yttui/application.cpp

// SPDX-License-Identifier: MIT

#include "application.h"

#define _X_OPEN_SOURCE

#include "tui.h"
#include "yt.h"
#include "db.h"
#include "subprocess.h"

#include <algorithm>
#include <chrono>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <unordered_map>
#include <fstream>

#include <time.h>
#include <libgen.h>
#include <stdio.h>

#include <curl/curl.h>
#include <nlohmann/json.hpp>

std::string user_home;

std::vector<UserFlag> userFlags;
std::vector<Channel> channels;
std::unordered_map<std::string, std::vector<Video>> videos;

size_t selected_channel;
size_t current_video_count = 0;
size_t selected_video = 0;
size_t videos_per_page = 0;
size_t current_page_count = 0;
size_t title_offset = 0;
bool any_title_in_next_half = false;
bool clear_channels_on_change = false;

static application_host *host = nullptr;

static termpaint_attr* get_attr(const AttributeSetType type, const bool highlight=false)
{
    return highlight ? attributes[type].highlight : attributes[type].normal;
}

void draw_channel_list(const std::vector<Video> &videos, bool show_channel_name=false)
{
    const size_t cols = termpaint_surface_width(surface);
    const size_t rows = termpaint_surface_height(surface);

    const size_t column_spacing = 2;

    const size_t date_column = 0;
    const size_t date_width = std::string("xxxx-xx-xx xx:xx").size();

    const size_t start_row = 2;
    const size_t available_rows = rows - 2;
    videos_per_page = available_rows;
    const int cur_page = selected_video / available_rows;
    const int pages = videos.size() / available_rows;

    size_t cur_entry = 0;

    std::map<std::string, std::string> channel_name_lookup;

    const size_t channel_name_column = date_column + date_width + column_spacing;
    size_t channel_name_width = show_channel_name * std::string("Channel").size();
    if(show_channel_name) {
        for(size_t i = cur_page*available_rows; i < videos.size(); i++) {
            const Video &video = videos.at(i);
            for(size_t c = 0; c<channels.size(); c++) {
                const Channel &channel = channels.at(c);
                if(video.channel_id == channel.id) {
                    channel_name_lookup[channel.id] = channel.name;
                    channel_name_width = std::max(channel_name_width, channel.tui_name_width);
                    break;
                }
            }
            if(++cur_entry > available_rows)
                break;
        }
    }

    const size_t first_name_column = date_column + date_width + column_spacing + channel_name_width + (channel_name_width > 0) * column_spacing;
    const size_t last_name_column = cols;
    const size_t name_quater = (last_name_column - first_name_column) / 4;

    const std::string channel_name = std::string("Channel: ") + channels[selected_channel].name;
    termpaint_surface_write_with_attr(surface, 0, 0, channel_name.c_str(), get_attr(ASNormal));

    if(pages > 1) {
        std::string text = "(Page " + std::to_string(cur_page + 1) + "/" + std::to_string(pages + 1) + ")";
        const size_t w = string_width(text);
        termpaint_surface_write_with_attr(surface, cols - w, 0, text.c_str(), attributes[ASNormal].normal);
    }

    termpaint_surface_write_with_attr(surface, date_column, 1, "Date", get_attr(ASNormal));
    if(show_channel_name)
        termpaint_surface_write_with_attr(surface, channel_name_column, 1, "Channel", get_attr(ASNormal));
    termpaint_surface_write_with_attr(surface, first_name_column, 1, "Title", get_attr(ASNormal));

    any_title_in_next_half = false;

    cur_entry = 0;
    for(size_t i = cur_page*available_rows; i < videos.size(); i++) {
        const size_t row = start_row + cur_entry;
        const bool selected = i == selected_video;
        const Video &video = videos.at(i);
        termpaint_attr *attr = get_attr(video.flags & kWatched ? ASWatched : ASUnwatched, selected);

        termpaint_surface_clear_rect_with_attr(surface, 0, row, cols, 1, attr);

        std::vector<char> dt(date_width + 10, 0);

        struct tm tm;
        memset(&tm, 0, sizeof(tm));
        const std::string &date_str = !video.published.empty() ? video.published : video.added_to_playlist;
        if(strptime(date_str.c_str(), "%FT%T%z", &tm) != nullptr) {
            strftime(dt.data(), date_width + 10, "%F %H:%M", &tm);
        }

        termpaint_surface_write_with_attr(surface, date_column, row, dt.data(), attr);
        if(show_channel_name) {
            termpaint_surface_write_with_attr(surface, channel_name_column, row, channel_name_lookup[video.channel_id].c_str(), attr);
        }

