#!/usr/bin/env bash
#
# Commit message validator for hyper-element
#
# Enforces:
#   1. Conventional Commits format: <type>: <message>
#   2. First line max 80 characters
#
# Allowed types:
#   feat, fix, docs, style, refactor, perf, test, build, ci, chore

set -euo pipefail

MSG_FILE="$1"
if [ ! -f "$MSG_FILE" ]; then
    echo "ERROR: commit-msg hook expects path to commit message file." >&2
    exit 1
fi

MSG_CONTENT=$(cat "$MSG_FILE")
FIRST_LINE=$(echo "$MSG_CONTENT" | sed -n '1p' | tr -d '\r')

# Skip merge commits
if printf '%s\n' "$FIRST_LINE" | grep -Eq "^Merge "; then
    exit 0
fi

TYPES="feat|fix|docs|style|refactor|perf|test|build|ci|chore"

# Check format: type: message (with optional ! for breaking changes)
if ! printf '%s\n' "$FIRST_LINE" | grep -Eq "^(${TYPES})(!)?:[[:space:]]+[^[:space:]]"; then
    cat >&2 <<'ERR'

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
  ✗ Invalid Commit Message Format
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

Commit messages must follow Conventional Commits format:

    <type>: <summary>

Allowed types:
    feat     - A new feature
    fix      - A bug fix
    docs     - Documentation only changes
    style    - Code style changes (formatting, etc)
    refactor - Code refactoring
    perf     - Performance improvements
    test     - Adding or updating tests
    build    - Build system changes
    ci       - CI/CD changes
    chore    - Other changes (deps, configs, etc)

Examples:
    feat: add dark mode toggle
    fix: resolve memory leak in event handler
    docs: update installation instructions

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
ERR
    exit 1
fi

# Enforce max line length (80 characters)
LENGTH=${#FIRST_LINE}
if [ "$LENGTH" -gt 80 ]; then
    cat >&2 <<ERR

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
  ✗ First Line Too Long
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

First line is ${LENGTH} characters (maximum is 80).

Keep the summary line concise. Details go in the body.

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
ERR
    exit 1
fi

exit 0