/*  This file is part of mastodon-cpp.
 *  Copyright © 2018, 2019 tastytea <tastytea@tastytea.de>
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Affero General Public License as published by
 *  the Free Software Foundation, version 3.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU Affero General Public License for more details.
 *
 *  You should have received a copy of the GNU Affero General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef MASTODON_CPP_HPP
#define MASTODON_CPP_HPP

#include <string>
#include <vector>
#include <memory>
#include <array>
#include <mutex>
#include <ostream>
#include <thread>
#include <cstdint>
#include <Poco/Net/HTMLForm.h>

#include "return_types.hpp"
#include "types.hpp"

using std::string;
using std::uint8_t;
using std::unique_ptr;
using Poco::Net::HTMLForm;

/*!
 *  @example example01_get_public_timeline.cpp
 *  @example example02_stream.cpp
 */

/*!
 *  @brief   Collection of things to interface with server software that
 *           implements the Mastodon API.
 */
namespace Mastodon
{
    /*!
     *  @brief  Interface to the Mastodon API.
     *
     *          All input is expected to be UTF-8. Binary data must be a
     *          filename.
     *
     *  @section error Error codes
     *  |      Code | Explanation                                |
     *  | --------: |:-------------------------------------------|
     *  |         0 | No error                                   |
     *  |         1 | Invalid argument                           |
     *  |        10 | URL changed (HTTP 301 or 308)              |
     *  |        11 | Connection timed out                       |
     *  |        12 | Connection refused (check http_error_code) |
     *  |        13 | No route to host / Could not resolve host  |
     *  |        14 | Encryption error                           |
     *  |       127 | Unknown error                              |
     *
     *  @since  before 0.11.0
     */
    class API
    {
    public:
        /*!
         *  @brief  http class. Do not use this directly.
         *
         *  @since  before 0.11.0
         */
        class http
        {
        public:
            /*!
             *  @brief  Constructs new http object.
             *
             *  @param  API          Parent object.
             *  @param  instance     Instance domain name
             *  @param  access_token Access token
             *
             *  @since  before 0.11.0
             */
            explicit http(const API &api, const string &instance,
                          const string &access_token);
            ~http();
            return_call request(const http_method &meth, const string &path);

            /*!
             *  @brief  HTTP Request.
             *
             *  @param  meth      A method defined in http::method.
             *  @param  path      The API call as string.
             *  @param  formdata  The form data for PATCH and POST requests.
             *
             *  @since  0.100.0
             */
            return_call request(const http_method &meth,
                                const string &path,
                                HTMLForm &formdata);

            /*!
             *  @brief HTTP Request for streams.
             *
             *  @param  path   The API call as string.
             *  @param  stream The stream of data that is returned.
             *
             *  @since  0.100.0
             */
            void request_stream(const string &path, string &stream);

            /*!
             *  @brief  Get all headers in a string
             */
            void get_headers(string &headers) const;

            /*!
             *  @brief  Cancels the stream. Use only with streams.
             *
             *          Cancels the stream next time data comes in. Can take a
             *          few seconds.  This works only with streams, because only
             *          streams have an own http object.
             *
             *  @since  0.12.2
             */
            void cancel_stream();

            /*!
             *  @brief  Gets the mutex guarding the string that is written to.
             *
             *          The mutex guards the function that writes to the string
             *          you specified in get_stream().
             *
             *  @return A reference of the mutex.
             *
             *  @since  0.12.3
             */
            std::mutex &get_mutex();

            /*!
             *  @brief  Set proxy. Do not call this directly.
             *
             *  @param  hostport host[:port]
             *  @param  userpw   user[:password] (optional)
             *
             *  @since  0.110.0
             */
            void set_proxy(const string &hostport, const string &userpw = "");

        private:
            const API &parent;
            const string _instance;
            const string _access_token;
            string _headers;
            bool _cancel_stream;
            std::mutex _mutex;
            std::thread _streamthread;

            return_call request_common(const http_method &meth,
                                       const string &path,
                                       HTMLForm &formdata,
                                       string &answer);
            size_t callback_write(char* data, size_t size, size_t nmemb,
                                  string *oss);
            double callback_progress(double /* dltotal */, double /* dlnow */,
                                     double /* ultotal */, double /* ulnow */);
        };

