git-commits 0.1.0

use std::borrow::Cow;
use std::fmt;

use git2::Repository;

#[cfg(feature = "chrono")]
use chrono::{DateTime, FixedOffset, Local, TimeZone, Utc};

use super::Changes;
use super::GitError;

pub struct Commit<'repo> {
    pub(crate) repo: &'repo Repository,
    pub(crate) commit: git2::Commit<'repo>,
}

impl<'repo> Commit<'repo> {
    #[inline]
    pub(crate) const fn new(repo: &'repo Repository, commit: git2::Commit<'repo>) -> Self {
        Self { repo, commit }
    }

    #[doc(alias = "hash")]
    #[inline]
    pub fn sha(&self) -> String {
        self.commit.id().to_string()
    }

    #[inline]
    pub fn message_bytes(&self) -> &[u8] {
        self.commit.message_bytes()
    }

    #[inline]
    pub fn message(&self) -> Option<&str> {
        self.commit.message()
    }

    #[inline]
    pub fn message_lossy(&self) -> String {
        let msg = self.message_bytes();
        String::from_utf8_lossy(msg).into_owned()
    }

    /// The author is the person who wrote the code.
    #[inline]
    pub fn author(&self) -> Signature<'_> {
        Signature {
            signature: self.commit.author(),
        }
    }

    /// The committer is the person who committed the code,
    /// on behalf of the author.
    #[inline]
    pub fn committer(&self) -> Signature<'_> {
        Signature {
            signature: self.commit.committer(),
        }
    }

    /// Returns the commit time (i.e. committer time) of a commit.
    ///
    /// Returns `(seconds, offset_minutes)`.
    ///
    /// _See also [`.time()`](Self::time) for a `chrono` `DateTime`._
    #[inline]
    pub fn when(&self) -> (i64, i32) {
        let time = self.commit.time();
        (time.seconds(), time.offset_minutes())
    }

    /// Returns the commit time (i.e. committer time) of a commit.
    ///
    /// Returns `None` for an invalid timestamp.
    #[cfg(feature = "chrono")]
    pub fn time(&self) -> Option<DateTime<FixedOffset>> {
        let time = self.commit.time();

        let offset = time.offset_minutes().checked_mul(60)?;
        let offset = FixedOffset::east_opt(offset)?;
        offset.timestamp_opt(time.seconds(), 0).single()
    }

    /// Returns the commit time (i.e. committer time) of a commit.
    ///
    /// Returns `None` for an invalid timestamp.
    #[cfg(feature = "chrono")]
    #[inline]
    pub fn time_utc(&self) -> Option<DateTime<Utc>> {
        let time = self.time()?.with_timezone(&Utc);
        Some(time)
    }

    /// Returns the commit time (i.e. committer time) of a commit.
    ///
    /// Returns `None` for an invalid timestamp.
    #[cfg(feature = "chrono")]
    #[inline]
    pub fn time_local(&self) -> Option<DateTime<Local>> {
        let time = self.time()?.with_timezone(&Local);
        Some(time)
    }

    /// Returns an iterator that produces all changes
    /// this commit performed.
    #[inline]
    pub fn changes(&self) -> Result<Changes<'repo, '_>, GitError> {
        Changes::from_commit(self)
    }
}

impl fmt::Display for Commit<'_> {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self.time() {
            Some(time) => write!(f, "[{time}]")?,
            None => write!(f, "[invalid time]")?,
        }

        let msg = self.message_lossy();
        let first_line = msg.trim().lines().next().unwrap_or_default();

        write!(f, " {} {first_line}", self.author().name_lossy())?;

        Ok(())
    }
}

pub struct Signature<'a> {
    signature: git2::Signature<'a>,
}

impl Signature<'_> {
    /// Returns `None` if the name is not valid UTF-8.
    #[inline]
    pub fn name(&self) -> Option<&str> {
        self.signature.name()
    }

    #[inline]
    pub fn name_bytes(&self) -> &[u8] {
        self.signature.name_bytes()
    }

    #[inline]
    pub fn name_lossy(&self) -> Cow<'_, str> {
        String::from_utf8_lossy(self.name_bytes())
    }

    /// Returns `None` if the email is not valid UTF-8.
    #[inline]
    pub fn email(&self) -> Option<&str> {
        self.signature.email()
    }

    #[inline]
    pub fn email_bytes(&self) -> &[u8] {
        self.signature.email_bytes()
    }

    #[inline]
    pub fn email_lossy(&self) -> Cow<'_, str> {
        String::from_utf8_lossy(self.email_bytes())
    }

    /// Returns `(seconds, offset_minutes)`.
    ///
    /// _See also [`.time()`](Self::time) for a `chrono` `DateTime`._
    #[inline]
    pub fn when(&self) -> (i64, i32) {
        let time = self.signature.when();
        (time.seconds(), time.offset_minutes())
    }

    /// Returns `None` for an invalid timestamp.
    #[cfg(feature = "chrono")]
    pub fn time(&self) -> Option<DateTime<FixedOffset>> {
        let time = self.signature.when();

        let offset = time.offset_minutes().checked_mul(60)?;
        let offset = FixedOffset::east_opt(offset)?;
        offset.timestamp_opt(time.seconds(), 0).single()
    }

    /// Returns `None` for an invalid timestamp.
    #[cfg(feature = "chrono")]
    #[inline]
    pub fn time_utc(&self) -> Option<DateTime<Utc>> {
        let time = self.time()?.with_timezone(&Utc);
        Some(time)
    }

    /// Returns `None` for an invalid timestamp.
    #[cfg(feature = "chrono")]
    #[inline]
    pub fn time_local(&self) -> Option<DateTime<Local>> {
        let time = self.time()?.with_timezone(&Local);
        Some(time)
    }
}

impl fmt::Display for Signature<'_> {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self.time() {
            Some(time) => write!(f, "[{time}]")?,
            None => write!(f, "[invalid time]")?,
        }

        write!(f, " {} <{}>", self.name_lossy(), self.email_lossy())?;

        Ok(())
    }
}