<?php

declare(strict_types=1);

namespace App\Http\Controllers;

use App\Models\{OauthToken, User};
use App\Services\UserAppAccessService;
use Illuminate\Container\Attributes\CurrentUser;
use Illuminate\Http\{RedirectResponse, Request};
use Illuminate\Support\Facades\Http;
use Illuminate\Support\Str;

class EntraController extends Controller
{
    // ── OAuth config from .env ────────────────────────────────────────────────

    private const string PROVIDER = 'microsoft';

    private const string SCOPES = 'openid profile email offline_access User.Read Mail.Read Mail.ReadWrite Mail.Send';

    private string $tenantId;

    private string $clientId;

    private string $clientSecret;

    private string $redirectUri;

    public function __construct()
    {
        $this->tenantId     = (string) config('services.microsoft.tenant_id');
        $this->clientId     = (string) config('services.microsoft.client_id');
        $this->clientSecret = (string) config('services.microsoft.client_secret');
        $this->redirectUri  = route('entra.callback');
    }

    // ── Step 1: Redirect user to Microsoft login ──────────────────────────────

    public function connect(#[CurrentUser] User $user): RedirectResponse
    {
        $user = auth()->user();

        if (! $user) {
            abort(403, 'Unauthorized');
        }

        $state = Str::random(40);
        session(['oauth_state' => $state]);

        $query = http_build_query([
            'client_id'     => $this->clientId,
            'response_type' => 'code',
            'redirect_uri'  => $this->redirectUri,
            'response_mode' => 'query',
            'scope'         => self::SCOPES,
            'state'         => $state,
            'prompt'        => 'select_account',
        ]);

        return redirect("https://login.microsoftonline.com/$this->tenantId/oauth2/v2.0/authorize?$query");
    }

    // ── Step 2: Handle callback, exchange code for tokens ────────────────────

    public function callback(Request $request): RedirectResponse
    {
        $user = auth()->user();

        if (! $user) {
            abort(403, 'Unauthorized');
        }

        $activeServices = app(UserAppAccessService::class)->getActiveServices($user);
        $hasAzureFdAccess = $activeServices->contains(fn ($service) => 'azure-fd' === $service->providerSlug);

        if (! $hasAzureFdAccess) {
            abort(403, 'You do not have permission to access the required application.');
        }

        // CSRF state check
        if (! hash_equals((string) session('oauth_state'), (string) $request->state)) {
            session()->forget('oauth_state');
            return redirect()->route('dashboard.user')
                ->with('entra_error', 'Invalid OAuth state. Please try again.');
        }

        session()->forget('oauth_state');

        if ($request->has('error')) {
            return redirect()->route('dashboard.user')
                ->with('entra_error', $request->error_description ?? 'Microsoft login failed.');
        }

        if (! $request->filled('code')) {
            return redirect()->route('dashboard.user')
                ->with('entra_error', 'No authorization code received from Microsoft.');
        }

        // Exchange authorization code for tokens
        $response = Http::asForm()->post(
            "https://login.microsoftonline.com/$this->tenantId/oauth2/v2.0/token",
            [
                'client_id'     => $this->clientId,
                'client_secret' => $this->clientSecret,
                'code'          => $request->code,
                'redirect_uri'  => $this->redirectUri,
                'grant_type'    => 'authorization_code',
                'scope'         => self::SCOPES,
            ]
        );

        if ($response->failed()) {
            return redirect()->route('dashboard.user')
                ->with('entra_error', $response->json('error_description', 'Failed to retrieve tokens from Microsoft.'));
        }

        $data = $response->json();

        OauthToken::updateOrCreate(
            [
                'user_id'  => $user->id,
                'provider' => self::PROVIDER,
            ],
            [
                'access_token'  => $data['access_token'],
                'refresh_token' => $data['refresh_token'] ?? null,
                'token_type'    => $data['token_type'] ?? 'Bearer',
                'scopes'        => self::SCOPES,
                'expires_at'    => now()->addSeconds((int) ($data['expires_in'] ?? 3600)),
            ]
        );

        return redirect()->route('dashboard.user')
            ->with('entra_success', 'Microsoft connected successfully!');
    }

    // ── Open Outlook (silent refresh if expired) ──────────────────────────────

    public function openEntra(): RedirectResponse
    {
        $user = auth()->user();

        if (! $user) {
            abort(403, 'Unauthorized');
        }

        $activeServices = app(UserAppAccessService::class)->getActiveServices($user);
        $hasAzureFdAccess = $activeServices->contains(fn ($service) => 'azure-fd' === $service->providerSlug);

        if (! $hasAzureFdAccess) {
            abort(403, 'You do not have permission to access the required application.');
        }

        $token = $user->oauthToken(self::PROVIDER);

        if (! $token) {
            return redirect()->route('entra.connect');
        }

        // Token still valid (5-min buffer)
        if ($token->expires_at->gt(now()->addMinutes(5))) {
            return redirect('https://outlook.office.com/mail/');
        }

        // Token expired — try silent refresh
        if ($this->refreshToken($token)) {
            return redirect('https://outlook.office.com/mail/');
        }

        // Refresh failed — force full re-login
        $token->delete();

        return redirect()->route('entra.connect');
    }

    // ── Disconnect ────────────────────────────────────────────────────────────

    private function refreshToken(OauthToken $token): bool
    {
        if (! $token->refresh_token) {
            return false;
        }

        $response = Http::asForm()->post(
            "https://login.microsoftonline.com/$this->tenantId/oauth2/v2.0/token",
            [
                'client_id'     => $this->clientId,
                'client_secret' => $this->clientSecret,
                'refresh_token' => $token->refresh_token,
                'grant_type'    => 'refresh_token',
                'scope'         => self::SCOPES,
            ]
        );

        if ($response->failed()) {
            return false;
        }

        $data = $response->json();

        $token->update([
            'access_token'  => $data['access_token'],
            'refresh_token' => $data['refresh_token'] ?? $token->refresh_token,
            'expires_at'    => now()->addSeconds((int) ($data['expires_in'] ?? 3600)),
        ]);

        return true;
    }

    // ── Internal: Refresh access token using refresh_token ───────────────────

    public function disconnect(): RedirectResponse
    {
        $user = auth()->user();
        if (! $user) {
            abort(403, 'Unauthorized');
        }

        $activeServices = app(UserAppAccessService::class)->getActiveServices($user);
        $hasAzureFdAccess = $activeServices->contains(fn ($service) => 'azure-fd' === $service->providerSlug);

        if (! $hasAzureFdAccess) {
            abort(403, 'You do not have permission to access the required application.');
        }

        $user->oauthToken(self::PROVIDER)?->delete();

        return redirect()->route('dashboard.user')->with('entra_success', 'Microsoft disconnected.');
    }
}