openmw-config 1.0.0

// SPDX-License-Identifier: MIT OR Apache-2.0
// Copyright (c) 2025 Dave Corley (S3kshun8)

use std::{borrow::Cow, fmt};

use crate::{ConfigError, GameSetting, GameSettingMeta, bail_config};

/// A `fallback=` setting whose value is an RGB colour triple (`r,g,b` with each component 0–255).
#[derive(Debug, Clone)]
pub struct ColorGameSetting {
    meta: GameSettingMeta,
    key: String,
    value: (u8, u8, u8),
    raw_value: String,
}

impl std::fmt::Display for ColorGameSetting {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(
            f,
            "{}fallback={},{}",
            self.meta.comment, self.key, self.raw_value
        )
    }
}

/// A `fallback=` setting whose value did not parse as a number or colour triple.
#[derive(Debug, Clone)]
pub struct StringGameSetting {
    meta: GameSettingMeta,
    key: String,
    value: String,
}

impl std::fmt::Display for StringGameSetting {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(
            f,
            "{}fallback={},{}",
            self.meta.comment, self.key, self.value
        )
    }
}

/// A `fallback=` setting whose value parsed as a floating-point number (contains a `.`).
#[derive(Debug, Clone)]
pub struct FloatGameSetting {
    meta: GameSettingMeta,
    key: String,
    value: f64,
    raw_value: String,
}

impl std::fmt::Display for FloatGameSetting {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(
            f,
            "{}fallback={},{}",
            self.meta.comment, self.key, self.raw_value
        )
    }
}

/// A `fallback=` setting whose value parsed as a 64-bit integer.
#[derive(Debug, Clone)]
pub struct IntGameSetting {
    meta: GameSettingMeta,
    key: String,
    value: i64,
    raw_value: String,
}

impl std::fmt::Display for IntGameSetting {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(
            f,
            "{}fallback={},{}",
            self.meta.comment, self.key, self.raw_value
        )
    }
}

/// A typed `fallback=Key,Value` entry from an `openmw.cfg` file.
///
/// The value is parsed into the most specific type that fits:
/// - Three comma-separated integers in 0–255 → [`Color`](Self::Color)
/// - A number containing `.` that parses as `f64` → [`Float`](Self::Float)
/// - A number that parses as `i64` → [`Int`](Self::Int)
/// - Anything else → [`String`](Self::String)
///
/// [`PartialEq`] comparisons are key-only *within the same variant*, matching `OpenMW`'s
/// last-defined-wins deduplication semantics used by [`game_settings`](crate::OpenMWConfiguration::game_settings).
#[derive(Debug, Clone)]
#[non_exhaustive]
pub enum GameSettingType {
    /// An RGB colour triple (`r,g,b`).
    Color(ColorGameSetting),
    /// A plain string value (catch-all for values that aren't numeric or colour).
    String(StringGameSetting),
    /// A floating-point value.
    Float(FloatGameSetting),
    /// A 64-bit integer value.
    Int(IntGameSetting),
}

impl GameSettingType {
    /// Returns the setting key — the text before the first comma in a `fallback=Key,Value` entry.
    ///
    /// ```
    /// use std::path::PathBuf;
    /// use openmw_config::GameSettingType;
    /// let setting = GameSettingType::try_from(
    ///     ("iMaxLevel,50".to_string(), PathBuf::default(), &mut String::new())
    /// ).unwrap();
    /// assert_eq!(setting.key(), "iMaxLevel");
    /// ```
    #[must_use]
    pub fn key(&self) -> &String {
        match self {
            GameSettingType::Color(setting) => &setting.key,
            GameSettingType::String(setting) => &setting.key,
            GameSettingType::Float(setting) => &setting.key,
            GameSettingType::Int(setting) => &setting.key,
        }
    }

