use git2::Repository;
use serde::Serialize;

#[allow(dead_code)]
#[derive(Debug, Serialize)]
struct CommitAuthor {
    email: String,
    name: String,
}

#[allow(dead_code)]
#[derive(Debug, Serialize)]
struct Commit {
    title: String,
    #[serde(skip_serializing_if = "Option::is_none")]
    message: Option<String>,
    author: CommitAuthor,
    time: i64,
}

pub fn get_git_log(path: String) -> eyre::Result<String> {
    let repo = Repository::open(path)?;
    let mut revwalk = repo.revwalk()?;
    revwalk.set_sorting(git2::Sort::TIME)?;

    let revspec = repo.revparse("HEAD")?;
    let from = revspec.from().ok_or(eyre::anyhow!("could not get HEAD"))?;
    revwalk.push(from.id())?;

    let mut commits: Vec<Commit> = Vec::new();
    for rev in revwalk.enumerate() {
        let oid = rev.1?;
        let commit = repo.find_commit(oid)?;
        let message = commit
            .message()
            .ok_or(eyre::anyhow!("could not find message from commit"))?;
        let timestamp = commit.time();
        let author = commit.author();

        let message_content = message.split("\n");
        let message_heading = message_content
            .clone()
            .take(1)
            .collect::<Vec<&str>>()
            .join("\n");
        let message_content = message_content
            .clone()
            .skip(1)
            .collect::<Vec<&str>>()
            .join("\n");

        let commit = Commit {
            title: message_heading,
            message: if message_content == "" {
                None
            } else {
                Some(message_content)
            },
            author: CommitAuthor {
                email: author
                    .email()
                    .ok_or(eyre::anyhow!("could not get authors email"))?
                    .to_string(),
                name: author
                    .name()
                    .ok_or(eyre::anyhow!("could not get authors name"))?
                    .to_string(),
            },
            time: timestamp.seconds(),
        };

        commits.push(commit);
    }

    let commits_str = serde_json::to_string(&commits)?;

    Ok(commits_str)
}