        bool in_this_quater = title_offset * name_quater < video.tui_title_width;
        any_title_in_next_half = any_title_in_next_half || ((title_offset + 2) * name_quater) < video.tui_title_width;
        if(in_this_quater)
            termpaint_surface_write_with_attr_clipped(surface, first_name_column, row, video.title.c_str() + (name_quater * title_offset), attr, first_name_column, last_name_column);
        else
            termpaint_surface_write_with_attr(surface, first_name_column, row, "←", attr);

        if(++cur_entry > available_rows)
            break;
    }

    if(!any_title_in_next_half && title_offset > 0)
        title_offset--;
}

void draw_no_channels_msg()
{
    const size_t cols = termpaint_surface_width(surface);
    const size_t rows = termpaint_surface_height(surface);

    const std::string text("No configured channels.\n"
                           "Press the following keys to add one:\n"
                           "a    Add channel by name\n"
                           "A    Add channel by ID\n"
                           "Or press F1 for help or C-q to quit.");
    {
        std::pair<size_t, size_t> size = string_size(text);
        write_multiline_string((cols - size.first) / 2, (rows - size.second) / 2, text, get_attr(ASNormal));
    }
}

void load_videos_for_channel(const Channel &channel, bool force=false)
{
    if(!force && videos.find(channel.id) != videos.end() && !videos[channel.id].empty())
        return;

    std::vector<Video> &channelVideos = videos[channel.id];
    if(channel.is_virtual) {
        channelVideos = Video::get_all_with_filter(channel.filter);
    } else {
        channelVideos = Video::get_all_for_channel(channel.id);
    }

    for(Video &video: channelVideos) {
        video.tui_title_width = string_width(video.title);
    }

    if(channels[selected_channel].id == channel.id)
        selected_video = 0;
}

int fetch_videos_for_channel(Channel &channel, bool name_in_title=false)
{
    if(channel.is_virtual) {
        std::vector<Video> &channelVideos = videos[channel.id];
        channelVideos = Video::get_all_with_filter(channel.filter);
        for(Video &video: channelVideos) {
            video.tui_title_width = string_width(video.title);
        }
        return 0;
    }

    std::string title("Refreshing");
    if(name_in_title)
        title.append(" ").append(channel.name);
    title.append("…");
    progress_info *info = begin_progress(title, 30);
    const int new_video_count = channel.fetch_new_videos(db, info);
    end_progress(info);
    load_videos_for_channel(channels[selected_channel], true);
    channel.load_info(db);

    return new_video_count;
}

bool startswith(const std::string &str, const std::string &with)
{
    const size_t len = with.length();
    return str.substr(0, len) == with;
}

std::string replace(const std::string &str, const std::string &what, const std::string &with)
{
    const size_t replace_length = what.size();
    std::string out = str;
    size_t pos = 0;
    while((pos = out.find(what, pos)) != std::string::npos) {
        out.replace(pos, replace_length, with);
    }
    return out;
}

void select_channel_by_index(const int index) {
    if(clear_channels_on_change) {
        for(auto &[k, v]: videos) {
            v.clear();
        }
    }
    selected_channel = index;
    const Channel &channel = channels.at(selected_channel);
    selected_video = 0;
    load_videos_for_channel(channel, clear_channels_on_change);
    current_video_count = videos[channel.id].size();
    clear_channels_on_change = channel.is_virtual;
}

void select_channel_by_name(const std::string &channel_name) {
    auto it = std::find_if(channels.cbegin(), channels.cend(), [&](const Channel &channel){ return channel.name == channel_name; });
    if(it == channels.cend())
        return;
    select_channel_by_index(std::distance(channels.cbegin(), it));
}

void select_channel_by_id(const std::string &channel_id) {
    auto it = std::find_if(channels.cbegin(), channels.cend(), [&](const Channel &channel){ return channel.id == channel_id; });
    if(it == channels.cend())
        return;
    select_channel_by_index(std::distance(channels.cbegin(), it));
}

void add_channel_to_list(Channel &channel)
{
    channel.load_info(db);
    channel.tui_name_width = string_width(channel.name);

    std::string selected_channel_id;
    if(selected_channel < channels.size())
        selected_channel_id = channels[selected_channel].id;
    channels.push_back(channel);

    std::sort(channels.begin(), channels.end(), [](const Channel &a, const Channel &b){ if(a.is_virtual != b.is_virtual) { return a.is_virtual > b.is_virtual; } return a.name < b.name; });