    /// Borrowed string view of [`Self::key`].
    #[must_use]
    pub fn key_str(&self) -> &str {
        match self {
            GameSettingType::Color(setting) => &setting.key,
            GameSettingType::String(setting) => &setting.key,
            GameSettingType::Float(setting) => &setting.key,
            GameSettingType::Int(setting) => &setting.key,
        }
    }

    /// Returns the setting value — the text after the first comma in a `fallback=Key,Value` entry.
    ///
    /// ```
    /// use std::path::PathBuf;
    /// use openmw_config::GameSettingType;
    /// let setting = GameSettingType::try_from(
    ///     ("iMaxLevel,50".to_string(), PathBuf::default(), &mut String::new())
    /// ).unwrap();
    /// assert_eq!(setting.value(), "50");
    /// ```
    #[must_use]
    pub fn value(&self) -> Cow<'_, str> {
        match self {
            GameSettingType::Color(setting) => {
                let _ = setting.value;
                Cow::Borrowed(&setting.raw_value)
            }
            GameSettingType::String(setting) => Cow::Borrowed(&setting.value),
            GameSettingType::Float(setting) => {
                let _ = setting.value;
                Cow::Borrowed(&setting.raw_value)
            }
            GameSettingType::Int(setting) => {
                let _ = setting.value;
                Cow::Borrowed(&setting.raw_value)
            }
        }
    }
}

impl std::fmt::Display for GameSettingType {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            GameSettingType::Color(s) => write!(f, "{s}"),
            GameSettingType::Float(s) => write!(f, "{s}"),
            GameSettingType::String(s) => write!(f, "{s}"),
            GameSettingType::Int(s) => write!(f, "{s}"),
        }
    }
}

impl GameSetting for GameSettingType {
    fn meta(&self) -> &GameSettingMeta {
        match self {
            GameSettingType::Color(s) => &s.meta,
            GameSettingType::String(s) => &s.meta,
            GameSettingType::Float(s) => &s.meta,
            GameSettingType::Int(s) => &s.meta,
        }
    }
}

impl PartialEq for GameSettingType {
    fn eq(&self, other: &Self) -> bool {
        use GameSettingType::{Color, Float, Int, String};

        match (self, other) {
            (Color(a), Color(b)) => a.key == b.key,
            (String(a), String(b)) => a.key == b.key,
            (Float(a), Float(b)) => a.key == b.key,
            (Int(a), Int(b)) => a.key == b.key,
            // Mismatched types should never be considered equal
            _ => false,
        }
    }
}

impl PartialEq<&str> for GameSettingType {
    fn eq(&self, other: &&str) -> bool {
        use GameSettingType::{Color, Float, Int, String};

        match self {
            Color(a) => a.key == *other,
            String(a) => a.key == *other,
            Float(a) => a.key == *other,
            Int(a) => a.key == *other,
        }
    }
}

impl Eq for GameSettingType {}

impl TryFrom<(String, std::path::PathBuf, &mut String)> for GameSettingType {
    type Error = ConfigError;

    fn try_from(
        (original_value, source_config, queued_comment): (String, std::path::PathBuf, &mut String),
    ) -> Result<Self, ConfigError> {
        let Some((key, value)) = original_value.split_once(',') else {
            bail_config!(invalid_game_setting, original_value, source_config);
        };

        let key = key.to_string();
        let value = value.to_string();

        let meta = GameSettingMeta {
            source_config,
            comment: queued_comment.clone(),
        };

        queued_comment.clear();

        if let Some(color) = parse_color_value(&value) {
            return Ok(GameSettingType::Color(ColorGameSetting {
                meta,
                key,
                value: color,
                raw_value: value,
            }));
        }

        if value.contains('.')
            && let Ok(f) = value.parse::<f64>()
        {
            return Ok(GameSettingType::Float(FloatGameSetting {
                meta,
                key,
                value: f,
                raw_value: value,
            }));
        }

        if let Ok(i) = value.parse::<i64>() {
            return Ok(GameSettingType::Int(IntGameSetting {
                meta,
                key,
                value: i,
                raw_value: value,
            }));
        }

