use std::error::Error;
use teloxide::{
    payloads::SendMessageSetters,
    prelude2::*,
    types::{
        InlineKeyboardButton, InlineKeyboardMarkup, InlineQueryResultArticle, InputMessageContent,
        InputMessageContentText,
    },
    utils::command::BotCommands,
};

#[derive(BotCommands)]
#[command(rename = "lowercase", description = "These commands are supported:")]
enum Command {
    #[command(description = "Display this text")]
    Help,
    #[command(description = "Start")]
    Start,
}

/// Creates a keyboard made by buttons in a big column.
fn make_keyboard() -> InlineKeyboardMarkup {
    let mut keyboard: Vec<Vec<InlineKeyboardButton>> = vec![];

    let debian_versions = [
        "Buzz", "Rex", "Bo", "Hamm", "Slink", "Potato", "Woody", "Sarge", "Etch", "Lenny",
        "Squeeze", "Wheezy", "Jessie", "Stretch", "Buster", "Bullseye",
    ];

    for versions in debian_versions.chunks(3) {
        let row = versions
            .iter()
            .map(|&version| InlineKeyboardButton::callback(version.to_owned(), version.to_owned()))
            .collect();

        keyboard.push(row);
    }

    InlineKeyboardMarkup::new(keyboard)
}

/// Parse the text wrote on Telegram and check if that text is a valid command
/// or not, then match the command. If the command is `/start` it writes a
/// markup with the `InlineKeyboardMarkup`.
async fn message_handler(
    m: Message,
    bot: AutoSend<Bot>,
) -> Result<(), Box<dyn Error + Send + Sync>> {
    if let Some(text) = m.text() {
        match BotCommands::parse(text, "buttons") {
            Ok(Command::Help) => {
                // Just send the description of all commands.
                bot.send_message(m.chat.id, Command::descriptions().to_string()).await?;
            }
            Ok(Command::Start) => {
                // Create a list of buttons and send them.
                let keyboard = make_keyboard();
                bot.send_message(m.chat.id, "Debian versions:").reply_markup(keyboard).await?;
            }

            Err(_) => {
                bot.send_message(m.chat.id, "Command not found!").await?;
            }
        }
    }

    Ok(())
}

async fn inline_query_handler(
    q: InlineQuery,
    bot: AutoSend<Bot>,
) -> Result<(), Box<dyn Error + Send + Sync>> {
    let choose_debian_version = InlineQueryResultArticle::new(
        "0",
        "Chose debian version",
        InputMessageContent::Text(InputMessageContentText::new("Debian versions:")),
    )
    .reply_markup(make_keyboard());

    bot.answer_inline_query(q.id, vec![choose_debian_version.into()]).await?;

    Ok(())
}

/// When it receives a callback from a button it edits the message with all
/// those buttons writing a text with the selected Debian version.
///
/// **IMPORTANT**: do not send privacy-sensitive data this way!!!
/// Anyone can read data stored in the callback button.
async fn callback_handler(
    q: CallbackQuery,
    bot: AutoSend<Bot>,
) -> Result<(), Box<dyn Error + Send + Sync>> {
    if let Some(version) = q.data {
        let text = format!("You chose: {}", version);

        match q.message {
            Some(Message { id, chat, .. }) => {
                bot.edit_message_text(chat.id, id, text).await?;
            }
            None => {
                if let Some(id) = q.inline_message_id {
                    bot.edit_message_text_inline(id, text).await?;
                }
            }
        }

        log::info!("You chose: {}", version);
    }

    Ok(())
}

#[tokio::main]
async fn main() -> Result<(), Box<dyn Error>> {
    pretty_env_logger::init();
    log::info!("Starting bot...");

    let bot = Bot::from_env().auto_send();

    let handler = dptree::entry()
        .branch(Update::filter_message().endpoint(message_handler))
        .branch(Update::filter_callback_query().endpoint(callback_handler))
        .branch(Update::filter_inline_query().endpoint(inline_query_handler));

    Dispatcher::builder(bot, handler).build().setup_ctrlc_handler().dispatch().await;

    log::info!("Closing bot... Goodbye!");

    Ok(())
}