package scripts.qa;

import java.io.File;
import java.nio.file.Files;
import java.sql.*;

/**
 * 真实 Kingbase 数据库 ROLLBACK-ONLY 事务回滚验证脚本。
 * 严禁 COMMIT 任何测试数据。验证真实数据库事务原子性与回滚机制。
 */
public class ValidateRealDbRollback {
    public static void main(String[] args) throws Exception {
        Class.forName("com.kingbase8.Driver");

        File envFile = new File(System.getProperty("user.home"), ".railwaysystem-qa.env");
        String pass = "";
        if (envFile.exists()) {
            for (String line : Files.readAllLines(envFile.toPath())) {
                line = line.trim();
                if (line.startsWith("QA_DB_PASSWORD=")) {
                    pass = line.substring("QA_DB_PASSWORD=".length()).trim();
                    if (pass.startsWith("\"") && pass.endsWith("\"")) {
                        pass = pass.substring(1, pass.length() - 1);
                    }
                }
            }
        }
        if (pass.isEmpty()) {
            throw new IllegalStateException("QA_DB_PASSWORD is required in ~/.railwaysystem-qa.env");
        }

        // 尝试直连或通过 SSH 端口转发 (14321) 连接
        String dbUrl = "jdbc:kingbase8://127.0.0.1:14321/railwaysystem_integrated_qa_20260916?useUnicode=true&characterEncoding=utf8";
        try (Connection conn = DriverManager.getConnection(dbUrl, "kingbase", pass)) {
            System.out.println("CONNECTED_TO_DB=TRUE");

            // 1. 验证当前数据库身份
            try (Statement st = conn.createStatement();
                 ResultSet rs = st.executeQuery("SELECT current_database(), current_user")) {
                if (rs.next()) {
                    System.out.println("CURRENT_DATABASE=" + rs.getString(1));
                    System.out.println("CURRENT_USER=" + rs.getString(2));
                    if (!"railwaysystem_integrated_qa_20260916".equals(rs.getString(1))) {
                        throw new IllegalStateException("数据库身份不符，安全终止！");
                    }
                }
            }

            // 2. 选择一条安全的已有记录读取原始状态
            String targetPlanId = null;
            int originalPlanStatus = -1;
            long targetEnrollmentId = -1;
            int originalEnrollmentStatus = -1;

            String selectSampleSql = "SELECT p.plan_id, p.plan_status, e.enrollment_id, e.enrollment_status " +
                    "FROM train_class_plan p " +
                    "JOIN train_enrollment e ON e.plan_id = p.plan_id " +
                    "LIMIT 1";
            try (Statement st = conn.createStatement();
                 ResultSet rs = st.executeQuery(selectSampleSql)) {
                if (rs.next()) {
                    targetPlanId = rs.getString(1);
                    originalPlanStatus = rs.getInt(2);
                    targetEnrollmentId = rs.getLong(3);
                    originalEnrollmentStatus = rs.getInt(4);
                }
            }

            if (targetPlanId == null) {
                System.out.println("NO_SAMPLE_DATA_FOUND");
                return;
            }

            System.out.println(String.format("SAMPLE_BEFORE: plan_id=%s, plan_status=%d, enrollment_id=%d, enrollment_status=%d",
                    targetPlanId, originalPlanStatus, targetEnrollmentId, originalEnrollmentStatus));

            // 3. 开启事务 (禁用 AutoCommit)
            conn.setAutoCommit(false);

            try {
                // 在未提交事务中模拟结训更新
                int mockPlanTargetStatus = (originalPlanStatus == 2) ? 1 : 2;
                int mockEnrollmentTargetStatus = (originalEnrollmentStatus == 4) ? 1 : 4;

                try (PreparedStatement pst = conn.prepareStatement(
                        "UPDATE train_class_plan SET plan_status = ?, update_time = now() WHERE plan_id = ?")) {
                    pst.setInt(1, mockPlanTargetStatus);
                    pst.setString(2, targetPlanId);
                    pst.executeUpdate();
                }

                try (PreparedStatement pst = conn.prepareStatement(
                        "UPDATE train_enrollment SET enrollment_status = ?, complete_time = now() WHERE enrollment_id = ?")) {
                    pst.setInt(1, mockEnrollmentTargetStatus);
                    pst.setLong(2, targetEnrollmentId);
                    pst.executeUpdate();
                }

                // 事务内查看临时修改值
                int inTxPlanStatus = -1;
                int inTxEnrollStatus = -1;
                try (Statement st = conn.createStatement();
                     ResultSet rs = st.executeQuery("SELECT p.plan_status, e.enrollment_status FROM train_class_plan p JOIN train_enrollment e ON e.plan_id = p.plan_id WHERE p.plan_id = '" + targetPlanId + "' AND e.enrollment_id = " + targetEnrollmentId)) {
                    if (rs.next()) {
                        inTxPlanStatus = rs.getInt(1);
                        inTxEnrollStatus = rs.getInt(2);
                    }
                }
                System.out.println(String.format("IN_TRANSACTION_MODIFIED: plan_status=%d, enrollment_status=%d", inTxPlanStatus, inTxEnrollStatus));

                // 4. 显式执行主动 ROLLBACK (严禁 COMMIT)
                conn.rollback();
                System.out.println("TRANSACTION_ROLLED_BACK=TRUE");

            } catch (Exception ex) {
                conn.rollback();
                throw ex;
            } finally {
                conn.setAutoCommit(true);
            }

            // 5. 验证回滚后数据完全恢复原样
            int afterRollbackPlanStatus = -1;
            int afterRollbackEnrollStatus = -1;
            try (Statement st = conn.createStatement();
                 ResultSet rs = st.executeQuery("SELECT p.plan_status, e.enrollment_status FROM train_class_plan p JOIN train_enrollment e ON e.plan_id = p.plan_id WHERE p.plan_id = '" + targetPlanId + "' AND e.enrollment_id = " + targetEnrollmentId)) {
                if (rs.next()) {
                    afterRollbackPlanStatus = rs.getInt(1);
                    afterRollbackEnrollStatus = rs.getInt(2);
                }
            }
            System.out.println(String.format("AFTER_ROLLBACK_VERIFIED: plan_status=%d, enrollment_status=%d", afterRollbackPlanStatus, afterRollbackEnrollStatus));

            boolean intact = (originalPlanStatus == afterRollbackPlanStatus) && (originalEnrollmentStatus == afterRollbackEnrollStatus);
            if (intact) {
                System.out.println("REAL_DB_TRANSACTION_ROLLBACK_VALIDATION=PASS");
            } else {
                System.err.println("REAL_DB_TRANSACTION_ROLLBACK_VALIDATION=FAIL (Data altered!)");
                System.exit(1);
            }
        }
    }
}