<?php

namespace App\Http\Controllers;

use App\Models\Expense;
use App\Models\Account;
use App\Models\ExpenseCategory;
use App\Models\Branch;
use Illuminate\Http\Request;
use Carbon\Carbon;

use Illuminate\Support\Facades\Auth;

class ExpenseController extends Controller
{
    public function index(Request $request)
    {
        $user = Auth::guard('web')->user() ?? Auth::guard('receptionist')->user();
        if (!$user) return response()->json(['message' => 'Unauthenticated'], 401);

        $query = Expense::with(['branch', 'category']);
        $branchId = $user->isReceptionist() ? $user->branch_id : $request->query('branch_id');
        $startDate = $request->query('start_date');
        $endDate = $request->query('end_date');

        if ($branchId) {
            $query->where('branch_id', $branchId);
        }
        if ($startDate) {
            $query->where('date', '>=', $startDate);
        }
        if ($endDate) {
            $query->where('date', '<=', $endDate);
        }

        return response()->json($query->orderBy('date', 'desc')->get());
    }

    public function store(Request $request)
    {
        $user = Auth::guard('web')->user() ?? Auth::guard('receptionist')->user();
        if (!$user) return response()->json(['message' => 'Unauthenticated'], 401);

        $data = $request->all();
        if ($user->isReceptionist()) {
            $data['branch_id'] = $user->branch_id;
        }

        $validated = \Illuminate\Support\Facades\Validator::make($data, [
            'date' => 'required|date',
            'branch_id' => 'required|exists:branches,id',
            'expense_category_id' => 'required|exists:expense_categories,id',
            'expense_type' => 'required|string|in:Account,Petty Cash',
            'amount' => 'required|numeric|min:0',
            'remarks' => 'nullable|string'
        ])->validate();

        // Security check for branch_id if receptionist
        if ($user->isReceptionist() && $validated['branch_id'] != $user->branch_id) {
            return response()->json(['message' => 'Unauthorized branch assignment'], 403);
        }

        $expense = Expense::create($validated);

        // Auto-ledgering: Debit from Accounts
        Account::create([
            'date' => $expense->date,
            'time' => Carbon::now()->toTimeString(),
            'credit' => 0,
            'debit' => $expense->amount,
            'type' => 'expense',
            'branch_id' => $expense->branch_id,
            'accountable_id' => $expense->id,
            'accountable_type' => Expense::class,
            'description' => "Expense: {$expense->category->name} - {$expense->remarks}"
        ]);

        return response()->json($expense->load(['branch', 'category']), 201);
    }

    public function getCategories()
    {
        return response()->json(ExpenseCategory::where('status', 'Active')->get());
    }

    public function getBranches()
    {
        $user = Auth::guard('web')->user() ?? Auth::guard('receptionist')->user();
        $query = Branch::where('status', 'Active');
        if ($user && $user->isReceptionist()) {
            $query->where('id', $user->branch_id);
        }
        return response()->json($query->get());
    }

    public function getSalaryHistory(Request $request)
    {
        $user = Auth::guard('web')->user() ?? Auth::guard('receptionist')->user();
        if (!$user) return response()->json(['message' => 'Unauthenticated'], 401);

        $salaryCategory = ExpenseCategory::where('name', 'Salary')->first();
        if (!$salaryCategory) return response()->json([]);

        $query = Expense::with(['branch'])
            ->where('expense_category_id', $salaryCategory->id);
        
        if ($user->isReceptionist()) {
            $query->where('branch_id', $user->branch_id);
        }
        
        $expenses = $query->orderBy('date', 'desc')->get();

        // Group by batch_id
        $grouped = $expenses->groupBy(function ($item) {
            return $item->batch_id ?? 'INDIVIDUAL-' . $item->id;
        })->map(function ($items, $batchId) {
            $first = $items->first();
            $isBulk = strpos($batchId, 'BATCH-') === 0;
            
            return [
                'batch_id' => $isBulk ? $batchId : null,
                'is_bulk' => $isBulk,
                'date' => $first->date,
                'branch' => $first->branch?->name ?? 'Mixed',
                'amount' => $items->sum('amount'),
                'remarks' => $isBulk ? "Bulk Salary Release" : $first->remarks,
                'count' => $items->count(),
                'items' => $items // Optional: for detail view
            ];
        })->values();

        return response()->json($grouped);
    }
}