use std::{
    collections::BTreeMap,
    net::SocketAddr,
    path::{Path, PathBuf},
};

use crossterm::event::{Event, EventStream, KeyEventKind};
use futures::{FutureExt, StreamExt};
use jocalsend::{JocalEvent, JocalService, ReceiveRequest, error::Result};
use julid::Julid;
use log::LevelFilter;
use ratatui::{
    Frame,
    widgets::{ListState, TableState, WidgetRef},
};
use ratatui_explorer::FileExplorer;
use simsearch::{SearchOptions, SimSearch};
use tokio::sync::mpsc::UnboundedReceiver;
use tui_input::Input;

pub mod widgets;

mod handle;

#[derive(Debug, Clone, PartialEq, Eq)]
pub struct Peer {
    pub alias: String,
    pub fingerprint: String,
    pub addr: SocketAddr,
}

#[derive(Clone)]
struct FileFinder {
    explorer: FileExplorer,
    fuzzy: SimSearch<usize>,
    working_dir: Option<PathBuf>,
    input: Input,
}

fn searcher() -> SimSearch<usize> {
    SimSearch::new_with(
        SearchOptions::new()
            .stop_words(vec![std::path::MAIN_SEPARATOR_STR.to_string()])
            .stop_whitespace(false),
    )
}

pub struct App {
    pub service: JocalService,
    pub events: EventStream,
    pub peers: Vec<Peer>,
    pub peer_state: ListState,
    pub receive_requests: BTreeMap<Julid, ReceiveRequest>,
    screen: Vec<CurrentScreen>,
    receiving_state: TableState,
    // for getting messages back from the web server or web client about things we've done; the
    // other end is held by the service
    event_listener: UnboundedReceiver<JocalEvent>,
    file_finder: FileFinder,
    text: Option<String>,
    input: Input,
}

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum CurrentScreen {
    Main,
    Sending(SendingScreen),
    Receiving,
    Stopping,
    Logging,
}

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum SendingScreen {
    Files(FileMode),
    Peers,
    Text,
}

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum FileMode {
    Picking,
    Fuzzy,
}

impl App {
    pub fn new(service: JocalService, event_listener: UnboundedReceiver<JocalEvent>) -> Self {
        App {
            service,
            event_listener,
            screen: vec![CurrentScreen::Main],
            file_finder: FileFinder::new().expect("could not create file explorer"),
            text: None,
            events: Default::default(),
            peers: Default::default(),
            peer_state: Default::default(),
            receive_requests: Default::default(),
            receiving_state: Default::default(),
            input: Default::default(),
        }
    }

    pub async fn handle_events(&mut self) -> Result<()> {
        tokio::select! {
            event = self.events.next().fuse() => {
                if let Some(Ok(evt)) = event {
                    match evt {
                        Event::Key(key)
                            if key.kind == KeyEventKind::Press
                            => self.handle_key_event(key, evt).await,
                        Event::Mouse(_) => {}
                        Event::Resize(_, _) => {}
                        _ => {}
                    }
                }
            }
            transfer_event = self.event_listener.recv().fuse() => {
                if let Some(event) = transfer_event {
                    log::trace!("got JocalEvent {event:?}");
                    match event {
                        JocalEvent::ReceiveRequest { id, request } => {
                            self.receive_requests.insert(id, request);
                        }
                        JocalEvent::Cancelled { session_id: id } | JocalEvent::ReceivedInbound(id) => {
                            self.receive_requests.remove(&id);
                        }
                        JocalEvent::SendApproved(id) => log::info!("remote recipient approved outbound transfer {id}"),
                        JocalEvent::SendDenied => log::warn!("outbound transfer request has been denied"),
                        JocalEvent::SendSuccess { content, session: _session } => log::info!("successfully sent {content}"),
                        JocalEvent::SendFailed { error } => log::error!("could not send content: {error}"),
                        JocalEvent::Tick => {}
                    }
                }
            }
        }

        Ok(())
    }

    pub fn input(&mut self) -> &mut Input {
        &mut self.input
    }

    pub fn files(&mut self) -> &mut FileExplorer {
        &mut self.file_finder.explorer
    }

    pub fn text(&mut self) -> &mut Option<String> {
        &mut self.text
    }

    pub fn screen(&self) -> CurrentScreen {
        *self.screen.last().unwrap()
    }
    pub fn screen_mut(&mut self) -> &mut CurrentScreen {
        self.screen.last_mut().unwrap()
    }

    pub fn draw(&mut self, frame: &mut Frame) {
        frame.render_widget(self, frame.area());
    }
}

impl FileFinder {
    pub fn new() -> Result<Self> {
        Ok(Self {
            explorer: FileExplorer::new()?,
            fuzzy: searcher(),
            working_dir: None,
            input: Default::default(),
        })
    }

    pub fn handle(&mut self, event: &Event) -> Result<()> {
        self.index();
        Ok(self.explorer.handle(event)?)
    }

    pub fn cwd(&self) -> &Path {
        self.explorer.cwd()
    }

    pub fn set_cwd(&mut self, cwd: &Path) -> Result<()> {
        self.explorer.set_cwd(cwd)?;
        self.index();
        Ok(())
    }

    pub fn widget(&self) -> impl WidgetRef {
        self.explorer.widget()
    }

    pub fn reset_fuzzy(&mut self) {
        self.clear_fuzzy();
        self.input.reset();
    }

    fn clear_fuzzy(&mut self) {
        self.fuzzy = searcher();
    }

    fn index(&mut self) {
        if let Some(owd) = self.working_dir.as_ref()
            && owd == self.cwd()
        {
            return;
        }
        self.working_dir = Some(self.cwd().to_path_buf());
        self.clear_fuzzy();

        for (i, f) in self.explorer.files().iter().enumerate() {
            self.fuzzy.insert(i, f.name());
        }
    }
}

fn change_log_level(delta: isize) {
    let level = log::max_level() as isize;
    let max = log::LevelFilter::max() as isize;
    let level = (level + delta).clamp(0, max) as usize;
    // levelfilter is repr(usize) so this is safe
    let level = unsafe { std::mem::transmute::<usize, LevelFilter>(level) };

    log::set_max_level(level);
}