#!/bin/bash

echo "☁️  Exporting data from TiDB Cloud..."

# Check if .env exists
if [ ! -f .env ]; then
    echo "❌ .env file not found!"
    echo "📝 Please create .env file with your TiDB Cloud credentials"
    exit 1
fi

# Source environment variables
source .env

# Validate required variables
if [ -z "$TEST_DB_HOST" ] || [ -z "$TEST_DB_USER" ] || [ -z "$TEST_DB_PASSWORD" ]; then
    echo "❌ Missing database credentials in .env"
    echo "📝 Required: TEST_DB_HOST, TEST_DB_USER, TEST_DB_PASSWORD"
    exit 1
fi

# Create export directory
EXPORT_DIR="/tmp/tidb-cloud-export"
mkdir -p $EXPORT_DIR

# Test connection
echo "🔍 Testing connection to TiDB Cloud..."
mysql -h $TEST_DB_HOST -P ${TEST_DB_PORT:-4000} -u $TEST_DB_USER -p$TEST_DB_PASSWORD -e "SELECT 1" >/dev/null 2>&1
if [ $? -ne 0 ]; then
    echo "❌ Cannot connect to TiDB Cloud"
    exit 1
fi

echo "✅ Connected successfully"

# Export schema using SQL queries
echo "📦 Exporting schema..."

# Create database statement
echo "CREATE DATABASE IF NOT EXISTS \`${DATABASE_NAME:-workflow_local}\`;
USE \`${DATABASE_NAME:-workflow_local}\`;
" > $EXPORT_DIR/schema.sql

# Get table schemas
for table in ${TABLES//,/ }; do
    echo "-- Table: $table"
    mysql -h $TEST_DB_HOST -P ${TEST_DB_PORT:-4000} -u $TEST_DB_USER -p$TEST_DB_PASSWORD -e "SHOW CREATE TABLE \`${DATABASE_NAME:-workflow_local}\`.$table;" -N -s | cut -f2 >> $EXPORT_DIR/schema.sql
    echo ";" >> $EXPORT_DIR/schema.sql
    echo "" >> $EXPORT_DIR/schema.sql
done

# Check if export was successful
if [ ! -s "$EXPORT_DIR/schema.sql" ]; then
    echo "❌ Schema export failed - empty file"
    exit 1
fi

echo "✅ Schema exported to $EXPORT_DIR/schema.sql"

# Export data using SQL
echo "📦 Exporting data..."

# Clear data file
> $EXPORT_DIR/data.sql

# Export data for each table
for table in ${TABLES//,/ }; do
    echo "-- Data for table: $table"
    # Simple approach: export as CSV and convert to INSERT statements
    mysql -h $TEST_DB_HOST -P ${TEST_DB_PORT:-4000} -u $TEST_DB_USER -p$TEST_DB_PASSWORD -e "SELECT * FROM \`${DATABASE_NAME:-workflow_local}\`.$table;" | sed '1d' > $EXPORT_DIR/${table}.csv
    
    # If we have data, convert to INSERT statements
    if [ -s "$EXPORT_DIR/${table}.csv" ]; then
        # This is a simplified approach - for production use, you'd want a more robust CSV to SQL converter
        echo "-- Note: Data export for $table requires manual conversion from CSV" >> $EXPORT_DIR/data.sql
        echo "-- CSV file location: $EXPORT_DIR/${table}.csv" >> $EXPORT_DIR/data.sql
    fi
done

echo "⚠️  Data export completed - CSV files created for manual import"
echo "📂 Export completed successfully!"
echo "   Schema: $EXPORT_DIR/schema.sql"
echo "   Data CSV files:"
for table in ${TABLES//,/ }; do
    echo "     $EXPORT_DIR/${table}.csv"
done