use std::{net::Ipv4Addr, sync::LazyLock};

use jocalsend::ReceiveRequest;
use log::LevelFilter;
use ratatui::{
    buffer::Buffer,
    layout::{Constraint, Flex, Layout, Margin, Rect},
    style::{Color, Style, Stylize},
    symbols::border,
    text::{Line, Text, ToLine},
    widgets::{
        Block, Borders, Clear, List, ListItem, ListState, Padding, Paragraph, Row, Table,
        TableState, Widget,
    },
};
use tui_logger::{TuiLoggerLevelOutput, TuiLoggerWidget, TuiWidgetState};

use super::{App, CurrentScreen, FileMode, Peer, SendingScreen};

static MAIN_MENU: LazyLock<Line> = LazyLock::new(|| {
    Line::from(vec![
        " Send ".into(),
        "<S>".blue().bold(),
        " Receive ".into(),
        "<R>".blue().bold(),
        " Logs ".into(),
        "<L>".blue().bold(),
        " Previous Screen ".into(),
        "<ESC>".blue().bold(),
        " Quit ".into(),
        "<Q>".blue().bold(),
    ])
});

static LOGGING_MENU: LazyLock<Line> = LazyLock::new(|| {
    Line::from(vec![
        " Reduce Logging Level ".into(),
        "<LEFT>".blue().bold(),
        " Increase Logging Level ".into(),
        "<RIGHT>".blue().bold(),
        " Previous Screen ".into(),
        "<ESC>".blue().bold(),
        " Quit ".into(),
        "<Q>".blue().bold(),
    ])
});

static CONTENT_RECEIVE_MENU: LazyLock<Line> = LazyLock::new(|| {
    Line::from(vec![
        " Select Previous ".into(),
        "<UP>".blue().bold(),
        " Select Next ".into(),
        "<DOWN>".blue().bold(),
        " Approve Selection ".into(),
        "<A>".blue().bold(),
        " Deny Selection ".into(),
        "<D>".blue().bold(),
        " Previous Screen ".into(),
        "<ESC>".blue().bold(),
        " Quit ".into(),
        "<Q>".blue().bold(),
    ])
});

static CONTENT_SEND_FILE_MENU: LazyLock<Line> = LazyLock::new(|| {
    Line::from(vec![
        " Fuzzy Search ".into(),
        "</>".blue().bold(),
        " Select Previous ".into(),
        "<UP>".blue().bold(),
        " Select Next ".into(),
        "<DOWN>".blue().bold(),
        " Send File ".into(),
        "<ENTER>".blue().bold(),
        " Enter Text ".into(),
        "<T>".blue().bold(),
        " Peers ".into(),
        "<TAB>".blue().bold(),
        " Previous Screen ".into(),
        "<ESC>".blue().bold(),
        " Quit ".into(),
        "<Q>".blue().bold(),
    ])
});

static CONTENT_SEND_PEERS_MENU: LazyLock<Line> = LazyLock::new(|| {
    Line::from(vec![
        " Select Previous ".into(),
        "<UP>".blue().bold(),
        " Select Next ".into(),
        "<DOWN>".blue().bold(),
        " Send to Peer ".into(),
        "<ENTER>".blue().bold(),
        " Enter Text ".into(),
        "<T>".blue().bold(),
        " Files ".into(),
        "<TAB>".blue().bold(),
        " Previous Screen ".into(),
        "<ESC>".blue().bold(),
        " Quit ".into(),
        "<Q>".blue().bold(),
    ])
});

static CONTENT_SEND_TEXT_MENU: LazyLock<Line> = LazyLock::new(|| {
    Line::from(vec![
        " Send Text ".into(),
        "<ENTER>".blue().bold(),
        " Peers ".into(),
        "<TAB>".blue().bold(),
        " Cancel ".into(),
        "<ESC>".blue().bold(),
    ])
});

impl Widget for &mut App {
    fn render(self, area: Rect, buf: &mut Buffer) {
        let main_layout = Layout::vertical([Constraint::Min(5), Constraint::Min(3)]);
        let [top, bottom] = main_layout.areas(area);

        let footer_layout =
            Layout::horizontal([Constraint::Percentage(30), Constraint::Percentage(70)]);
        let [footer_left, footer_right] = footer_layout.areas(bottom);
        let footer_margin = Margin::new(1, 1);

        let header_layout =
            Layout::horizontal([Constraint::Percentage(50), Constraint::Percentage(50)]);
        let [header_left, header_right] = header_layout.areas(top);
        let header_margin = Margin::new(1, 2);

        let subscreen_margin = Margin::new(1, 2);

