<?php

namespace Bluesquare\Connect;

use Bluesquare\Connect\Traits\HasConnectData;
use Bluesquare\Connect\Traits\HasConnectTokens;
use Bluesquare\Connect\Traits\HasConnectWebhook;
use GuzzleHttp\Client;
use Illuminate\Contracts\Foundation\Application;
use Illuminate\Http\Request;
use Illuminate\Routing\Router;
use Illuminate\Support\Facades\Log;
use Illuminate\Support\Facades\Route;
use Illuminate\Support\Str;
use Psr\Http\Message\StreamInterface;

class Connect
{
    protected $app;

    public function __construct(Application $app)
    {
        $this->app = $app;
    }

    // API

    /**
     * @param $method
     * @param $uri
     * @param null $data
     * @return array
     * @throws ConnectException
     */
    public function request($method, $uri, $data = null, $access_token = null): array
    {
        $url = $this->getUrl();
        $url = $url . '/' . trim($uri, '/');

        $client = new Client();

        $config = [
            'headers' => [
                'Accept' => 'application/json'
            ]
        ];

        if (! is_null($access_token)) {
            $config['headers']['Authorization'] = 'Bearer ' . $access_token;
        }

        if (! is_null($data)) {
            $config['form_params'] = $data;
        }

        try {
            $response = $client->request($method, $url, $config);
            $body = (string) $response->getBody();

            if ($response->getStatusCode() !== 200)
                throw new ConnectException($body);

            return json_decode($body, true);

        } catch(\Exception $e) {
            $this->flushTokens();

            throw new ConnectException($e->getMessage());
        }
    }

    // Authorization flow

    public function redirect($state = null)
    {
        if (is_null($state))
            $state = Str::random();

        $states = session()->get('connect_states');

        if (! is_array($states))
            $states = [];

        $states[] = $state;

        session()->put('connect_states', $states);

        $query = http_build_query([
            'client_id' => config('bconnect.client_id'),
            'scope' => config('bconnect.scopes'),
            'redirect_uri' => config('bconnect.redirect_url'),
            'response_type' => 'code',
            'state' => $state
        ]);

        $url = $this->getUrl() . '/oauth/authorize?' . $query;

        return redirect($url);
    }

    public function checkState(Request $request)
    {
        if (! session()->has('connect_states'))
            return false;

        $states = session()->get('connect_states');

        if (! is_array($states))
            return false;

        if (! $request->has('state') || ! in_array($request->state, $states))
            return false;

        unset($states[array_search($request->state, $states)]);

        session()->put('connect_states', $states);

        return true;
    }

    public function loginFromCallback(Request $request, $redirect_to = '/')
    {
        if (! $this->checkState($request) || ! $request->has('code'))
            return redirect('/');

        // Access token

        $expires_at = now();
        $connect_data = $this->getAccessTokenFromAuthorizationCode($request->get('code'));
        $connect_data['expires_at'] = $expires_at->addSeconds($connect_data['expires_in']);

        // User data

        $user_data = $this->getUserData($connect_data['access_token']);

        $user = $this->sync('create', $user_data);
        $this->updateUserConnectData($user, $connect_data);
        $user->save();

        // Login

        auth()->login($user, config('bconnect.login_remember', true));

        return redirect($redirect_to);
    }

    // OAuth methods

    public function getAccessTokenFromAuthorizationCode($code)
    {
        return $this->request('post', 'oauth/token', [
            'grant_type' => 'authorization_code',
            'client_id' => config('bconnect.client_id'),
            'client_secret' => config('bconnect.client_secret'),
            'scope' => config('bconnect.user_scopes'),
            'redirect_uri' => config('bconnect.redirect_url'),
            'code' => $code
        ]);
    }

    public function getAccessTokenFromRefreshToken($refresh_token)
    {
        return $this->request('post', 'oauth/token', [
            'grant_type' => 'refresh_token',
            'client_id' => config('bconnect.client_id'),
            'client_secret' => config('bconnect.client_secret'),
            'scope' => config('bconnect.user_scopes'),
            'redirect_uri' => config('bconnect.redirect_url'),
            'refresh_token' => $refresh_token
        ]);
    }

    public function getUserData($access_token)
    {
        return $this->request('get', 'api/user', null, $access_token);
    }

    public function getUserAccessToken($model)
    {
        $class = get_class($model);
        $has_fields = in_array(HasConnectTokens::class, class_uses($class));

        if (! $has_fields) {
            throw new ConnectException("$class does not implement HasConnectTokens");
        }

        if ($model->connect_expires_at <= now()->addHour()) {
            $connect_data = $this->getAccessTokenFromRefreshToken($model->connect_refresh_token);
            $this->updateUserConnectData($model, $connect_data);
            return $connect_data['access_token'];
        }

        return $model->connect_access_token;
    }

    // Sync

    public function sync(string $event, array $data)
    {
        $class = config('bconnect.model');

        if (in_array($event, ['update', 'delete'])) {
            $model = $this->resolveUser($data);

            if (! $model->exists() && $event === 'delete')
                return $model;
        }
        else {
            $hasSoftDeletes = in_array(\Illuminate\Database\Eloquent\SoftDeletes::class, class_uses($class));
            $model = $this->resolveUser($data, $hasSoftDeletes);

            if ($model->exists()) {
                if ($hasSoftDeletes && $model->trashed()) {
                    $event = 'restore';
                } else {
                    $event = 'update';
                }
            }
        }

        if (in_array(HasConnectWebhook::class, class_uses($class))) {
            $method = 'onConnect' . ucfirst($event);
            $model->$method($data);
        } else {
            $this->updateUserData($model, $data);
            $model->save();

            if (in_array(HasConnectData::class, class_uses($model))) {
                $model->postFillConnectData($data);
            }
        }

        return $model;
    }

    public function updateUserConnectData($user, $data)
    {
        if (in_array(HasConnectTokens::class, class_uses(get_class($user))))
            $user->fillConnectTokens($data);
    }

    public function updateUserData($user, $data)
    {
        if (in_array(HasConnectData::class, class_uses(get_class($user))))
            $user->fillConnectData($data);
    }

    protected function resolveUser($data, $withTrashed = false)
    {
        $class = config('bconnect.model');
        $query = $class::query();

        if ($withTrashed)
            $query->withTrashed();

        $model = new $class;

        if (in_array(HasConnectData::class, class_uses($class))) {
            $id = $model->getConnectIdentifier();

            $origin = is_array($id) ? $id[0] : $id;
            $target = is_array($id) ? $id[1] : $id;

            $model = $query->where($target, $data[$origin])->first() ?? $model;
            $model->$target = $data[$origin];
        } else {
            $model = $query->where('email', $data['email'])->first() ?? $model;

            if (! $model->exists())
                $model->email = $data['email'];
        }

        return $model;
    }

    // Routing

    public function routes()
    {
        Route::namespace('\Bluesquare\Connect\Controllers')
            ->group(function () {
                Route::get('connect/authorize', 'ConnectController@authorize');
                Route::get('connect/callback', 'ConnectController@callback');
            });
    }

    public function apiRoutes()
    {
        Route::namespace('\Bluesquare\Connect\Controllers')
            ->group(function () {
                Route::post('connect/webhook', 'ConnectController@webhook');
            });
    }

    // Misc

    protected function flushTokens()
    {
        session()->forget('bconnect.access_token');
        session()->forget('bconnect.access_token_expiration');
    }

    protected function getUrl()
    {
        return config('bconnect.url') ?? 'https://connect.bluesquare.io';
    }
}