#!/usr/bin/env bash
# Pre-commit hook: run clang-format and clang-tidy on staged C/H files.

set -e

# ── Find clang-format ────────────────────────────────────────────────
CLANG_FORMAT=""
for cmd in clang-format clang-format-14 clang-format-15 clang-format-16; do
  if command -v "$cmd" &>/dev/null; then
    CLANG_FORMAT="$cmd"
    break
  fi
done
if [ -z "$CLANG_FORMAT" ]; then
  for path in /opt/homebrew/bin/clang-format /usr/local/bin/clang-format; do
    if [ -x "$path" ]; then
      CLANG_FORMAT="$path"
      break
    fi
  done
fi
if [ -z "$CLANG_FORMAT" ]; then
  echo "pre-commit: clang-format not found — skipping format check"
  echo "  Install: brew install clang-format"
  exit 0
fi

# ── Collect staged C/H files ────────────────────────────────────────
# Exclude vendored/third-party paths. The local clang-format (22+) drifts
# from CI's clang-format (18) on alignment in components/u8g2-hal-esp-idf/;
# auto-reformatting there causes CI format-check failures.
STAGED=$(git diff --cached --name-only --diff-filter=ACMR -- '*.c' '*.h' \
  | { grep -v '^components/u8g2-hal-esp-idf/' || true; } \
  | { grep -v '^components/u8g2/' || true; })
if [ -z "$STAGED" ]; then
  exit 0
fi

# ── Format check ────────────────────────────────────────────────────
UNFORMATTED=""
for file in $STAGED; do
  if ! "$CLANG_FORMAT" --dry-run --Werror "$file" &>/dev/null; then
    UNFORMATTED="$UNFORMATTED $file"
  fi
done

if [ -n "$UNFORMATTED" ]; then
  echo "pre-commit: formatting issues found — fixing automatically"
  for file in $UNFORMATTED; do
    "$CLANG_FORMAT" -i "$file"
    git add "$file"
  done
  echo "pre-commit: formatted and re-staged:$UNFORMATTED"
fi

# ── Lint (clang-tidy) ───────────────────────────────────────────────
# Only run if compile_commands.json exists (requires a prior build).
if [ ! -f build/compile_commands.json ]; then
  echo "pre-commit: build/compile_commands.json not found — skipping lint"
  exit 0
fi

# Prefer brew llvm if available (macOS)
if command -v brew &>/dev/null; then
  LLVM_PREFIX="$(brew --prefix llvm 2>/dev/null)" || true
  [ -n "$LLVM_PREFIX" ] && export PATH="$LLVM_PREFIX/bin:$PATH"
fi

if ! command -v clang-tidy &>/dev/null; then
  echo "pre-commit: clang-tidy not found — skipping lint"
  exit 0
fi

echo "pre-commit: running clang-tidy on staged files..."
WARNINGS=0
for file in $STAGED; do
  OUTPUT=$(clang-tidy -p build "$file" 2>&1 || true)
  FILTERED=$(echo "$OUTPUT" | grep -v "file not found \[clang-diagnostic" || true)
  if echo "$FILTERED" | grep -q ": warning:"; then
    echo "$FILTERED" | grep -E "(: warning:|: note:)"
    WARNINGS=1
  fi
done

if [ "$WARNINGS" -ne 0 ]; then
  echo ""
  echo "pre-commit: clang-tidy found issues — commit aborted"
  exit 1
fi