    if(!selected_channel_id.empty()) {
        const size_t new_index = std::distance(channels.cbegin(), std::find_if(channels.cbegin(), channels.cend(), [&](const Channel &ch){ return ch.id == selected_channel_id; }));
        selected_channel = new_index;
    }
}

void make_virtual_unwatched_channel()
{
    ChannelFilter filter;
    filter.video_mask = kWatched;
    Channel channel = Channel::add_virtual("All Unwatched", filter);
    std::vector<Video> &channelVideos = videos[channel.id];
    channelVideos = Video::get_all_with_filter(channel.filter);
    for(Video &video: channelVideos) {
        video.tui_title_width = string_width(video.title);
    }
    add_channel_to_list(channel);
}

void action_add_channel_by_name()
{
    std::string channel_name = get_string("Add new Channel", "Enter channel name");
    if(channel_name.empty()) {
        return;
    } else if(std::find_if(channels.cbegin(), channels.cend(), [&](const Channel &channel){ return channel.name == channel_name; }) != channels.cend()) {
        message_box("Can't add channel", "A channel with this name is already in the list!");
        return;
    } else {
        Channel ch = Channel::add(db, "forUsername", channel_name);
        if(ch.is_valid()) {
            add_channel_to_list(ch);
            select_channel_by_id(ch.id);
            tp_flush();
            if(message_box("Update now?", "Fetch videos for this channel now?", Button::Yes | Button::No, Button::Yes) == Button::Yes) {
                fetch_videos_for_channel(ch);
            }
        } else {
            message_box("Can't add channel", "There is no channel with this name!");
        }
    }
}

void action_add_channel_by_id()
{
    std::string channel_id = get_string("Add new Channel", "Enter channel ID");
    if(channel_id.empty()) {
        return;
    } else if(std::find_if(channels.cbegin(), channels.cend(), [&](const Channel &channel){ return channel.id == channel_id; }) != channels.cend()) {
        message_box("Can't add channel", "A channel with this ID is already in the list!");
        return;
    } else {
        Channel ch = Channel::add(db, "id", channel_id);
        if(ch.is_valid()) {
            add_channel_to_list(ch);
            select_channel_by_id(ch.id);
            tp_flush();
            if(message_box("Update now?", "Fetch videos for this channel now?", Button::Yes | Button::No, Button::Yes) == Button::Yes) {
                fetch_videos_for_channel(ch);
            }
        } else {
            message_box("Can't add channel", "There is no channel with this ID!");
        }
    }
}

void action_select_channel() {
    if(channels.empty()) {
        message_box("Can't select channel", "No channels configured.\n Please configure one.");
    } else {
        std::vector<std::string> names;
        names.reserve(channels.size());
        for(const Channel &c: channels)
            names.push_back(c.name + " (" + std::to_string(c.unwatched) + ")");
        const int channel = get_selection("Switch Channel", names, selected_channel, Align::VCenter | Align::Left);
        if(channel != -1)
            select_channel_by_index(channel);
    }
}

bool run_command(const std::vector<std::string> &cmd, const std::vector<std::pair<std::string, std::string>> &placeholders={}) {
    const size_t cmd_size = cmd.size();

    if(!cmd_size)
        return true;

    const char *cmdline[cmd_size + 1];
    for(size_t c=0; c<cmd_size; c++) {
        std::string arg = cmd[c];
        for(size_t p=0; p<placeholders.size(); p++) {
            const auto &[what, with] = placeholders.at(p);
            arg = replace(arg, what, with);
        }
        cmdline[c] = strdup(arg.c_str());
    }
    cmdline[cmd_size] = nullptr;

    subprocess_s proc;
    const int rc = subprocess_create(cmdline, subprocess_option_inherit_environment, &proc);
    if(rc != 0) {
        const std::string message = cmd.at(0) + " failed with error " + std::to_string(rc);
        message_box("Failed to run command", message);
    }
    subprocess_join(&proc, nullptr);
    for(size_t i=0; i<cmd_size; i++) {
        free((void*)cmdline[i]);
    }
    return rc == 0;
}

std::vector<std::string> notify_channel_new_video_command;
std::vector<std::string> notify_channel_new_videos_command;
std::vector<std::string> notify_channels_new_videos_command;

