<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;
use App\Models\PhoneVerification;
use App\Models\Coupon;
use Illuminate\Support\Str;
use Illuminate\Support\Facades\Log;

class VerificationController extends Controller
{
    public function index()
    {
        if (request()->cookie('device_registered')) {
            return redirect()->route('verification.congratulations');
        }

        if (session()->has('coupon_code')) {
            return redirect()->route('verification.congratulations');
        }

        return view('verification.index');
    }

    public function sendOtp(Request $request)
    {
        if ($request->cookie('device_registered')) {
            return back()->withErrors(['phone' => 'Siz eýýäm agza bolduňyz.']);
        }

        $request->validate([
            'phone' => ['required', 'regex:/^\+993 [67]\d \d{2} \d{2} \d{2}$/']
        ], [
            'phone.regex' => 'Telefon belgiňiz şu formatda bolmaly: +993 KX XX XX XX (bu ýerde K 6 ýa-da 7).'
        ]);

        $phone = unmask_phone($request->phone);

        $existingCoupon = Coupon::query()->where('phone', $phone)->first();
        if ($existingCoupon) {
            return back()->withErrors(['phone' => 'Bu telefon belgisi eýýäm ulanyldy.'])->withInput();
        }
        
        // Generate a 4-digit OTP
        $otp = (string) rand(1000, 9999);
        
        // Store in DB
        PhoneVerification::updateOrCreate(
            ['phone' => $phone],
            [
                'otp' => $otp,
                'expires_at' => now()->addMinutes(10),
                'verified' => false
            ]
        );

        sendSMS($phone, 'Tassyklaýyş belgi: ' . $otp);

        // Store phone in session for the next step
        session()->put('verify_phone', $phone);

        return redirect()->route('verification.verify.form');
    }

    public function verifyForm()
    {
        if (request()->cookie('device_registered')) {
            return redirect()->route('verification.congratulations');
        }

        if (session()->has('coupon_code')) {
            return redirect()->route('verification.congratulations');
        }

        if (! session()->has('verify_phone')) {
            return redirect()->route('verification.index');
        }

        return view('verification.verify', [
            'phone' => session()->get('verify_phone')
        ]);
    }

    public function resendOtp()
    {
        $phone = session()->get('verify_phone');

        if (!$phone) {
            return redirect()->route('verification.index');
        }

        // Generate a 4-digit OTP
        $otp = (string) rand(1000, 9999);
        
        // Store in DB
        PhoneVerification::updateOrCreate(
            ['phone' => $phone],
            [
                'otp' => $otp,
                'expires_at' => now()->addMinutes(10),
                'verified' => false
            ]
        );

        sendSMS($phone, $otp);

        return back()->with('status', 'Täze kod iberildi!');
    }

    public function verifyOtp(Request $request)
    {
        $request->validate([
            'phone' => 'required',
            'otp' => 'required|digits:4'
        ]);

        $verification = PhoneVerification::query()->where('phone', $request->phone)->first();

        if (!$verification || $verification->otp !== $request->otp) {
            return back()->withErrors(['otp' => 'Nädogry kod.']);
        }

        if ($verification->expires_at < now()) {
            return back()->withErrors(['otp' => 'Kodyň möhleti gutardy.']);
        }

        // Mark as verified
        $verification->update(['verified' => true]);

        // Generate or get Coupon
        $coupon = Coupon::firstOrCreate(
            ['phone' => $request->phone],
            ['code' => $this->generateCouponCode()]
        );

        // Put coupon code in session for the congratulations page
        session()->put('coupon_code', $coupon->code);

        // We set a long-lived cookie to mark this device as registered (e.g. 5 years)
        return redirect()->route('verification.congratulations')
            ->cookie('device_registered', 'true', 60 * 24 * 365 * 5);
    }

    public function congratulations()
    {
        // If they have the cookie but lost the session, we don't know their code unless we query
        // But for simplicity based on the flow, we'll try to find it by phone if available
        if (!session()->has('coupon_code') && !request()->cookie('device_registered')) {
            return redirect()->route('verification.index');
        }

        $code = session()->get('coupon_code');

        if (!$code && session()->has('verify_phone')) {
             $coupon = Coupon::query()->where('phone', session()->get('verify_phone'))->first();
             if ($coupon) {
                 $code = $coupon->code;
                 session()->put('coupon_code', $code);
             }
        }

        // If for some reason code is completely lost (e.g. cookie exists but session cleared and no phone),
        // we can't show a specific code. In this specific scenario, we'll default to redirecting back.
        if (!$code) {
             return redirect()->route('verification.index')->withoutCookie('device_registered');
        }

        return view('verification.congratulations', [
            'code' => $code
        ]);
    }

    private function generateCouponCode()
    {
        // Format X_YYYY (X is integer, Y is capital char)
        $x = rand(1, 9);
        $yyyy = substr(str_shuffle("ABCDEFGHIJKLMNOPQRSTUVWXYZ"), 0, 4);

        return "{$x}_{$yyyy}";
    }
}