<?php

namespace Modules\MaterialLogistics\Http\Controllers;

use App\Http\Controllers\Controller;
use Barryvdh\DomPDF\Facade\Pdf;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\DB;
use Inertia\Inertia;
use Modules\ApprovalWorkflow\Services\ApprovalService;
use Modules\MasterData\Models\Material;
use Modules\MaterialLogistics\Models\MaterialRequisition;
use Modules\MasterData\Models\MaterialGroup;
use Modules\MaterialLogistics\Services\DocumentNumberService;
use Modules\ProjectManagement\Models\Project;
use Modules\ProjectManagement\Services\ProjectWorkflowService;

class MaterialRequisitionController extends Controller
{
    public function index(Request $request)
    {
        $query = MaterialRequisition::with([
            // The requisition is already tenant/project-scoped. Load the
            // display names without User's tenant scope so a valid requester
            // from the assigned project is not serialized as null.
            'requester' => fn ($userQuery) => $userQuery->withoutGlobalScopes()->select('id', 'ulid', 'name'),
            'approver' => fn ($userQuery) => $userQuery->withoutGlobalScopes()->select('id', 'ulid', 'name'),
            'project:id,ulid,name,code',
            'items:id,material_requisition_id,quantity,unit_cost'
        ]);

        // Requisitions inherit visibility from their projects.
        $query->whereIn('project_id', $this->availableProjectsQuery()->select('projects.id'));

        if ($request->filled('project_ulid')) {
            $project = Project::where('ulid', $request->project_ulid)->first();
            if ($project) {
                $query->where('project_id', $project->id);
            }
        }

        $requisitions = $query->latest()->paginate(20);

        return Inertia::render('MaterialLogistics::Requisitions/Index', [
            'requisitions' => $requisitions,
            'projects' => Project::active()->where('current_wizard_step', '>=', 8)->select('id', 'ulid', 'name', 'code', 'client_name', 'location', 'start_date', 'target_end_date', 'status', 'contract_value')->get(),
        ]);
    }

    public function create(Request $request)
    {
        $selectedProject = null;
        $prefilledItems = [];

        if ($request->filled('project_ulid')) {
            $selectedProject = $this->availableProjectsQuery()
                ->where('ulid', $request->project_ulid)
                ->with('materialsEstimates.material:id,ulid,name,unit,unit_cost')
                ->firstOrFail();

            $workflowService = new ProjectWorkflowService();
            if (!$workflowService->canCreateRequisition($selectedProject)) {
                return redirect()->back()->with('error', 'Cannot create material requisition: Project is not in scheduled/procuring state or task resources are missing.');
            }

            // Auto-populate from project materials estimation
            foreach ($selectedProject->materialsEstimates as $estimate) {
                $prefilledItems[] = [
                    'material_ulid' => $estimate->material->ulid,
                    'material_name' => $estimate->material->name,
                    'unit' => $estimate->material->unit,
                    'quantity' => (float) $estimate->estimated_qty,
                    'unit_cost' => (float) $estimate->unit_cost,
                ];
            }
        }

        $materials = Material::select('id', 'ulid', 'name', 'unit', 'unit_cost', 'sku', 'category', 'status')
            ->where('status', 'active')
            ->orderBy('category')
            ->orderBy('name')
            ->get();

        $materialGroups = Material::with('components.component:id,ulid,name,sku,category,unit,unit_cost')
            ->whereIn('type', ['kit', 'assembly'])
            ->where('status', 'active')
            ->orderBy('name')
            ->get()
            ->map(function ($kit) {
                return [
                    'id' => $kit->id,
                    'ulid' => $kit->ulid,
                    'name' => $kit->name,
                    'description' => $kit->description ?? '',
                    'status' => $kit->status,
                    'materials' => $kit->components->map(function ($comp) {
                        return array_merge($comp->component->toArray(), [
                            'pivot' => ['quantity' => $comp->quantity]
                        ]);
                    })->toArray()
                ];
            });

        return Inertia::render('MaterialLogistics::Requisitions/Form', [
            'materials' => $materials,
            'materialGroups' => $materialGroups,
            'projects' => $this->availableProjectsQuery()
                ->active()
                ->where('current_wizard_step', '>=', 8)
                ->with('contractor:id,company_name')
                ->select('id', 'ulid', 'name', 'code', 'contractor_id', 'client_name', 'location', 'start_date', 'target_end_date', 'status', 'contract_value')
                ->get(),
            'selectedProject' => $selectedProject,
            'prefilledItems' => $prefilledItems,
        ]);
    }

    public function store(Request $request)
    {
        $validated = $request->validate([
            'project_ulid' => 'required|string|exists:projects,ulid',
            'notes' => 'nullable|string|max:1000',
            'items' => 'required|array|min:1',
            'items.*.material_ulid' => 'required|string',
            'items.*.quantity' => 'required|numeric|min:0.01',
            'items.*.unit_cost' => 'required|numeric|min:0',
        ]);

