<?php

namespace App\Services;

use App\Models\TelegramAccount;
use App\Models\User;
use Illuminate\Support\Facades\Http;
use Illuminate\Support\Facades\Log;

class TelegramBotService
{
    private ?string $botToken;
    private ?string $webhookUrl;

    public function __construct()
    {
        $this->botToken = config('services.telegram.bot_token');
        $this->webhookUrl = rtrim(config('app.url'), '/') . '/telegram/webhook';
    }

    public function handleUpdate(array $update): array
    {
        if (!isset($update['message'])) {
            return ['ok' => false, 'error' => 'No message found'];
        }

        $message = $update['message'];
        $chatId = $message['chat']['id'];
        $text = $message['text'] ?? '';

        Log::info('Telegram update received', ['chat_id' => $chatId, 'text' => $text]);

        $telegramAccount = TelegramAccount::where('chat_id', $chatId)->first();

        if (!$telegramAccount || !$telegramAccount->is_verified) {
            return $this->handleUnverifiedUser($chatId, $text);
        }

        if ($telegramAccount->bot_state) {
            return $this->handleBotState($telegramAccount, $text, $chatId);
        }

        return $this->handleCommand($telegramAccount, $text, $chatId);
    }

    private function handleUnverifiedUser(string $chatId, string $text): array
    {
        if (strlen($text) === 6 && is_numeric($text)) {
            $telegramAccount = TelegramAccount::where('verification_code', $text)
                ->where('is_verified', false)
                ->first();

            if ($telegramAccount) {
                $telegramAccount->update(['chat_id' => $chatId, 'is_verified' => true, 'verification_code' => null]);
                $this->sendMenu($chatId, "¡Hola {$telegramAccount->user->name}! 👋\n\nVerificación exitosa. He activado tu menú de control:");
                return ['ok' => true, 'verified' => true];
            }
        }

        $this->sendMessage($chatId, "👋 ¡Hola! Soy el bot de Nómina Pegaso.\n\nPara empezar, envía el código de 6 dígitos de tu panel web.");
        return ['ok' => true, 'verified' => false];
    }

    private function handleBotState(TelegramAccount $account, string $text, string $chatId): array
    {
        try {
            $state = $account->bot_state;
            $data = $account->bot_data ?? [];

            // Permitir cancelar
            if (strtolower(trim($text)) === '/cancelar' || $text === '❌ Cancelar') {
                $account->update(['bot_state' => null, 'bot_data' => null]);
                $this->sendMenu($chatId, "❌ Operación cancelada.");
                return ['ok' => true];
            }

            switch ($state) {
                // --- FLUJO VENTA ---
                case 'AWAITING_SALE_DATE':
                    $data['date'] = $this->parseDate($text);
                    $account->update(['bot_state' => 'AWAITING_SALE_USER_AMOUNT', 'bot_data' => $data]);
                    $this->sendMessage($chatId, "💰 Ingresa el monto vendido por el *usuario*:", $this->cancelKeyboard());
                    break;

                case 'AWAITING_SALE_USER_AMOUNT':
                    if (!is_numeric($text)) return $this->sendInvalidNumeric($chatId);
                    $data['user_sales'] = (float) $text;
                    $account->update(['bot_state' => 'AWAITING_SALE_SYSTEM_AMOUNT', 'bot_data' => $data]);
                    $this->sendMessage($chatId, "🖥️ Ingresa el monto vendido según el *sistema*:", $this->cancelKeyboard());
                    break;

                case 'AWAITING_SALE_SYSTEM_AMOUNT':
                    if (!is_numeric($text)) return $this->sendInvalidNumeric($chatId);
                    $data['system_sales'] = (float) $text;
                    
                    $user = $account->user;
                    $month = $user->getCurrentMonth();
                    if (!$month) return $this->sendNoOpenMonth($chatId, $account);

                    $month->dailySales()->create([
                        'user_id' => $user->id,
                        'date' => $data['date'],
                        'user_sales' => $data['user_sales'],
                        'system_sales' => $data['system_sales'],
                    ]);

