<?php

namespace Modules\Admin\app\Http\Controllers;

use App\Http\Controllers\Controller;
use App\Traits\HasFilterRequest;
use App\Traits\HasOrderByRequest;
use App\Traits\HasSearchRequest;
use Illuminate\Http\Request;
use Modules\Admin\app\Models\ElectricityBill;
use Illuminate\Support\Facades\Log;
use Barryvdh\DomPDF\Facade\Pdf;
use Carbon\Carbon;
use Illuminate\Support\Facades\Storage;

class ElectricityBillController extends Controller
{
    use HasOrderByRequest;
    use HasFilterRequest;
    use HasSearchRequest;

    /**
     * Get all electricity bills with pagination
     */
    public function index(Request $request)
    {
        try {
            $bills = new ElectricityBill;

            // Order by
            $this->orderByRequest($bills, $request);

            // Filter
            $this->filterRequest(
                builder: $bills,
                request: $request,
                filterKeys: [
                    'billing_date' => self::F_TEXT,
                ]
            );

            // Search
            $this->searchRequest(
                builder: $bills,
                value: $request->get('search'),
                fields: ['billing_date', 'notes']
            );

            $responseData = $bills
                ->leftJoin('users as creator', 'electricity_bills.created_by', '=', 'creator.id')
                ->leftJoin('users as updater', 'electricity_bills.updated_by', '=', 'updater.id')
                ->orderBy('electricity_bills.billing_date', 'desc')
                ->select(
                    'electricity_bills.*',
                    'creator.name as creator_name',
                    'updater.name as updater_name'
                )
                ->paginate($request->get('per_page', 15));

            return AbstractController::ResultSuccess($responseData);
        } catch (\Exception $e) {
            Log::error('Error fetching electricity bills: ' . $e->getMessage());
            return AbstractController::ResultError($e->getMessage());
        }
    }

    /**
     * Create new electricity bill
     */
    public function create(Request $request)
    {
        try {
            $validated = $request->validate([
                'billing_date' => 'required|string',
                'previous_reading' => 'required|numeric|min:0',
                'current_reading' => 'required|numeric|min:0',
                'unit_price' => 'required|numeric|min:0',
                'notes' => 'nullable|string',
            ]);

            // Check if billing_date already exists
            $existingBill = ElectricityBill::where('billing_date', $validated['billing_date'])->first();
            if ($existingBill) {
                return AbstractController::ResultError('Bill for this month already exists', 422);
            }

            // Calculate total amount
            $consumption = $validated['current_reading'] - $validated['previous_reading'];
            $totalAmount = $consumption * $validated['unit_price'];

            $bill = ElectricityBill::create([
                'billing_date' => $validated['billing_date'],
                'previous_reading' => $validated['previous_reading'],
                'current_reading' => $validated['current_reading'],
                'unit_price' => $validated['unit_price'],
                'total_amount' => $totalAmount,
                'notes' => $validated['notes'] ?? null,
                'created_by' => auth('admins')->user()->id ?? null,
            ]);

            return AbstractController::ResultSuccess($bill, 'Electricity bill created successfully');
        } catch (\Exception $e) {
            Log::error('Error creating electricity bill: ' . $e->getMessage());
            return AbstractController::ResultError($e->getMessage());
        }
    }

    /**
     * Update electricity bill
     */
    public function update(Request $request, $id)
    {
        try {
            $validated = $request->validate([
                'billing_date' => 'sometimes|string',
                'previous_reading' => 'sometimes|numeric|min:0',
                'current_reading' => 'sometimes|numeric|min:0',
                'unit_price' => 'sometimes|numeric|min:0',
                'notes' => 'nullable|string',
            ]);

            $bill = ElectricityBill::findOrFail($id);

            // Check if billing_date already exists (excluding current record)
            if (isset($validated['billing_date'])) {
                $existingBill = ElectricityBill::where('billing_date', $validated['billing_date'])
                    ->where('id', '!=', $id)
                    ->first();
                if ($existingBill) {
                    return AbstractController::ResultError('Bill for this month already exists', 422);
                }
            }

            // Recalculate total if any reading or price changed
            $previousReading = $validated['previous_reading'] ?? $bill->previous_reading;
            $currentReading = $validated['current_reading'] ?? $bill->current_reading;
            $unitPrice = $validated['unit_price'] ?? $bill->unit_price;
            $consumption = $currentReading - $previousReading;
            $totalAmount = $consumption * $unitPrice;

