use std::{path::PathBuf, sync::Arc, time::Duration};

use clap::Args;
use color_eyre::eyre::Result;
use fluent_templates::Loader;
use novel_api::{CiweimaoClient, CiyuanjiClient, Client, Comment, CommentType, SfacgClient};
use ratatui::{
    buffer::Buffer,
    crossterm::event::{
        self, Event, KeyCode, KeyEvent, KeyEventKind, KeyModifiers, MouseEvent, MouseEventKind,
    },
    layout::{Alignment, Constraint, Direction, Layout, Rect},
    widgets::{block::Title, Block, Paragraph, StatefulWidget, Tabs, Widget, Wrap},
    Frame,
};
use ratatui_image::{
    picker::Picker, protocol::StatefulProtocol, FilterType, Resize, StatefulImage,
};
use strum::{Display, EnumIter, FromRepr, IntoEnumIterator};
use tokio::{runtime::Handle, task};
use tracing::{debug, error};
use tui_scrollview::ScrollViewState;
use url::Url;

use super::{Mode, ScrollableParagraph};
use crate::{
    cmd::{Convert, Source},
    utils, Tui, LANG_ID, LOCALES,
};

#[must_use]
#[derive(Args)]
#[command(arg_required_else_help = true,
    about = LOCALES.lookup(&LANG_ID, "info_command"))]
pub struct Info {
    #[arg(help = LOCALES.lookup(&LANG_ID, "novel_id"))]
    pub novel_id: u32,

    #[arg(short, long,
        help = LOCALES.lookup(&LANG_ID, "source"))]
    pub source: Source,

    #[arg(short, long, value_enum, value_delimiter = ',',
        help = LOCALES.lookup(&LANG_ID, "converts"))]
    pub converts: Vec<Convert>,

    #[arg(long, default_value_t = false,
        help = LOCALES.lookup(&LANG_ID, "ignore_keyring"))]
    pub ignore_keyring: bool,

    #[arg(long, num_args = 0..=1, default_missing_value = super::DEFAULT_PROXY,
        help = LOCALES.lookup(&LANG_ID, "proxy"))]
    pub proxy: Option<Url>,

    #[arg(long, default_value_t = false,
        help = LOCALES.lookup(&LANG_ID, "no_proxy"))]
    pub no_proxy: bool,

    #[arg(long, num_args = 0..=1, default_missing_value = super::default_cert_path(),
        help = super::cert_help_msg())]
    pub cert: Option<PathBuf>,
}

pub async fn execute(config: Info) -> Result<()> {
    match config.source {
        Source::Sfacg => {
            let mut client = SfacgClient::new().await?;
            super::set_options(&mut client, &config.proxy, &config.no_proxy, &config.cert);
            do_execute(client, config).await?
        }
        Source::Ciweimao => {
            let mut client = CiweimaoClient::new().await?;
            super::set_options(&mut client, &config.proxy, &config.no_proxy, &config.cert);
            utils::log_in(&client, &config.source, config.ignore_keyring).await?;
            do_execute(client, config).await?
        }
        Source::Ciyuanji => {
            let mut client = CiyuanjiClient::new().await?;
            super::set_options(&mut client, &config.proxy, &config.no_proxy, &config.cert);
            utils::log_in_without_password(&client).await?;
            do_execute(client, config).await?
        }
    }

    Ok(())
}

async fn do_execute<T>(client: T, config: Info) -> Result<()>
where
    T: Client + Send + Sync + 'static,
{
    let client = Arc::new(client);
    super::handle_ctrl_c(&client);

    let mut terminal = crate::init_terminal()?;
    App::new(client, config).await?.run(&mut terminal)?;
    crate::restore_terminal()?;

    Ok(())
}

struct App<T> {
    mode: Mode,
    tab: Tab,
    info_tab: InfoTab,
    short_comment_tab: CommentTab<T>,
    long_comment_tab: CommentTab<T>,
}

impl<T> App<T>
where
    T: Client + Send + Sync + 'static,
{
    async fn new(client: Arc<T>, config: Info) -> Result<Self> {
        Ok(App {
            mode: Mode::default(),
            tab: Tab::default(),
            info_tab: InfoTab::new(Arc::clone(&client), &config).await?,
            short_comment_tab: CommentTab::new(Arc::clone(&client), &config, CommentType::Short)
                .await?,
            long_comment_tab: CommentTab::new(Arc::clone(&client), &config, CommentType::Long)
                .await?,
        })
    }

    fn run(&mut self, terminal: &mut Tui) -> Result<()> {
        self.draw(terminal)?;

        while self.is_running() {
            if self.handle_events()? {
                self.draw(terminal)?;
            }
        }

