get_pull_requests_since_last_version

#!/bin/bash

github_repo_url="$1" # Replace this with repo url
specific_tag="$2"  # Replace this with the tag name you want to use

# Extract owner and repo from a GitHub URL
get_repo_and_owner() {
    # Extract repository owner and name from GitHub URL
    repo_owner=$(echo "$github_repo_url" | awk -F'/' '{print $4}')
    repository_directory=$(echo "$github_repo_url" | awk -F'/' '{print $5}')

    echo "Repo owner: $repo_owner; Repo name: $repository_directory"
}

# Extract pull request numbers from commit messages
get_pull_request_numbers() {
    echo "$1" | grep -o "\#\d\+" | grep -o "\d\+"
}

# TODO optionally replace with GH CLI
# Check if a pull request is closed and merged
is_pull_request_closed_and_merged() {
    pr_number=$1
    gh api \
      -H "Accept: application/vnd.github+json" \
      -H "X-GitHub-Api-Version: 2022-11-28" \
      /repos/${repo_owner}/$repository_directory/pulls/$pr_number/merge
}

# Get commit messages for a merged pull request
get_pull_request_commits() {
    pr_number=$1
    commits=$(gh api \
                 -H "Accept: application/vnd.github+json" \
                 -H "X-GitHub-Api-Version: 2022-11-28" \
                 "/repos/${repo_owner}/$repository_directory/pulls/${pr_number}/commits" | jq -r '.[].commit.message')

    echo "$commits"
}

# TODO refactor these two get_pull_request into one API call because this is wasteful
# Function to get the GitHub user responsible for a pull request using GitHub API
get_pull_request_user() {
    pr_number=$1
    user=$(gh api \
                 -H "Accept: application/vnd.github+json" \
                 -H "X-GitHub-Api-Version: 2022-11-28" \
                 "/repos/${repo_owner}/$repository_directory/pulls/${pr_number}" | jq -r '.user.login')
    echo "$user"
}

# Function to get the GitHub pull request title using GitHub API
get_pull_request_title() {
    pr_number=$1
    title=$(gh api \
                 -H "Accept: application/vnd.github+json" \
                 -H "X-GitHub-Api-Version: 2022-11-28" \
                 "/repos/${repo_owner}/$repository_directory/pulls/${pr_number}" | jq -r '.title')
    echo "$title"
}

get_repo_and_owner "$github_repo_url"

export repo_owner repository_directory

rm -rf "$repository_directory"
git clone "$github_repo_url"
cd "$repository_directory"

# Fetch specific tag from remote repository
git pull
git fetch origin "refs/tags/$specific_tag:refs/tags/$specific_tag"

# Get commits since the specific tag
git log --oneline "$specific_tag"..HEAD > commits.tmp
echo "" > clean.tmp

# Iterate through the commits and print information about closed and merged pull requests
CUR_BULLET=1
while IFS="" read -r commit; do
    commit_message=$(echo "$commit" | cut -d' ' -f2-)
    pull_request_numbers=$(get_pull_request_numbers "$commit_message")
    has_merged_pull_requests=false

    # Check each pull request and print information about merged ones
    for pr_number in $pull_request_numbers; do
        if is_pull_request_closed_and_merged "$pr_number"; then
            user=$(get_pull_request_user "$pr_number")
            if [[ -n "$user" ]]; then
                user_profile_url="https://github.com/$user"
                pr_title=$(get_pull_request_title "$pr_number")
                echo "* $CUR_BULLET $pr_title ([#${pr_number}]($github_repo_url/pull/${pr_number}), [@${user}](${user_profile_url}))"
                echo "* $pr_title ([#${pr_number}]($github_repo_url/pull/${pr_number}), [@${user}](${user_profile_url}))" >> clean.tmp
                    echo "  Associated commit messages:"
                      pull_request_commits=$(get_pull_request_commits "$pr_number")
                      # This pipe chain deletes any commit messages that are blank, repeats, or contain "Signed-off"
                      echo "$pull_request_commits" | uniq | sed -e '/Signed-off.*/d' -e '/^$/d' -e 's/^/    - /'
                has_merged_pull_requests=true
                ((CUR_BULLET++))
            fi
        fi
    done

    # Print an empty line between commits with merged pull requests
    if $has_merged_pull_requests; then
        echo
    fi
done <<< "$(cat commits.tmp)"

cat clean.tmp