#include "../include/VideoPlayer.hpp"
#include "../include/Storage.hpp"
#include "../include/Program.hpp"
#include "../include/Utils.hpp"
#include "../include/StringUtils.hpp"
#include "../include/Notification.hpp"
#include <string>
#include <json/reader.h>
#include <json/writer.h>
#include <memory>
#include <assert.h>

#include <sys/socket.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <fcntl.h>
#include <signal.h>

const int RETRY_TIME_MS = 500;
const int MAX_RETRIES_CONNECT = 1000;
const int READ_TIMEOUT_MS = 200;

namespace QuickMedia {
    static std::string media_chapters_to_ffmetadata_chapters(const std::vector<MediaChapter> &chapters) {
        std::string result = ";FFMETADATA1\n\n";
        for(size_t i = 0; i < chapters.size(); ++i) {
            const MediaChapter &chapter = chapters[i];
            result += "[CHAPTER]\n";
            result += "TIMEBASE=1/1\n";
            result += "START=" + std::to_string(chapter.start_seconds) + "\n";
            result += "END=" + std::to_string(i + 1 == chapters.size() ? chapter.start_seconds : chapters[i + 1].start_seconds) + "\n";
            std::string title = chapter.title;
            string_replace_all(title, '\n', ' ');
            result += "title=" + std::move(title) + "\n\n";
        }
        return result;
    }

    // If |chapters| is empty then |tmp_chapters_filepath| is removed, otherwise the file is overwritten
    static bool create_tmp_file_with_chapters_data(char *tmp_chapters_filepath, const std::vector<MediaChapter> &chapters) {
        if(chapters.empty()) {
            if(tmp_chapters_filepath[0] != '\0') {
                remove(tmp_chapters_filepath);
                tmp_chapters_filepath[0] = '\0';
            }
            return true;
        }

        if(tmp_chapters_filepath[0] == '\0') {
            strcpy(tmp_chapters_filepath, "/tmp/qm-mpv-chapter-XXXXXX");
            mktemp(tmp_chapters_filepath);
            if(tmp_chapters_filepath[0] == '\0') {
                fprintf(stderr, "Failed to create temporay file\n");
                return false;
            }
        }

        if(file_overwrite(tmp_chapters_filepath, media_chapters_to_ffmetadata_chapters(chapters)) == 0) {
            return true;
        } else {
            remove(tmp_chapters_filepath);
            tmp_chapters_filepath[0] = '\0';
            return false;
        }
    }

    VideoPlayer::VideoPlayer(bool no_video, bool use_system_mpv_config, bool keep_open, EventCallbackFunc _event_callback, VideoPlayerWindowCreateCallback _window_create_callback, const std::string &resource_root, int monitor_height, std::string plugin_name) :
        exit_status(0),
        plugin_name(std::move(plugin_name)),
        no_video(no_video),
        use_system_mpv_config(use_system_mpv_config),
        keep_open(keep_open),
        use_youtube_dl(true),
        video_process_id(-1),
        connected_to_ipc(false),
        connect_tries(0),
        find_window_tries(0),
        monitor_height(monitor_height),
        event_callback(_event_callback),
        window_create_callback(_window_create_callback),
        window_handle(0),
        parent_window(0),
        display(nullptr),
        request_id(1),
        expected_request_id(0),
        request_response_data(Json::nullValue),
        response_data_status(ResponseDataStatus::NONE),
        resource_root(resource_root)
    {
        tmp_chapters_filepath[0] = '\0';
        display = XOpenDisplay(NULL);
        if (!display) {
            show_notification("QuickMedia", "Failed to open display to X11 server", Urgency::CRITICAL);
            abort();
        }
        fprintf(stderr, "Video max height: %d\n", monitor_height);
        ipc_server_path[0] = '\0';
    }

    VideoPlayer::~VideoPlayer() {
        if(video_process_id != -1) {
            kill(video_process_id, SIGTERM);
            wait_program(video_process_id);
        }
        
        if(ipc_socket != -1)
            close(ipc_socket);
        
        if(video_process_id != -1 && ipc_server_path[0] != '\0')
            remove(ipc_server_path);

        if(display)
            XCloseDisplay(display);

        if(tmp_chapters_filepath[0] != '\0')
            remove(tmp_chapters_filepath);
    }

    VideoPlayer::Error VideoPlayer::launch_video_process(const char *path, const char *audio_path, sf::WindowHandle _parent_window, const std::string &title, const std::string &start_time) {
        parent_window = _parent_window;

        if(!tmpnam(ipc_server_path)) {
            perror("Failed to generate ipc file name");
            return Error::FAIL_TO_GENERATE_IPC_FILENAME;
        }

        const std::string parent_window_str = std::to_string(parent_window);
        std::vector<const char*> args;

        std::string input_ipc_server_arg = "--input-ipc-server=";
        input_ipc_server_arg += ipc_server_path;
        std::string wid_arg = "--wid=";
        wid_arg += parent_window_str;

        std::string input_conf = "--input-conf=" + resource_root + "input.conf";
        std::string cache_dir = "--cache-dir=" + std::move(get_cache_dir().join("media").data);

