#!/usr/bin/env bash
set -euo pipefail

# ECC Codex Git Hook: pre-commit
# Blocks commits that add high-signal secrets.

if [[ "${ECC_SKIP_GIT_HOOKS:-0}" == "1" || "${ECC_SKIP_PRECOMMIT:-0}" == "1" ]]; then
  exit 0
fi

if [[ -f ".ecc-hooks-disable" || -f ".git/ecc-hooks-disable" ]]; then
  exit 0
fi

if ! git rev-parse --is-inside-work-tree >/dev/null 2>&1; then
  exit 0
fi

staged_files="$(git diff --cached --name-only --diff-filter=ACMR || true)"
if [[ -z "$staged_files" ]]; then
  exit 0
fi

has_findings=0

scan_added_lines() {
  local file="$1"
  local name="$2"
  local regex="$3"
  local added_lines
  local hits

  added_lines="$(git diff --cached -U0 -- "$file" | awk '/^\+\+\+ /{next} /^\+/{print substr($0,2)}')"
  if [[ -z "$added_lines" ]]; then
    return 0
  fi

  if hits="$(printf '%s\n' "$added_lines" | rg -n --pcre2 "$regex" 2>/dev/null)"; then
    printf '\n[ECC pre-commit] Potential secret detected (%s) in %s\n' "$name" "$file" >&2
    printf '%s\n' "$hits" | head -n 3 >&2
    has_findings=1
  fi
}

while IFS= read -r file; do
  [[ -z "$file" ]] && continue

  case "$file" in
    *.png|*.jpg|*.jpeg|*.gif|*.svg|*.pdf|*.zip|*.gz|*.lock|pnpm-lock.yaml|package-lock.json|yarn.lock|bun.lockb)
      continue
      ;;
  esac

  scan_added_lines "$file" "OpenAI key" 'sk-[A-Za-z0-9]{20,}'
  scan_added_lines "$file" "GitHub classic token" 'ghp_[A-Za-z0-9]{36}'
  scan_added_lines "$file" "GitHub fine-grained token" 'github_pat_[A-Za-z0-9_]{20,}'
  scan_added_lines "$file" "AWS access key" 'AKIA[0-9A-Z]{16}'
  scan_added_lines "$file" "private key block" '-----BEGIN (RSA|EC|OPENSSH|DSA|PRIVATE) KEY-----'
  scan_added_lines "$file" "generic credential assignment" "(?i)\\b(api[_-]?key|secret|password|token)\\b\\s*[:=]\\s*['\\\"][^'\\\"]{12,}['\\\"]"
done <<< "$staged_files"

if [[ "$has_findings" -eq 1 ]]; then
  cat >&2 <<'EOF'

[ECC pre-commit] Commit blocked to prevent secret leakage.
Fix:
1) Remove secrets from staged changes.
2) Move secrets to env vars or secret manager.
3) Re-stage and commit again.

Temporary bypass (not recommended):
  ECC_SKIP_PRECOMMIT=1 git commit ...
EOF
  exit 1
fi

exit 0