<?php

declare(strict_types=1);

namespace App\Http\Controllers;

use App\Models\{ConnectedApp, OauthToken};
use App\Services\UserAppAccessService;
use Illuminate\Http\{RedirectResponse, Request};
use Illuminate\Support\Facades\Log;

class KekaController extends Controller
{
    /**
     * Step 1: Redirect the user to Keka's external login page.
     */
    public function connect(): RedirectResponse
    {
        $user = auth()->user();
        if (! $user) {
            abort(403, 'Unauthorized');
        }

        $activeServices = app(UserAppAccessService::class)->getActiveServices($user);
        $hasKekaAccess = $activeServices->contains(fn ($service) => 'keka-hr' === $service->provider_slug);

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

        $app = ConnectedApp::whereHas('provider', function ($query): void {
            $query->where('slug', 'keka-hr');
        })->first();

        if (! $app) {
            abort(404, 'Keka HR app registration not found.');
        }

        $kekaUrl = data_get($app->settings, 'keka.keka_url') ?? data_get($app->settings, 'keka_url') ?? 'https://sentientgeeks.keka.com';
        $provider = data_get($app->settings, 'keka.provider') ?? data_get($app->settings, 'provider') ?? 'Office365';

        $redirectUrl = $this->getKekaExternalLoginUrl((string) $kekaUrl, (string) $provider);

        Log::info('Redirecting user to Keka external login page.', [
            'user_id' => $user->id,
            'keka_url' => $kekaUrl,
            'redirect_url' => $redirectUrl,
        ]);

        return redirect($redirectUrl);
    }

    /**
     * Parse the configured Keka URL to build the correct external login URL.
     */
    private function getKekaExternalLoginUrl(string $configuredUrl, string $provider): string
    {
        $parsed = parse_url($configuredUrl);
        $host = $parsed['host'] ?? 'login.keka.com';

        $query = [];
        if (isset($parsed['query'])) {
            parse_str($parsed['query'], $query);
        }

        $companyId = $query['companyId'] ?? $query['companyid'] ?? null;

        if (! $companyId && 'login.keka.com' !== $host) {
            $parts = explode('.', $host);
            if (count($parts) >= 2) {
                $companyId = $parts[0];
            }
        }

        $buildQuery = [
            'provider' => $provider,
        ];

        //        if ($companyId) {
        //            $buildQuery['companyId'] = $companyId;
        //        }

        $queryString = http_build_query($buildQuery);

        return "https://login.keka.com/Account/ExternalLogin?{$queryString}";
    }

    /**
     * Step 2: Handle the Microsoft callback redirection.
     * We record/store the tokens in the database, and then pass the code/state to Keka.
     */
    public function callback(Request $request)
    {
        $user = auth()->user();
        if (! $user) {
            abort(403, 'Unauthorized');
        }

        $activeServices = app(UserAppAccessService::class)->getActiveServices($user);
        $hasKekaAccess = $activeServices->contains(fn ($service) => 'keka-hr' === $service->provider_slug);

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

        $code = $request->input('code');
        $state = $request->input('state');

        if (empty($code)) {
            return redirect()->route('dashboard.user')->with('keka_error', 'Keka connection failed: Missing code.');
        }

        // Retrieve Keka App configurations
        $app = ConnectedApp::whereHas('provider', function ($query): void {
            $query->where('slug', 'keka-hr');
        })->first();

        if (! $app) {
            abort(404, 'Keka HR app registration not found.');
        }

        $kekaUrl = data_get($app->settings, 'keka.keka_url') ?? data_get($app->settings, 'keka_url') ?? 'https://sentientgeeks.keka.com';
        $callbackPath = data_get($app->settings, 'keka.callback_path') ?? 'signin-oidc';
        $callbackUrl = $this->getKekaCallbackUrl((string) $kekaUrl, (string) $callbackPath);

        // Store token details (Option B: copy user's existing Microsoft token or save code/placeholder)
        $microsoftToken = $user->oauthToken('microsoft');

        if ($microsoftToken) {
            $accessToken = $microsoftToken->access_token;
            $refreshToken = $microsoftToken->refresh_token;
            $tokenType = $microsoftToken->token_type;
            $scopes = $microsoftToken->scopes;
            $expiresAt = $microsoftToken->expires_at;
        } else {
            $accessToken = (string) $code;
            $refreshToken = 'keka-placeholder-refresh';
            $tokenType = 'Bearer';
            $scopes = 'openid profile email';
            $expiresAt = now()->addHour();
        }

        OauthToken::updateOrCreate(
            [
                'user_id' => $user->id,
                'provider' => 'keka',
            ],
            [
                'access_token' => $accessToken,
                'refresh_token' => $refreshToken,
                'token_type' => $tokenType,
                'scopes' => $scopes,
                'expires_at' => $expiresAt,
            ]
        );

        Log::info('Keka tokens stored successfully. Passing OIDC response to Keka.', [
            'user_id' => $user->id,
            'callback_url' => $callbackUrl,
            'method' => $request->method(),
        ]);

        if ($request->isMethod('post')) {
            $inputs = '';
            foreach ($request->all() as $key => $value) {
                $safeKey = htmlspecialchars((string) $key, ENT_QUOTES, 'UTF-8');
                $safeValue = htmlspecialchars((string) $value, ENT_QUOTES, 'UTF-8');
                $inputs .= "<input type=\"hidden\" name=\"{$safeKey}\" value=\"{$safeValue}\" />\n";
            }

            $html = <<<HTML
<!DOCTYPE html>
<html>
<head>
    <title>Forwarding to Keka...</title>
</head>
<body onload="document.forms[0].submit()">
    <form method="post" action="{$callbackUrl}">
        {$inputs}
        <noscript>
            <p>JavaScript is required to connect to Keka. Click the button below to continue.</p>
            <input type="submit" value="Continue" />
        </noscript>
    </form>
</body>
</html>
HTML;

            return response($html);
        }

        $queryParams = $request->query();
        $queryString = http_build_query($queryParams);

        return redirect("{$callbackUrl}?{$queryString}");
    }

    /**
     * Parse the configured Keka URL to construct the callback URL.
     */
    private function getKekaCallbackUrl(string $configuredUrl, string $callbackPath): string
    {
        $parsed = parse_url($configuredUrl);
        $host = $parsed['host'] ?? 'login.keka.com';

        if ('login.keka.com' !== $host) {
            $parts = explode('.', $host);
            if (count($parts) >= 2 && 'keka' === $parts[1]) {
                $host = 'login.keka.com';
            }
        }

        $scheme = $parsed['scheme'] ?? 'https';

        return "{$scheme}://{$host}/".mb_ltrim($callbackPath, '/');
    }

    /**
     * Disconnect/Revoke the Keka integration for the user.
     */
    public function disconnect(): RedirectResponse
    {
        $user = auth()->user();
        if (! $user) {
            abort(403, 'Unauthorized');
        }

        $activeServices = app(UserAppAccessService::class)->getActiveServices($user);
        $hasKekaAccess = $activeServices->contains(fn ($service) => 'keka-hr' === $service->provider_slug);

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

        $user->oauthToken('keka')?->delete();

        Log::info('Keka integration disconnected for user.', [
            'user_id' => $user->id,
        ]);

        return redirect()->route('dashboard.user')->with('keka_success', 'Keka HR disconnected.');
    }
}