void-audit-tui 0.0.4

//! Main application for void-audit-tui.
//!
//! Provides an interactive TUI for auditing repository objects.

use std::io::{self, Stdout};
use std::sync::Arc;
use std::time::Instant;

use crossterm::{
    execute,
    terminal::{disable_raw_mode, enable_raw_mode, EnterAlternateScreen, LeaveAlternateScreen},
};
use rayon::prelude::*;
use ratatui::{
    backend::CrosstermBackend,
    layout::{Constraint, Direction, Layout, Rect},
    style::{Modifier, Style},
    text::{Line, Span},
    widgets::{Block, Borders, Clear, Paragraph},
    Frame, Terminal,
};
use thiserror::Error;
use void_core::VoidContext;

use crate::{
    color::ColorTheme,
    event::{init as init_events, AppEvent, UserEvent},
    keybind::KeyBind,
    void_backend::{
        self, AuditResult, Format, ObjectInfo, ObjectType,
    },
    widget::{
        audit_detail::{AuditDetail, AuditDetailState, AuditLoading},
        object_list::{ObjectList, ObjectListState},
    },
};

/// Error type for application operations.
#[derive(Debug, Error)]
pub enum AppError {
    #[error("io error: {0}")]
    Io(#[from] io::Error),

    #[error("backend error: {0}")]
    Backend(#[from] crate::void_backend::VoidBackendError),

    #[error("void error: {0}")]
    Void(#[from] void_core::VoidError),
}

/// Result type for application operations.
pub type Result<T> = std::result::Result<T, AppError>;

/// Current view state of the application.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
enum AppView {
    /// Main object list view
    List,
    /// Help overlay
    Help,
}

/// Run the void-audit-tui application.
///
/// Takes a fully constructed `VoidContext` from the CLI caller.
pub fn run(ctx: VoidContext) -> Result<()> {
    let store = ctx.open_store()?;

    // Enumerate all objects
    let cids = void_backend::list_all_objects(&ctx);
    if cids.is_empty() {
        eprintln!("No objects found in repository");
        return Ok(());
    }

    // Show loading message
    eprintln!("Building index...");
    let start = Instant::now();

    // Build index by walking commit history once
    let index = void_backend::build_index(&ctx, &store, 1000)?;

    let index_time = start.elapsed();
    eprintln!("Index built in {:.2}s", index_time.as_secs_f64());

    // Wrap shared state in Arc for parallel access
    let ctx = Arc::new(ctx);
    let store = Arc::new(store);
    let index = Arc::new(index);

    // Now audit all objects in parallel using the index
    eprintln!("Categorizing {} objects...", cids.len());
    let audit_start = Instant::now();

    let audit_results: Vec<(ObjectInfo, AuditResult)> = cids
        .par_iter()
        .map(|cid| {
            let mut info = void_backend::categorize_object(&store, &index, cid);
            let audit = void_backend::audit_object_indexed(&ctx, &store, &index, cid);
            // Update type and format from audit result
            info.object_type = match &audit {
                AuditResult::Commit(_) => ObjectType::Commit,
                AuditResult::Metadata(_) => ObjectType::Metadata,
                AuditResult::Manifest(_) => ObjectType::Manifest,
                AuditResult::RepoManifest(_) => ObjectType::RepoManifest,
                AuditResult::Shard(_) => ObjectType::Shard,
                AuditResult::Error(_) => ObjectType::Unknown,
            };
            info.format = match &audit {
                AuditResult::Commit(_) => Format::CommitV1,
                AuditResult::Metadata(_) => Format::MetadataV1,
                AuditResult::Manifest(_) => Format::ManifestV1,
                AuditResult::RepoManifest(_) => Format::RepoManifestV1,
                AuditResult::Shard(_) => Format::ShardV1,
                AuditResult::Error(_) => Format::Unknown,
            };
            (info, audit)
        })
        .collect();

    let audit_time = audit_start.elapsed();
    let total_time = start.elapsed();
    eprintln!(
        "Categorized {} objects in {:.2}s ({:.0} objects/sec)",
        cids.len(),
        audit_time.as_secs_f64(),
        cids.len() as f64 / audit_time.as_secs_f64()
    );
    eprintln!("Total startup: {:.2}s", total_time.as_secs_f64());

    // Split into objects and pre-populated cache
    let mut objects = Vec::with_capacity(audit_results.len());
    let mut audit_cache: rustc_hash::FxHashMap<String, AuditResult> =
        rustc_hash::FxHashMap::default();

    for (info, audit) in audit_results {
        audit_cache.insert(info.cid.clone(), audit);
        objects.push(info);
    }

