void_graph/widget/

commit_detail.rs

//! Commit detail widget.
//!
//! Displays detailed information about a single commit including CID,
//! message, timestamp, parents, and signature status.
//!
//! Adapted from [Serie](https://github.com/lusingander/serie) by lusingander.

use ratatui::{
    buffer::Buffer,
    layout::Rect,
    style::{Color, Modifier, Style},
    text::{Line, Span},
    widgets::{Block, Borders, Paragraph, StatefulWidget, Widget, Wrap},
};

use crate::color::ColorTheme;
use crate::void_backend::{RefKind, VoidCommit, VoidRef};

/// State for the commit detail widget.
#[derive(Debug, Default)]
pub struct CommitDetailState {
    /// Scroll offset for long content
    offset: usize,
    /// Viewport height (set during render)
    viewport_height: usize,
    /// Total content height (set during render)
    content_height: usize,
}

impl CommitDetailState {
    /// Create a new detail state.
    pub fn new() -> Self {
        Self::default()
    }

    /// Scroll down one line.
    pub fn scroll_down(&mut self) {
        if self.offset + self.viewport_height < self.content_height {
            self.offset += 1;
        }
    }

    /// Scroll up one line.
    pub fn scroll_up(&mut self) {
        self.offset = self.offset.saturating_sub(1);
    }

    /// Scroll down half a page.
    pub fn scroll_down_half(&mut self) {
        let half = self.viewport_height / 2;
        for _ in 0..half {
            self.scroll_down();
        }
    }

    /// Scroll up half a page.
    pub fn scroll_up_half(&mut self) {
        let half = self.viewport_height / 2;
        for _ in 0..half {
            self.scroll_up();
        }
    }

    /// Scroll down a full page.
    pub fn scroll_down_page(&mut self) {
        for _ in 0..self.viewport_height {
            self.scroll_down();
        }
    }

    /// Scroll up a full page.
    pub fn scroll_up_page(&mut self) {
        for _ in 0..self.viewport_height {
            self.scroll_up();
        }
    }

    /// Jump to the top.
    pub fn select_first(&mut self) {
        self.offset = 0;
    }

    /// Jump to the bottom.
    pub fn select_last(&mut self) {
        self.offset = self.content_height.saturating_sub(self.viewport_height);
    }

    /// Reset scroll position (call when changing commits).
    pub fn reset(&mut self) {
        self.offset = 0;
    }
}

/// The commit detail widget.
pub struct CommitDetail<'a> {
    /// The commit to display
    commit: &'a VoidCommit,
    /// Refs pointing at this commit
    refs: Vec<&'a VoidRef>,
    /// Color theme
    theme: &'a ColorTheme,
}

impl<'a> CommitDetail<'a> {
    /// Create a new commit detail widget.
    pub fn new(commit: &'a VoidCommit, refs: Vec<&'a VoidRef>, theme: &'a ColorTheme) -> Self {
        Self { commit, refs, theme }
    }

    /// Build the content lines for display.
    fn build_content(&self) -> Vec<Line<'a>> {
        let mut lines = Vec::new();
        let label_style = Style::default().fg(self.theme.detail_label_fg);

        // CID
        lines.push(Line::from(vec![
            Span::styled("CID:       ", label_style),
            Span::styled(
                self.commit.cid.0.clone(),
                Style::default().fg(self.theme.detail_hash_fg),
            ),
        ]));

        // Parents
        if self.commit.parents.is_empty() {
            lines.push(Line::from(vec![
                Span::styled("Parents:   ", label_style),
                Span::styled("(none - root commit)", Style::default().fg(Color::DarkGray)),
            ]));
        } else {
            for (i, parent) in self.commit.parents.iter().enumerate() {
                let prefix = if i == 0 { "Parents:   " } else { "           " };
                lines.push(Line::from(vec![
                    Span::styled(prefix, label_style),
                    Span::styled(
                        parent.0.clone(),
                        Style::default().fg(self.theme.detail_hash_fg),
                    ),
                ]));
            }
        }