        Ok(())
    }

    fn is_running(&self) -> bool {
        self.mode != Mode::Quit
    }

    fn draw(&mut self, terminal: &mut Tui) -> Result<()> {
        terminal.draw(|frame| self.render_frame(frame))?;
        Ok(())
    }

    fn render_frame(&mut self, frame: &mut Frame) {
        frame.render_widget(self, frame.size());
    }

    fn handle_events(&mut self) -> Result<bool> {
        if event::poll(Duration::from_secs_f64(1.0 / 60.0))? {
            return match event::read()? {
                Event::Key(key_event) if key_event.kind == KeyEventKind::Press => {
                    Ok(self.handle_key_event(key_event))
                }
                Event::Mouse(mouse_event) => Ok(self.handle_mouse_event(mouse_event)),
                _ => Ok(false),
            };
        }
        Ok(false)
    }

    fn handle_key_event(&mut self, key_event: KeyEvent) -> bool {
        match key_event.code {
            KeyCode::Char('q') | KeyCode::Esc => self.exit(),
            KeyCode::Char('c') if key_event.modifiers.contains(KeyModifiers::CONTROL) => {
                self.exit()
            }
            KeyCode::Tab => self.next_tab(),
            KeyCode::Left => match self.tab {
                Tab::ShortComment => self.prev_page_short_comment_tab(),
                Tab::LongComment => self.prev_page_long_comment_tab(),
                _ => false,
            },
            KeyCode::Right => match self.tab {
                Tab::ShortComment => self.next_page_short_comment_tab(),
                Tab::LongComment => self.next_page_long_comment_tab(),
                _ => false,
            },
            KeyCode::Up => match self.tab {
                Tab::Info => self.scroll_up_info_tab(),
                Tab::ShortComment => self.scroll_up_short_comment_tab(),
                Tab::LongComment => self.scroll_up_long_comment_tab(),
            },
            KeyCode::Down => match self.tab {
                Tab::Info => self.scroll_down_info_tab(),
                Tab::ShortComment => self.scroll_down_short_comment_tab(),
                Tab::LongComment => self.scroll_down_long_comment_tab(),
            },
            _ => false,
        }
    }

    fn handle_mouse_event(&mut self, mouse_event: MouseEvent) -> bool {
        match mouse_event.kind {
            MouseEventKind::ScrollUp => match self.tab {
                Tab::Info => self.scroll_up_info_tab(),
                Tab::ShortComment => self.scroll_up_short_comment_tab(),
                Tab::LongComment => self.scroll_up_long_comment_tab(),
            },
            MouseEventKind::ScrollDown => match self.tab {
                Tab::Info => self.scroll_down_info_tab(),
                Tab::ShortComment => self.scroll_down_short_comment_tab(),
                Tab::LongComment => self.scroll_down_long_comment_tab(),
            },
            _ => false,
        }
    }

    fn exit(&mut self) -> bool {
        self.mode = Mode::Quit;
        false
    }

    fn next_tab(&mut self) -> bool {
        self.tab = self.tab.next();
        true
    }

    fn scroll_up_info_tab(&mut self) -> bool {
        self.info_tab.scroll_view_state.scroll_up();
        true
    }

    fn scroll_down_info_tab(&mut self) -> bool {
        self.info_tab.scroll_view_state.scroll_down();
        true
    }

    fn scroll_up_short_comment_tab(&mut self) -> bool {
        self.short_comment_tab.scroll_view_state.scroll_up();
        true
    }

    fn scroll_down_short_comment_tab(&mut self) -> bool {
        self.short_comment_tab.scroll_view_state.scroll_down();
        true
    }

    fn scroll_up_long_comment_tab(&mut self) -> bool {
        self.long_comment_tab.scroll_view_state.scroll_up();
        true
    }

    fn scroll_down_long_comment_tab(&mut self) -> bool {
        self.long_comment_tab.scroll_view_state.scroll_down();
        true
    }

    fn prev_page_short_comment_tab(&mut self) -> bool {
        self.short_comment_tab.prev_page();
        self.short_comment_tab.scroll_view_state.scroll_to_top();
        true
    }