void action_refresh_channel() {
    Channel &ch = channels.at(selected_channel);
    const int new_videos = fetch_videos_for_channel(channels.at(selected_channel));
    if(new_videos == 0 || ch.is_virtual)
        return;
    if(new_videos == 1) {
        if(host && host->notify_channel_single_video) {
            host->notify_channel_single_video(ch.name, videos[ch.id].front().title);
        } else if(!notify_channel_new_video_command.empty()) {
            run_command(notify_channel_new_video_command, {
                            {"{{channelName}}", ch.name},
                            {"{{videoTitle}}", videos[ch.id].front().title},
                        });
        }
    } else {
        if(host && host->notify_channel_multiple_videos) {
            host->notify_channel_multiple_videos(ch.name, new_videos);
        } else if(!notify_channel_new_videos_command.empty()) {
            run_command(notify_channel_new_videos_command, {
                            {"{{channelName}}", ch.name},
                            {"{{newVideos}}", std::to_string(new_videos)}
                        });
        }
    }
}

void action_refresh_all_channels(bool ask=true) {
    if(ask && message_box("Refresh all channels?", "Do you want to refresh all " + std::to_string(channels.size()) + " channels?", Button::Yes | Button::No, Button::No) != Button::Yes)
        return;
    int updated_channels = 0;
    int new_videos = 0;
    for(Channel &channel: channels) {
        const int count = fetch_videos_for_channel(channel, true);
        if(channel.is_virtual)
            continue;
        new_videos += count;
        if(count)
            updated_channels++;
    }
    if(updated_channels && new_videos) {
        if(host && host->notify_channels_multiple_videos) {
            host->notify_channels_multiple_videos(updated_channels, new_videos);
        } else if(!notify_channels_new_videos_command.empty()) {
            run_command(notify_channels_new_videos_command, {
                            {"{{updatedChannels}}", std::to_string(updated_channels)},
                            {"{{newVideos}}", std::to_string(new_videos)}
                        });
        }
    }
}

void action_mark_video_watched() {
    Channel &ch = channels.at(selected_channel);
    Video &video = videos[ch.id][selected_video];
    video.set_flag(db, kWatched);
    ch.load_info(db);
}

std::vector<std::string> watch_command = {"xdg-open", "https://youtube.com/watch?v={{vid}}"};

void action_watch_video() {
    Channel &ch = channels.at(selected_channel);
    Video &video = videos[ch.id][selected_video];

    if(run_command(watch_command, {{"{{vid}}", video.id}})) {
        video.set_flag(db, kWatched);
        ch.load_info(db);
    }
}

void action_mark_video_unwatched() {
    Channel &ch = channels.at(selected_channel);
    Video &selected = videos[ch.id][selected_video];
    selected.set_flag(db, kWatched, false);
    ch.load_info(db);
}

void action_mark_all_videos_watched() {
    Channel &ch = channels.at(selected_channel);
    if(message_box("Mark all as watched", "Do you want to mark all videos of " + ch.name + " as watched?", Button::Yes | Button::No, Button::No) != Button::Yes)
        return;
    {
        db_transaction transaction;
        for(Video &video: videos[ch.id]) {
            video.set_flag(db, kWatched);
        }
    }
    ch.load_info(db);
}

void action_select_prev_channel() {
    if(selected_channel > 0)
        select_channel_by_index(selected_channel - 1);
}

void action_select_next_channel() {
    if(selected_channel < channels.size() - 1)
        select_channel_by_index(selected_channel + 1);
}

void action_select_prev_video() {
    if(selected_video > 0)
        selected_video--;
}

void action_select_next_video() {
    if(selected_video < current_video_count - 1)
        selected_video++;
}

void action_select_prev_video_page() {
    if(selected_video > 0)
        selected_video -= std::min(selected_video, videos_per_page);
}

void action_select_next_video_page() {
    if(selected_video < current_video_count - 1)
        selected_video += std::min(current_video_count - 1 - selected_video, videos_per_page);
}

void action_select_first_video() {
    selected_video = 0;
}

void action_select_last_video() {
    selected_video = current_video_count - 1;
}

void action_scroll_title_left() {
    if(title_offset > 0)
        title_offset--;
}

void action_scroll_title_right() {
    if(any_title_in_next_half)
        title_offset++;
}

void action_show_video_detail() {
    const size_t cols = termpaint_surface_width(surface);

    const Channel &ch = channels.at(selected_channel);
    const Video &selected = videos[ch.id][selected_video];
    std::string text;
    text.append("Video:\t").append(selected.title).append("\n");
    text.append("Published:\t").append(selected.published).append("\n");
    text.append("Added to playlist:\t").append(selected.added_to_playlist).append("\n");
    text.append("\n").append(selected.description);

    message_box("Video Information", text_wrap(text, cols / 8 * 7));
}

void action_add_new_user_flag() {
    std::string name = get_string("Flag name");
    if(name.empty())
        return;
    userFlags.push_back(UserFlag::create(db, name));
}

