<?php

namespace Kirby\Api;

use Closure;
use Exception;
use Throwable;

use Kirby\Exception\NotFoundException;
use Kirby\Http\Router;
use Kirby\Http\Response;
use Kirby\Toolkit\F;
use Kirby\Toolkit\Properties;
use Kirby\Toolkit\Str;

/**
 * The API class is a generic container
 * for API routes, models and collections and is used
 * to run our REST API. You can find our API setup
 * in `kirby/config/api.php`.
 *
 * @package   Kirby Api
 * @author    Bastian Allgeier <bastian@getkirby.com>
 * @link      https://getkirby.com
 * @copyright Bastian Allgeier GmbH
 * @license   https://getkirby.com/license
 */
class Api
{
    use Properties;

    /**
     * Authentication callback
     *
     * @var Closure
     */
    protected $authentication;

    /**
     * Debugging flag
     *
     * @var boolean
     */
    protected $debug = false;

    /**
     * Collection definition
     *
     * @var array
     */
    protected $collections = [];

    /**
     * Injected data/dependencies
     *
     * @var array
     */
    protected $data = [];

    /**
     * Model definitions
     *
     * @var array
     */
    protected $models = [];

    /**
     * The current route
     *
     * @var Route
     */
    protected $route;

    /**
     * The Router instance
     *
     * @var Router
     */
    protected $router;

    /**
     * Route definition
     *
     * @var array
     */
    protected $routes = [];

    /**
     * Request data
     * [query, body, files]
     *
     * @var array
     */
    protected $requestData = [];

    /**
     * The applied request method
     * (GET, POST, PATCH, etc.)
     *
     * @var string
     */
    protected $requestMethod;

    /**
     * Magic accessor for any given data
     *
     * @param string $method
     * @param array $args
     * @return mixed
     */
    public function __call(string $method, array $args = [])
    {
        return $this->data($method, ...$args);
    }

    /**
     * Creates a new API instance
     *
     * @param array $props
     */
    public function __construct(array $props)
    {
        $this->setProperties($props);
    }

    /**
     * Runs the authentication method
     * if set
     *
     * @return mixed
     */
    public function authenticate()
    {
        if ($auth = $this->authentication()) {
            return $auth->call($this);
        }

        return true;
    }

    /**
     * Returns the authentication callback
     *
     * @return Closure|null
     */
    public function authentication()
    {
        return $this->authentication;
    }

    /**
     * Execute an API call for the given path,
     * request method and optional request data
     *
     * @param string $path
     * @param string $method
     * @param array $requestData
     * @return mixed
     */
    public function call(string $path = null, string $method = 'GET', array $requestData = [])
    {
        $path = rtrim($path, '/');

        $this->setRequestMethod($method);
        $this->setRequestData($requestData);

        $this->router = new Router($this->routes());
        $this->route  = $this->router->find($path, $method);
        $auth   = $this->route->attributes()['auth'] ?? true;

        if ($auth !== false) {
            $this->authenticate();
        }

        $output = $this->route->action()->call($this, ...$this->route->arguments());

        if (is_object($output) === true) {
            return $this->resolve($output)->toResponse();
        }

        return $output;
    }

    /**
     * Setter and getter for an API collection
     *
     * @param string $name
     * @param array|null $collection
     * @return Kirby\Api\Collection
     *
     * @throws NotFoundException If no collection for `$name` exists
     */
    public function collection(string $name, $collection = null)
    {
        if (isset($this->collections[$name]) === false) {
            throw new NotFoundException(sprintf('The collection "%s" does not exist', $name));
        }

        return new Collection($this, $collection, $this->collections[$name]);
    }

    /**
     * Returns the collections definition
     *
     * @return array
     */
    public function collections(): array
    {
        return $this->collections;
    }

    /**
     * Returns the injected data array
     * or certain parts of it by key
     *
     * @param string|null $key
     * @param mixed ...$args
     * @return mixed
     *
     * @throws NotFoundException If no data for `$key` exists
     */
    public function data($key = null, ...$args)
    {
        if ($key === null) {
            return $this->data;
        }

        if ($this->hasData($key) === false) {
            throw new NotFoundException(sprintf('Api data for "%s" does not exist', $key));
        }

        // lazy-load data wrapped in Closures
        if (is_a($this->data[$key], 'Closure') === true) {
            return $this->data[$key]->call($this, ...$args);
        }

        return $this->data[$key];
    }

    /**
     * Returns the debugging flag
     *
     * @return boolean
     */
    public function debug(): bool
    {
        return $this->debug;
    }

    /**
     * Checks if injected data exists for the given key
     *
     * @param string $key
     * @return boolean
     */
    public function hasData(string $key): bool
    {
        return isset($this->data[$key]) === true;
    }