        // TODO: Resume playback if the last video played matches the first video played next time QuickMedia is launched
        args.insert(args.end(), {
            "mpv",
            input_ipc_server_arg.c_str(),
            "--cursor-autohide=no", /* "--no-input-default-bindings", "--input-vo-keyboard=no", "--no-input-cursor", */
            "--no-terminal",
            "--save-position-on-quit=no",
            "--profile=pseudo-gui", // For gui when playing audio, requires a version of mpv that isn't ancient
            "--no-resume-playback",
            // TODO: Disable hr seek on low power devices?
            "--hr-seek=yes",
            //"--cache=no",
            "--force-seekable=yes",
            "--image-display-duration=5",
            "--cache-pause=yes",
            "--cache=yes",
            "--cache-on-disk=yes",
            "--cache-secs=86400", // 24 hours
            "--sub-font-size=35",
            "--sub-margin-y=45",
            "--sub-border-size=1.6",
            "--sub-border-color=0.01",
            cache_dir.c_str(),
            input_conf.c_str(),
            wid_arg.c_str()
        });

        if(is_running_wayland()) {
            args.push_back("--gpu-context=x11egl");
            fprintf(stderr, "Wayland detected. Launching mpv in x11egl mode\n");
        }

        if(keep_open)
            args.push_back("--keep-open=yes");

        std::string ytdl_format;
        if(no_video)
            ytdl_format = "--ytdl-format=bestaudio/best";
        else
            ytdl_format = "--ytdl-format=bestvideo[height<=?" + std::to_string(monitor_height) + "]+bestaudio/best";

        if(!use_youtube_dl)
            args.push_back("--no-ytdl");
        else
            args.push_back(ytdl_format.c_str());

        if(!use_system_mpv_config) {
            args.insert(args.end(), {
                "--no-config",
                "--profile=gpu-hq",
                "--vo=gpu,vdpau,x11",
                "--hwdec=auto"
            });
        }

        std::string force_media_title_arg;
        if(!title.empty()) {
            force_media_title_arg = "--force-media-title=" + title;
            args.push_back(force_media_title_arg.c_str());
        }

        if(no_video)
            args.push_back("--no-video");

        std::string chapters_file_arg;
        if(tmp_chapters_filepath[0] != '\0') {
            chapters_file_arg = std::string("--chapters-file=") + tmp_chapters_filepath;
            args.push_back(chapters_file_arg.c_str());
        }

        std::string audio_file_arg;
        if(audio_path && audio_path[0] != '\0') {
            audio_file_arg = std::string("--audio-file=") + audio_path;
            args.push_back(audio_file_arg.c_str());
        }

        std::string start_time_arg;
        if(!start_time.empty()) {
            start_time_arg = "--start=" + start_time;
            args.push_back(start_time_arg.c_str());
        }

        args.insert(args.end(), { "--", path, nullptr });

        fprintf(stderr, "mpv input ipc server: %s\n", ipc_server_path);

        if((ipc_socket = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) {
            perror("Failed to create socket for video player");
            return Error::FAIL_TO_CREATE_SOCKET;
        }

        ipc_addr.sun_family = AF_UNIX;
        strcpy(ipc_addr.sun_path, ipc_server_path);

        int flags = fcntl(ipc_socket, F_GETFL, 0);
        if(flags != -1) // TODO: Proper error handling
            fcntl(ipc_socket, F_SETFL, flags | O_NONBLOCK);

        if(exec_program_async(args.data(), &video_process_id) != 0) {
            close(ipc_socket);
            ipc_socket = -1;
            return Error::FAIL_TO_LAUNCH_PROCESS;
        }

        return Error::OK;
    }

    VideoPlayer::Error VideoPlayer::load_video(const char *path, const char *audio_path, sf::WindowHandle _parent_window, bool use_youtube_dl, const std::string &title, const std::string &start_time, const std::vector<MediaChapter> &chapters) {
        // This check is to make sure we dont change window that the video belongs to. This is not a usecase we will have so
        // no need to support it for now at least.
        assert(parent_window == 0 || parent_window == _parent_window);
        assert(path);
        this->use_youtube_dl = use_youtube_dl;
        if(!create_tmp_file_with_chapters_data(tmp_chapters_filepath, chapters))
            fprintf(stderr, "Warning: failed to create chapters file. Chapters will not be displayed\n");

        fprintf(stderr, "Playing video: %s, audio: %s\n", path ? path : "", audio_path ? audio_path : "");
        if(video_process_id == -1)
            return launch_video_process(path, audio_path, _parent_window, title, start_time);

