#!/bin/sh
# Conventional Commits validation hook
# Spec: https://www.conventionalcommits.org/zh-hans/v1.0.0/

COMMIT_MSG=$(cat "$1")
FIRST_LINE=$(echo "$COMMIT_MSG" | head -1)

# Skip merge commits, reverts, and interactive rebase autosquash
case "$FIRST_LINE" in
    Merge\ *|Revert\ \"*|fixup!\ *|squash!\ *) exit 0 ;;
esac

# Format: <type>[optional scope][!]: <description>
TYPES="build|chore|ci|docs|feat|fix|perf|refactor|revert|style|test"
PATTERN="^($TYPES)(\([^)]+\))?!?: .+"

if ! echo "$FIRST_LINE" | grep -qE "$PATTERN"; then
    echo "ERROR: commit message does not follow Conventional Commits"
    echo ""
    echo "Format: <type>[optional scope]: <description>"
    echo "Valid types: build, chore, ci, docs, feat, fix, perf, refactor, revert, style, test"
    echo ""
    echo "Examples:"
    echo "  feat(title): add 34 Minecraft-themed lottery titles"
    echo "  fix(lottery): correct draw probability calculation"
    echo "  docs: update README"
    echo ""
    echo "Your message:"
    echo "  $FIRST_LINE"
    exit 1
fi

# Warn if description is too short
DESC=$(echo "$FIRST_LINE" | sed -E 's/^[^:]+: //')
if [ ${#DESC} -lt 4 ]; then
    echo "WARNING: commit description is very short, consider adding more detail"
fi

exit 0