            $bill->update(array_merge($validated, [
                'total_amount' => $totalAmount,
                'updated_by' => auth('admins')->user()->id ?? null,
            ]));

            return AbstractController::ResultSuccess($bill, 'Electricity bill updated successfully');
        } catch (\Exception $e) {
            Log::error('Error updating electricity bill: ' . $e->getMessage());
            return AbstractController::ResultError($e->getMessage());
        }
    }

    /**
     * Delete electricity bill
     */
    public function delete(Request $request, $id)
    {
        try {
            $bill = ElectricityBill::findOrFail($id);
            $bill->delete();

            return AbstractController::ResultSuccess(null, 'Electricity bill deleted successfully');
        } catch (\Exception $e) {
            Log::error('Error deleting electricity bill: ' . $e->getMessage());
            return AbstractController::ResultError($e->getMessage());
        }
    }

    /**
     * Export electricity bill to PDF
     */
    public function exportPdf(Request $request, $id)
    {
        try {
            $bill = ElectricityBill::findOrFail($id);

            // Get month name from billing_date
            $consumption = $bill->current_reading - $bill->previous_reading;
            $totalText = $this->numberToVietnamese($bill->total_amount);
            $date = Carbon::parse($bill->billing_date);

            $dateNow = 'Ngày ' . $date->day .
                ' tháng ' . $date->month .
                ' năm ' . $date->year;

            // Generate PDF
            $pdf = Pdf::loadView('admin::admin.electricity_bills.pdf', [
                'bill' => $bill,
                'consumption' => $consumption,
                'dateNow' => $dateNow,
                'totalText' => $totalText
            ]);

            $fileName = 'electricity_bill_' . $bill->billing_date . '.pdf';
            $filePath = 'electricity_bills/' . $fileName;

            // đảm bảo folder tồn tại
            if (!Storage::disk('public')->exists('electricity_bills')) {
                Storage::disk('public')->makeDirectory('electricity_bills');
            }

            // 👇 render 1 lần
            $pdfContent = $pdf->output();

            // 👇 lưu file
            Storage::disk('public')->put($filePath, $pdfContent);

            // update DB
            $bill->update(['file_path' => $filePath]);

            // 👇 trả về đúng file đã tạo
            return response($pdfContent)
                ->header('Content-Type', 'application/pdf')
                ->header('Content-Disposition', 'attachment; filename="' . $fileName . '"');
        } catch (\Exception $e) {
            Log::error('Error exporting electricity bill to PDF: ' . $e->getMessage());
            return AbstractController::ResultError($e->getMessage());
        }
    }

    /**
     * Get electricity bill by ID
     */
    public function show($id)
    {
        try {
            $bill = ElectricityBill::with(['creator', 'updater'])->findOrFail($id);
            return AbstractController::ResultSuccess($bill);
        } catch (\Exception $e) {
            Log::error('Error fetching electricity bill: ' . $e->getMessage());
            return AbstractController::ResultError($e->getMessage());
        }
    }

    function numberToVietnamese($number)
    {
        $units = ["", "một", "hai", "ba", "bốn", "năm", "sáu", "bảy", "tám", "chín"];
        $levels = ["", "nghìn", "triệu", "tỷ"];

        if ($number == 0) return "không đồng";

        $number = (int)$number;
        $result = "";
        $level = 0;

        while ($number > 0) {
            $threeDigits = $number % 1000;
            if ($threeDigits != 0) {
                $result = $this->readThreeDigits($threeDigits, $units) . " " . $levels[$level] . " " . $result;
            }
            $number = floor($number / 1000);
            $level++;
        }

        return ucfirst(trim(preg_replace('/\s+/', ' ', $result))) . " đồng";
    }

    function readThreeDigits($number, $units)
    {
        $hundreds = floor($number / 100);
        $tens = floor(($number % 100) / 10);
        $ones = $number % 10;

        $result = "";

        if ($hundreds > 0) {
            $result .= $units[$hundreds] . " trăm";
            if ($tens == 0 && $ones > 0) {
                $result .= " lẻ";
            }
        }

        if ($tens > 1) {
            $result .= " " . $units[$tens] . " mươi";
            if ($ones == 1) {
                $result .= " mốt";
            } elseif ($ones == 5) {
                $result .= " lăm";
            } elseif ($ones > 0) {
                $result .= " " . $units[$ones];
            }
        } elseif ($tens == 1) {
            $result .= " mười";
            if ($ones == 5) {
                $result .= " lăm";
            } elseif ($ones > 0) {
                $result .= " " . $units[$ones];
            }
        } elseif ($ones > 0) {
            $result .= " " . $units[$ones];
        }

        return trim($result);
    }
}