//! Output color themes: named palettes applied to help, tables, the
//! version output and the completion menu.
//!
//! A theme is a set of SGR (Select Graphic Rendition) parameter strings
//! (e.g. "1;38;5;75" = bold + 256-color 75). Painting wraps the text in
//! "\x1b[<sgr>m...\x1b[0m". The "mono" theme uses empty sequences and is
//! therefore plain text.

/// One color theme.
#[derive(Debug, Clone, Copy)]
pub struct Theme {
    /// Machine name ("default", "ocean", ...).
    pub name: &'static str,
    /// Human-readable title.
    pub title: &'static str,
    /// Section headers ("Usage:", table header rows, ...) — bold.
    pub header: &'static str,
    /// Accent color: prompts, command names, status "running".
    pub accent: &'static str,
    /// Secondary color: types, values, status "installed".
    pub info: &'static str,
    /// Faint: search terms, secondary text, "not-installed".
    pub dim: &'static str,
    /// Frame color: the borders of tables and boxes (list, version, ls...).
    pub border: &'static str,
    /// Warnings and "external" status.
    pub warn: &'static str,
    /// Errors and "not-installable".
    pub error: &'static str,
    /// Success / "ok".
    pub ok: &'static str,
    /// Version table keys.
    pub key: &'static str,
    /// Version table values.
    pub value: &'static str,
}

pub static THEMES: &[Theme] = &[
    Theme {
        name: "default",
        title: "Default (green/cyan)",
        header: "1;36",
        accent: "1;32",
        info: "36",
        dim: "2",
        border: "36",
        warn: "33",
        error: "31",
        ok: "1;32",
        key: "36",
        value: "1",
    },
    Theme {
        name: "ocean",
        title: "Ocean (blues)",
        header: "1;38;5;75",
        accent: "1;38;5;81",
        info: "38;5;117",
        dim: "2",
        border: "38;5;75",
        warn: "38;5;221",
        error: "38;5;203",
        ok: "1;38;5;81",
        key: "38;5;111",
        value: "1",
    },
    Theme {
        name: "sunset",
        title: "Sunset (orange/pink)",
        header: "1;38;5;209",
        accent: "1;38;5;215",
        info: "38;5;213",
        dim: "2",
        border: "38;5;209",
        warn: "38;5;221",
        error: "38;5;203",
        ok: "1;38;5;215",
        key: "38;5;213",
        value: "1",
    },
    Theme {
        name: "forest",
        title: "Forest (greens)",
        header: "1;38;5;71",
        accent: "1;38;5;107",
        info: "38;5;72",
        dim: "2",
        border: "38;5;71",
        warn: "38;5;179",
        error: "38;5;167",
        ok: "1;38;5;107",
        key: "38;5;108",
        value: "1",
    },
    Theme {
        name: "dracula",
        title: "Dracula (purple/green)",
        header: "1;38;5;141",
        accent: "1;38;5;84",
        info: "38;5;117",
        dim: "2",
        border: "38;5;141",
        warn: "38;5;228",
        error: "38;5;203",
        ok: "1;38;5;84",
        key: "38;5;141",
        value: "1",
    },
    Theme {
        name: "nord",
        title: "Nord (arctic frost)",
        header: "1;38;5;109",
        accent: "1;38;5;108",
        info: "38;5;110",
        dim: "2",
        border: "38;5;109",
        warn: "38;5;222",
        error: "38;5;167",
        ok: "1;38;5;108",
        key: "38;5;110",
        value: "1",
    },
    Theme {
        name: "solarized",
        title: "Solarized (dark)",
        header: "1;38;5;32",
        accent: "1;38;5;100",
        info: "38;5;37",
        dim: "2",
        border: "38;5;102",
        warn: "38;5;136",
        error: "38;5;160",
        ok: "1;38;5;100",
        key: "38;5;37",
        value: "1",
    },
    Theme {
        name: "gruvbox",
        title: "Gruvbox (retro warm)",
        header: "1;38;5;109",
        accent: "1;38;5;142",
        info: "38;5;66",
        dim: "2",
        border: "38;5;59",
        warn: "38;5;214",
        error: "38;5;167",
        ok: "1;38;5;142",
        key: "38;5;108",
        value: "1",
    },
    Theme {
        name: "catppuccin",
        title: "Catppuccin (pastel)",
        header: "1;38;5;111",
        accent: "1;38;5;114",
        info: "38;5;117",
        dim: "2",
        border: "38;5;111",
        warn: "38;5;229",
        error: "38;5;210",
        ok: "1;38;5;114",
        key: "38;5;140",
        value: "1",
    },
    Theme {
        name: "tokyo-night",
        title: "Tokyo Night (neon)",
        header: "1;38;5;111",
        accent: "1;38;5;114",
        info: "38;5;117",
        dim: "2",
        border: "38;5;111",
        warn: "38;5;215",
        error: "38;5;204",
        ok: "1;38;5;114",
        key: "38;5;141",
        value: "1",
    },
    Theme {
        name: "monokai",
        title: "Monokai (classic IDE)",
        header: "1;38;5;81",
        accent: "1;38;5;148",
        info: "38;5;81",
        dim: "2",
        border: "38;5;81",
        warn: "38;5;185",
        error: "38;5;197",
        ok: "1;38;5;148",
        key: "38;5;141",
        value: "1",
    },
    Theme {
        name: "matrix",
        title: "Matrix (green phosphor)",
        header: "1;38;5;46",
        accent: "1;38;5;40",
        info: "38;5;34",
        dim: "2",
        border: "38;5;34",
        warn: "38;5;190",
        error: "38;5;196",
        ok: "1;38;5;40",
        key: "38;5;40",
        value: "1",
    },
    Theme {
        name: "rose-pine",
        title: "Rose Pine (elegant pink)",
        header: "1;38;5;183",
        accent: "1;38;5;216",
        info: "38;5;117",
        dim: "2",
        border: "38;5;183",
        warn: "38;5;180",
        error: "38;5;204",
        ok: "1;38;5;216",
        key: "38;5;183",
        value: "1",
    },
    Theme {
        name: "amber",
        title: "Amber (retro CRT)",
        header: "1;38;5;214",
        accent: "1;38;5;215",
        info: "38;5;178",
        dim: "2",
        border: "38;5;172",
        warn: "38;5;220",
        error: "38;5;196",
        ok: "1;38;5;215",
        key: "38;5;214",
        value: "1",
    },
    Theme {
        name: "mono",
        title: "Mono (no colors)",
        header: "1",
        accent: "",
        info: "",
        dim: "",
        border: "",
        warn: "",
        error: "",
        ok: "1",
        key: "",
        value: "",
    },
];