        Ok(GameSettingType::String(StringGameSetting {
            meta,
            key,
            value,
        }))
    }
}

fn parse_color_value(value: &str) -> Option<(u8, u8, u8)> {
    let mut parts = value.split(',').map(str::trim);
    let r = parts.next()?.parse::<u8>().ok()?;
    let g = parts.next()?.parse::<u8>().ok()?;
    let b = parts.next()?.parse::<u8>().ok()?;

    if parts.next().is_some() {
        return None;
    }

    Some((r, g, b))
}

#[cfg(test)]
mod tests {
    use std::path::PathBuf;

    use super::*;

    fn default_meta() -> GameSettingMeta {
        GameSettingMeta {
            source_config: PathBuf::default(),
            comment: String::default(),
        }
    }

    #[test]
    fn test_value_string_setting() {
        let setting = GameSettingType::String(StringGameSetting {
            meta: default_meta(),
            key: "greeting".into(),
            value: "hello world".into(),
        });

        assert_eq!(setting.value(), "hello world");
    }

    #[test]
    fn test_value_int_setting() {
        let setting = GameSettingType::Int(IntGameSetting {
            meta: default_meta(),
            key: "MaxEyesOfTodd".into(),
            value: 3,
            raw_value: "3".into(),
        });

        assert_eq!(setting.value(), "3");
    }

    #[test]
    fn test_value_float_setting() {
        let setting = GameSettingType::Float(FloatGameSetting {
            meta: default_meta(),
            key: "FLightAttenuationEnfuckulation".into(),
            value: 0.75,
            raw_value: "0.75".into(),
        });

        assert_eq!(setting.value(), "0.75");
    }

    #[test]
    fn test_value_color_setting() {
        let setting = GameSettingType::Color(ColorGameSetting {
            meta: default_meta(),
            key: "hud_color".into(),
            value: (255, 128, 64),
            raw_value: "255,128,64".into(),
        });

        assert_eq!(setting.value(), "255,128,64");
    }

    #[test]
    fn test_to_string_for_string_setting() {
        let setting = GameSettingType::String(StringGameSetting {
            meta: default_meta(),
            key: "sGreeting".into(),
            value: "Hello, Nerevar.".into(),
        });

        assert_eq!(setting.to_string(), "fallback=sGreeting,Hello, Nerevar.");
    }

    #[test]
    fn test_to_string_for_int_setting() {
        let setting = GameSettingType::Int(IntGameSetting {
            meta: default_meta(),
            key: "iMaxSpeed".into(),
            value: 42,
            raw_value: "42".into(),
        });

        assert_eq!(setting.to_string(), "fallback=iMaxSpeed,42");
    }

    #[test]
    fn test_to_string_for_float_setting() {
        let setting = GameSettingType::Float(FloatGameSetting {
            meta: default_meta(),
            key: "fJumpHeight".into(),
            value: 1.75,
            raw_value: "1.75".into(),
        });

        assert_eq!(setting.to_string(), "fallback=fJumpHeight,1.75");
    }

    #[test]
    fn test_to_string_for_color_setting() {
        let setting = GameSettingType::Color(ColorGameSetting {
            meta: default_meta(),
            key: "iHUDColor".into(),
            value: (128, 64, 255),
            raw_value: "128,64,255".into(),
        });

        assert_eq!(setting.to_string(), "fallback=iHUDColor,128,64,255");
    }

    #[test]
    fn test_commented_string() {
        let setting = GameSettingType::Color(ColorGameSetting {
            meta: GameSettingMeta {
                source_config: PathBuf::from("$HOME/.config/openmw/openmw.cfg"),
                comment: String::from("#Monochrome UI Settings\n#\n#\n#\n#######\n##\n##\n##\n"),
            },
            key: "iHUDColor".into(),
            value: (128, 64, 255),
            raw_value: "128,64,255".into(),
        });

        assert_eq!(
            setting.to_string(),
            "#Monochrome UI Settings\n#\n#\n#\n#######\n##\n##\n##\nfallback=iHUDColor,128,64,255"
        );
    }