    /**
     * Returns an API model instance by name
     *
     * @param string $name
     * @param mixed $object
     * @return Kirby\Api\Model
     *
     * @throws NotFoundException If no model for `$name` exists
     */
    public function model(string $name, $object = null)
    {
        if (isset($this->models[$name]) === false) {
            throw new NotFoundException(sprintf('The model "%s" does not exist', $name));
        }

        return new Model($this, $object, $this->models[$name]);
    }

    /**
     * Returns all model definitions
     *
     * @return array
     */
    public function models(): array
    {
        return $this->models;
    }

    /**
     * Getter for request data
     * Can either get all the data
     * or certain parts of it.
     *
     * @param string $type
     * @param string $key
     * @param mixed $default
     * @return mixed
     */
    public function requestData(string $type = null, string $key = null, $default = null)
    {
        if ($type === null) {
            return $this->requestData;
        }

        if ($key === null) {
            return $this->requestData[$type] ?? [];
        }

        $data = array_change_key_case($this->requestData($type));
        $key  = strtolower($key);

        return $data[$key] ?? $default;
    }

    /**
     * Returns the request body if available
     *
     * @param string $key
     * @param mixed $default
     * @return mixed
     */
    public function requestBody(string $key = null, $default = null)
    {
        return $this->requestData('body', $key, $default);
    }

    /**
     * Returns the files from the request if available
     *
     * @param string $key
     * @param mixed $default
     * @return mixed
     */
    public function requestFiles(string $key = null, $default = null)
    {
        return $this->requestData('files', $key, $default);
    }

    /**
     * Returns all headers from the request if available
     *
     * @param string $key
     * @param mixed $default
     * @return mixed
     */
    public function requestHeaders(string $key = null, $default = null)
    {
        return $this->requestData('headers', $key, $default);
    }

    /**
     * Returns the request method
     *
     * @return string
     */
    public function requestMethod(): string
    {
        return $this->requestMethod;
    }

    /**
     * Returns the request query if available
     *
     * @param string $key
     * @param mixed $default
     * @return mixed
     */
    public function requestQuery(string $key = null, $default = null)
    {
        return $this->requestData('query', $key, $default);
    }

    /**
     * Turns a Kirby object into an
     * API model or collection representation
     *
     * @param mixed $object
     * @return Kirby\Api\Model|Kirby\Api\Collection
     *
     * @throws NotFoundException If `$object` cannot be resolved
     */
    public function resolve($object)
    {
        if (is_a($object, 'Kirby\Api\Model') === true || is_a($object, 'Kirby\Api\Collection') === true) {
            return $object;
        }

        $className = strtolower(get_class($object));
        $lastDash  = strrpos($className, '\\');

        if ($lastDash !== false) {
            $className = substr($className, $lastDash + 1);
        }

        if (isset($this->models[$className]) === true) {
            return $this->model($className, $object);
        }

        if (isset($this->collections[$className]) === true) {
            return $this->collection($className, $object);
        }

        // now models deeply by checking for the actual type
        foreach ($this->models as $modelClass => $model) {
            if (is_a($object, $model['type']) === true) {
                return $this->model($modelClass, $object);
            }
        }

        throw new NotFoundException(sprintf('The object "%s" cannot be resolved', $className));
    }

    /**
     * Returns all defined routes
     *
     * @return array
     */
    public function routes(): array
    {
        return $this->routes;
    }

    /**
     * Setter for the authentication callback
     *
     * @param Closure $authentication
     * @return self
     */
    protected function setAuthentication(Closure $authentication = null)
    {
        $this->authentication = $authentication;
        return $this;
    }

    /**
     * Setter for the collections definition
     *
     * @param array $collections
     * @return self
     */
    protected function setCollections(array $collections = null)
    {
        if ($collections !== null) {
            $this->collections = array_change_key_case($collections);
        }
        return $this;
    }

    /**
     * Setter for the injected data
     *
     * @param array $data
     * @return self
     */
    protected function setData(array $data = null)
    {
        $this->data = $data ?? [];
        return $this;
    }

    /**
     * Setter for the debug flag
     *
     * @param boolean $debug
     * @return self
     */
    protected function setDebug(bool $debug = false)
    {
        $this->debug = $debug;
        return $this;
    }

    /**
     * Setter for the model definitions
     *
     * @param array $models
     * @return self
     */
    protected function setModels(array $models = null)
    {
        if ($models !== null) {
            $this->models = array_change_key_case($models);
        }

        return $this;
    }

    /**
     * Setter for the request data
     *
     * @param array $requestData
     * @return self
     */
    protected function setRequestData(array $requestData = null)
    {
        $defaults = [
            'query' => [],
            'body'  => [],
            'files' => []
        ];

        $this->requestData = array_merge($defaults, (array)$requestData);
        return $this;
    }