void action_rename_user_flag() {
    std::vector<std::string> names;
    names.resize(userFlags.size());
    for(const UserFlag &flag: userFlags) {
        names.push_back(flag.name);
    }
    int index = get_selection("Select flag to rename", names);
    if(index < 0)
        return;
    UserFlag &flag = userFlags.at(index);
    std::string name = edit_string("Enter new name", std::string(), flag.name);
    if(name.empty())
        return;
    flag.name = name;
    flag.save(db);
}

constexpr const char userflag_keys[] = "1234567890"
                                       "abcdefghij"
                                       "klmnopqrst"
                                       "uv";
static_assert(sizeof(userflag_keys) == UserFlag::max_flag_count + 1, "There must be a key for each UserFlag"); // +1 to accomodate for the 0 byte at the end
const std::string userflag_keys_str(userflag_keys);

void action_manage_user_flags() {
    bool done = false;

    size_t channel_name_width = 0;
    for(const Channel &c: channels) {
        channel_name_width = std::max(channel_name_width, c.tui_name_width);
    }

    const char *box_chars[] = {"┬", "│", "┴"};
    size_t selected_channel = 0;
    char key_buf[] = " ";

    std::vector<action> actions = {
        {TERMPAINT_EV_KEY, "F2", 0, action_add_new_user_flag, "Add new user flag"},
        {TERMPAINT_EV_KEY, "F3", 0, action_rename_user_flag, "Rename user flag"},
        {TERMPAINT_EV_KEY, "Escape", 0, [&]{ done = true; }, "Stop user flag management"},
        {TERMPAINT_EV_KEY, "ArrowUp", 0, [&]{ if(selected_channel > 0) selected_channel--; }, "Previous channel"},
        {TERMPAINT_EV_KEY, "ArrowDown", 0, [&]{ if(selected_channel < channels.size()) selected_channel++; }, "Next channel"},
        {EV_IGNORE, "1..0,a..v", 0, nullptr, "Toggle user flags for selected channel"},
    };

    do {
        size_t flag_name_width = 0;
        for(const UserFlag &flag: userFlags) {
            flag_name_width = std::max(flag_name_width, string_width(flag.name));
        }

        const size_t content_rows_needed = std::max(userFlags.size(), channels.size());
        const size_t box_cols = 1 + channel_name_width + 3 + 2 + flag_name_width + 1;
        const size_t box_rows = 1 + content_rows_needed + 1;

        const size_t channel_name_pos = 1;
        const size_t divider_pos = channel_name_pos + channel_name_width + 1;
        const size_t flag_char_pos = divider_pos + 1;
        const size_t flag_name_pos = flag_char_pos + 2;

        Channel &current_channel = channels[selected_channel];

        draw_box_with_caption(0, 0, box_cols, box_rows);
        for(size_t row=0; row<box_rows; row++) {
            if(row<channels.size()) {
                termpaint_surface_write_with_attr(surface, channel_name_pos, 1 + row, channels[row].name.c_str(), get_attr(ASNormal, selected_channel == row));
            }
            const char *box_char = box_chars[(row > 0) + (row+1 == box_rows)];
            termpaint_surface_write_with_attr(surface, divider_pos, row, box_char, get_attr(ASNormal, false));
            if(!current_channel.is_virtual && row < userFlags.size()) {
                const UserFlag &flag = userFlags.at(row);
                termpaint_attr *attr = get_attr(current_channel.user_flags & flag.id ? ASUnwatched : ASWatched, false);
                key_buf[0] = userflag_keys[int(log2(flag.id))];
                termpaint_surface_write_with_attr(surface, flag_char_pos, 1 + row, key_buf, attr);
                termpaint_surface_write_with_attr(surface, flag_name_pos, 1 + row, flag.name.c_str(), attr);
            }
        }
        tp_flush(false);

        auto event = tp_wait_for_event();
        if(!event)
            abort();

        if(!tui_handle_action(*event, actions)) {
            if(event->type == TERMPAINT_EV_CHAR && event->string.length() == 1) {
                if(current_channel.is_virtual)
                    continue;
                const size_t index = userflag_keys_str.find(event->string[0]);
                if(index == std::string::npos)
                    continue;
                if(std::find_if(userFlags.cbegin(), userFlags.cend(),
                                [&](const UserFlag &f) { return f.id == (1<<index); }) == userFlags.cend())
                    continue;

                current_channel.user_flags ^= (1 << index);
                current_channel.save_user_flags(db);
            }
        }
    } while (!done);
}

void edit_channel_filter(ChannelFilter &filter) {
    bool done = false;