    fn next_page_short_comment_tab(&mut self) -> bool {
        self.short_comment_tab.next_page();
        self.short_comment_tab.scroll_view_state.scroll_to_top();
        true
    }

    fn prev_page_long_comment_tab(&mut self) -> bool {
        self.long_comment_tab.prev_page();
        self.long_comment_tab.scroll_view_state.scroll_to_top();
        true
    }

    fn next_page_long_comment_tab(&mut self) -> bool {
        self.long_comment_tab.next_page();
        self.long_comment_tab.scroll_view_state.scroll_to_top();
        true
    }

    fn render_tabs(&self, area: Rect, buf: &mut Buffer) {
        Tabs::new(Tab::iter().map(Tab::title))
            .select(self.tab as usize)
            .render(area, buf);
    }

    fn render_selected_tab(&mut self, area: Rect, buf: &mut Buffer) {
        match self.tab {
            Tab::Info => self.info_tab.render(area, buf),
            Tab::ShortComment => self.short_comment_tab.render(area, buf),
            Tab::LongComment => self.long_comment_tab.render(area, buf),
        };
    }
}

impl<T> Widget for &mut App<T>
where
    T: Client + Send + Sync + 'static,
{
    fn render(self, area: Rect, buf: &mut Buffer) {
        let vertical = Layout::vertical([Constraint::Length(1), Constraint::Min(0)]);
        let [header_area, tab_area] = vertical.areas(area);

        self.render_tabs(header_area, buf);
        self.render_selected_tab(tab_area, buf);
    }
}

#[derive(Clone, Copy, Default, Display, FromRepr, EnumIter)]
enum Tab {
    #[default]
    #[strum(to_string = "简介")]
    Info,
    #[strum(to_string = "短评")]
    ShortComment,
    #[strum(to_string = "长评")]
    LongComment,
}

impl Tab {
    fn next(self) -> Self {
        let current_index = self as usize;
        let next_index = current_index.saturating_add(1);
        Self::from_repr(next_index).unwrap_or(Tab::Info)
    }

    fn title(self) -> String {
        format!(" {self} ")
    }
}

struct InfoTab {
    novel_info_str: String,
    cover_state: Option<Box<dyn StatefulProtocol>>,
    scroll_view_state: ScrollViewState,
}

impl InfoTab {
    async fn new<T>(client: Arc<T>, config: &Info) -> Result<Self>
    where
        T: Client + Send + Sync + 'static,
    {
        let novel_info = utils::novel_info(&client, config.novel_id).await?;
        let novel_info_str = utils::novel_info_to_string(&novel_info, &config.converts)?;

        let font_size = (12, 24);
        #[cfg(not(target_os = "windows"))]
        let mut picker = Picker::from_termios().unwrap_or(Picker::new(font_size));
        #[cfg(target_os = "windows")]
        let mut picker = Picker::new(font_size);

        debug!("font size: {:?}", picker.font_size);

        picker.guess_protocol();

        let mut cover_image = None;
        if let Some(ref url) = novel_info.cover_url {
            match client.image(url).await {
                Ok(image) => cover_image = Some(image),
                Err(err) => {
                    error!("Cover image download failed: `{err}`");
                }
            }
        }

        let cover_state = cover_image.map(|image| {
            let size = utils::terminal_size();
            let width = (size.0 as u32 * picker.font_size.0 as u32) / 2;
            let height = size.1 as u32 * picker.font_size.1 as u32;

            picker.new_resize_protocol(image.resize(width, height, FilterType::Lanczos3))
        });

        Ok(Self {
            novel_info_str,
            cover_state,
            scroll_view_state: ScrollViewState::default(),
        })
    }

    fn render_image(&mut self, area: Rect, buf: &mut Buffer) {
        if let Some(cover_state) = self.cover_state.as_mut() {
            let block = Block::bordered();
            let block_area = block.inner(area);
            Widget::render(block, area, buf);

