#!/usr/bin/env bash

# clones repositories using Github Actions environment variables
# https://docs.github.com/en/actions/reference/environment-variables#default-environment-variables

set -eu

repo_name="$(echo "${GITHUB_REPOSITORY}" | cut -d'/' -f2)"
git config --global --add safe.directory "/__w/$repo_name/$repo_name"

# default clone depth for push events
PUSH_DEPTH="${PUSH_DEPTH:-2}"
# default clone depth for PR events
PULL_DEPTH="${PULL_DEPTH:-1}"
# only used when event isnt a push or pull_request
DEFAULT_BRANCH="${DEFAULT_BRANCH:-master}"

"$(dirname "${BASH_SOURCE[0]}")/delete-repo.sh"

git init
# Fake username because some combination of GitHub and Git are total... Gits.
git remote add origin "https://token:$GITHUB_TOKEN@github.com/$GITHUB_REPOSITORY"

if [ "$GITHUB_EVENT_NAME" == "push" ]; then
  echo "This is a push event, only cloning pushed ref."
  # fetch by Sha instead of Ref because there may be multiple pushes in rapid
  # sequence to eg, master. this ensures we get commit that triggered
  # event
  git fetch origin "$GITHUB_SHA" --depth="$PUSH_DEPTH"
  # get last part of refs/heads/$BRANCH
  git switch -c "${GITHUB_REF#'refs/heads/'}" "$GITHUB_SHA"
elif [ "$GITHUB_EVENT_NAME" == "pull_request" ]; then
  echo "This is a pull_request event, cloning incoming and base refs."
  # fetch base and PR branches so that comparisons can be done
  git fetch origin \
    --update-head-ok \
    --force \
    "+refs/heads/$GITHUB_BASE_REF:refs/heads/$GITHUB_BASE_REF" \
    "refs/heads/$GITHUB_HEAD_REF:refs/heads/$GITHUB_HEAD_REF" \
    --depth=1
  echo "Checking out $GITHUB_HEAD_REF"
  git checkout "$GITHUB_HEAD_REF"
else
  echo "Not a pull_request or push event, cloning $DEFAULT_BRANCH"
  git fetch origin "$DEFAULT_BRANCH" --depth=1
  git checkout "$DEFAULT_BRANCH"
fi

echo "Done."