#!/usr/bin/env bash
# Pre-commit hook: block large files from being committed.
# Install: git config core.hooksPath .githooks
#
# Max allowed file size (bytes). Override with GIT_MAX_FILE_SIZE env var.
MAX_SIZE="${GIT_MAX_FILE_SIZE:-2097152}"  # 2 MB default

errors=0

while IFS= read -r line; do
  # Format: :old_mode new_mode old_sha new_sha status\tpath
  status=$(echo "$line" | awk '{print $5}' | cut -c1)
  file=$(echo "$line" | awk '{print $6}')

  # Skip deleted files
  [ "$status" = "D" ] && continue

  sha=$(echo "$line" | awk '{print $4}')
  size=$(git cat-file -s "$sha" 2>/dev/null || echo 0)

  if [ "$size" -gt "$MAX_SIZE" ]; then
    printf "BLOCKED: %s is %s bytes (max %s)\n" "$file" "$size" "$MAX_SIZE" >&2
    errors=$((errors + 1))
  fi
done < <(git diff --cached --raw)

if [ "$errors" -gt 0 ]; then
  echo >&2
  echo "Commit blocked: $errors file(s) exceed the ${MAX_SIZE}-byte limit." >&2
  echo "If intentional, bypass with: git commit --no-verify" >&2
  exit 1
fi