        $project = $this->availableProjectsQuery()
            ->where('ulid', $validated['project_ulid'])
            ->firstOrFail();
        if ($project->current_wizard_step < 7) {
            return redirect()->back()->with('error', 'Cannot create material requisition: Project estimation is not submitted or approved.');
        }

        $workflowService = new ProjectWorkflowService();
        if (!$workflowService->canCreateRequisition($project)) {
            return redirect()->back()->with('error', 'Cannot create material requisition: Project is not in scheduled/procuring state.');
        }

        // Validate that all items are in the project's materials estimates
        $estimatedMaterialIds = $project->materialsEstimates()->pluck('material_id')->toArray();
        foreach ($validated['items'] as $item) {
            $material = Material::where('ulid', $item['material_ulid'])->firstOrFail();
            if (!in_array($material->id, $estimatedMaterialIds)) {
                return redirect()->back()->with('error', "Cannot create material requisition: Material '{$material->name}' is not in the project's approved estimation.");
            }
        }

        $docService = new DocumentNumberService();

        $mr = DB::transaction(function () use ($validated, $project, $docService) {
            $mr = MaterialRequisition::create([
                'project_id' => $project->id,
                'document_number' => $docService->nextMrNumber(),
                'status' => 'draft',
                'requested_by' => auth()->id(),
                'notes' => $validated['notes'] ?? null,
            ]);

            foreach ($validated['items'] as $item) {
                $material = Material::where('ulid', $item['material_ulid'])->firstOrFail();
                $mr->items()->create([
                    'material_id' => $material->id,
                    'quantity' => $item['quantity'],
                    'unit_cost' => $item['unit_cost'],
                ]);
            }

            return $mr;
        });

        return redirect()->route('requisitions.show', $mr)->with('success', 'Material Requisition created.');
    }

    public function edit(MaterialRequisition $requisition)
    {
        if ($requisition->status !== 'draft') {
            return redirect()->back()->with('error', 'Only draft requisitions can be edited.');
        }

        $requisition->load('items.material:id,ulid,name,unit,unit_cost', 'project:id,ulid,name,code');

        $materials = Material::select('id', 'ulid', 'name', 'sku', 'category', 'unit', 'unit_cost', 'status')
            ->where('status', 'active')
            ->orderBy('category')
            ->orderBy('name')
            ->get();

        $materialGroups = Material::with('components.component:id,ulid,name,sku,category,unit,unit_cost')
            ->whereIn('type', ['kit', 'assembly'])
            ->where('status', 'active')
            ->orderBy('name')
            ->get()
            ->map(function ($kit) {
                return [
                    'id' => $kit->id,
                    'ulid' => $kit->ulid,
                    'name' => $kit->name,
                    'description' => $kit->description ?? '',
                    'status' => $kit->status,
                    'materials' => $kit->components->map(function ($comp) {
                        return array_merge($comp->component->toArray(), [
                            'pivot' => ['quantity' => $comp->quantity]
                        ]);
                    })->toArray()
                ];
            });

        return Inertia::render('MaterialLogistics::Requisitions/Form', [
            'requisition' => $requisition,
            'materials' => $materials,
            'materialGroups' => $materialGroups,
            'projects' => $this->availableProjectsQuery()
                ->active()
                ->where('current_wizard_step', '>=', 8)
                ->select('id', 'ulid', 'name', 'code', 'client_name', 'location', 'start_date', 'target_end_date', 'status', 'contract_value')
                ->get(),
        ]);
    }

    public function update(Request $request, MaterialRequisition $requisition)
    {
        if ($requisition->status !== 'draft') {
            return redirect()->back()->with('error', 'Only draft requisitions can be updated.');
        }

        $validated = $request->validate([
            'project_ulid' => 'required|string|exists:projects,ulid',
            'notes' => 'nullable|string|max:1000',
            'items' => 'required|array|min:1',
            'items.*.material_ulid' => 'required|string',
            'items.*.quantity' => 'required|numeric|min:0.01',
            'items.*.unit_cost' => 'required|numeric|min:0',
        ]);

        $project = $this->availableProjectsQuery()
            ->where('ulid', $validated['project_ulid'])
            ->firstOrFail();
        if ($project->current_wizard_step < 8) {
            return redirect()->back()->with('error', 'Cannot update material requisition: Project estimation is not approved.');
        }

        $workflowService = new ProjectWorkflowService();
        if (!$workflowService->canCreateRequisition($project)) {
            return redirect()->back()->with('error', 'Cannot update material requisition: Project is not in scheduled/procuring state.');
        }

