package org.jeecg;

import java.sql.*;
import java.util.ArrayList;
import java.util.List;

public class OracleToPgSync {

    // 数据库连接配置
    private static final String ORACLE_URL = "jdbc:oracle:thin:@//127.0.0.1:1521/orcl";
    private static final String ORACLE_USER = "idctest";
    private static final String ORACLE_PASSWORD = "12345678";

    private static final String PG_URL = "jdbc:postgresql://127.0.0.1:5432/oracleToPg";
    private static final String PG_USER = "postgres";
    private static final String PG_PASSWORD = "root";

    public static void main(String[] args) {
        try {
            // 获取Oracle用户下的所有表
            List<String> tables = getAllOracleTables();

            // 同步每个表
            for (String table : tables) {
                System.out.println("正在同步表: " + table);
                syncTable(table);
            }

            System.out.println("所有表同步完成!");
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    /**
     * 获取Oracle用户下的所有表
     */
    private static List<String> getAllOracleTables() throws SQLException {
        List<String> tables = new ArrayList<>();

        try (Connection oracleConn = DriverManager.getConnection(ORACLE_URL, ORACLE_USER, ORACLE_PASSWORD)) {
            DatabaseMetaData metaData = oracleConn.getMetaData();

            // 获取当前用户下的所有表
            try (ResultSet rs = metaData.getTables(null, ORACLE_USER.toUpperCase(), "%", new String[]{"TABLE"})) {
                while (rs.next()) {
                    String tableName = rs.getString("TABLE_NAME");
                    tables.add(tableName.toUpperCase()); // 表名转为大写
                }
            }
        }

        return tables;
    }

    /**
     * 同步单个表
     */
    private static void syncTable(String tableName) throws SQLException {
        try (Connection oracleConn = DriverManager.getConnection(ORACLE_URL, ORACLE_USER, ORACLE_PASSWORD);
             Connection pgConn = DriverManager.getConnection(PG_URL, PG_USER, PG_PASSWORD)) {

            // 1. 获取表结构并创建PG表
            createPgTable(oracleConn, pgConn, tableName);
        }
    }

    /**
     * 在PostgreSQL中创建表结构（表名和字段名全大写）
     */
    private static void createPgTable(Connection oracleConn, Connection pgConn, String tableName)
            throws SQLException {

        // 获取Oracle表结构
        DatabaseMetaData oracleMeta = oracleConn.getMetaData();
        ResultSet columns = oracleMeta.getColumns(null, ORACLE_USER.toUpperCase(), tableName, "%");

        StringBuilder createSql = new StringBuilder("CREATE TABLE IF NOT EXISTS \"")
                .append(tableName.toUpperCase()).append("\" (");

        boolean first = true;
        while (columns.next()) {
            if (!first) {
                createSql.append(", ");
            }
            first = false;

            String columnName = columns.getString("COLUMN_NAME").toUpperCase();
            String typeName = columns.getString("TYPE_NAME");
            int dataType = columns.getInt("DATA_TYPE");
            int columnSize = columns.getInt("COLUMN_SIZE");
            int decimalDigits = columns.getInt("DECIMAL_DIGITS");
            String isNullable = columns.getString("IS_NULLABLE");

            // 转换Oracle数据类型到PostgreSQL
            String pgType = convertOracleTypeToPg(typeName, dataType, columnSize, decimalDigits);

            // 所有列名都用双引号包围，确保大小写敏感
            createSql.append("\"").append(columnName).append("\" ")
                    .append(pgType);

            if ("NO".equalsIgnoreCase(isNullable)) {
                createSql.append(" NOT NULL");
            }
        }
        createSql.append(")");

        // 执行创建表
        try (Statement stmt = pgConn.createStatement()) {
            stmt.execute(createSql.toString());
        }
    }

    /**
     * Oracle数据类型转换为PostgreSQL数据类型
     */
    private static String convertOracleTypeToPg(String oracleType, int dataType, int size, int decimalDigits) {
        switch (oracleType.toUpperCase()) {
            case "VARCHAR2":
            case "NVARCHAR2":
            case "CHAR":
            case "NCHAR":
                return "VARCHAR(" + (size > 0 ? size : 255) + ")";
            case "NUMBER":
                if (decimalDigits > 0) {
                    return "NUMERIC(" + size + "," + decimalDigits + ")";
                } else if (size > 0) {
                    return "NUMERIC(" + size + ")";
                } else {
                    return "NUMERIC";
                }
            case "DATE":
                return "TIMESTAMP";
            case "TIMESTAMP":
                return "TIMESTAMP";
            case "CLOB":
                return "TEXT";
            case "BLOB":
                return "BYTEA";
            case "FLOAT":
                return "FLOAT8";
            case "BINARY_FLOAT":
                return "FLOAT4";
            case "BINARY_DOUBLE":
                return "FLOAT8";
            default:
                return "TEXT"; // 默认转为TEXT类型
        }
    }

}