        /*!
         *  @brief  A list of all v1 API calls.
         *
         *          The original `/` are substituted by `_`.
         *
         *  @since  before 0.11.0
         */
        enum class v1
        {
            // Mastodon
            accounts_id,
            accounts,
            accounts_verify_credentials,
            accounts_update_credentials,
            accounts_id_followers,
            accounts_id_following,
            accounts_id_statuses,
            accounts_id_follow,
            accounts_id_unfollow,
            accounts_relationships,
            accounts_search,

            apps,
            apps_verify_credentials,

            blocks,
            accounts_id_block,
            accounts_id_unblock,

            custom_emojis,

            domain_blocks,

            endorsements,
            accounts_id_pin,
            accounts_id_unpin,

            favourites,
            statuses_id_favourite,
            statuses_id_unfavourite,

            filters,
            filters_id,

            follow_requests,
            follow_requests_id_authorize,
            follow_requests_id_reject,

            suggestions,
            suggestions_accountid,

            instance,

            lists,
            accounts_id_lists,
            lists_id_accounts,
            lists_id,

            media,
            media_id,

            mutes,
            accounts_id_mute,
            accounts_id_unmute,
            statuses_id_mute,
            statuses_id_unmute,

            notifications,
            notifications_id,
            notifications_clear,
            notifications_dismiss,
            push_subscription,

            polls_id,
            polls_id_votes,

            reports,

            // scheduled_statuses,
            // scheduled_statuses_id,

            statuses_id,
            statuses_id_context,
            statuses_id_card,
            statuses_id_reblogged_by,
            statuses_id_favourited_by,
            statuses,
            statuses_id_reblog,
            statuses_id_unreblog,
            statuses_id_pin,
            statuses_id_unpin,

            timelines_home,
            conversations,
            timelines_public,
            timelines_tag_hashtag,
            timelines_list_list_id,

            streaming_health,
            streaming_user,
            streaming_public,
            streaming_public_local,
            streaming_hashtag,
            streaming_hashtag_local,
            streaming_list,
            streaming_direct,

            // Glitch-Soc
            bookmarks,
            statuses_id_bookmark,
            statuses_id_unbookmark
        };

        /*!
         *  @brief  A list of all v2 API calls.
         *
         *          The original `/` are substituted by `_`.
         *
         *  @since  0.16.0
         */
        enum class v2
        {
            search
        };

        /*!
         *  @brief  Constructs a new API object.
         *
         *          To register your application, leave access_token blank and
         *          call register_app1() and register_app2().
         *
         *  @param  instance      The hostname of your instance
         *  @param  access_token  Your access token.
         *
         *  @since  before 0.11.0
         */
        explicit API(const string &instance, const string &access_token);

        /*!
         *  @brief  Destroys the object.
         *
         *  @since  0.100.0
         */
        virtual ~API();

        /*!
         *  @brief  Sets the useragent. Default is mastodon-cpp/version.
         *
         *  @param  useragent  The useragent
         *
         *  @since  before 0.11.0
         */
        void set_useragent(const string &useragent);

        /*!
         *  @brief  Gets the useragent.
         *
         *  @return The useragent.
         *
         *  @since  before 0.11.0
         */
        const string get_useragent() const;

        /*!
         *  @brief  Returns the instance.
         *
         *  @return The instance.
         *
         *  @since  before 0.11.0
         */
        const string get_instance() const;

        /*!
         *  @brief  Alias for Mastodon::urlencode.
         *
         *  @param  str     The string
         *
         *  @return The percent-encoded string
         *
         *  @since  before 0.11.0
         */
        [[deprecated("Replaced by Mastodon::urlencode")]]
        static const string urlencode(const string &str);

        /*!
         *  @brief  Alias for Mastodon::urldecode.
         *
         *  @param  str     The string
         *
         *  @return The decoded string
         *
         *  @since  0.18.0
         */
        [[deprecated("Replaced by Mastodon::urldecode")]]
        static const string urldecode(const string &str);

        /*!
         *  @brief  Register application, step 1/2
         *
         *  @param  client_name    The name of the application
         *  @param  redirect_uri   urn:ietf:wg:oauth:2.0:oob for none
         *  @param  scopes         Scopes (`read`, `write`, `follow`, `push`;
         *                         space separated)
         *  @param  website        The website of the application
         *  @param  client_id      Returned
         *  @param  client_secret  Returned
         *  @param  url            Returned, used to generate code for
         *                         register_app2
         *
         *  @since  before 0.100.0
         */
        return_call register_app1(const string &client_name,
                                  const string &redirect_uri,
                                  const string &scopes,
                                  const string &website,
                                  string &client_id,
                                  string &client_secret,
                                  string &url);