                    $account->update(['bot_state' => null, 'bot_data' => null]);
                    $this->sendMenu($chatId, "✅ *Venta registrada!*\n\n📅 {$data['date']}\n👤 U: $" . number_format($data['user_sales'], 2) . "\n🖥️ S: $" . number_format($data['system_sales'], 2));
                    break;

                // --- FLUJO GASTO ---
                case 'AWAITING_EXPENSE_DATE':
                    $data['date'] = $this->parseDate($text);
                    $account->update(['bot_state' => 'AWAITING_EXPENSE_AMOUNT', 'bot_data' => $data]);
                    $this->sendMessage($chatId, "💸 Ingresa el monto del gasto:", $this->cancelKeyboard());
                    break;

                case 'AWAITING_EXPENSE_AMOUNT':
                    if (!is_numeric($text)) return $this->sendInvalidNumeric($chatId);
                    $data['amount'] = (float) $text;
                    $account->update(['bot_state' => 'AWAITING_EXPENSE_DESC', 'bot_data' => $data]);
                    $this->sendMessage($chatId, "📝 Describe el gasto:", $this->cancelKeyboard());
                    break;

                case 'AWAITING_EXPENSE_DESC':
                    $data['description'] = $text;
                    $user = $account->user;
                    $month = $user->getCurrentMonth();
                    if (!$month) return $this->sendNoOpenMonth($chatId, $account);

                    $month->expenses()->create([
                        'user_id' => $user->id,
                        'date' => $data['date'],
                        'amount' => $data['amount'],
                        'description' => $data['description'],
                        'type' => 'other',
                    ]);

                    $account->update(['bot_state' => null, 'bot_data' => null]);
                    $this->sendMenu($chatId, "✅ *Gasto registrado!*\n\n📅 {$data['date']}\n💰 $" . number_format($data['amount'], 2) . "\n📝 {$data['description']}");
                    break;
            }
        } catch (\Exception $e) {
            Log::error('Bot interaction error: ' . $e->getMessage());
            $account->update(['bot_state' => null, 'bot_data' => null]);
            $this->sendMenu($chatId, "❌ Ocurrió un error al guardar los datos. Por favor intenta de nuevo.");
        }

        return ['ok' => true];
    }

    private function handleCommand(TelegramAccount $account, string $text, string $chatId): array
    {
        $cmd = strtolower(trim($text));
        $user = $account->user;

        switch ($cmd) {
            case '/start':
            case '/menu':
            case '🏠 menú':
                $this->sendMenu($chatId, "Control de Nómina - {$user->name}");
                break;
            case '/resumen':
            case '💵 resumen':
                $this->showSummary($user, $chatId);
                break;
            case '/agregar_venta':
            case '➕ agregar venta':
                $account->update(['bot_state' => 'AWAITING_SALE_DATE']);
                $this->sendMessage($chatId, "🗓️ ¿Fecha de la venta?", $this->dateKeyboard());
                break;
            case '/agregar_gasto':
            case '➖ agregar gasto':
                $account->update(['bot_state' => 'AWAITING_EXPENSE_DATE']);
                $this->sendMessage($chatId, "🗓️ ¿Fecha del gasto?", $this->dateKeyboard());
                break;
            case '/ventas':
            case '💰 mis ventas':
                $this->showSales($user, $chatId);
                break;
            case '/gastos':
            case '📝 mis gastos':
                $this->showExpenses($user, $chatId);
                break;
            case '/help':
                $this->sendMenu($chatId, "Usa los botones del teclado para navegar o enviar comandos.");
                break;
            default:
                $this->sendMenu($chatId, "❓ No entiendo ese comando.");
        }
        return ['ok' => true];
    }

    private function sendMenu(string $chatId, string $text)
    {
        $keyboard = [
            'keyboard' => [
                [['text' => '💵 Resumen'], ['text' => '🏠 Menú']],
                [['text' => '➕ Agregar Venta'], ['text' => '➖ Agregar Gasto']],
                [['text' => '💰 Mis Ventas'], ['text' => '📝 Mis Gastos']]
            ],
            'resize_keyboard' => true,
            'one_time_keyboard' => false
        ];
        return $this->sendMessage($chatId, $text, $keyboard);
    }

