {
        $equipment = Equipment::query()->where('department_id', $request->user()->department_id)->orderBy('code')->get(['id', 'code', 'description']);
        $parts = SparePart::query()->whereIn('id', EquipmentSparePart::query()->whereIn('equipment_id', $equipment->pluck('id'))->select('spare_part_id'))->get(['id', 'stock_item_id']);

        return ['equipment' => $equipment, 'spareParts' => $parts, 'stockItems' => StockItem::query()->whereIn('id', $parts->pluck('stock_item_id'))->get(['id', 'code', 'name', 'unit'])];
    }

    public function technical(Request $request, Requisition $requisition): RedirectResponse
    {
        $data = $request->validate(['basis_hash' => 'required|string|size:64', 'decision' => ['required', Rule::in(['approved', 'rejected'])], 'reason' => 'required|string|max:4000']);
        app(EquipmentWorkflow::class)->review($request->user(), $requisition, $data['basis_hash'], $data['decision'], $data['reason']);

        return back();
    }

    public function update(StoreRequisitionRequest $request, Requisition $requisition, RequisitionWorkflow $workflow): RedirectResponse
    {
        $workflow->save($request->user(), $request->validated(), $requisition);

        return to_route('requisitions.show', $requisition);
    }

    public function submit(Request $request, Requisition $requisition, RequisitionWorkflow $workflow): RedirectResponse
    {
        $workflow->submit($request->user(), $requisition);

        return back();
    }

    public function decide(Request $request, Requisition $requisition, RequisitionWorkflow $workflow): RedirectResponse
    {
        $data = $request->validate([
            'decision' => ['required', Rule::in(['approved', 'rejected'])],
            'comment' => ['nullable', 'required_if:decision,rejected', 'string', 'max:2000'],
        ]);
        $workflow->decide($request->user(), $requisition, $data['decision'], $data['comment'] ?? null);

        return back();
    }

    public function dashboard(Request $request): Response
    {
        $visible = Requisition::query()->visibleTo($request->user());
        $pending = (clone $visible)->where('status', 'pending')->with('steps')->get();

        return Inertia::render('dashboard', [
            'company' => $request->user()->tenant_id ? Tenant::query()->find($request->user()->tenant_id) : null,
            'stats' => [
                'total' => (clone $visible)->count(),
                'pending' => $pending->count(),
                'approved' => (clone $visible)->where('status', 'approved')->count(),
                'approvedMinor' => (clone $visible)->where('status', 'approved')->sum('total_minor'),
                'awaitingMe' => $pending->filter(fn (Requisition $r) => $r->canDecide($request->user()))->count(),
            ],
            'recent' => (clone $visible)->with(['requester:id,name', 'department:id,name'])->latest()->limit(6)->get(),
            'approvals' => $pending->filter(fn (Requisition $r) => $r->canDecide($request->user()))->take(5)->values(),
        ]);
    }
}