    // Setup terminal
    enable_raw_mode()?;
    let mut stdout = io::stdout();
    execute!(stdout, EnterAlternateScreen)?;
    let backend = CrosstermBackend::new(stdout);
    let mut terminal = Terminal::new(backend)?;
    terminal.clear()?;

    // Run the app and capture result
    let result = run_app_with_cache(&mut terminal, objects, audit_cache);

    // Cleanup terminal (always, even on error)
    disable_raw_mode()?;
    execute!(terminal.backend_mut(), LeaveAlternateScreen)?;
    terminal.show_cursor()?;

    result
}

/// Main application loop with pre-populated audit cache.
fn run_app_with_cache(
    terminal: &mut Terminal<CrosstermBackend<Stdout>>,
    objects: Vec<ObjectInfo>,
    audit_cache: rustc_hash::FxHashMap<String, AuditResult>,
) -> Result<()> {
    // Initialize resources
    let theme = ColorTheme::default();
    let keybind = KeyBind::new();
    let (_tx, rx) = init_events();

    // Initialize state
    let mut list_state = ObjectListState::new(objects);
    let mut detail_state = AuditDetailState::new();
    let mut app_view = AppView::List;

    // Track viewport height for navigation
    let mut viewport_height: usize = 20;

    // Main loop
    loop {
        // Render
        terminal.draw(|frame| {
            let area = frame.area();
            viewport_height = area.height.saturating_sub(4) as usize; // Account for borders + status

            match app_view {
                AppView::List => {
                    render_main_view(
                        frame,
                        area,
                        &mut list_state,
                        &mut detail_state,
                        &audit_cache,
                        &theme,
                        &keybind,
                    );
                }
                AppView::Help => {
                    // Render main view in background, then help overlay
                    render_main_view(
                        frame,
                        area,
                        &mut list_state,
                        &mut detail_state,
                        &audit_cache,
                        &theme,
                        &keybind,
                    );
                    render_help_overlay(frame, area, &keybind, &theme);
                }
            }
        })?;

        // Handle events
        match rx.recv() {
            AppEvent::Key(key) => {
                if let Some(user_event) = keybind.get(&key) {
                    match handle_event(
                        *user_event,
                        &mut app_view,
                        &mut list_state,
                        &mut detail_state,
                        viewport_height,
                    ) {
                        EventResult::Continue => {}
                        EventResult::Quit => break,
                    }
                }
            }
            AppEvent::Resize(_, _) => {
                // Terminal will handle resize automatically
            }
            AppEvent::Quit => break,
        }
    }

    Ok(())
}

/// Result of handling an event.
enum EventResult {
    Continue,
    Quit,
}

/// Handle a user event and return the result.
fn handle_event(
    event: UserEvent,
    view: &mut AppView,
    list_state: &mut ObjectListState,
    detail_state: &mut AuditDetailState,
    viewport_height: usize,
) -> EventResult {
    match event {
        // Quit events
        UserEvent::Quit | UserEvent::ForceQuit => {
            return EventResult::Quit;
        }

        // Help toggle
        UserEvent::HelpToggle => {
            *view = match *view {
                AppView::Help => AppView::List,
                _ => AppView::Help,
            };
        }

        // Cancel/close - return to list from help
        UserEvent::Cancel | UserEvent::Close => {
            if *view != AppView::List {
                *view = AppView::List;
            }
        }

        // Navigation events
        UserEvent::NavigateDown => {
            list_state.select_next(viewport_height);
            detail_state.reset();
        }
        UserEvent::NavigateUp => {
            list_state.select_prev();
            detail_state.reset();
        }
        UserEvent::HalfPageDown => {
            list_state.scroll_down_half(viewport_height);
            detail_state.reset();
        }
        UserEvent::HalfPageUp => {
            list_state.scroll_up_half(viewport_height);
            detail_state.reset();
        }
        UserEvent::PageDown => {
            list_state.scroll_down_page(viewport_height);
            detail_state.reset();
        }
        UserEvent::PageUp => {
            list_state.scroll_up_page(viewport_height);
            detail_state.reset();
        }
        UserEvent::GoToTop => {
            list_state.select_first();
            detail_state.reset();
        }
        UserEvent::GoToBottom => {
            list_state.select_last(viewport_height);
            detail_state.reset();
        }

        // Scroll detail view content
        UserEvent::ScrollDown => {
            detail_state.scroll_down();
        }
        UserEvent::ScrollUp => {
            detail_state.scroll_up();
        }

        // Confirm - could be used for future expansion (e.g., copy CID)
        UserEvent::Confirm => {
            // Currently no action
        }
    }

