#!/bin/bash
# -----------------------------------------------------------------------------
# disaster-swap-endpoint.sh
# Sprint: SPRINT_20260125_003_Attestor_trust_workflows_conformance
# Task: WORKFLOW-003 - Create disaster endpoint swap script
# Description: Emergency endpoint swap via TUF (no client reconfiguration)
# -----------------------------------------------------------------------------

set -euo pipefail

RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m'

log_info() { echo -e "${GREEN}[INFO]${NC} $1"; }
log_warn() { echo -e "${YELLOW}[WARN]${NC} $1"; }
log_error() { echo -e "${RED}[ERROR]${NC} $1"; }
log_step() { echo -e "${BLUE}[STEP]${NC} $1"; }

usage() {
    echo "Usage: $0 --repo <dir> --new-rekor-url <url> [options]"
    echo ""
    echo "Emergency endpoint swap via TUF update."
    echo "Clients will auto-discover new endpoints without reconfiguration."
    echo ""
    echo "Options:"
    echo "  --repo DIR             TUF repository directory (required)"
    echo "  --new-rekor-url URL    New Rekor URL (required)"
    echo "  --new-fulcio-url URL   New Fulcio URL (optional)"
    echo "  --note TEXT            Note explaining the change"
    echo "  --version N            New service map version (auto-increment if not specified)"
    echo "  -h, --help             Show this help message"
    echo ""
    echo "Example:"
    echo "  $0 --repo /path/to/tuf \\"
    echo "     --new-rekor-url https://rekor-mirror.internal:8080 \\"
    echo "     --note 'Emergency: Production Rekor outage'"
    echo ""
    echo "IMPORTANT: This changes where ALL clients send requests!"
    exit 1
}

REPO_DIR=""
NEW_REKOR_URL=""
NEW_FULCIO_URL=""
NOTE=""
VERSION=""

while [[ $# -gt 0 ]]; do
    case $1 in
        --repo) REPO_DIR="$2"; shift 2 ;;
        --new-rekor-url) NEW_REKOR_URL="$2"; shift 2 ;;
        --new-fulcio-url) NEW_FULCIO_URL="$2"; shift 2 ;;
        --note) NOTE="$2"; shift 2 ;;
        --version) VERSION="$2"; shift 2 ;;
        -h|--help) usage ;;
        *) log_error "Unknown argument: $1"; usage ;;
    esac
done

if [[ -z "$REPO_DIR" ]] || [[ -z "$NEW_REKOR_URL" ]]; then
    log_error "--repo and --new-rekor-url are required"
    usage
fi

if [[ ! -d "$REPO_DIR" ]]; then
    log_error "TUF repository not found: $REPO_DIR"
    exit 1
fi

echo ""
echo "================================================"
echo -e "${RED}  EMERGENCY ENDPOINT SWAP${NC}"
echo "================================================"
echo ""
log_warn "This will redirect ALL clients to new endpoints!"
echo ""
log_info "TUF Repository: $REPO_DIR"
log_info "New Rekor URL: $NEW_REKOR_URL"
if [[ -n "$NEW_FULCIO_URL" ]]; then
    log_info "New Fulcio URL: $NEW_FULCIO_URL"
fi
if [[ -n "$NOTE" ]]; then
    log_info "Note: $NOTE"
fi
echo ""

read -p "Type 'SWAP' to confirm endpoint change: " CONFIRM
if [[ "$CONFIRM" != "SWAP" ]]; then
    log_error "Aborted"
    exit 1
fi

# Find current service map
CURRENT_MAP=$(ls "$REPO_DIR/targets/" 2>/dev/null | grep -E '^sigstore-services-v[0-9]+\.json$' | sort -V | tail -1 || echo "")

if [[ -z "$CURRENT_MAP" ]]; then
    log_error "No service map found in $REPO_DIR/targets/"
    exit 1
fi

CURRENT_PATH="$REPO_DIR/targets/$CURRENT_MAP"
log_info "Current service map: $CURRENT_MAP"

# Determine new version
if [[ -z "$VERSION" ]]; then
    CURRENT_VERSION=$(echo "$CURRENT_MAP" | grep -oE '[0-9]+' | tail -1)
    VERSION=$((CURRENT_VERSION + 1))
fi

NEW_MAP="sigstore-services-v${VERSION}.json"
NEW_PATH="$REPO_DIR/targets/$NEW_MAP"

log_step "Creating new service map: $NEW_MAP"

# Read current map and update
if command -v python3 &>/dev/null; then
    python3 - "$CURRENT_PATH" "$NEW_PATH" "$NEW_REKOR_URL" "$NEW_FULCIO_URL" "$NOTE" "$VERSION" << 'PYTHON_SCRIPT'
import json
import sys
from datetime import datetime

current_path = sys.argv[1]
new_path = sys.argv[2]
new_rekor_url = sys.argv[3]
new_fulcio_url = sys.argv[4] if len(sys.argv) > 4 and sys.argv[4] else None
note = sys.argv[5] if len(sys.argv) > 5 and sys.argv[5] else None
version = int(sys.argv[6]) if len(sys.argv) > 6 else 1

with open(current_path) as f:
    data = json.load(f)

# Update endpoints
data['version'] = version
data['rekor']['url'] = new_rekor_url

if new_fulcio_url and 'fulcio' in data:
    data['fulcio']['url'] = new_fulcio_url

# Update metadata
if 'metadata' not in data:
    data['metadata'] = {}
data['metadata']['updated_at'] = datetime.utcnow().strftime('%Y-%m-%dT%H:%M:%SZ')
if note:
    data['metadata']['note'] = note

with open(new_path, 'w') as f:
    json.dump(data, f, indent=2)

print(f"Created: {new_path}")
PYTHON_SCRIPT
else
    # Fallback: simple JSON creation
    cat > "$NEW_PATH" << EOF
{
  "version": $VERSION,
  "rekor": {
    "url": "$NEW_REKOR_URL"
  },
  "metadata": {
    "updated_at": "$(date -u +%Y-%m-%dT%H:%M:%SZ)",
    "note": "$NOTE"
  }
}
EOF
fi

log_info "New service map created: $NEW_PATH"

# Add to targets
log_step "Adding new service map to TUF targets..."

if [[ -x "$REPO_DIR/scripts/add-target.sh" ]]; then
    "$REPO_DIR/scripts/add-target.sh" "$NEW_PATH" "$NEW_MAP" --repo "$REPO_DIR"
fi

echo ""
echo "================================================"
echo -e "${GREEN}  Endpoint Swap Prepared${NC}"
echo "================================================"
echo ""
log_warn "NEXT STEPS (REQUIRED):"
echo "  1. Review the new service map: cat $NEW_PATH"
echo "  2. Sign the updated targets.json with targets key"
echo "  3. Update snapshot.json and sign with snapshot key"
echo "  4. Update timestamp.json and sign with timestamp key"
echo "  5. Deploy updated metadata to TUF server"
echo ""
log_info "Clients will auto-discover the new endpoint within their refresh interval."
log_info "For immediate effect, clients can run: stella trust sync --force"
echo ""
log_warn "Monitor client traffic to ensure failover is working!"
echo ""