zesdex/crates/zesdex-backend/src/app/mode/mod.rs

//! TUI mode definitions and per-mode input/action handlers, one submodule
//! per overlay/mode (bash, editor, effort, mcp, quit confirm, rewind, etc.).
//! Each mode encapsulates its own keyboard input parsing, state transitions,
//! and view rendering so the top-level event loop can dispatch generically.

pub mod bash;         // Shell-command input overlay: prompt, history, execution
pub mod editor;       // Multi-line text editor overlay (write/edit tool content)
pub mod effort;       // Reasoning-effort selector overlay
pub mod key_input;    // Generic single-key prompt overlay (e.g. rename, search)
pub mod mcp;          // MCP tool argument builder overlay

pub mod learning;     // Learning/reflection input overlay
pub mod quit_confirm; // Quit confirmation dialog overlay
pub mod rewind;       // Rewind/undo checkpoint selection overlay
pub mod settings;     // Settings panel overlay
pub mod todo;         // TODO-list management overlay

/// Cycle `current` in the range `[0, len)`.
///
/// * `forward = true` — increment (wrap at len)
/// * `forward = false` — decrement (wrap at 0), saturating at 0 when len is 0
///
/// Return: `0` when `len == 0`, otherwise the wrapped index.
pub fn cycle_selected_index(current: usize, len: usize, forward: bool) -> usize {
    if len == 0 {
        return 0;
    }
    if forward {
        (current + 1) % len
    } else if current == 0 {
        len.saturating_sub(1)
    } else {
        current - 1
    }
}