    EventResult::Continue
}

/// Render the main split-pane view.
fn render_main_view(
    frame: &mut Frame,
    area: Rect,
    list_state: &mut ObjectListState,
    detail_state: &mut AuditDetailState,
    audit_cache: &rustc_hash::FxHashMap<String, AuditResult>,
    theme: &ColorTheme,
    _keybind: &KeyBind,
) {
    // Split into three areas: list, detail, and status bar
    let main_chunks = Layout::default()
        .direction(Direction::Vertical)
        .constraints([Constraint::Min(5), Constraint::Length(1)])
        .split(area);

    let content_area = main_chunks[0];
    let status_area = main_chunks[1];

    // Split content into left (list) and right (detail)
    let chunks = Layout::default()
        .direction(Direction::Horizontal)
        .constraints([Constraint::Percentage(40), Constraint::Percentage(60)])
        .split(content_area);

    // Render object list
    let list_widget = ObjectList::new(theme);
    frame.render_stateful_widget(list_widget, chunks[0], list_state);

    // Render detail panel
    if let Some(obj) = list_state.selected_object() {
        if let Some(audit) = audit_cache.get(&obj.cid) {
            let detail_widget = AuditDetail::new(obj, audit, theme);
            frame.render_stateful_widget(detail_widget, chunks[1], detail_state);
        } else {
            let loading_widget = AuditLoading::new(obj, theme);
            frame.render_widget(loading_widget, chunks[1]);
        }
    }

    // Render status bar
    render_status_bar(frame, status_area, _keybind, theme);
}

/// Render the status bar with key hints.
fn render_status_bar(frame: &mut Frame, area: Rect, _keybind: &KeyBind, theme: &ColorTheme) {
    let hints = [
        ("j/k", "navigate"),
        ("Ctrl-d/u", "scroll"),
        ("g/G", "top/bottom"),
        ("?", "help"),
        ("q", "quit"),
    ];

    let spans: Vec<Span> = hints
        .iter()
        .enumerate()
        .flat_map(|(i, (key, desc))| {
            let mut result = vec![
                Span::styled(
                    *key,
                    Style::default()
                        .fg(theme.help_key_fg)
                        .add_modifier(Modifier::BOLD),
                ),
                Span::raw(": "),
                Span::raw(*desc),
            ];
            if i < hints.len() - 1 {
                result.push(Span::raw("  "));
            }
            result
        })
        .collect();

    let line = Line::from(spans);
    let paragraph = Paragraph::new(line);
    frame.render_widget(paragraph, area);
}

/// Render the help overlay.
fn render_help_overlay(frame: &mut Frame, area: Rect, keybind: &KeyBind, theme: &ColorTheme) {
    // Calculate centered popup area
    let popup_width = 50.min(area.width.saturating_sub(4));
    let popup_height = 16.min(area.height.saturating_sub(4));
    let popup_x = (area.width.saturating_sub(popup_width)) / 2;
    let popup_y = (area.height.saturating_sub(popup_height)) / 2;
    let popup_area = Rect::new(popup_x, popup_y, popup_width, popup_height);

    // Clear the popup area
    frame.render_widget(Clear, popup_area);

    // Build help content
    let help_items = [
        (UserEvent::NavigateDown, "Move down"),
        (UserEvent::NavigateUp, "Move up"),
        (UserEvent::HalfPageDown, "Half page down"),
        (UserEvent::HalfPageUp, "Half page up"),
        (UserEvent::PageDown, "Page down"),
        (UserEvent::PageUp, "Page up"),
        (UserEvent::GoToTop, "Go to top"),
        (UserEvent::GoToBottom, "Go to bottom"),
        (UserEvent::ScrollDown, "Scroll detail down"),
        (UserEvent::ScrollUp, "Scroll detail up"),
        (UserEvent::HelpToggle, "Toggle help"),
        (UserEvent::Quit, "Quit"),
    ];

    let mut lines: Vec<Line> = Vec::new();
    for (event, description) in help_items {
        let keys = keybind.keys_for_event(event);
        let key_str = if keys.is_empty() {
            "(unbound)".to_string()
        } else {
            keys.join(", ")
        };

        lines.push(Line::from(vec![
            Span::styled(
                format!("{:>15}", key_str),
                Style::default()
                    .fg(theme.help_key_fg)
                    .add_modifier(Modifier::BOLD),
            ),
            Span::raw("  "),
            Span::raw(description),
        ]));
    }

    let help_paragraph = Paragraph::new(lines)
        .block(
            Block::default()
                .borders(Borders::ALL)
                .title(" Help ")
                .title_style(Style::default().fg(theme.help_block_title_fg)),
        )
        .style(Style::default().fg(theme.fg).bg(theme.bg));

    frame.render_widget(help_paragraph, popup_area);
}