    size_t max_flag_name_width = std::max(string_width("Watched"), string_width("Downloaded"));
    for(const UserFlag &flag: userFlags) {
        max_flag_name_width = std::max(max_flag_name_width, string_width(flag.name));
    }
    const size_t space_per_column = 3+max_flag_name_width+1; // " x Flag name "

    std::vector<action> actions = {
        {EV_IGNORE, "F3", 0, nullptr, "Rename channel filter"},
        {TERMPAINT_EV_KEY, "Escape", 0, [&]{ done = true; }, "Stop channel filter editing"},
        {EV_IGNORE, ".", 0, nullptr, "Toggle \"Downloaded\" flag for selected filter"},
        {EV_IGNORE, ",", 0, nullptr, "Toggle \"Watched\" flag for selected filter"},
        {EV_IGNORE, "1..0,a..v", 0, nullptr, "Toggle user flags for selected filter"},
    };

    const auto draw_flag = [&](int x, int y, const char key, const std::string &name, bool active, bool value) {
        char key_buf[2] = {key, 0};
        termpaint_attr *attr = get_attr(active ? ASUnwatched : ASWatched, active && !value);
        termpaint_surface_write_with_attr(surface, x + 0, y, key_buf, attr);
        termpaint_surface_write_with_attr(surface, x + 2, y, name.c_str(), attr);
    };

    const auto toggle_flag = [&](uint32_t &mask, uint32_t &value, unsigned int flag) {
        // 0,0 -> 1,1 -> 1,0 -> ...
        if((mask & flag) == 0 && (value & flag) == 0) {
            mask |= flag;
            value |= flag;
        } else if(mask & flag && value & flag) {
            value &= ~flag;
        } else {
            mask &= ~flag;
            value &= ~flag;
        }
    };

    do {
        const size_t filer_name_width = string_width(filter.name);
        const size_t content_rows_needed = 1+1+UserFlag::max_flag_count/2;
        const size_t box_cols = 1 + 1 + std::max(2*space_per_column, filer_name_width) + 1;
        const size_t box_rows = 1 + content_rows_needed + 1;

        const size_t filter_name_pos = 1;
        const size_t divider_pos = box_cols / 2;
        const size_t flag_pos = 2;

        draw_box_with_caption(0, 0, box_cols, box_rows);
        termpaint_surface_write_with_attr(surface, filter_name_pos, 1, filter.name.c_str(), get_attr(ASNormal));
        draw_flag(flag_pos, 2, ',', "Watched", filter.video_mask & kWatched, filter.video_value & kWatched);
        draw_flag(divider_pos+flag_pos, 2, '.', "Downloaded", filter.video_mask & kDownloaded, filter.video_value & kDownloaded);

        for(size_t i=0; i<userFlags.size(); i++) {
            const int row = 3 + i / 2;
            const int col = i % 2;
            const UserFlag &f = userFlags.at(i);
            if(i < userFlags.size()) {
                draw_flag(divider_pos*col + flag_pos, row, userflag_keys_str.at(i), f.name, filter.user_mask & f.id, filter.user_value & f.id);
            }
        }

        tp_flush(false);

        auto event = tp_wait_for_event();
        if(!event)
            abort();

        if(!tui_handle_action(*event, actions)) {
            if(event->type == TERMPAINT_EV_CHAR && event->string.length() == 1) {
                const char ch(event->string[0]);
                const size_t index = userflag_keys_str.find(ch);
                if(index == std::string::npos) {
                    if(ch == ',') {
                        toggle_flag(filter.video_mask, filter.video_value, kWatched);
                        filter.save(db);
                    } else if(ch == '.') {
                        toggle_flag(filter.video_mask, filter.video_value, kDownloaded);
                        filter.save(db);
                    } else {
                        continue;
                    }
                }

                auto flag = std::find_if(userFlags.cbegin(), userFlags.cend(), [&](const UserFlag &f) { return f.id == (1<<index); });
                if(flag  == userFlags.cend())
                    continue;
                toggle_flag(filter.user_mask, filter.user_value, flag->id);
                filter.save(db);
            } else if(event->type == TERMPAINT_EV_KEY && event->string == "F3") {
                std::string name = edit_string("Enter new name", std::string(), filter.name);
                if(name.empty())
                    return;
                filter.name = name;
                filter.save(db);
            }
        }
    } while (!done);
}

void action_manage_channel_fitlers() {

    bool done = false;

