<?php

namespace App\Http\Controllers\Api;

use App\Http\Controllers\Controller;
use App\Models\TripExpense;
use App\Models\Trip;
use App\Models\User;
use App\Services\EmployeeService;
use Illuminate\Http\Request;
use Exception;

class ReimbursementApiController extends Controller
{
    protected EmployeeService $employeeService;

    public function __construct(EmployeeService $employeeService)
    {
        $this->employeeService = $employeeService;
    }

    public function index(Request $request)
    {
        $user = $request->user();

        $expenses = TripExpense::with('trip')
            ->where('created_by', $user->id)
            ->orderBy('expense_date', 'desc')
            ->get();

        return response()->json([
            'success' => true,
            'data' => $expenses->map(function ($e) {
                $rawStatus = strtolower($e->status ?? ($e->trip->reimbursement_status ?? ($e->trip->status ?? 'pending')));
                if (in_array($rawStatus, ['approved', 'paid', 'completed', 'reconciled'])) {
                    $status = 'approved';
                } elseif (in_array($rawStatus, ['rejected', 'cancelled'])) {
                    $status = 'rejected';
                } else {
                    $status = 'pending';
                }

                return [
                    'id' => $e->id,
                    'item_name' => $e->description ?? $e->expense_type,
                    'amount' => (float)$e->amount,
                    'category' => $e->expense_type ?? 'General',
                    'purchase_date' => $e->expense_date ? $e->expense_date->format('Y-m-d') : date('Y-m-d'),
                    'status' => $status,
                    'raw_status' => $rawStatus,
                    'receipt_url' => $e->receipt ? asset('storage/' . $e->receipt) : null,
                    'notes' => $e->description,
                ];
            }),
            'message' => null,
            'errors' => null,
        ]);
    }

    public function store(Request $request)
    {
        $request->validate([
            'item_name' => 'required|string',
            'amount' => 'required|numeric|min:0',
            'category' => 'nullable|string',
            'purchase_date' => 'required|date',
            'notes' => 'nullable|string',
            'receipt' => 'nullable|file|mimes:jpg,jpeg,png,pdf|max:10240',
        ]);

        $user = $request->user();
        $employee = $this->employeeService->resolveEmployee($user);

        $receiptPath = null;
        if ($request->hasFile('receipt')) {
            $receiptPath = $request->file('receipt')->store('receipts', 'public');
        }

        $trip = Trip::firstOrCreate(
            ['employee_id' => $user->id, 'purpose' => 'General Employee Expenses'],
            [
                'title' => 'Reimbursement Trip for ' . $user->name,
                'destination' => 'Local',
                'start_date' => date('Y-m-d'),
                'end_date' => date('Y-m-d'),
                'status' => 'approved',
                'created_by' => $user->id,
            ]
        );

        $expense = TripExpense::create([
            'trip_id' => $trip->id,
            'expense_type' => $request->category ?? 'General',
            'expense_date' => $request->purchase_date,
            'amount' => $request->amount,
            'currency' => 'PHP',
            'description' => $request->item_name . ($request->notes ? ' - ' . $request->notes : ''),
            'receipt' => $receiptPath,
            'is_reimbursable' => true,
            'status' => 'pending',
            'created_by' => $user->id,
        ]);

        return response()->json([
            'success' => true,
            'message' => 'Reimbursement claim submitted successfully',
            'data' => [
                'id' => $expense->id,
                'item_name' => $request->item_name,
                'amount' => (float)$expense->amount,
                'category' => $expense->expense_type,
                'purchase_date' => $expense->expense_date ? $expense->expense_date->format('Y-m-d') : date('Y-m-d'),
                'status' => $expense->status,
                'receipt_url' => $receiptPath ? asset('storage/' . $receiptPath) : null,
            ],
            'errors' => null,
        ], 201);
    }

    public function updateStatus(Request $request, $id)
    {
        $request->validate([
            'status' => 'required|string|in:approved,rejected,pending,cancelled',
        ]);

        $user = $request->user();
        $expense = TripExpense::find($id);

        if (!$expense) {
            return response()->json([
                'success' => false,
                'data' => null,
                'message' => 'Reimbursement claim not found',
                'errors' => null,
            ], 404);
        }

        // Authorization checks
        if ($request->status === 'cancelled') {
            if ($expense->created_by !== $user->id && !in_array($user->type, ['company', 'hr', 'superadmin', 'manager'])) {
                return response()->json([
                    'success' => false,
                    'data' => null,
                    'message' => 'Unauthorized to cancel this claim',
                    'errors' => null,
                ], 403);
            }
        } else { // approved or rejected
            $userType = strtolower($user->type ?? '');
            $isElevatedRole = in_array($userType, ['company', 'hr', 'superadmin', 'manager']);

            if (!$isElevatedRole) {
                try {
                    $isElevatedRole = $user->hasAnyRole(['company', 'hr', 'superadmin', 'manager']);
                } catch (\Throwable $e) {
                    $isElevatedRole = false;
                }
            }

            $isSelf = ($expense->created_by === $user->id) && ($userType === 'employee' || !$isElevatedRole);

            $appCreator = User::find($expense->created_by) 
                ?? Employee::find($expense->created_by)?->user;

            $appCompanyId = $appCreator ? ($appCreator->type === 'company' ? $appCreator->id : ($appCreator->created_by ?: $appCreator->id)) : null;
            $approverCompanyId = $user->type === 'company' ? $user->id : ($user->created_by ?: $user->id);

            $isSuperAdmin = in_array($userType, ['superadmin']);
            $isSameCompany = ($appCompanyId !== null && $approverCompanyId !== null && (int)$appCompanyId === (int)$approverCompanyId);

            if (!$isElevatedRole || $isSelf || (!$isSameCompany && !$isSuperAdmin)) {
                return response()->json([
                    'success' => false,
                    'data' => null,
                    'message' => 'Unauthorized to review this reimbursement claim. Approval requires authorized manager or HR within the same organization.',
                    'errors' => null,
                ], 403);
            }
        }

        $expense->update(['status' => $request->status]);

        return response()->json([
            'success' => true,
            'message' => 'Reimbursement claim status updated to ' . $request->status,
            'data' => $expense,
            'errors' => null,
        ]);
    }

    public function approve(Request $request, $id)
    {
        return $this->updateStatus($request->merge(['status' => 'approved']), $id);
    }

    public function reject(Request $request, $id)
    {
        return $this->updateStatus($request->merge(['status' => 'rejected']), $id);
    }
}