        // Date
        lines.push(Line::from(vec![
            Span::styled("Date:      ", label_style),
            Span::styled(
                format_timestamp_full(self.commit.timestamp_ms),
                Style::default().fg(self.theme.detail_date_fg),
            ),
        ]));

        // Author (signer identity)
        if let Some(ref author) = self.commit.author {
            // Show first 16 chars of the public key hex
            let short_author = if author.len() > 16 {
                format!("{}...", &author[..16])
            } else {
                author.clone()
            };
            lines.push(Line::from(vec![
                Span::styled("Author:    ", label_style),
                Span::styled(short_author, Style::default().fg(self.theme.detail_name_fg)),
            ]));
        }

        // Signature status
        let sig_line = if self.commit.is_signed {
            match self.commit.signature_valid {
                Some(true) => Line::from(vec![
                    Span::styled("Signature: ", label_style),
                    Span::styled(
                        "Valid",
                        Style::default()
                            .fg(Color::Green)
                            .add_modifier(Modifier::BOLD),
                    ),
                ]),
                Some(false) => Line::from(vec![
                    Span::styled("Signature: ", label_style),
                    Span::styled(
                        "Invalid",
                        Style::default()
                            .fg(Color::Red)
                            .add_modifier(Modifier::BOLD),
                    ),
                ]),
                None => Line::from(vec![
                    Span::styled("Signature: ", label_style),
                    Span::styled("Signed (unverified)", Style::default().fg(Color::Yellow)),
                ]),
            }
        } else {
            Line::from(vec![
                Span::styled("Signature: ", label_style),
                Span::styled("Unsigned", Style::default().fg(Color::DarkGray)),
            ])
        };
        lines.push(sig_line);

        // Refs
        if !self.refs.is_empty() {
            let mut ref_spans = vec![Span::styled("Refs:      ", label_style)];

            for (i, r) in self.refs.iter().enumerate() {
                if i > 0 {
                    ref_spans.push(Span::raw(", "));
                }
                let color = match r.kind {
                    RefKind::Branch => self.theme.detail_ref_branch_fg,
                    RefKind::Tag => self.theme.detail_ref_tag_fg,
                };
                ref_spans.push(Span::styled(r.name.clone(), Style::default().fg(color)));
            }

            lines.push(Line::from(ref_spans));
        }

        // Empty line before message
        lines.push(Line::from(""));

        // Message
        for line in self.commit.message.lines() {
            lines.push(Line::from(line.to_string()));
        }

        lines
    }
}

impl<'a> StatefulWidget for CommitDetail<'a> {
    type State = CommitDetailState;

    fn render(self, area: Rect, buf: &mut Buffer, state: &mut Self::State) {
        let block = Block::default()
            .borders(Borders::ALL)
            .title(" Commit Details ");
        let inner = block.inner(area);
        block.render(area, buf);

        state.viewport_height = inner.height as usize;

        let content = self.build_content();
        state.content_height = content.len();

        // Apply scroll offset
        let visible_content: Vec<Line> = content
            .into_iter()
            .skip(state.offset)
            .take(state.viewport_height)
            .collect();

        let paragraph = Paragraph::new(visible_content).wrap(Wrap { trim: false });

        paragraph.render(inner, buf);
    }
}

/// Format a Unix timestamp (in milliseconds) as full datetime.
fn format_timestamp_full(ts_ms: u64) -> String {
    use std::time::{Duration, UNIX_EPOCH};
    let d = UNIX_EPOCH + Duration::from_millis(ts_ms);
    let datetime: chrono::DateTime<chrono::Utc> = d.into();
    datetime.format("%Y-%m-%d %H:%M:%S UTC").to_string()
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_commit_detail_state_scroll() {
        let mut state = CommitDetailState::new();
        state.viewport_height = 10;
        state.content_height = 20;

        state.scroll_down();
        assert_eq!(state.offset, 1);

        state.scroll_up();
        assert_eq!(state.offset, 0);

        state.select_last();
        assert_eq!(state.offset, 10);

        state.select_first();
        assert_eq!(state.offset, 0);
    }
}