        // it's safe to call `unwrap()` here because we ensure there's always at least
        // one element in `self.screen`; see the `self.pop()` method
        let current_screen = self.screen();
        match current_screen {
            CurrentScreen::Main => {
                let rx_reqs: Vec<_> = self.receive_requests.values().collect();
                outer_frame(&current_screen, &MAIN_MENU, area, buf);
                logger(header_right.inner(header_margin), buf);
                peers(
                    &self.peers,
                    &mut self.peer_state,
                    footer_right.inner(footer_margin),
                    buf,
                );
                network_info(
                    &self.service.config.local_ip_addr,
                    footer_left.inner(footer_margin),
                    buf,
                );
                receive_requests(
                    &rx_reqs,
                    &mut self.receiving_state,
                    header_left.inner(header_margin),
                    buf,
                );
            }
            CurrentScreen::Help => {
                // TODO: display help
            }
            CurrentScreen::Logging | CurrentScreen::Stopping => {
                outer_frame(&current_screen, &LOGGING_MENU, area, buf);
                logger(area.inner(subscreen_margin), buf);
            }
            CurrentScreen::Receiving => {
                let rx_reqs: Vec<_> = self.receive_requests.values().collect();
                outer_frame(&current_screen, &CONTENT_RECEIVE_MENU, area, buf);
                receive_requests(
                    &rx_reqs,
                    &mut self.receiving_state,
                    top.inner(subscreen_margin),
                    buf,
                );
                logger(bottom.inner(subscreen_margin), buf);
            }
            CurrentScreen::Sending(sending_screen) => {
                match sending_screen {
                    SendingScreen::Files(_) => {
                        outer_frame(&current_screen, &CONTENT_SEND_FILE_MENU, area, buf)
                    }
                    SendingScreen::Peers => {
                        outer_frame(&current_screen, &CONTENT_SEND_PEERS_MENU, area, buf)
                    }
                    SendingScreen::Text => {
                        outer_frame(&current_screen, &CONTENT_SEND_TEXT_MENU, area, buf);
                    }
                }

                let file_area = header_left.inner(header_margin);

                match sending_screen {
                    SendingScreen::Files(FileMode::Picking) => {
                        self.file_finder.widget().render(file_area, buf);
                    }
                    SendingScreen::Files(FileMode::Fuzzy) => {
                        let layout = Layout::vertical([Constraint::Max(6), Constraint::Min(5)]);
                        let [input, files] = layout.areas(file_area);
                        text_popup(self.file_finder.input.value(), "fuzzy search", input, buf);
                        self.file_finder.widget().render(files, buf);
                    }
                    _ => {}
                }

                logger(header_right.inner(header_margin), buf);

                peers(
                    &self.peers,
                    &mut self.peer_state,
                    bottom.inner(subscreen_margin),
                    buf,
                );

                if sending_screen == SendingScreen::Text {
                    let rect = centered_rect(area, Constraint::Percentage(80), Constraint::Max(10));
                    let text = if let Some(text) = self.text.as_ref() {
                        text
                    } else {
                        ""
                    };

                    text_popup(text, " Enter Text to Send ", rect, buf);
                    // TODO: add cursor, need to do that in the `draw` method
                    // because we need the frame to do it; add cursor position
                    // fields to `App` and mutate them in the text input
                    // function
                }
            }
        }
    }
}

fn outer_frame(screen: &CurrentScreen, menu: &Line, area: Rect, buf: &mut Buffer) {
    let title = Line::from(" Jocalsend ".bold());
    let block = Block::bordered()
        .title(title.centered())
        .title_bottom(menu.clone().centered())
        .border_set(border::THICK);

    let current_screen = format!("{screen:?}",);
    let text = Text::from(Line::from(current_screen.yellow()));

    Paragraph::new(text)
        .centered()
        .block(block)
        .render(area, buf);
}

fn text_popup(text: &str, title: &str, area: Rect, buf: &mut Buffer) {
    let title = Line::from(title.bold());
    let block = Block::bordered().title(title.centered());
    Clear.render(area, buf);

    block.render(area, buf);

    let (_, len) = unicode_segmentation::UnicodeSegmentation::graphemes(text, true).size_hint();
    let len = len.unwrap_or(text.len()) as u16 + 2;
    let area = centered_rect(area, Constraint::Length(len), Constraint::Length(1));

