neyuki 0.6.1

//! Semantic versions and version constraints.

use std::cmp::Ordering;
use std::fmt;
use std::str::FromStr;

#[derive(Clone, Debug, Eq, PartialEq, Hash)]
pub struct Version {
    pub major: u64,
    pub minor: u64,
    pub patch: u64,
    pub pre: Option<String>,
}

impl Version {
    pub fn new(major: u64, minor: u64, patch: u64) -> Self {
        Self {
            major,
            minor,
            patch,
            pre: None,
        }
    }

    pub fn with_pre(mut self, pre: impl Into<String>) -> Self {
        self.pre = Some(pre.into());
        self
    }
}

impl Ord for Version {
    fn cmp(&self, other: &Self) -> Ordering {
        match self.major.cmp(&other.major) {
            Ordering::Equal => match self.minor.cmp(&other.minor) {
                Ordering::Equal => match self.patch.cmp(&other.patch) {
                    Ordering::Equal => match (&self.pre, &other.pre) {
                        (None, None) => Ordering::Equal,
                        (Some(_), None) => Ordering::Less, // pre-release is lower precedence
                        (None, Some(_)) => Ordering::Greater,
                        (Some(a), Some(b)) => a.cmp(b),
                    },
                    other_ord => other_ord,
                },
                other_ord => other_ord,
            },
            other_ord => other_ord,
        }
    }
}

impl PartialOrd for Version {
    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
        Some(self.cmp(other))
    }
}

impl fmt::Display for Version {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "{}.{}.{}", self.major, self.minor, self.patch)?;
        if let Some(pre) = &self.pre {
            write!(f, "-{}", pre)?;
        }
        Ok(())
    }
}

impl FromStr for Version {
    type Err = String;

    fn from_str(s: &str) -> Result<Self, Self::Err> {
        let trimmed = s.trim();
        let (num_part, pre_part) = if let Some((n, p)) = trimmed.split_once('-') {
            (n, Some(p.to_string()))
        } else {
            (trimmed, None)
        };

        let parts: Vec<&str> = num_part.split('.').collect();
        if parts.len() > 3 || parts.is_empty() {
            return Err(format!("invalid semver string '{}'", s));
        }

        let major = parts[0]
            .parse::<u64>()
            .map_err(|_| format!("invalid major in '{}'", s))?;
        let minor = if parts.len() > 1 {
            parts[1]
                .parse::<u64>()
                .map_err(|_| format!("invalid minor in '{}'", s))?
        } else {
            0
        };
        let patch = if parts.len() > 2 {
            parts[2]
                .parse::<u64>()
                .map_err(|_| format!("invalid patch in '{}'", s))?
        } else {
            0
        };

        Ok(Self {
            major,
            minor,
            patch,
            pre: pre_part,
        })
    }
}

#[derive(Clone, Debug, PartialEq, Eq)]
pub enum VersionReq {
    Any,
    Exact(Version),
    Caret(Version),
    Tilde(Version),
    GreaterOrEqual(Version),
    LessThan(Version),
}

impl VersionReq {
    pub fn parse(s: &str) -> Result<Self, String> {
        let trimmed = s.trim();
        if trimmed == "*" || trimmed.is_empty() {
            return Ok(Self::Any);
        }

        if let Some(rest) = trimmed.strip_prefix('^') {
            let ver = Version::from_str(rest)?;
            return Ok(Self::Caret(ver));
        }

        if let Some(rest) = trimmed.strip_prefix('~') {
            let ver = Version::from_str(rest)?;
            return Ok(Self::Tilde(ver));
        }

        if let Some(rest) = trimmed.strip_prefix(">=") {
            let ver = Version::from_str(rest)?;
            return Ok(Self::GreaterOrEqual(ver));
        }

        if let Some(rest) = trimmed.strip_prefix('<') {
            let ver = Version::from_str(rest)?;
            return Ok(Self::LessThan(ver));
        }

        if let Some(rest) = trimmed.strip_prefix('=') {
            let ver = Version::from_str(rest)?;
            return Ok(Self::Exact(ver));
        }

        // Default bare version "1.2.3" treated as Caret "^1.2.3" like npm/cargo
        let ver = Version::from_str(trimmed)?;
        Ok(Self::Caret(ver))
    }

    pub fn matches(&self, ver: &Version) -> bool {
        match self {
            Self::Any => true,
            Self::Exact(v) => ver == v,
            Self::GreaterOrEqual(v) => ver >= v,
            Self::LessThan(v) => ver < v,
            Self::Caret(v) => {
                if ver < v {
                    return false;
                }
                if v.major > 0 {
                    ver.major == v.major
                } else if v.minor > 0 {
                    ver.major == 0 && ver.minor == v.minor
                } else {
                    ver.major == 0 && ver.minor == 0 && ver.patch == v.patch
                }
            }
            Self::Tilde(v) => {
                if ver < v {
                    return false;
                }
                ver.major == v.major && ver.minor == v.minor
            }
        }
    }
}

impl fmt::Display for VersionReq {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            Self::Any => write!(f, "*"),
            Self::Exact(v) => write!(f, "={}", v),
            Self::Caret(v) => write!(f, "^{}", v),
            Self::Tilde(v) => write!(f, "~{}", v),
            Self::GreaterOrEqual(v) => write!(f, ">={}", v),
            Self::LessThan(v) => write!(f, "<{}", v),
        }
    }
}