    // --- TryFrom parsing ---

    fn parse(s: &str) -> Result<GameSettingType, crate::ConfigError> {
        GameSettingType::try_from((s.to_string(), PathBuf::default(), &mut String::new()))
    }

    #[test]
    fn test_parse_string_value() {
        let setting = parse("sMyKey,hello world").unwrap();
        assert!(matches!(setting, GameSettingType::String(_)));
        assert_eq!(setting.key(), "sMyKey");
        assert_eq!(setting.key_str(), "sMyKey");
        assert_eq!(setting.value(), "hello world");
    }

    #[test]
    fn test_parse_integer_value() {
        let setting = parse("iSpeed,42").unwrap();
        assert!(matches!(setting, GameSettingType::Int(_)));
        assert_eq!(setting.value(), "42");
    }

    #[test]
    fn test_parse_negative_integer() {
        let setting = parse("iDepth,-100").unwrap();
        assert!(matches!(setting, GameSettingType::Int(_)));
        assert_eq!(setting.value(), "-100");
    }

    #[test]
    fn test_parse_float_value() {
        let setting = parse("fGravity,9.81").unwrap();
        assert!(matches!(setting, GameSettingType::Float(_)));
        assert_eq!(setting.value(), "9.81");
    }

    #[test]
    fn test_parse_color_value() {
        let setting = parse("iSkyColor,100,149,237").unwrap();
        assert!(matches!(setting, GameSettingType::Color(_)));
        assert_eq!(setting.value(), "100,149,237");
    }

    #[test]
    fn test_parse_missing_comma_errors() {
        assert!(parse("NoCommaAtAll").is_err());
    }

    #[test]
    fn test_parse_value_with_comma_stays_string() {
        // A string value that contains a comma should not be misidentified as color
        let setting = parse("sMessage,Hello, traveller").unwrap();
        assert!(matches!(setting, GameSettingType::String(_)));
        assert_eq!(setting.value(), "Hello, traveller");
    }

    #[test]
    fn test_parse_ambiguous_two_number_value_is_string() {
        // Two comma-separated numbers is NOT a valid color (needs 3), must fall back to String
        let setting = parse("sKey,10,20").unwrap();
        assert!(matches!(setting, GameSettingType::String(_)));
    }

    #[test]
    fn test_parse_color_out_of_u8_range_is_string() {
        // Values > 255 can't be u8 so the whole thing should parse as String
        let setting = parse("sBig,256,0,0").unwrap();
        assert!(matches!(setting, GameSettingType::String(_)));
    }

    #[test]
    fn test_parse_comment_consumed() {
        let mut comment = String::from("# some note\n");
        let setting =
            GameSettingType::try_from(("iVal,1".to_string(), PathBuf::default(), &mut comment))
                .unwrap();
        assert_eq!(setting.meta().comment, "# some note\n");
        assert!(comment.is_empty(), "comment should be consumed");
    }

    // --- Equality ---

    #[test]
    fn test_same_key_same_type_are_equal() {
        let a = parse("iKey,1").unwrap();
        let b = parse("iKey,2").unwrap();
        assert_eq!(a, b, "equality is key-only within the same type");
    }

    #[test]
    fn test_different_keys_not_equal() {
        let a = parse("iKey,1").unwrap();
        let b = parse("iOther,1").unwrap();
        assert_ne!(a, b);
    }

    #[test]
    fn test_mismatched_types_not_equal() {
        // "1" parses as Int; "1.0" parses as Float — same logical key, different types
        let int_setting = parse("iKey,1").unwrap();
        let float_setting = parse("iKey,1.0").unwrap();
        assert_ne!(int_setting, float_setting);
    }

    #[test]
    fn test_eq_with_str_key() {
        let setting = parse("iMaxLevel,50").unwrap();
        assert_eq!(setting, "iMaxLevel");
        assert_ne!(setting, "iOtherKey");
    }
}