pub mod callback_data;
pub mod commands;

use core::fmt::Debug;

use smartstring::alias::String as SmartString;

use smallvec::SmallVec;
use teloxide::{
    adaptors::{CacheMe, Throttle},
    dispatching::UpdateFilterExt,
    dptree,
    prelude::*,
};
use tracing::log;

use crate::bots::approved_bot::{
    services::{
        book_library::{
            formatters::{Format, FormatTitle},
            get_author_books, get_sequence_books, get_translator_books,
            types::Page,
        },
        user_settings::get_user_or_default_lang_codes,
    },
    tools::filter_callback_query,
};

use self::{callback_data::BookCallbackData, commands::BookCommand};

use super::utils::{filter_command::filter_command, pagination::generic_get_pagination_keyboard};

async fn send_book_handler<T, P, Fut>(
    message: Message,
    bot: CacheMe<Throttle<Bot>>,
    command: BookCommand,
    books_getter: fn(id: u32, page: u32, allowed_langs: SmallVec<[SmartString; 3]>) -> Fut,
) -> crate::bots::BotHandlerInternal
where
    T: Format + Clone + Debug,
    P: FormatTitle + Clone + Debug,
    Fut: std::future::Future<Output = anyhow::Result<Page<T, P>>>,
{
    let id = match command {
        BookCommand::Author { id } => id,
        BookCommand::Translator { id } => id,
        BookCommand::Sequence { id } => id,
    };

    let chat_id = message.chat.id;
    let user_id = message.from.map(|from| from.id);

    let user_id = match user_id {
        Some(v) => v,
        None => {
            return match bot
                .send_message(chat_id, "Повторите запрос сначала")
                .send()
                .await
            {
                Ok(_) => Ok(()),
                Err(err) => Err(err.into()),
            }
        }
    };

    let allowed_langs = get_user_or_default_lang_codes(user_id).await;

    let items_page = match books_getter(id, 1, allowed_langs.clone()).await {
        Ok(v) => v,
        Err(err) => {
            bot.send_message(chat_id, "Ошибка! Попробуйте позже :(")
                .send()
                .await?;
            return Err(err);
        }
    };

    if items_page.pages == 0 {
        bot.send_message(chat_id, "Книги не найдены!")
            .send()
            .await?;
        return Ok(());
    };

    let formatted_page = items_page.format(1, 4096);

    let callback_data = match command {
        BookCommand::Author { id } => BookCallbackData::Author { id, page: 1 },
        BookCommand::Translator { id } => BookCallbackData::Translator { id, page: 1 },
        BookCommand::Sequence { id } => BookCallbackData::Sequence { id, page: 1 },
    };

    let keyboard = generic_get_pagination_keyboard(1, items_page.pages, callback_data, true);

    bot.send_message(chat_id, formatted_page)
        .reply_markup(keyboard)
        .send()
        .await?;

    Ok(())
}

async fn send_pagination_book_handler<T, P, Fut>(
    cq: CallbackQuery,
    bot: CacheMe<Throttle<Bot>>,
    callback_data: BookCallbackData,
    books_getter: fn(id: u32, page: u32, allowed_langs: SmallVec<[SmartString; 3]>) -> Fut,
) -> crate::bots::BotHandlerInternal
where
    T: Format + Clone + Debug,
    P: FormatTitle + Clone + Debug,
    Fut: std::future::Future<Output = anyhow::Result<Page<T, P>>>,
{
    let (id, page) = match callback_data {
        BookCallbackData::Author { id, page } => (id, page),
        BookCallbackData::Translator { id, page } => (id, page),
        BookCallbackData::Sequence { id, page } => (id, page),
    };

    let chat_id = cq.message.as_ref().map(|message| message.chat().id);
    let user_id = cq.from.id;
    let message_id = cq.message.as_ref().map(|message| message.id());

    let (chat_id, message_id) = match (chat_id, message_id) {
        (Some(chat_id), Some(message_id)) => (chat_id, message_id),
        (Some(chat_id), None) => {
            bot.send_message(chat_id, "Повторите поиск сначала")
                .send()
                .await?;
            return Ok(());
        }
        _ => {
            return Ok(());
        }
    };

    let allowed_langs = get_user_or_default_lang_codes(user_id).await;

    let mut items_page = match books_getter(id, page, allowed_langs.clone()).await {
        Ok(v) => v,
        Err(err) => {
            match bot
                .send_message(chat_id, "Ошибка! Попробуйте позже :(")
                .send()
                .await
            {
                Ok(_) => (),
                Err(err) => log::error!("{err:?}"),
            }
            return Err(err);
        }
    };

    if items_page.pages == 0 {
        bot.send_message(chat_id, "Книги не найдены!")
            .send()
            .await?;
        return Ok(());
    };

    if page > items_page.pages {
        items_page = match books_getter(id, items_page.pages, allowed_langs.clone()).await {
            Ok(v) => v,
            Err(err) => {
                bot.send_message(chat_id, "Ошибка! Попробуйте позже :(")
                    .send()
                    .await?;

                return Err(err);
            }
        };
    }

    let formatted_page = items_page.format(page, 4096);

    let keyboard = generic_get_pagination_keyboard(page, items_page.pages, callback_data, true);

    bot.edit_message_text(chat_id, message_id, formatted_page)
        .reply_markup(keyboard)
        .send()
        .await?;

    Ok(())
}

pub fn get_book_handler() -> crate::bots::BotHandler {
    dptree::entry()
        .branch(
            Update::filter_message()
                .chain(filter_command::<BookCommand>())
                .endpoint(
                    |message: Message, bot: CacheMe<Throttle<Bot>>, command: BookCommand| async move {
                        match command {
                            BookCommand::Author { .. } => {
                                send_book_handler(
                                    message,
                                    bot,
                                    command,
                                    get_author_books,
                                )
                                .await
                            }
                            BookCommand::Translator { .. } => {
                                send_book_handler(
                                    message,
                                    bot,
                                    command,
                                    get_translator_books,
                                )
                                .await
                            }
                            BookCommand::Sequence { .. } => {
                                send_book_handler(
                                    message,
                                    bot,
                                    command,
                                    get_sequence_books,
                                )
                                .await
                            }
                        }
                    },
                ),
        )
        .branch(
            Update::filter_callback_query()
                .chain(filter_callback_query::<BookCallbackData>())
                .endpoint(|cq: CallbackQuery, bot: CacheMe<Throttle<Bot>>, callback_data: BookCallbackData| async move {
                    match callback_data {
                        BookCallbackData::Author { .. } => send_pagination_book_handler(cq, bot, callback_data, get_author_books).await,
                        BookCallbackData::Translator { .. } => send_pagination_book_handler(cq, bot, callback_data,  get_translator_books).await,
                        BookCallbackData::Sequence { .. } => send_pagination_book_handler(cq, bot, callback_data,  get_sequence_books).await,
                    }
                }),
        )
}