#!/usr/bin/bash

#
# This loosely implements the commit message linting check described by
# Conventional Commit (https://www.conventionalcommits.org). Commits merged in
# branches on this repository are expected to meet that general format:
#
# <prefix>: <message>
#
# where <prefix> is one of the prefixes included in the filters below.
#

CURRENT_HEAD=$(git rev-parse HEAD)
COMMITS=$(git log origin/main..$CURRENT_HEAD --oneline --format=%s)

if [[ -z "$COMMITS" ]]; then
    echo "No commits."
    exit 0
fi

INVALID_COMMITS_FOUND=0

while IFS='\n' read -r line; do
    if [[ $line =~ ^"Merge "[0-9a-z]+" into "[0-9a-z]+$ ]]; then
        continue
    elif [[ ($line =~ ^(test|feat|chore|fix|refactor|wip|docs|build|ci|perf):) ]]; then
        echo "VALID - $line"
    else
        echo "INVALID - $line"
        INVALID_COMMITS_FOUND=$((INVALID_COMMITS_FOUND+1))
    fi;
done <<< "$COMMITS"

if [[ $INVALID_COMMITS_FOUND -gt 0 ]]; then
    echo "$INVALID_COMMITS_FOUND bad commit messages found."
    exit 1
fi