    do {
        std::vector<ChannelFilter> filters = ChannelFilter::get_all(db);
        std::vector<std::string> names = {"Create new"};
        for(const ChannelFilter &filter: std::as_const(filters))
            names.push_back(filter.name);
        const int selected = get_selection("Select channel filter", names);
        if(selected < 0) {
            done = true;
        } else if(selected == 0) {
            std::string name = get_string("Filter name", "Please enter a name for your filter:");
            if(!name.empty()) {
                ChannelFilter::add(db, name);
            }
        } else if(selected-1 < (int)filters.size()) {
            edit_channel_filter(filters.at(selected-1));
        }
    } while(!done);
}

using json = nlohmann::json;
std::optional<json> load_json(const std::string &filename) {
    std::ifstream ifs(filename);
    if(!ifs.is_open())
        return {};
    try {
        json data;
        ifs >> data;
        return data;
    } catch (json::parse_error &err) {
        tui_abort("Failed to parse JSON file %s: %s", filename.c_str(), err.what());
        return {};
    }
}

bool save_json(const std::string &filename, const json &data) {
    std::ofstream ofs(filename);
    if(!ofs.is_open())
        return false;
    try {
        ofs << data;
        return true;
    }  catch (json::exception &err) {
        return false;
    }
}

static std::string get_module_path() {
    std::string str;
    char *exe = realpath("/proc/self/exe", nullptr);
    if(exe) {
        str = std::string(exe);
        free(exe);
        exe = nullptr;
    } else {
        perror("realpath");
    }
    exe = dirname((char*)str.c_str());

    return std::string(exe);
}

void config_get_string_list(std::vector<std::string> &buffer, const json &obj, const std::string &key) {
    if(!obj.contains(key) || !obj[key].is_array())
        return;
    buffer.clear();

    for(const json &elem: obj[key]) {
        if(!elem.is_string()) {
            tui_abort("Configuration error: " + key + " element " + elem.dump() + " is not a string but " + elem.type_name() + ".");
        }
        buffer.push_back(elem);
    }
}

static void run()
{
    const std::string module_path = get_module_path();
    user_home = std::string(std::getenv("HOME"));
    std::string database_filename = user_home + "/.local/share/yttui.db";

    curl_global_init(CURL_GLOBAL_ALL);

    const std::vector<std::string> config_locations{user_home + "/.config", module_path};
    std::string config_file;
    nlohmann::json config;
    for(const std::string &location: config_locations) {
        config_file = location + "/yttui.conf";
        auto config_data = load_json(config_file);
        if(config_data) {
            config = *config_data;
            break;
        }
    }

    if(config.count("apiKey") && config["apiKey"].is_string()) {
        yt_config.api_key = config["apiKey"];
    } else {
        tui_abort("A YouTube API key is required for this application to function.\nPlease provide one in the config file.\n\nCurrent config file:\n" + config_file);
    }
    if(config.count("extraHeaders") && config["extraHeaders"].is_array()) {
        for(const json &elem: config["extraHeaders"]) {
            if(elem.count("key") && elem["key"].is_string() && elem.count("value") && elem["value"].is_string()) {
                yt_config.extra_headers.emplace(elem["key"], elem["value"]);
            }
        }
    }
    if(config.count("database") && config["database"].is_string()) {
        database_filename = replace(config["database"], "$HOME", user_home);
    }
    config_get_string_list(watch_command, config, "watchCommand");
    if(config.contains("notifications") && config["notifications"].is_object()) {
        const json &notifications = config["notifications"];
        config_get_string_list(notify_channel_new_video_command, notifications, "channelNewVideoCommand");
        config_get_string_list(notify_channel_new_videos_command, notifications, "channelNewVideosCommand");
        config_get_string_list(notify_channels_new_videos_command, notifications, "channelsNewVideosCommand");
    }

    int auto_refresh_interval = -1; // In seconds
    if(config.count("autoRefreshInterval") && config["autoRefreshInterval"].is_number_integer()) {
        auto_refresh_interval = config["autoRefreshInterval"];
        auto_refresh_interval = std::max(-1, auto_refresh_interval);
    }
    std::chrono::system_clock::time_point next_update = std::chrono::system_clock::now() + std::chrono::seconds(auto_refresh_interval);
    std::chrono::system_clock::time_point last_user_action;

    db_init(database_filename);

    userFlags = UserFlag::get_all(db);
    make_virtual_unwatched_channel();
    for(Channel &channel: Channel::get_all(db)) {
        add_channel_to_list(channel);
    }

    for(const ChannelFilter &filter: ChannelFilter::get_all(db)) {
        Channel ch = Channel::add_virtual(filter.name, filter);
        add_channel_to_list(ch);
    }

