#!/bin/bash

# Database Variable Migration Script
# This script helps migrate from MYSQL_* to unified DB_* variable names
# 
# Usage: ./scripts/migrate-db-vars.sh [--dry-run]

set -e

DRY_RUN=false
if [[ "$1" == "--dry-run" ]]; then
  DRY_RUN=true
  echo "🔍 DRY RUN MODE - No files will be modified"
  echo ""
fi

# Color codes for output
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m' # No Color

echo -e "${BLUE}================================================${NC}"
echo -e "${BLUE}  Database Variable Migration Script${NC}"
echo -e "${BLUE}================================================${NC}"
echo ""
echo "This script will standardize database configuration variables:"
echo "  MYSQL_ROOT_PASSWORD → DB_ROOT_PASSWORD"
echo "  MYSQL_PASSWORD → DB_PASSWORD"
echo "  MYSQL_DATABASE → DB_NAME (already standardized)"
echo "  MYSQL_USER → DB_USER (already standardized)"
echo ""

# Check if .env file exists
if [ -f ".env" ]; then
  echo -e "${YELLOW}⚠️  Found .env file${NC}"
  echo ""
  echo "Current database variables in .env:"
  grep -E "^(MYSQL_|DB_)" .env 2>/dev/null || echo "  (none found)"
  echo ""
  
  if [ "$DRY_RUN" = false ]; then
    read -p "Do you want to update your .env file? (y/N) " -n 1 -r
    echo ""
    if [[ $REPLY =~ ^[Yy]$ ]]; then
      # Backup .env
      cp .env .env.backup.$(date +%Y%m%d_%H%M%S)
      echo -e "${GREEN}✓ Created backup of .env${NC}"
      
      # Replace variables
      if grep -q "^MYSQL_ROOT_PASSWORD=" .env; then
        sed -i.tmp 's/^MYSQL_ROOT_PASSWORD=/DB_ROOT_PASSWORD=/' .env
        echo -e "${GREEN}✓ Renamed MYSQL_ROOT_PASSWORD → DB_ROOT_PASSWORD${NC}"
      fi
      
      if grep -q "^MYSQL_PASSWORD=" .env; then
        sed -i.tmp 's/^MYSQL_PASSWORD=/DB_PASSWORD=/' .env
        echo -e "${GREEN}✓ Renamed MYSQL_PASSWORD → DB_PASSWORD${NC}"
      fi
      
      # Clean up temp files
      rm -f .env.tmp
      
      echo ""
      echo -e "${GREEN}✓ .env file updated successfully${NC}"
      echo ""
      echo "Updated variables in .env:"
      grep -E "^DB_" .env 2>/dev/null || echo "  (none found)"
    else
      echo -e "${YELLOW}⚠️  Skipped .env update${NC}"
    fi
  else
    echo -e "${BLUE}[DRY RUN] Would update .env file${NC}"
  fi
else
  echo -e "${YELLOW}⚠️  No .env file found (this is OK if using docker-compose)${NC}"
fi

echo ""
echo -e "${BLUE}================================================${NC}"
echo -e "${GREEN}✓ Migration script completed${NC}"
echo -e "${BLUE}================================================${NC}"
echo ""
echo "Next steps:"
echo "1. Review the changes in docker-compose.yml"
echo "2. Update any deployment scripts or CI/CD pipelines"
echo "3. Restart your services: docker-compose down && docker-compose up -d"
echo ""
echo "Variable mapping reference:"
echo "  DB_ROOT_PASSWORD - MySQL root password"
echo "  DB_PASSWORD      - Application database password"
echo "  DB_USER          - Application database user (default: voxblog)"
echo "  DB_NAME          - Application database name (default: voxblog)"
echo "  DB_HOST          - Database host (default: mysql in docker, localhost otherwise)"
echo "  DB_PORT          - Database port (default: 3306)"
echo ""