#!/bin/bash
#
# Pre-commit hook: ruff lint check on staged Python files.
# Catches syntax errors, unused imports, and basic issues before commit.
# To bypass in emergency: git commit --no-verify
#

RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
NC='\033[0m'

REPO_ROOT=$(git rev-parse --show-toplevel)
cd "$REPO_ROOT"

STAGED_PY=$(git diff --cached --name-only --diff-filter=ACM -z -- '*.py')
if [ -z "$STAGED_PY" ]; then
    exit 0
fi

echo "ruff check on staged files..."

# Stash unstaged changes so ruff only operates on staged content.
# Without this, ruff --fix runs on the full working tree file (staged +
# unstaged), and the subsequent git add would silently include unstaged
# changes in the commit — breaking git add -p workflows.
STASHED=0
if git stash --keep-index -q 2>/dev/null; then
    STASHED=1
fi

# Auto-fix what we can, then re-stage the fixed files
printf '%s' "$STAGED_PY" | xargs -0 ruff check --fix --exit-zero
printf '%s' "$STAGED_PY" | xargs -0 git add

# Restore unstaged changes
if [ $STASHED -eq 1 ]; then
    git stash pop -q
fi

# Now check for remaining unfixable issues
printf '%s' "$STAGED_PY" | xargs -0 ruff check
RUFF_EXIT=$?

if [ $RUFF_EXIT -ne 0 ]; then
    echo ""
    echo -e "${RED}Pre-commit checks failed (unfixable issues). Commit blocked.${NC}"
    echo -e "${YELLOW}To bypass (not recommended): git commit --no-verify${NC}"
    exit 1
fi

echo -e "${GREEN}All checks passed.${NC}"
exit 0