#!/bin/bash
set -euo pipefail

# Phase 6, Plan 02, Task 2: Restore from Backup
# Supports both Docker and Standalone deployment modes
# Usage: ./restore.sh <backup_file> [--validate]

BACKUP_FILE="${1:-}"
VALIDATE="${2:---validate}"

RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
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"; exit 1; }

# Validate input
[[ -z "$BACKUP_FILE" ]] && log_error "Usage: ./restore.sh <backup_file>"
[[ ! -f "$BACKUP_FILE" ]] && log_error "Backup file not found: $BACKUP_FILE"

log_info "Restoring from: $BACKUP_FILE"

# Triple confirmation (security requirement)
echo "⚠️  WARNING: This will overwrite current data!"
read -p "Type 'RESTORE' to confirm (1/3): " confirm1
[[ "$confirm1" != "RESTORE" ]] && log_error "Restore cancelled"

read -p "Type 'RESTORE' again to confirm (2/3): " confirm2
[[ "$confirm2" != "RESTORE" ]] && log_error "Restore cancelled"

read -p "Type 'RESTORE' one more time to confirm (3/3): " confirm3
[[ "$confirm3" != "RESTORE" ]] && log_error "Restore cancelled"

log_warn "Proceeding with restore..."

# Determine deployment mode
if command -v docker-compose &> /dev/null; then
  log_info "Docker deployment mode detected"
  IS_DOCKER=true

  # 1. Stop services
  log_info "Stopping services..."
  docker-compose down

  # 2. Backup current data (safety copy)
  log_info "Creating safety backup of current data..."
  mkdir -p data/backups_before_restore
  tar -czf "data/backups_before_restore/backup-before-restore-$(date +%s).tar.gz" \
      data/inventory.db data/inventory.db-* 2>/dev/null || true

  # 3. Extract backup
  log_info "Extracting backup..."
  tar -xzf "$BACKUP_FILE" -C . || log_error "Backup extraction failed"

  # 4. Verify essential files
  log_info "Verifying restored files..."
  [[ -f "data/inventory.db" ]] || log_error "Database not found in backup"
  [[ -f "inventory.env" ]] || log_error "inventory.env not found in backup"

  # 5. Restart services
  log_info "Restarting services..."
  docker-compose up -d

  # 6. Wait for health
  log_info "Waiting for services to be healthy..."
  max_attempts=30
  attempt=0
  while [[ $attempt -lt $max_attempts ]]; do
    if curl -sf "http://localhost:8000/health" > /dev/null 2>&1; then
      log_info "Services healthy!"
      break
    fi
    attempt=$((attempt + 1))
    sleep 2
  done

  if [[ $attempt -eq $max_attempts ]]; then
    log_warn "Services did not become healthy within 60 seconds"
    docker-compose logs backend
    exit 1
  fi

  # 7. Validation tests (if requested)
  if [[ "$VALIDATE" == "--validate" ]]; then
    log_info "Running validation tests..."

    # Test 1: Database accessible
    DB_ITEMS=$(docker-compose exec backend sqlite3 /app/data/inventory.db \
      "SELECT COUNT(*) FROM items" 2>/dev/null || echo "0")
    log_info "✓ Database has $DB_ITEMS items"

    # Test 2: API responsive
    if curl -sf "http://localhost:8000/health" > /dev/null; then
      log_info "✓ API health check passed"
    else
      log_error "API health check failed"
    fi

    # Test 3: Frontend loads
    if curl -sf "http://localhost:3000" > /dev/null 2>&1; then
      log_info "✓ Frontend loads"
    else
      log_warn "⚠ Frontend check failed (normal on first startup)"
    fi
  fi

else
  log_info "Standalone deployment mode detected"
  IS_DOCKER=false

  # 1. Kill any running servers
  log_info "Stopping running services..."
  pkill -f "next start" || true
  pkill -f "uvicorn" || true
  sleep 2

  # 2. Backup current data
  log_info "Creating safety backup of current data..."
  mkdir -p data/backups_before_restore
  tar -czf "data/backups_before_restore/backup-before-restore-$(date +%s).tar.gz" \
      data/inventory.db data/inventory.db-* 2>/dev/null || true

  # 3. Extract backup
  log_info "Extracting backup..."
  tar -xzf "$BACKUP_FILE" -C . || log_error "Backup extraction failed"

  # 4. Verify essential files
  log_info "Verifying restored files..."
  [[ -f "data/inventory.db" ]] || log_error "Database not found in backup"
  [[ -f "inventory.env" ]] || log_error "inventory.env not found in backup"

  log_info "✓ Restore complete"
  log_warn "Remember to start services: ./start_server.sh"
fi

log_info "Restore complete!"
log_warn "Remember to verify data in the application before returning to production"