<?php

namespace App\Http\Controllers\student;

use App\Http\Controllers\Controller;
use App\Models\Application;
use App\Models\FileUploader;
use App\Models\Instructors;
use App\Models\User;
use Illuminate\Http\Request;
use Illuminate\Http\RedirectResponse;
use App\Providers\RouteServiceProvider;
use Illuminate\Support\Facades\Session;
use Illuminate\Support\Facades\Validator;
use Illuminate\Support\Str;
use Illuminate\Support\Facades\Http;
use Illuminate\Support\Facades\Log;
use Illuminate\Support\Facades\DB;

class BecomeInstructorController extends Controller
{
    public function index()
    {
        $view_path = 'frontend.' . get_frontend_settings('theme') . '.student.become_instructor.index';
        return view($view_path);
    }

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

        $rules = [
            'nidn' => ['required', 'string', 'max:11'],
            'phone' => 'required',
            'document' => ['required', 'file', 'mimes:pdf,doc,docx', 'max:2048'],
            'description' => 'required',
        ];

        // Validate data
        $validator = Validator::make($request->all(), $rules, [
            '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'),
            'description.required' => get_phrase('Description is required'),
        ]);

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

        $user = auth()->user();

        try {
            DB::beginTransaction();

            $result = $this->processInstructorApplication($request, $user);

            if ($result instanceof RedirectResponse && $result->getSession()->get('error')) {
                DB::rollBack();
                return $result;
            }

            DB::commit();

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

        } catch (\Exception $e) {
            DB::rollBack();
            Log::error('Instructor application error:', ['error' => $e->getMessage()]);
            Session::flash('error', get_phrase('Error during application submission. Please try again.'));
            return redirect()->back()->withInput();
        }
    }

    private function processInstructorApplication(Request $request, User $user): RedirectResponse
    {
        // Check if application already exists (redundant but safe)
        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();
        }

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

            $uploadResult = FileUploader::upload($doc, $fileName, null, null, 300);

            if (!$uploadResult) {
                Session::flash('error', get_phrase('Document upload failed. Please try again.'));
                return redirect()->back()->withInput();
            }
        } else {
            Session::flash('error', get_phrase('Document upload failed or no document selected.'));
            return redirect()->back()->withInput();
        }

        // Prepare instructor data
        $instructorData = [
            '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:', $instructorData);

        // Prepare application data - INCLUDING DOCUMENT PATH
        $application = [
            'user_id' => $user->id,
            'nidn' => $nidn,
            'phone' => $request->phone,
            'description' => $request->description,
            'document' => $fileName,
            'status' => 0
        ];

        //send notification to user
        $user->notify(new \App\Notifications\InstructorApplicant($application));

        Log::info('Application data to be saved:', $application);

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

        return redirect()->back(); // This return won't be used due to the try-catch structure
    }
}