        // TODO: When these are used, add audio_path, title and start_time. Also handle is_youtube
        Json::Value command_data(Json::arrayValue);
        command_data.append("loadfile");
        command_data.append(path);
        Json::Value command(Json::objectValue);
        command["command"] = command_data;

        Json::StreamWriterBuilder builder;
        builder["commentStyle"] = "None";
        builder["indentation"] = "";
        const std::string cmd_str = Json::writeString(builder, command) + "\n";
        return send_command(cmd_str.c_str(), cmd_str.size());
    }

    static std::vector<Window> get_child_window(Display *display, Window window) {
        std::vector<Window> result;
        Window root_window;
        Window parent_window;
        Window *child_window = nullptr;
        unsigned int num_children = 0;
        if(XQueryTree(display, window, &root_window, &parent_window, &child_window, &num_children) && child_window) {
            for(unsigned int i = 0; i < num_children; i++)
                result.push_back(child_window[i]);
            XFree(child_window);
        }
        return result;
    }

    VideoPlayer::Error VideoPlayer::update() {
        const int max_retries_find_window = 1000;

        if(video_process_id != -1) {
            if(wait_program_non_blocking(video_process_id, &exit_status)) {
                fprintf(stderr, "The video player exited!, status: %d\n", exit_status);
                close(ipc_socket);
                remove(ipc_server_path);
                ipc_server_path[0] = '\0';
                video_process_id = -1;
                ipc_socket = -1;
                window_handle = None;
                connected_to_ipc = false;
                return Error::EXITED;
            }
        }

        if(ipc_socket == -1)
            return Error::INIT_FAILED;

        if(connect_tries == MAX_RETRIES_CONNECT)
            return Error::FAIL_TO_CONNECT_TIMEOUT;

        if(find_window_tries == max_retries_find_window)
            return Error::FAIL_TO_FIND_WINDOW;

        if(!connected_to_ipc && retry_timer.getElapsedTime().asMilliseconds() >= RETRY_TIME_MS) {
            retry_timer.restart();
            if(connect(ipc_socket, (struct sockaddr*)&ipc_addr, sizeof(ipc_addr)) == -1) {
                ++connect_tries;
                if(connect_tries == MAX_RETRIES_CONNECT) {
                    fprintf(stderr, "Failed to connect to mpv ipc after %d seconds, last error: %s\n", (RETRY_TIME_MS * MAX_RETRIES_CONNECT)/1000, strerror(errno));
                    return Error::FAIL_TO_CONNECT_TIMEOUT;
                }
            } else {
                connected_to_ipc = true;
            }
        }

        if(connected_to_ipc && window_handle == 0 && retry_timer.getElapsedTime().asMilliseconds() >= RETRY_TIME_MS) {
            retry_timer.restart();
            std::vector<Window> child_windows = get_child_window(display, parent_window);
            size_t num_children = child_windows.size();
            if(num_children == 0) {
                ++find_window_tries;
                if(find_window_tries == max_retries_find_window) {
                    fprintf(stderr, "Failed to find mpv window after %d seconds\n", (RETRY_TIME_MS * max_retries_find_window)/1000);
                    return Error::FAIL_TO_FIND_WINDOW_TIMEOUT;
                }
            } else if(num_children == 1) {
                window_handle = child_windows[0];
                if(window_create_callback)
                    window_create_callback(window_handle);
            } else {
                fprintf(stderr, "Expected window to have one child (the video player) but it has %zu\n", num_children);
                return Error::UNEXPECTED_WINDOW_ERROR;
            }
        }

        if(connected_to_ipc && window_handle && event_callback) {
            Error err = read_ipc_func();
            if(err != Error::OK)
                return err;
        }

        return Error::OK;
    }

    VideoPlayer::Error VideoPlayer::read_ipc_func() {
        assert(connected_to_ipc);
        Json::Value json_root;
        Json::CharReaderBuilder json_builder;
        std::unique_ptr<Json::CharReader> json_reader(json_builder.newCharReader());
        std::string json_errors;

        char buffer[2048];
        ssize_t bytes_read = read(ipc_socket, buffer, sizeof(buffer));
        if(bytes_read == -1) {
            int err = errno;
            if(err != EAGAIN && err != EWOULDBLOCK) {
                fprintf(stderr, "Failed to read from ipc socket, error: %s\n", strerror(err));
                return Error::FAIL_TO_READ;
            }
        } else if(bytes_read > 0) {
            int start = 0;
            for(int i = 0; i < bytes_read; ++i) {
                if(buffer[i] != '\n')
                    continue;

