#!/bin/sh

commit_msg_file="$1"

if [ ! -f "$commit_msg_file" ]; then
  echo "commit-msg hook error: commit message file not found"
  exit 1
fi

header="$(sed -n '/^[[:space:]]*#/!{/^[[:space:]]*$/!{p;q;}}' "$commit_msg_file")"

if [ -z "$header" ]; then
  echo "Invalid commit message: empty message"
  exit 1
fi

case "$header" in
  Merge\ *|Revert\ *|fixup!\ *|squash!\ *)
    exit 0
    ;;
esac

type_pattern="feat|fix|docs|style|refactor|perf|test|build|ci|chore|revert|wip|workflow|types|release"
commit_pattern="^($type_pattern)(\([a-z0-9][a-z0-9._/-]*\))?!?: .{1,}$"

if ! printf '%s\n' "$header" | grep -Eq "$commit_pattern"; then
  echo "Invalid commit message format."
  echo ""
  echo "Expected Conventional Commits format:"
  echo "  <type>[optional scope][optional !]: <description>"
  echo ""
  echo "Allowed types:"
  echo "  feat, fix, docs, style, refactor, perf, test, build, ci, chore,"
  echo "  revert, wip, workflow, types, release"
  echo ""
  echo "Examples:"
  echo "  feat: add user search"
  echo "  fix(backend): handle token expiry"
  echo "  docs(readme): update setup guide"
  echo "  refactor(web)!: remove legacy auth flow"
  exit 1
fi

exit 0