            StatefulWidget::render(
                StatefulImage::new(None).resize(Resize::Fit(Some(FilterType::Lanczos3))),
                block_area,
                buf,
                cover_state,
            );
        }
    }

    fn render_paragraph(&mut self, area: Rect, buf: &mut Buffer) {
        let paragraph = ScrollableParagraph::new(self.novel_info_str.as_str());
        StatefulWidget::render(paragraph, area, buf, &mut self.scroll_view_state);
    }
}

impl Widget for &mut InfoTab {
    fn render(self, area: Rect, buf: &mut Buffer) {
        if self.cover_state.is_some() {
            let layout = Layout::default()
                .direction(Direction::Horizontal)
                .constraints(vec![Constraint::Percentage(50), Constraint::Percentage(50)])
                .split(area);

            self.render_image(layout[0], buf);
            self.render_paragraph(layout[1], buf);
        } else {
            self.render_paragraph(area, buf);
        }
    }
}

struct CommentTab<T> {
    client: Arc<T>,
    comments: Vec<Comment>,
    scroll_view_state: ScrollViewState,
    novel_id: u32,
    page: u16,
    size: u16,
    max_page: Option<u16>,
    comment_type: CommentType,
    converts: Vec<Convert>,
}

impl<T> CommentTab<T>
where
    T: Client + Send + Sync + 'static,
{
    async fn new(client: Arc<T>, config: &Info, comment_type: CommentType) -> Result<Self> {
        let size = match comment_type {
            CommentType::Short => 20,
            CommentType::Long => 5,
        };

        Ok(Self {
            client,
            comments: Vec::new(),
            scroll_view_state: ScrollViewState::default(),
            novel_id: config.novel_id,
            page: 0,
            size,
            max_page: None,
            comment_type,
            converts: config.converts.clone(),
        })
    }

    fn prev_page(&mut self) -> bool {
        if self.page >= 1 {
            self.page -= 1;
            true
        } else {
            false
        }
    }

    fn next_page(&mut self) -> bool {
        if !self.gte_max_page() {
            self.page += 1;
            true
        } else {
            false
        }
    }

    fn gte_max_page(&self) -> bool {
        self.max_page
            .as_ref()
            .is_some_and(|max_page| self.page >= *max_page)
    }

    fn comments(&self) -> Result<Option<Vec<Comment>>> {
        let page = self.page;
        let size = self.size;
        let novel_id = self.novel_id;
        let comment_type = self.comment_type;
        let client = Arc::clone(&self.client);

        let comments = task::block_in_place(move || {
            Handle::current().block_on(async move {
                client
                    .comments(novel_id, comment_type, false, page, size)
                    .await
            })
        })?;

        Ok(comments)
    }

    fn title(&self) -> Result<String> {
        let title = if let Some(max_page) = self.max_page {
            format!("第 {} 页，共 {} 页", self.page + 1, max_page + 1)
        } else {
            format!("第 {} 页", self.page + 1)
        };

        utils::convert_str(title, &self.converts, false)
    }

    fn content(&self) -> Result<String> {
        let content = self
            .comments
            .iter()
            .skip((self.page * self.size) as usize)
            .take(self.size as usize)
            .map(|comment| match comment {
                Comment::Short(comment) => comment.content.join("\n"),
                Comment::Long(comment) => {
                    format!("{}\n{}", comment.title, comment.content.join("\n"))
                }
            })
            .collect::<Vec<String>>()
            .join("\n\n\n");

        utils::convert_str(content, &self.converts, false)
    }
}

impl<T> Widget for &mut CommentTab<T>
where
    T: Client + Send + Sync + 'static,
{
    fn render(self, area: Rect, buf: &mut Buffer) {
        if T::has_this_type_of_comments(self.comment_type) {
            if !self.gte_max_page() && self.comments.len() < ((self.page + 1) * self.size) as usize
            {
                let comments = self.comments().expect("failed to get comments");

                if let Some(comments) = comments {
                    if comments.len() < self.size as usize {
                        self.max_page = Some(self.page);
                    }
                    self.comments.extend(comments);
                } else {
                    self.max_page = Some(self.page - 1);
                    self.page -= 1;
                }
            }

            let paragraph =
                ScrollableParagraph::new(self.content().expect("failed to get content")).title(
                    Title::from(self.title().expect("failed to get title"))
                        .alignment(Alignment::Right),
                );
            StatefulWidget::render(paragraph, area, buf, &mut self.scroll_view_state);
        } else {
            let content = utils::convert_str("无此类型评论", &self.converts, false)
                .expect("convert_str() failed");
            let paragraph = Paragraph::new(content)
                .wrap(Wrap { trim: false })
                .block(Block::bordered());
            Widget::render(paragraph, area, buf);
        }
    }
}