use anyhow::{Error, Result};
use git2::BranchType;

use crate::config::RepoConfig;

pub fn pull_or_clone_and_build_and_push(repo: &RepoConfig) -> Result<(), BuildError> {
    let git_repo = pull_or_clone(repo)?;
    build(&git_repo)?;
    push(&git_repo)?;

    Ok(())
}

fn pull_or_clone(repo: &RepoConfig) -> Result<git2::Repository, BuildError> {
    match git2::Repository::open(&repo.local_git_repo) {
        Ok(git_repo) => {
            pull(&git_repo).map_err(|err| BuildError::FailedToPull(err))?;
            Ok(git_repo)
        },

        Err(open_err) =>  match git2::Repository::clone(&repo.remote_git_repo, &repo.local_git_repo) {
            Ok(git_repo) => Ok(git_repo),
            Err(clone_err) => Err(BuildError::FailedToOpenOrClone(open_err.into(), clone_err.into())),
        }
    }
}

fn build(git_repo: &git2::Repository) -> Result<(), BuildError> {
    todo!()
}

fn push(git_repo: &git2::Repository) -> Result<(), BuildError> {
    todo!()
}

fn pull(git_repo: &git2::Repository) -> Result<()> {
    let mut origin = git_repo.find_remote("origin")?;
    let (main_branch, main_branch_name) = git_repo.find_branch("main", BranchType::Local).map(|b| (b, "main"))
        .or_else(|_| git_repo.find_branch("master", BranchType::Local).map(|b| (b, "master")))?;
    let upstream_main_branch = main_branch.upstream()?;

    git_repo.set_head(main_branch_name)?;
    origin.fetch(&[main_branch_name], None, None)?;
    let upstream_commit = git_repo.reference_to_annotated_commit(&upstream_main_branch.into_reference())?;
    git_repo.merge(&[&upstream_commit], None, None)?;
    Ok(())
}

pub enum BuildError {
    FailedToOpenOrClone(Error, Error),
    FailedToPull(Error),
}