shep 0.22.0

//! [`Role`] bound to `anstyle`, for the box-drawn table.
//!
//! A second, independent binding of the roles `lookout/theme.rs` binds to
//! `ratatui`: the two style types come from different crates. Colour
//! numbers are copied from `theme.rs` and pinned against it by that
//! module's tests. Faces and the status-to-role mapping live in
//! `vocabulary.rs`, never here.

use anstyle::{Ansi256Color, AnsiColor, Color, Style};

use crate::vocabulary::Role;

/// One role's colour, at the depth `deep` selects.
///
/// `deep` is resolved at the seam (`style::Presentation::new`) and threaded
/// down as `Presentation::deep_colour`, never read from the environment
/// here. The 256-colour indices are `lookout/theme.rs::Palette::detect`'s
/// own, each the nearest xterm-256 neighbour of the design language's hex;
/// the 16-colour fallback uses the same four named colours.
#[must_use]
pub(crate) fn style_for(role: Role, deep: bool) -> Style {
    let colour = match (role, deep) {
        (Role::Meadow, true) => Color::Ansi256(Ansi256Color(29)),
        (Role::Bark, true) => Color::Ansi256(Ansi256Color(166)),
        (Role::Butter, true) => Color::Ansi256(Ansi256Color(221)),
        (Role::Ink3, true) => Color::Ansi256(Ansi256Color(245)),
        (Role::Meadow, false) => Color::Ansi(AnsiColor::Green),
        (Role::Bark, false) => Color::Ansi(AnsiColor::Red),
        (Role::Butter, false) => Color::Ansi(AnsiColor::Yellow),
        (Role::Ink3, false) => Color::Ansi(AnsiColor::BrightBlack),
        // Sky is lookout-only: `shep flock` has no memory gauge to colour.
        // Matched here so the mapping stays total, with the same colours
        // `lookout/theme.rs::Palette::detect` uses for its own sky.
        (Role::Sky, true) => Color::Ansi256(Ansi256Color(74)),
        (Role::Sky, false) => Color::Ansi(AnsiColor::Blue),
    };
    Style::new().fg_color(Some(colour))
}

/// clap's help styles, in the palette's roles.
///
/// Headings and `Usage:` are butter and bold, flags and verbs meadow,
/// placeholders sky. Every other slot, the error ones included, stays plain:
/// [`crate::entry`] renders usage errors plain regardless. `deep` is
/// [`style_for`]'s. [`crate::cli::dress_help_template`] paints the
/// hand-written verb listing with these same styles.
#[must_use]
pub(crate) fn help_styles(deep: bool) -> clap::builder::Styles {
    let heading = style_for(Role::Butter, deep).bold();
    clap::builder::Styles::plain()
        .header(heading)
        .usage(heading)
        .literal(style_for(Role::Meadow, deep))
        .placeholder(style_for(Role::Sky, deep))
}

#[cfg(test)]
mod tests {
    use super::*;
    use clap::CommandFactory as _;

    use crate::cli::Cli;

    /// The sequences are the 256-colour palette's own indices, written out
    /// rather than derived from `style_for`.
    #[test]
    fn coloured_help_paints_headings_flags_and_placeholders_in_the_palette() {
        let coloured = Cli::command().styles(help_styles(true)).render_help();
        let ansi = coloured.ansi().to_string();
        assert!(
            ansi.contains("\x1b[1m\x1b[38;5;221mUsage:\x1b[0m"),
            "bold butter heading, got {ansi:?}"
        );
        assert!(
            ansi.contains("\x1b[38;5;29m--format\x1b[0m"),
            "meadow flag, got {ansi:?}"
        );
        assert!(
            ansi.contains("\x1b[38;5;74m<FORMAT>\x1b[0m"),
            "sky placeholder, got {ansi:?}"
        );
    }

    #[test]
    fn coloured_help_has_the_same_text_as_the_help_it_replaces() {
        let today = Cli::command().render_help().to_string();
        let coloured = Cli::command().styles(help_styles(true)).render_help();
        assert!(coloured.ansi().to_string().contains('\x1b'));
        assert_eq!(coloured.to_string(), today);
    }

    #[test]
    fn the_sixteen_colour_tier_uses_named_colours() {
        let ansi = Cli::command()
            .styles(help_styles(false))
            .render_help()
            .ansi()
            .to_string();
        assert!(ansi.contains("\x1b[32m--format\x1b[0m"), "got {ansi:?}");
    }

    /// No "off" case: `NO_COLOR` is vetoed upstream, in
    /// `Presentation::colour`.
    #[test]
    fn every_role_resolves_a_foreground_at_both_tiers() {
        for role in [Role::Meadow, Role::Bark, Role::Butter, Role::Ink3] {
            for deep in [true, false] {
                assert!(
                    style_for(role, deep).get_fg_color().is_some(),
                    "{role:?} at deep={deep} must set a foreground"
                );
            }
        }
    }

    /// Checked as "no other role resolves bark's colour": this module has no
    /// `ProcStatus` to switch on.
    #[test]
    fn bark_is_the_only_role_painted_bark() {
        for deep in [true, false] {
            let bark = style_for(Role::Bark, deep);
            for other in [Role::Meadow, Role::Butter, Role::Ink3] {
                assert_ne!(
                    style_for(other, deep),
                    bark,
                    "{other:?} at deep={deep} must not share bark's colour"
                );
            }
        }
    }

    #[test]
    fn the_four_roles_are_pairwise_distinct_at_each_tier() {
        for deep in [true, false] {
            let styles = [
                style_for(Role::Meadow, deep),
                style_for(Role::Bark, deep),
                style_for(Role::Butter, deep),
                style_for(Role::Ink3, deep),
            ];
            for (i, a) in styles.iter().enumerate() {
                for (j, b) in styles.iter().enumerate() {
                    if i != j {
                        assert_ne!(
                            a, b,
                            "roles at index {i} and {j} share a colour at deep={deep}"
                        );
                    }
                }
            }
        }
    }
}