    Paragraph::new(text).centered().yellow().render(area, buf);
}

fn logger(area: Rect, buf: &mut Buffer) {
    let title = Line::from(format!(" {} logs ", log::max_level().as_str()));
    let logger = TuiLoggerWidget::default()
        .output_separator('|')
        .output_timestamp(Some("%H:%M:%S%.3f".to_string()))
        .output_level(Some(TuiLoggerLevelOutput::Abbreviated))
        .output_target(true)
        .output_file(false)
        .output_line(false)
        .block(Block::bordered().title(title.centered()))
        .style(Style::default())
        .state(&TuiWidgetState::new().set_default_display_level(LevelFilter::Trace));
    logger.render(area, buf);
}

fn receive_requests(
    requests: &[&ReceiveRequest],
    state: &mut TableState,
    area: Rect,
    buf: &mut Buffer,
) {
    let title = Line::from(" Incoming Transfer Requests ").bold();
    let block = Block::bordered().title(title.centered());

    let mut rows = Vec::new();
    for &req in requests {
        let src = req.alias.to_line().left_aligned();
        let mut size = 0;
        let files = req
            .files
            .values()
            .map(|f| {
                size += f.size;
                f.file_name.clone()
            })
            .collect::<Vec<_>>();
        let files = files.join(", ");
        let files = Line::from(files).centered();
        let size = Line::from(format!("{size}")).centered();
        rows.push(Row::new([src, size, files]).yellow());
    }

    if state.selected().is_none() && !rows.is_empty() {
        state.select(Some(0));
    } else if rows.is_empty() {
        state.select(None);
    };

    let widths = [
        Constraint::Max(20),
        Constraint::Max(15),
        Constraint::Min(50),
    ];

    let table = Table::new(rows, widths)
        .block(block)
        .header(Row::new([
            "Sender".bold().into_left_aligned_line(),
            "Bytes".bold().into_centered_line(),
            "Files".bold().into_centered_line(),
        ]))
        .row_highlight_style(Style::new().bg(Color::Rgb(99, 99, 99)));

    ratatui::widgets::StatefulWidget::render(table, area, buf, state);

    if let Some(idx) = state.selected() {
        let area = centered_rect(area, Constraint::Percentage(80), Constraint::Max(7));
        let request = requests[idx];
        if let Some(md) = request.files.values().next()
            && let Some(ref preview) = md.preview
        {
            Clear.render(area, buf);
            text_popup(preview, " preview ", area, buf);
        }
    }
}

fn peers(peers: &[Peer], state: &mut ListState, area: Rect, buf: &mut Buffer) {
    if peers.is_empty() {
        state.select(None);
    }
    if state.selected().is_none() {
        state.select(Some(0));
    }

    let mut items = Vec::with_capacity(peers.len());
    for Peer {
        addr,
        alias,
        fingerprint,
    } in peers
    {
        let item = format!("{alias} ({addr:?}) -- {fingerprint}");
        let s = Line::from(item.yellow());
        let item = ListItem::new(s);
        items.push(item);
    }
    let title = Line::from(" Peers ".bold()).centered();
    let block = Block::default()
        .title(title)
        .borders(Borders::all())
        .padding(Padding::uniform(1));
    let list = List::new(items)
        .block(block)
        .highlight_style(Style::new().bg(Color::Rgb(99, 99, 99)));
    ratatui::widgets::StatefulWidget::render(list, area, buf, state);
}

fn network_info(local_ip_addr: &Ipv4Addr, area: Rect, buf: &mut Buffer) {
    let local_addr = format!("{local_ip_addr:?}:{}", jocalsend::DEFAULT_PORT);
    let local_addr = local_addr.to_line().right_aligned();

    let http = "HTTP address";
    let http = Row::new(vec![http.to_line().left_aligned(), local_addr.clone()]).yellow();

    let udp = "UDP socket";
    let udp = udp.to_line().left_aligned();
    let udp = Row::new(vec![udp, local_addr]).yellow();

    let mip = format!(
        "{:?}:{:?}",
        jocalsend::MULTICAST_IP,
        jocalsend::DEFAULT_PORT
    );
    let multicast = "Multicast address";
    let multicast = Row::new(vec![
        multicast.to_line().left_aligned(),
        mip.to_line().right_aligned(),
    ])
    .yellow();

    let rows = vec![http, udp, multicast];
    let widths = vec![Constraint::Percentage(50), Constraint::Percentage(50)];

    let title = Line::from(" Listeners ".bold()).centered();

    let block = Block::default()
        .title(title)
        .borders(Borders::all())
        .padding(Padding::uniform(1));

    let table = Table::new(rows, widths).block(block);
    table.render(area, buf);
}

// helpers
fn centered_rect(area: Rect, horizontal: Constraint, vertical: Constraint) -> Rect {
    let [area] = Layout::horizontal([horizontal])
        .flex(Flex::Center)
        .areas(area);
    let [area] = Layout::vertical([vertical]).flex(Flex::Center).areas(area);
    area
}