        /*!
         *  @brief  Register application, step 2/2
         *
         *          The access token will be used in all subsequent calls.
         *
         *  @param  client_id
         *  @param  client_secret
         *  @param  redirect_uri   urn:ietf:wg:oauth:2.0:oob for none
         *  @param  code           The code generated by the website
         *  @param  access_token   Returned
         *
         *  @since  before 0.100.0
         */
        return_call register_app2(const string &client_id,
                                  const string &client_secret,
                                  const string &redirect_uri,
                                  const string &code,
                                  string &access_token);

        /*!
         *  @brief  Gets the header from the last answer. Case insensitive.
         *
         *  @param  header  The header to get
         *
         *  @return The header, or "" on error.
         *
         *  @since  before 0.11.0
         */
        const string get_header(string header) const;

        /*!
         *  @brief  Turn exceptions on or off. Defaults to off.
         *
         *          Most exceptions will be thrown at you to handle if on.
         *
         *  @param  value   true for on, false for off
         *
         *  @return true if exceptions are turned on, false otherwise
         *
         *  @since  before 0.11.0
         */
        bool exceptions(const bool &value);

        /*!
         *  @brief  Returns true if exceptions are turned on, false otherwise
         */
        bool exceptions() const;

        /*!
         *  @brief  Alias for Mastodon::unescape_html.
         *
         *  @since  0.12.0
         */
        [[deprecated("Replaced by Mastodon::unescape_html")]]
        static const string unescape_html(const string &html);

        /*!
         *  @brief  Sets the proxy.
         *
         *          Both the username and the password will be URL decoded
         *          before use.
         *
         *  @param  hostport host[:port]
         *  @param  userpw   username[:password] (optional)
         *
         *  @since  0.15.0
         */
        void set_proxy(const string &hostport, const string &userpw = "");

        /*!
         *  @brief  Make a GET request that doesn't require parameters.
         *
         *  @param  call    A call defined in Mastodon::API::v1
         *
         *  @since  0.100.0
         */
        const return_call get(const Mastodon::API::v1 &call);

        /*!
         *  @brief  Make a GET request that requires parameters.
         *
         *  @param  call        A call defined in Mastodon::API::v1
         *  @param  parameters  A Mastodon::parametermap containing
         *                      parameters
         *
         *  @since  0.100.0
         */
        const return_call get(const Mastodon::API::v1 &call,
                              const parameters &parameters);

        /*!
         *  @brief  Make a GET request that requires parameters.
         *
         *  @param  call        A call defined in Mastodon::API::v2
         *  @param  parameters  A Mastodon::parametermap containing
         *                      parameters
         *
         *  @since  0.100.0
         */
        const return_call get(const Mastodon::API::v2 &call,
                              const parameters &parameters);

        /*!
         *  @brief  Make a custom GET request.
         *
         *  @param  call    String in the form `/api/v1/example`
         *
         *  @since  0.100.0
         */
        const return_call get(const string &call);

        /*!
         *  @brief  Make a streaming GET request.
         *
         *  @param  call        A call defined in Mastodon::API::v1
         *  @param  parameters  A Mastodon::parametermap containing
         *                      parameters
         *  @param  ptr         Pointer to the http object. Can be used to call
         *                      ptr->cancel_stream()
         *
         *  @since  0.100.0
         */
        void get_stream(const Mastodon::API::v1 &call,
                        const parameters &parameters,
                        unique_ptr<Mastodon::API::http> &ptr,
                        string &stream);

        /*!
         *  @brief  Make a streaming GET request.
         *
         *  @param  call    A call defined in Mastodon::API::v1
         *  @param  ptr     Pointer to the http object. Can be used to call
         *                  ptr->cancel_stream()
         *
         *  @since  0.100.0
         */
        void get_stream(const Mastodon::API::v1 &call,
                        unique_ptr<Mastodon::API::http> &ptr,
                        string &stream);

        /*!
         *  @brief  Make a streaming GET request.
         *
         *  @param  call    String in the form `/api/v1/example`
         *  @param  ptr     Pointer to the http object. Can be used to call
         *                  ptr->cancel_stream()
         *
         *  @since  0.100.0
         */
        void get_stream(const string &call,
                        unique_ptr<Mastodon::API::http> &ptr,
                        string &stream);

        /*!
         *  @brief  Make a PATCH request.
         *
         *          Binary data must be a filename.
         *
         *  @param  call        A call defined in Mastodon::API::v1
         *  @param  parameters  A Mastodon::parametermap containing
         *                      parameters
         *
         *  @since  0.100.0
         */
        return_call patch(const Mastodon::API::v1 &call,
                          const parameters &parameters);