        // Validate that all items are in the project's materials estimates
        $estimatedMaterialIds = $project->materialsEstimates()->pluck('material_id')->toArray();
        foreach ($validated['items'] as $item) {
            $material = Material::where('ulid', $item['material_ulid'])->firstOrFail();
            if (!in_array($material->id, $estimatedMaterialIds)) {
                return redirect()->back()->with('error', "Cannot update material requisition: Material '{$material->name}' is not in the project's approved estimation.");
            }
        }

        DB::transaction(function () use ($validated, $project, $requisition) {
            $requisition->update([
                'project_id' => $project->id,
                'notes' => $validated['notes'] ?? null,
            ]);

            $requisition->items()->delete(); // remove old items

            foreach ($validated['items'] as $item) {
                $material = Material::where('ulid', $item['material_ulid'])->firstOrFail();
                $requisition->items()->create([
                    'material_id' => $material->id,
                    'quantity' => $item['quantity'],
                    'unit_cost' => $item['unit_cost'],
                ]);
            }
        });

        return redirect()->route('requisitions.show', $requisition)->with('success', 'Material Requisition updated.');
    }

    public function show(MaterialRequisition $requisition)
    {
        $requisition->load([
            'requester:id,ulid,name',
            'approver:id,ulid,name',
            'items.material' => function ($query) {
                $query->select('id', 'ulid', 'name', 'unit', 'unit_cost', 'type')
                      ->with('components.component:id,name,unit');
            },
            'approvalChains.steps.approver:id,ulid,name',
        ]);

        return Inertia::render('MaterialLogistics::Requisitions/Show', [
            'requisition' => $requisition,
        ]);
    }

    public function submitForApproval(MaterialRequisition $requisition)
    {
        if ($requisition->status !== 'draft') {
            return back()->with('error', 'Only draft requisitions can be submitted.');
        }

        // Material Requests may be approved by an explicit permission or by
        // the system's Project Manager/executive roles. Query without the
        // tenant scope so a site user can submit a request for an assigned
        // project even when the approver belongs to another tenant context.
        $approverIds = \App\Models\User::withoutGlobalScopes()
            ->where('user_type', '!=', 'contractor')
            ->whereDoesntHave('roles', function ($roleQuery) {
                $roleQuery->whereIn('name', [
                    'Contractor Admin',
                    'Contractor',
                    'Subcontractor Staff',
                    'Site Technical',
                    'Construction Supervisor',
                ]);
            })
            ->where(function ($query) {
                $query->whereHas('roles', function ($roleQuery) {
                    $roleQuery->whereIn('name', [
                        'Project Manager',
                        'project_manager',
                        'Super Admin',
                        'admin',
                    ]);
                })
                ->orWhere('user_type', 'admin');
            })
            ->where('status', 'active')
            ->pluck('id')
            ->values()
            ->toArray();

        if (empty($approverIds)) {
            return back()->with('error', 'No approvers found in the system for Material Requests.');
        }

        $approvalService = app(ApprovalService::class);
        $approvalService->createChain(
            $requisition,
            $approverIds,
            'material_requisition',
            auth()->id(),
        );

        $requisition->update(['status' => 'submitted']);

        return back()->with('success', 'Material Requisition submitted for approval.');
    }

    public function downloadPdf(MaterialRequisition $requisition)
    {
        $requisition->load([
            'requester' => fn ($query) => $query->withoutGlobalScopes()->select('id', 'name'),
            'approver' => fn ($query) => $query->withoutGlobalScopes()->select('id', 'name'),
            'items.material:id,name,unit',
            'approvalChains.steps.approver:id,name',
        ]);

        // Global approver roles
        $approverDetails = [];
        if ($requisition->approvalChains->isNotEmpty()) {
            $chain = $requisition->approvalChains->sortByDesc('created_at')->first();
            foreach ($chain->steps as $step) {
                $stepStatus = $step->status instanceof \BackedEnum ? $step->status->value : $step->status;
                $approver = $step->approver ?: ($step->approver_id
                    ? \App\Models\User::withoutGlobalScopes()->find($step->approver_id)
                    : null);
                if ($stepStatus === 'approved' && $approver) {
                    $approverDetails[] = [
                        'name' => $approver->name,
                        'role' => 'Approver',
                        'date' => $step->acted_at?->format('M d, Y'),
                    ];
                }
            }
        }

        if (empty($approverDetails) && $requisition->status === 'approved' && $requisition->approver) {
            $approverDetails[] = [
                'name' => $requisition->approver->name,
                'role' => 'Approver',
                'date' => $requisition->approved_at ? $requisition->approved_at->format('M d, Y') : null,
            ];
        }

        $pdf = Pdf::loadView('materiallogistics::pdf.material-requisition', [
            'requisition' => $requisition,
            'approverDetails' => $approverDetails,
        ]);

        return $pdf->download("MR-{$requisition->document_number}.pdf");
    }

    private function availableProjectsQuery()
    {
        // Project's TenantScope is the source of truth for project visibility.
        return Project::query();
    }
}