use super::Headers;
#[derive(Debug, thiserror::Error)]
pub enum ParseError {
#[error("invalid utf-8")]
Utf8(#[source] std::str::Utf8Error),
#[error("missing tree")]
MissingTree,
#[error("invalid tree")]
InvalidTree,
#[error("invalid format")]
InvalidFormat,
#[error("invalid parent")]
InvalidParent,
#[error("invalid header")]
InvalidHeader,
#[error("invalid author")]
InvalidAuthor,
#[error("missing author")]
MissingAuthor,
#[error("invalid committer")]
InvalidCommitter,
#[error("missing committer")]
MissingCommitter,
}
pub fn parse_commit_header<
Tree: std::str::FromStr,
Parent: std::str::FromStr,
Signature: std::str::FromStr,
>(
header: &str,
) -> Result<(Tree, Vec<Parent>, Signature, Signature, Headers), ParseError> {
let mut lines = header.lines();
let tree = match lines.next() {
Some(tree) => tree
.strip_prefix("tree ")
.map(Tree::from_str)
.transpose()
.map_err(|_| ParseError::InvalidTree)?
.ok_or(ParseError::MissingTree)?,
None => return Err(ParseError::MissingTree),
};
let mut parents = Vec::new();
let mut author: Option<Signature> = None;
let mut committer: Option<Signature> = None;
let mut headers = Headers::new();
for line in lines {
// Check if a signature is still being parsed
if let Some(rest) = line.strip_prefix(' ') {
let value: &mut String = headers
.0
.last_mut()
.map(|(_, v)| v)
.ok_or(ParseError::InvalidFormat)?;
value.push('\n');
value.push_str(rest);
continue;
}
if let Some((name, value)) = line.split_once(' ') {
match name {
"parent" => parents.push(
value
.parse::<Parent>()
.map_err(|_| ParseError::InvalidParent)?,
),
"author" => {
author = Some(
value
.parse::<Signature>()
.map_err(|_| ParseError::InvalidAuthor)?,
)
}
"committer" => {
committer = Some(
value
.parse::<Signature>()
.map_err(|_| ParseError::InvalidCommitter)?,
)
}
_ => headers.push(name, value),
}
continue;
}
}
Ok((
tree,
parents,
author.ok_or(ParseError::MissingAuthor)?,
committer.ok_or(ParseError::MissingCommitter)?,
headers,
))
}