        /*!
         *  @brief  Make a POST request that doesn't require parameters.
         *
         *  @param  call    A call defined in Mastodon::API::v1
         *
         *  @since  0.100.0
         */
        return_call post(const Mastodon::API::v1 &call);

        /*!
         *  @brief  Make a POST request that requires parameters.
         *
         *          Binary data must be a filename.
         *
         *  @param  call        A call defined in Mastodon::API::v1
         *  @param  parameters  A Mastodon::parametermap containing
         *                      parameters
         *
         *  @since  0.100.0
         */
        return_call post(const Mastodon::API::v1 &call,
                         const parameters &parameters);

        /*!
         *  @brief  Make a custom POST request.
         *
         *          Binary data must be a filename.
         *
         *  @param  call        String in the form `/api/v1/example`
         *  @param  parameters  A Mastodon::parametermap containing
         *                      parameters
         *
         *  @since  0.100.0
         */
        return_call post(const string &call,
                         const parameters &parameters);

        /*!
         *  @brief  Make a PUT request that requires parameters.
         *
         *  @param  call        A call defined in Mastodon::API::v1
         *  @param  parameters  A Mastodon::parametermap containing
         *                      parameters
         *
         *  @since  0.100.0
         */
        return_call put(const Mastodon::API::v1 &call,
                        const parameters &parameters);

        /*!
         *  @brief  Make a custom PUT request.
         *
         *  @param  call        String in the form `/api/v1/example`
         *  @param  parameters  A Mastodon::parametermap containing
         *                      parameters
         *
         *  @since  0.100.0
         */
        return_call put(const string &call, const parameters &parameters);

        /*!
         *  @brief  Make a DELETE request that requires parameters.
         *
         *  @param  call        A call defined in Mastodon::API::v1
         *  @param  parameters  A Mastodon::parametermap containing
         *                      parameters
         *
         *  @since  0.100.0
         */
        return_call del(const Mastodon::API::v1 &call,
                        const parameters &parameters);

        /*!
         *  @brief  Make a custom DELETE request.
         *
         *  @param  call        String in the form `/api/v1/example`
         *  @param  parameters  A Mastodon::parametermap containing
         *                      parameters
         *
         *  @since  0.100.0
         */
        return_call del(const string &call, const parameters &parameters);

    private:
        const string _instance;
        string _access_token;
        string _useragent;
        http _http;
        bool _exceptions;

        /*!
         *  @brief  Converts map of parameters into a string.
         *
         *  @param  map         Map of parameters
         *  @param  firstparam  Contains this map the first parameter?
         *
         *  @return String of parameters
         */
        const string maptostr(const parameters &map,
                              const bool &firstparam = true);

        /*!
         *  @brief  Converts map of parameters into form data
         *
         *  @param  map     Map of parameters
         *
         *  @return Form data as Poco::Net::HTMLForm.
         */
        unique_ptr<HTMLForm> maptoformdata(const parameters &map);

        /*!
         *  @brief  Delete Mastodon::param from Mastodon::parameters.
         *
         *  @param  params Old vector of parameters.
         *  @param  key    keys of Mastodon::param to delete.
         *
         *  @return New vector of parameters.
         *
         *  @since  0.102.0
         */
        const parameters delete_params(const parameters &params,
                                       const vector<string> &keys);
    };

    /*!
     *  @brief  Percent-encodes a string.
     *
     *
     *          This is done automatically where necessary. The only time you
     *          should use this, is if you use get(const string &call, string
     *          &answer).
     *
     *          See RFC 3986 section 2.1 for more info.
     *
     *  @param  str The string to encode.
     *
     *  @return The percent-encoded string.
     *
     *  @since  0.105.0
     */
    const string urlencode(const string &str);

    /*!
     *  @brief  Decodes a percent-encoded string.
     *
     *          See RFC 3986 section 2.1 for more info.
     *
     *  @param  str The string to decode.
     *
     *  @return The decoded string.
     *
     *  @since  0.105.0
     */
    const string urldecode(const string &str);

    /*!
     *  @brief  Replaces HTML entities with UTF-8 characters.
     *
     *          Supports named and numbered entities, decimal and
     *          hexadecimal.
     *
     *  @param  html The html to unescape.
     *
     *  @return The unescaped string.
     *
     *  @since  0.105.0
     */
    const string unescape_html(const string &html);
}

#endif