<?php

namespace App\Http\Controllers\Auth;

use App\Http\Controllers\Controller;
use App\Models\Application;
use App\Models\FileUploader;
use App\Models\Instructors;
use App\Models\User;
use App\Providers\RouteServiceProvider;
use Carbon\Carbon;
use Illuminate\Auth\Events\Registered;
use Illuminate\Http\RedirectResponse;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Auth;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Hash;
use Illuminate\Support\Facades\Http;
use Illuminate\Support\Facades\Validator;
use Illuminate\Validation\Rules;
use Illuminate\View\View;
use Illuminate\Support\Facades\Session;
use Illuminate\Support\Str;
use Illuminate\Support\Facades\Log;

class RegisteredUserController extends Controller
{
    public function create(): View
    {
        return view('auth.register');
    }

    public function store(Request $request): RedirectResponse
    {
        $input = $request->all();

        if (get_frontend_settings('recaptcha_status') == true && check_recaptcha($input['g-recaptcha-response']) == false) {
            Session::flash('error', get_phrase('Recaptcha verification failed'));
            return redirect(route('register.form'));
        }

        $validator = Validator::make($request->all(), [
            'name' => ['required', 'string', 'max:255'],
            'email' => ['required', 'string', 'email', 'unique:users,email'],
            'password' => ['required', Rules\Password::defaults()],
        ], [
            'name.required' => get_phrase('Name is required'),
            'name.string' => get_phrase('Name must be a valid text'),
            'name.max' => get_phrase('Name may not be greater than 255 characters'),
            'email.required' => get_phrase('Email is required'),
            'email.string' => get_phrase('Email must be a valid text'),
            'email.email' => get_phrase('Please enter a valid email address'),
            'email.unique' => get_phrase('This email is already registered. Please use a different email.'),
            'password.required' => get_phrase('Password is required'),
            'password.min' => get_phrase('Password must be at least 8 characters'),
        ]);

        if ($validator->fails()) {
            $firstError = $validator->errors()->first();
            Session::flash('error', $firstError);
            return redirect()->back()->withErrors($validator)->withInput();
        }

        // Check if the user is applying to be an instructor and validate instructor fields
        if ($request->has('instructor') && $request->instructor == 1) {
            // Validate instructor-specific fields (NIDN, Phone, Document)
            $instructorValidator = Validator::make($request->all(), [
                'nidn' => ['required', 'string', 'max:11'],
                'phone' => ['required', 'string'],
                'document' => ['required', 'file', 'mimes:pdf,doc,docx', 'max:2048'],
            ], [
                'nidn.required' => get_phrase('NIDN is required'),
                'nidn.string' => get_phrase('NIDN must be a valid number'),
                'nidn.max' => get_phrase('NIDN may not be greater than 11 characters'),
                'phone.required' => get_phrase('Phone number is required'),
                'document.required' => get_phrase('Document is required'),
                'document.file' => get_phrase('Document must be a valid file'),
                'document.mimes' => get_phrase('Document must be PDF, DOC, or DOCX'),
                'document.max' => get_phrase('Document size must be less than 2MB'),
            ]);

            if ($instructorValidator->fails()) {
                $firstError = $instructorValidator->errors()->first();
                Session::flash('error', $firstError);
                return redirect()->back()->withErrors($instructorValidator)->withInput();
            }
        }

        // Start database transaction for the entire registration process
        $user = null;

        try {
            DB::beginTransaction();

            $user_data = [
                'name' => $request->name,
                'email' => $request->email,
                'role' => 'student',
                'status' => 1,
                'password' => Hash::make($request->password),
            ];

            if (get_settings('student_email_verification') != 1) {
                $user_data['email_verified_at'] = Carbon::now();
            }

            $user = User::create($user_data);
            event(new Registered($user));

            // If applying as an instructor, process the application
            if ($request->has('instructor')) {
                $result = $this->processInstructorApplication($request, $user);
                if ($result instanceof RedirectResponse && $result->getSession()->get('error')) {
                    // If there was an error in instructor application, rollback
                    DB::rollBack();
                    return $result;
                }
            }

            DB::commit();

            // Log the user in after successful registration
            Auth::login($user);

            //send notification to user
            $application = Application::max('id') + 1;
            $user->notify(new \App\Notifications\InstructorApplicant($application));
            return redirect(RouteServiceProvider::HOME);

        } catch (\Exception $e) {
            if (DB::transactionLevel() > 0) {
                DB::rollBack();
            }

            Log::error('Registration error:', ['error' => $e->getMessage()]);
            Session::flash('error', get_phrase('Error during registration. Please try again.'));
            return redirect()->back()->withInput();
        }
    }

    private function processInstructorApplication(Request $request, User $user): RedirectResponse
    {
        // Check if application already exists
        if (Application::where('user_id', $user->id)->exists()) {
            Session::flash('error', get_phrase('Your request is in process. Please wait for admin to respond.'));
            return redirect()->route('become.instructor');
        }

        // Check if NIDN already exists in Instructors table with status = 1 (active)
        $nidn = $request->nidn;
        $existingInstructor = Instructors::where('nidn', $nidn)
            ->where('status', 1)
            ->first();

        if ($existingInstructor) {
            Session::flash('error', get_phrase('This NIDN is already registered as an active instructor.'));
            return redirect()->back()->withInput();
        }

        // Check NIDN with the API
        $api_url = "https://sindig.unesa.ac.id/apipddikti/api?nidn={$nidn}&auto=1";

        $response = Http::timeout(30)->get($api_url);
        $data = $response->json();

        Log::info('API Response for NIDN: ' . $nidn, ['response' => $data]);

        // Extract matched dosen data
        $matched_dosen = $data['matched_dosen'][0];
        Log::info('Instructor data to be saved:', $matched_dosen);

        if (!isset($data['ok']) || !isset($data['matched_dosen']) || count($data['matched_dosen']) == 0) {
            Session::flash('error', get_phrase('NIDN not found in the system. Please check your NIDN.'));
            return redirect()->back()->withInput();
        } else if (strtolower($matched_dosen['nama']) !=  strtolower($user->name)) {
            Session::flash('error', get_phrase('Name does not match PDDikti records. Please check your name.'));
            return redirect()->back()->withInput();
        }

        // Prepare instructor data - adjust fields according to your database
        $instructor = [
            'user_id' => $user->id,
            'nidn' => $nidn,
            'name' => $matched_dosen['nama'] ?? $user->name,
            'id_sdm' => $matched_dosen['id'] ?? null,
            'id_sms' => $matched_dosen['nama_prodi'] ?? null,
            'id_pt' => $matched_dosen['nama_pt'] ?? null,
            'status' => 0
        ];

        Log::info('Instructor data to be saved:', $instructor);

        // Upload document
        if ($request->hasFile('document') && $request->file('document')->isValid()) {
            $doc = $request->file('document');
            $fileName = 'uploads/applications/' . $user->id . Str::random(20) . '.' . $doc->extension();

            FileUploader::upload($doc, $fileName, null, null, 300);
        } else {
            Session::flash('error', 'Document upload failed or no document selected.');
            return redirect()->back()->withInput();
        }

        // Prepare application data
        $application = [
            'user_id' => $user->id,
            'phone' => $request->phone,
            'description' => $request->description
        ];

        // Create both application and instructor records
        Application::create($application);
        Instructors::create($instructor);

        Session::flash('success', get_phrase('Your application has been submitted successfully.'));
        return redirect(RouteServiceProvider::HOME);
    }
}