    private function dateKeyboard() {
        return [
            'keyboard' => [[['text' => 'Hoy'], ['text' => 'Ayer']], [['text' => '❌ Cancelar']]],
            'resize_keyboard' => true,
            'one_time_keyboard' => true
        ];
    }

    private function cancelKeyboard() {
        return [
            'keyboard' => [[['text' => '❌ Cancelar']]],
            'resize_keyboard' => true,
            'one_time_keyboard' => true
        ];
    }

    public function sendMessage(string $chatId, string $text, $replyMarkup = null): array
    {
        if (!$this->botToken) return ['ok' => false];
        $params = ['chat_id' => $chatId, 'text' => $text, 'parse_mode' => 'Markdown'];
        if ($replyMarkup) $params['reply_markup'] = json_encode($replyMarkup);

        try {
            return Http::post("https://api.telegram.org/bot{$this->botToken}/sendMessage", $params)->json();
        } catch (\Exception $e) { return ['ok' => false]; }
    }

    private function parseDate(string $text): string
    {
        $text = strtolower(trim($text));
        if ($text === 'hoy') return date('Y-m-d');
        if ($text === 'ayer') return date('Y-m-d', strtotime('-1 day'));
        $ts = strtotime($text);
        return $ts ? date('Y-m-d', $ts) : date('Y-m-d');
    }

    private function sendInvalidNumeric(string $chatId): array
    {
        $this->sendMessage($chatId, "⚠️ Ingresa solo números.", $this->cancelKeyboard());
        return ['ok' => true];
    }

    private function sendNoOpenMonth(string $chatId, $account): array
    {
        $account->update(['bot_state' => null, 'bot_data' => null]);
        $this->sendMenu($chatId, "❌ No hay mes abierto.");
        return ['ok' => true];
    }

    private function showSummary(User $user, string $chatId) {
        $month = $user->getCurrentMonth();
        if (!$month) return $this->sendMessage($chatId, "No hay mes abierto.");
        $data = \App\Services\CommissionCalculator::calculateForMonth($user, $month);
        $text = "💵 *Resumen Financiero*\n\n" .
                "• Comisiones: \$" . number_format($data['commission_amount'], 2) . "\n" .
                "• Salario: \$" . number_format($data['monthly_salary'], 2) . "\n" .
                "• Gastos: \$" . number_format($data['total_expenses'], 2) . "\n" .
                "⭐ *Neto: \$" . number_format($data['total_earning'], 2) . "*";
        $this->sendMenu($chatId, $text);
    }

    private function showSales(User $user, string $chatId) {
        $month = $user->getCurrentMonth();
        if (!$month) return;
        $u = $month->dailySales()->sum('user_sales');
        $s = $month->dailySales()->sum('system_sales');
        $this->sendMenu($chatId, "💰 *Ventas*\n👤 U: \$" . number_format($u, 2) . "\n🖥️ S: \$" . number_format($s, 2));
    }

    private function showExpenses(User $user, string $chatId) {
        $month = $user->getCurrentMonth();
        if (!$month) return;
        $t = $month->expenses()->sum('amount');
        $this->sendMenu($chatId, "📝 *Total Gastos:* \$" . number_format($t, 2));
    }

    public static function generateVerificationCode(): string { return str_pad((string) random_int(0, 999999), 6, '0', STR_PAD_LEFT); }
    public function setWebhook(): bool { try { return Http::post("https://api.telegram.org/bot{$this->botToken}/setWebhook", ['url' => $this->webhookUrl])->json('ok', false); } catch (\Exception $e) { return false; } }
    public function getWebhookInfo(): array { try { return Http::get("https://api.telegram.org/bot{$this->botToken}/getWebhookInfo")->json(); } catch (\Exception $e) { return ['ok' => false]; } }
    public function deleteWebhook(): bool { try { return Http::post("https://api.telegram.org/bot{$this->botToken}/deleteWebhook")->json('ok', false); } catch (\Exception $e) { return false; } }
}