gitoxide-core 0.63.0

use std::io::Write;

use gix::{
    Result,
    error::{OptionExt, ResultExt, bail, message},
};

/// Note that this is a quick implementation of commit signature verification that ignores a lot of what
/// git does and can do, while focussing on the gist of it.
/// For this to go into `gix`, one will have to implement many more options and various validation programs.
pub fn verify(repo: gix::Repository, rev_spec: Option<&str>) -> Result<()> {
    let rev_spec = rev_spec.unwrap_or("HEAD");
    let commit = repo
        .rev_parse_single(format!("{rev_spec}^{{commit}}").as_str())?
        .object()?
        .into_commit();
    let outcome = commit
        .verify_signature()
        .or_raise(|| message("Could not verify commit signature"))?
        .ok_or_raise(|| message!("Commit at {rev_spec} is not signed"))?;
    std::io::stderr().write_all(&outcome.output).or_error()?;
    if !outcome.is_valid() {
        bail!("Commit at {rev_spec} has an invalid or untrusted signature");
    }
    Ok(())
}

/// Sign an unsigned commit using repository configuration and print its object ID.
pub fn sign(repo: gix::Repository, rev_spec: Option<&str>, mut out: impl std::io::Write) -> Result<()> {
    let rev_spec = rev_spec.unwrap_or("HEAD");
    let commit = repo
        .rev_parse_single(format!("{rev_spec}^{{commit}}").as_str())?
        .object()?
        .into_commit();
    if commit.signature()?.is_some() {
        gix::trace::info!("The commit {id} is already signed, did nothing", id = commit.id);
        writeln!(out, "{id}", id = commit.id).or_error()?;
        return Ok(());
    }

    let signed = commit.signed()?;
    writeln!(out, "{id}", id = signed.id).or_error()?;

    Ok(())
}

pub fn describe(
    mut repo: gix::Repository,
    rev_spec: Option<&str>,
    mut out: impl std::io::Write,
    mut err: impl std::io::Write,
    describe::Options {
        all_tags,
        all_refs,
        first_parent,
        always,
        statistics,
        max_candidates,
        long_format,
        dirty_suffix,
    }: describe::Options,
) -> Result<()> {
    repo.object_cache_size_if_unset(4 * 1024 * 1024);
    let commit = match rev_spec {
        Some(spec) => repo.rev_parse_single(spec)?.object()?.try_into_commit()?,
        None => repo.head_commit()?,
    };
    use gix::commit::describe::SelectRef::*;
    let select_ref = if all_refs {
        AllRefs
    } else if all_tags {
        AllTags
    } else {
        Default::default()
    };
    let resolution = commit
        .describe()
        .names(select_ref)
        .traverse_first_parent(first_parent)
        .id_as_fallback(always)
        .max_candidates(max_candidates)
        .try_resolve()?
        .ok_or_raise(|| message!("Did not find a single candidate ref for naming id '{}'", commit.id))?;

    if statistics {
        writeln!(err, "traversed {} commits", resolution.outcome.commits_seen).or_error()?;
    }

    let mut describe_id = resolution.format_with_dirty_suffix(dirty_suffix)?;
    describe_id.long(long_format);

    writeln!(out, "{describe_id}").or_error()?;
    Ok(())
}

pub mod describe {
    #[derive(Debug, Clone)]
    pub struct Options {
        pub all_tags: bool,
        pub all_refs: bool,
        pub first_parent: bool,
        pub always: bool,
        pub long_format: bool,
        pub statistics: bool,
        pub max_candidates: usize,
        pub dirty_suffix: Option<String>,
    }
}