use git2::{BranchType, Error, Repository};
use std::{path::PathBuf, time::Duration};

use crate::{parser::Parser, project::Project};

#[derive(Debug, Clone)]
pub struct Git;

impl Parser for Git {
    type Error = Error;

    #[tracing::instrument]
    fn parse(&self, path_buf: PathBuf) -> Result<Project, Self::Error> {
        Repository::open(&path_buf)?.parse(path_buf)
    }
}

impl Parser for Repository {
    type Error = Error;

    fn parse(&self, path_buf: PathBuf) -> Result<Project, Self::Error> {
        let opt_commit = self
            .branches(Some(BranchType::Local))?
            .map(|branch| -> Result<_, Error> {
                let (branch, _) = branch?;

                let name = branch
                    .name()?
                    .ok_or_else(|| Error::from_str("Failed to get branch name"))?;

                self.revparse_single(name)?.peel_to_commit()
            })
            .inspect(|res| {
                if let Err(err) = res {
                    tracing::warn!(%err, "Skipping errored branch")
                }
            })
            .flatten()
            .max_by_key(|c| c.time().seconds() as u64);

        let timestamp = match opt_commit {
            Some(c) => {
                let time = c.time().seconds();
                let id = c.id();
                tracing::debug!(?path_buf, ?id, ?time, "Latest commit");
                Duration::from_secs(c.time().seconds() as u64)
            }
            None => {
                tracing::warn!(?path_buf, "No commit found, using default");
                Duration::default()
            }
        };

        Ok(Project {
            path_buf,
            timestamp,
        })
    }
}