    /**
     * Setter for the request method
     *
     * @param string $requestMethod
     * @return self
     */
    protected function setRequestMethod(string $requestMethod = null)
    {
        $this->requestMethod = $requestMethod ?? 'GET';
        return $this;
    }

    /**
     * Setter for the route definitions
     *
     * @param array $routes
     * @return self
     */
    protected function setRoutes(array $routes = null)
    {
        $this->routes = $routes ?? [];
        return $this;
    }

    /**
     * Renders the API call
     *
     * @param string $path
     * @param string $method
     * @param array $requestData
     * @return mixed
     */
    public function render(string $path, $method = 'GET', array $requestData = [])
    {
        try {
            $result = $this->call($path, $method, $requestData);
        } catch (Throwable $e) {
            if (is_a($e, 'Kirby\Exception\Exception') === true) {
                $result = [
                    'status' => 'error',
                    'route'  => $this->route->pattern()
                ] + $e->toArray();
            } else {
                // remove the document root from the file path
                $file = $e->getFile();
                if (empty($_SERVER['DOCUMENT_ROOT']) === false) {
                    $file = ltrim(Str::after($file, $_SERVER['DOCUMENT_ROOT']), '/');
                }

                $result = [
                    'status'    => 'error',
                    'exception' => get_class($e),
                    'message'   => $e->getMessage(),
                    'file'      => $file,
                    'line'      => $e->getLine(),
                    'code'      => empty($e->getCode()) === false ? $e->getCode() : 500,
                    'route'     => $this->route ? $this->route->pattern() : null
                ];
            }
        }

        if ($result === null) {
            $result = [
                'status'  => 'error',
                'message' => 'not found',
                'code'    => 404,
            ];
        }

        if ($result === true) {
            $result = [
                'status' => 'ok',
            ];
        }

        if ($result === false) {
            $result = [
                'status'  => 'error',
                'message' => 'bad request',
                'code'    => 400,
            ];
        }

        if (is_array($result) === false) {
            return $result;
        }

        // pretty print json data
        $pretty = (bool)($requestData['query']['pretty'] ?? false) === true;

        // remove critical info from the result set if
        // debug mode is switched off
        if ($this->debug !== true) {
            unset(
                $result['file'],
                $result['exception'],
                $result['line'],
                $result['route']
            );
        }

        if (($result['status'] ?? 'ok') === 'error') {
            $code = $result['code'] ?? 400;

            // sanitize the error code
            if ($code < 400 || $code > 599) {
                $code = 500;
            }

            return Response::json($result, $code, $pretty);
        }

        return Response::json($result, 200, $pretty);
    }

    /**
     * Upload helper method
     *
     * @param Closure $callback
     * @param boolean $single
     * @return array
     *
     * @throws Exception If request has no files
     * @throws Exception If there was an error with the upload
     */
    public function upload(Closure $callback, $single = false): array
    {
        $trials  = 0;
        $uploads = [];
        $errors  = [];
        $files   = $this->requestFiles();

        if (empty($files) === true) {
            throw new Exception('No uploaded files');
        }

        foreach ($files as $upload) {
            if (isset($upload['tmp_name']) === false && is_array($upload)) {
                continue;
            }

            $trials++;

            try {
                if ($upload['error'] !== 0) {
                    throw new Exception('Upload error');
                }

                // get the extension of the uploaded file
                $extension = F::extension($upload['name']);

                // try to detect the correct mime and add the extension
                // accordingly. This will avoid .tmp filenames
                if (empty($extension) === true || in_array($extension, ['tmp', 'temp'])) {
                    $mime      = F::mime($upload['tmp_name']);
                    $extension = F::mimeToExtension($mime);
                    $filename  = F::name($upload['name']) . '.' .$extension;
                } else {
                    $filename = basename($upload['name']);
                }

                $source = dirname($upload['tmp_name']) . '/' . uniqid() . '.' . $filename;

                // move the file to a location including the extension,
                // for better mime detection
                if (move_uploaded_file($upload['tmp_name'], $source) === false) {
                    throw new Exception('The uploaded file could not be moved');
                }

                $data = $callback($source, $filename);

                if (is_object($data) === true) {
                    $data = $this->resolve($data)->toArray();
                }

                $uploads[$upload['name']] = $data;
            } catch (Exception $e) {
                $errors[$upload['name']] = $e->getMessage();
            }

            if ($single === true) {
                break;
            }
        }

        // return a single upload response
        if ($trials === 1) {
            if (empty($errors) === false) {
                return [
                    'status'  => 'error',
                    'message' => current($errors)
                ];
            }

            return [
                'status' => 'ok',
                'data'   => current($uploads)
            ];
        }

        if (empty($errors) === false) {
            return [
                'status' => 'error',
                'errors' => $errors
            ];
        }

        return [
            'status' => 'ok',
            'data'   => $uploads
        ];
    }
}