                if(json_reader->parse(buffer + start, buffer + i, &json_root, &json_errors) && json_root.isObject()) {
                    const Json::Value &event = json_root["event"];
                    const Json::Value &request_id_json = json_root["request_id"];
                    if(event.isString()) {
                        if(event_callback)
                            event_callback(event.asCString());
                    }

                    if(expected_request_id != 0 && request_id_json.isNumeric() && request_id_json.asUInt() == expected_request_id) {
                        if(json_root["error"].isNull())
                            response_data_status = ResponseDataStatus::ERROR;
                        else
                            response_data_status = ResponseDataStatus::OK;
                        request_response_data = json_root["data"];
                    }
                } else {
                    fprintf(stderr, "Failed to parse json for ipc: |%.*s|, reason: %s\n", (int)bytes_read, buffer, json_errors.c_str());
                }

                start = i + 1;
            }
        }
        return Error::OK;
    }

    VideoPlayer::Error VideoPlayer::get_time_in_file(double *result) {
        Json::Value time_pos_json;
        Error err = get_property("time-pos", &time_pos_json, Json::realValue);
        if(err != Error::OK)
            return err;

        *result = time_pos_json.asDouble();
        return err;
    }

    VideoPlayer::Error VideoPlayer::set_property(const std::string &property_name, const Json::Value &value) {
        Json::Value command_data(Json::arrayValue);
        command_data.append("set_property");
        command_data.append(property_name);
        command_data.append(value);
        Json::Value command(Json::objectValue);
        command["command"] = std::move(command_data);

        Json::StreamWriterBuilder builder;
        builder["commentStyle"] = "None";
        builder["indentation"] = "";
        const std::string cmd_str = Json::writeString(builder, command) + "\n";
        return send_command(cmd_str.c_str(), cmd_str.size());
    }

    VideoPlayer::Error VideoPlayer::get_property(const std::string &property_name, Json::Value *result, Json::ValueType result_type) {
        unsigned int cmd_request_id = request_id;
        ++request_id;
        // Overflow check. 0 is defined as no request, 1 is the first valid one
        if(request_id == 0)
            request_id = 1;

        Json::Value command_data(Json::arrayValue);
        command_data.append("get_property");
        command_data.append(property_name);
        Json::Value command(Json::objectValue);
        command["command"] = std::move(command_data);
        command["request_id"] = cmd_request_id;

        Json::StreamWriterBuilder builder;
        builder["commentStyle"] = "None";
        builder["indentation"] = "";
        const std::string cmd_str = Json::writeString(builder, command) + "\n";

        Error err = send_command(cmd_str.c_str(), cmd_str.size());
        if(err != Error::OK)
            return err;

        sf::Clock read_timer;
        expected_request_id = cmd_request_id;
        do {
            err = read_ipc_func();
            if(err != Error::OK)
                goto cleanup;

            if(response_data_status != ResponseDataStatus::NONE)
                break;
        } while(read_timer.getElapsedTime().asMilliseconds() < READ_TIMEOUT_MS);

        if(response_data_status == ResponseDataStatus::OK) {
            if(request_response_data.type() == result_type)
                *result = request_response_data;
            else
                err = Error::READ_INCORRECT_TYPE;
        } else if(response_data_status == ResponseDataStatus::ERROR) {
            err = Error::READ_RESPONSE_ERROR;
            goto cleanup;
        } else {
            err = Error::READ_TIMEOUT;
            goto cleanup;
        }

        cleanup:
        expected_request_id = 0;
        response_data_status = ResponseDataStatus::NONE;
        request_response_data = Json::Value(Json::nullValue);
        return err;
    }

    VideoPlayer::Error VideoPlayer::add_subtitle(const std::string &url, const std::string &title, const std::string &lang) {
        Json::Value command_data(Json::arrayValue);
        command_data.append("sub-add");
        command_data.append(url);
        command_data.append("auto");
        if(!title.empty()) {
            command_data.append(title);
            if(!lang.empty())
                command_data.append(lang);
        }
        Json::Value command(Json::objectValue);
        command["command"] = std::move(command_data);

        Json::StreamWriterBuilder builder;
        builder["commentStyle"] = "None";
        builder["indentation"] = "";
        const std::string cmd_str = Json::writeString(builder, command) + "\n";
        return send_command(cmd_str.c_str(), cmd_str.size());
    }

    VideoPlayer::Error VideoPlayer::send_command(const char *cmd, size_t size) {
        if(!connected_to_ipc)
            return Error::FAIL_NOT_CONNECTED;

        if(send(ipc_socket, cmd, size, 0) == -1) {
            fprintf(stderr, "Failed to send to ipc socket, error: %s, command: %.*s\n", strerror(errno), (int)size, cmd);
            return Error::FAIL_TO_SEND;
        }

        return Error::OK;
    }
}