verco 6.1.0

A simple Git/Mercurial/PlasticSCM tui client based on keyboard shortcuts
use std::thread;

use crate::{
    backend::{RevisionEntry, RevisionInfo, SelectableRevisionEntry},
    mode::{ModeContext, ModeResponse, ModeStatus, Output, SelectMenu, SelectMenuAction},
    platform::Key,
    ui::{Drawer, RESERVED_LINES_COUNT},
};

pub enum Response {
    Info(RevisionInfo),
    Diff(String),
}

enum State {
    Idle,
    Waiting,
    ViewDiff,
}
impl Default for State {
    fn default() -> Self {
        Self::Idle
    }
}

#[derive(Default)]
pub struct Mode {
    state: State,
    entries: Vec<SelectableRevisionEntry>,
    output: Output,
    select: SelectMenu,
    show_full_message: bool,
}
impl Mode {
    fn get_selected_entries(&self) -> Vec<RevisionEntry> {
        let entries: Vec<_> = self
            .entries
            .iter()
            .filter(|e| e.selected)
            .map(|e| RevisionEntry {
                name: e.name.clone(),
                status: e.status.clone(),
            })
            .collect();
        entries
    }

    pub fn on_enter(&mut self, ctx: &ModeContext, revision: &str) {
        if let State::Waiting = self.state {
            return;
        }
        self.state = State::Waiting;

        self.output.set(String::new());
        self.select.saturate_cursor(0);
        self.show_full_message = false;

        let ctx = ctx.clone();
        let revision = revision.to_string();
        thread::spawn(move || {
            let mut info = match ctx.backend.revision_details(&revision) {
                Ok(info) => info,
                Err(error) => RevisionInfo {
                    message: error,
                    entries: Vec::new(),
                },
            };
            info.entries
                .sort_unstable_by(|a, b| a.status.cmp(&b.status));

            ctx.event_sender
                .send_response(ModeResponse::RevisionDetails(Response::Info(info)));
        });
    }

    pub fn on_key(&mut self, ctx: &ModeContext, revision: &str, key: Key) -> ModeStatus {
        let available_height = (ctx.viewport_size.1 as usize).saturating_sub(RESERVED_LINES_COUNT);

        match self.state {
            State::Idle => {
                match self
                    .select
                    .on_key(self.entries.len(), available_height, key)
                {
                    SelectMenuAction::None => (),
                    SelectMenuAction::Toggle(i) => {
                        self.entries[i].selected = !self.entries[i].selected
                    }
                    SelectMenuAction::ToggleAll => {
                        let all_selected = self.entries.iter().all(|e| e.selected);
                        for entry in &mut self.entries {
                            entry.selected = !all_selected;
                        }
                    }
                }

                match key {
                    Key::Tab => {
                        self.show_full_message = !self.show_full_message;
                    }
                    Key::Char('d') => {
                        if !self.entries.is_empty() {
                            self.state = State::ViewDiff;
                            self.output.set(String::new());

                            let entries = self.get_selected_entries();

                            let ctx = ctx.clone();
                            let revision = revision.to_string();
                            thread::spawn(move || {
                                let output = match ctx.backend.diff(Some(&revision), &entries) {
                                    Ok(output) => output,
                                    Err(error) => error,
                                };
                                ctx.event_sender
                                    .send_response(ModeResponse::RevisionDetails(Response::Diff(
                                        output,
                                    )));
                            });
                        }
                    }
                    _ => (),
                }
            }
            State::ViewDiff => self.output.on_key(available_height, key),
            _ => (),
        }

        ModeStatus {
            pending_input: false,
        }
    }

    pub fn on_response(&mut self, response: Response) {
        match response {
            Response::Info(info) => {
                if let State::Waiting = self.state {
                    self.state = State::Idle;
                }
                if let State::Idle = self.state {
                    self.output.set(info.message);
                }

                self.entries = info.entries.into_iter().map(Into::into).collect();
                self.select.saturate_cursor(self.entries.len());
            }
            Response::Diff(output) => {
                if let State::ViewDiff = self.state {
                    self.output.set(output);
                }
            }
        }
    }

    pub fn is_waiting_response(&self) -> bool {
        match self.state {
            State::Idle => false,
            State::Waiting => true,
            State::ViewDiff => self.output.text().is_empty(),
        }
    }

    pub fn header(&self) -> (&str, &str, &str) {
        match self.state {
            State::Idle | State::Waiting => (
                "revision details",
                "[d]diff",
                "[arrows]move [space]toggle [a]toggle all",
            ),
            State::ViewDiff => ("diff", "", "[arrows]move"),
        }
    }

    pub fn draw(&self, drawer: &mut Drawer) {
        let show_full_output = !matches!(self.state, State::Idle) || self.show_full_message;
        let line_count = if show_full_output {
            drawer.output(&self.output)
        } else {
            let output = self.output.text().lines().next().unwrap_or("");
            let output = match output
                .char_indices()
                .nth(drawer.viewport_size.0.saturating_sub(1) as _)
            {
                Some((i, c)) => &output[..i + c.len_utf8()],
                None => output,
            };
            drawer.str(output);
            drawer.next_line();
            1
        };

        if let State::Idle = self.state {
            drawer.next_line();
            drawer.select_menu(
                &self.select,
                (line_count + 1).min(u16::MAX as _) as _,
                false,
                self.entries.iter(),
            );
        }
    }
}