/// The theme used when nothing else is configured.
pub fn default_theme() -> &'static Theme {
    &THEMES[0]
}

/// Look a theme up by name (case-insensitive).
pub fn find(name: &str) -> Option<&'static Theme> {
    let lower = name.trim().to_lowercase();
    THEMES.iter().find(|t| t.name.to_lowercase() == lower)
}

/// Machine names of every theme, for error messages and help.
pub fn names() -> Vec<&'static str> {
    THEMES.iter().map(|t| t.name).collect()
}

/// One line per theme: "name - title", for the help output.
pub fn describe_all() -> Vec<String> {
    THEMES
        .iter()
        .map(|t| format!("{} - {}", t.name, t.title))
        .collect()
}

impl Theme {
    /// Wrap text in this SGR sequence (empty sequence = plain text).
    pub fn paint(&self, sgr: &str, text: &str) -> String {
        if sgr.is_empty() || text.is_empty() {
            text.to_string()
        } else {
            format!("\x1b[{sgr}m{text}\x1b[0m")
        }
    }

    pub fn hdr(&self, text: &str) -> String {
        self.paint(self.header, text)
    }

    pub fn acc(&self, text: &str) -> String {
        self.paint(self.accent, text)
    }

    pub fn inf(&self, text: &str) -> String {
        self.paint(self.info, text)
    }

    pub fn dimmed(&self, text: &str) -> String {
        self.paint(self.dim, text)
    }

    pub fn frame(&self, text: &str) -> String {
        self.paint(self.border, text)
    }

    pub fn warn(&self, text: &str) -> String {
        self.paint(self.warn, text)
    }

    pub fn err(&self, text: &str) -> String {
        self.paint(self.error, text)
    }

    pub fn ok(&self, text: &str) -> String {
        self.paint(self.ok, text)
    }

    pub fn key(&self, text: &str) -> String {
        self.paint(self.key, text)
    }

    pub fn val(&self, text: &str) -> String {
        self.paint(self.value, text)
    }
}

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

    #[test]
    fn finds_themes_case_insensitively() {
        assert_eq!(find("Ocean").unwrap().name, "ocean");
        assert_eq!(find("default").unwrap().name, "default");
        assert_eq!(find("DRACULA").unwrap().name, "dracula");
        assert!(find("blorp").is_none());
    }

    #[test]
    fn default_is_first() {
        assert_eq!(default_theme().name, "default");
    }

    #[test]
    fn mono_theme_paints_nothing() {
        let mono = find("mono").unwrap();
        // Bold (structure) survives; colors are gone.
        assert_eq!(mono.hdr("x"), "x");
        assert_eq!(mono.acc("x"), "x");
        assert_eq!(mono.inf("x"), "x");
        assert_eq!(mono.dimmed("x"), "x");
        assert_eq!(mono.key("x"), "x");
        assert_eq!(mono.val("x"), "x");
    }

    #[test]
    fn paint_wraps_with_ansi() {
        let t = default_theme();
        let s = t.acc("ok");
        assert!(s.starts_with("\x1b[1;32m"));
        assert!(s.ends_with("\x1b[0m"));
    }

    #[test]
    fn every_theme_has_a_description() {
        for t in THEMES {
            assert!(!t.title.is_empty(), "{}: missing title", t.name);
        }
    }

    #[test]
    fn theme_names_are_unique() {
        let mut names: Vec<&str> = THEMES.iter().map(|t| t.name).collect();
        names.sort();
        names.dedup();
        assert_eq!(names.len(), THEMES.len(), "duplicate theme names");
    }

    #[test]
    fn extended_catalog_is_findable() {
        for name in [
            "nord",
            "solarized",
            "gruvbox",
            "catppuccin",
            "tokyo-night",
            "monokai",
            "matrix",
            "rose-pine",
            "amber",
        ] {
            assert!(find(name).is_some(), "missing theme {name}");
        }
        assert_eq!(THEMES.len(), 15);
    }

    #[test]
    fn frame_paints_with_the_theme_border_color() {
        let t = find("ocean").unwrap();
        let s = t.frame("╭──╮");
        assert!(s.starts_with(""));
        assert_eq!(find("mono").unwrap().frame("x"), "x");
    }
}