    if(!channels.empty()) {
        select_channel_by_index(0);
    }

    bool exit = false;
    bool force_repaint = false;
    std::vector<action> actions = {
        {TERMPAINT_EV_CHAR, "a", 0, action_add_channel_by_name, "Add channel by name"},
        {TERMPAINT_EV_CHAR, "A", 0, action_add_channel_by_id, "Add channel by Id"},
        {TERMPAINT_EV_CHAR, "c", 0, action_select_channel, "Select channel"},
        {TERMPAINT_EV_CHAR, "j", 0, action_select_prev_channel, "Select previous channel"},
        {TERMPAINT_EV_CHAR, "k", 0, action_select_next_channel, "Select next channel"},
        {TERMPAINT_EV_CHAR, "r", 0, action_refresh_channel, "Refresh selected channel"},
        {TERMPAINT_EV_CHAR, "R", 0, [&](){ action_refresh_all_channels(); }, "Refresh all channels"},
        {TERMPAINT_EV_CHAR, "w", 0, action_watch_video, "Watch video"},
        {TERMPAINT_EV_CHAR, "w", TERMPAINT_MOD_ALT, action_mark_video_watched, "Mark video as watched"},
        {TERMPAINT_EV_CHAR, "u", 0, action_mark_video_unwatched, "Mark video as unwatched"},
        {TERMPAINT_EV_CHAR, "W", 0, action_mark_all_videos_watched, "Mark channel as watched"},
        {TERMPAINT_EV_CHAR, "q", TERMPAINT_MOD_CTRL, [&](){ exit = true; }, "Quit"},

        {TERMPAINT_EV_KEY, "Enter", 0, action_show_video_detail, "Show video details"},
        {TERMPAINT_EV_KEY, "Space", 0, action_show_video_detail, "Show video details"},
        {TERMPAINT_EV_KEY, "ArrowUp", 0, action_select_prev_video, "Previous video"},
        {TERMPAINT_EV_KEY, "ArrowDown", 0, action_select_next_video, "Next video"},
        {TERMPAINT_EV_KEY, "PageUp", 0, action_select_prev_video_page, "Previous video page"},
        {TERMPAINT_EV_KEY, "PageDown", 0, action_select_next_video_page, "Next video page"},
        {TERMPAINT_EV_KEY, "Home", 0, action_select_first_video, "First video"},
        {TERMPAINT_EV_KEY, "End", 0, action_select_last_video, "Last video"},
        {TERMPAINT_EV_KEY, "ArrowLeft", 0, action_scroll_title_left, "Scroll title left"},
        {TERMPAINT_EV_KEY, "ArrowRight", 0, action_scroll_title_right, "Scroll title right"},
        {TERMPAINT_EV_CHAR, "l", TERMPAINT_MOD_CTRL, [&](){ force_repaint = true; }, "Force redraw"},
        {TERMPAINT_EV_KEY, "F2", 0, action_manage_user_flags, "Manage user flags"},
        {TERMPAINT_EV_KEY, "F3", 0, action_manage_channel_fitlers, "Manage channel filters"},
    };

    bool draw = true;
    do {
        if(host && host->quit && host->quit()) {
            break;
        }

        if(draw) {
            Channel &channel = channels.at(selected_channel);
            termpaint_surface_clear(surface, TERMPAINT_DEFAULT_COLOR, TERMPAINT_DEFAULT_COLOR);
            draw_channel_list(videos[channel.id], channel.is_virtual);
            tp_flush(force_repaint);
            force_repaint = false;
        }
        draw = true;

        auto event = tp_wait_for_event(500);
        if(!event)
            abort();

        if(event->type == EV_TIMEOUT) {
            draw = false;
            const bool update_pending = next_update < std::chrono::system_clock::now();
            const bool inactivity_threshold = (std::chrono::system_clock::now() - last_user_action) > std::chrono::seconds(30);
            if(auto_refresh_interval != -1 && update_pending && inactivity_threshold) {
                action_refresh_all_channels(false);
                next_update = std::chrono::system_clock::now() + std::chrono::seconds(auto_refresh_interval);
                draw = true;
            }
        } else if(tui_handle_action(*event, actions)) {
            last_user_action = std::chrono::system_clock::now();
        }
    } while (!exit);

    db_shutdown();
    curl_global_cleanup();
}

void run_standalone()
{
    tp_init();
    run();
    tp_shutdown();
}

void run_embedded(int pty_fd, application_host *_host)
{
    tp_init_from_fd(pty_fd);
    host = _host;
    run();
    tp_shutdown();
}