/*
 * Copyright 2004-2023 H2 Group. Multiple-Licensed under the MPL 2.0,
 * and the EPL 1.0 (https://h2database.com/html/license.html).
 * Initial Developer: H2 Group
 */
package org.h2.test.db;

import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.concurrent.TimeUnit;

import org.h2.api.DatabaseEventListener;
import org.h2.api.ErrorCode;
import org.h2.engine.Constants;
import org.h2.store.fs.FileUtils;
import org.h2.test.TestBase;
import org.h2.test.TestDb;
import org.h2.tools.Restore;
import org.h2.util.Task;

/**
 * Tests opening and closing a database.
 */
public class TestOpenClose extends TestDb {

    private int nextId = 10;

    /**
     * Run just this test.
     *
     * @param a ignored
     */
    public static void main(String... a) throws Exception {
        TestBase.createCaller().init().testFromMain();
    }

    @Override
    public void test() throws Exception {
        testErrorMessageLocked();
        testErrorMessageWrongSplit();
        testCloseDelay();
        testBackup();
        testCase();
        testReconnectFast();
        test1_1();
        deleteDb("openClose");
    }

    private void testErrorMessageLocked() throws Exception {
        if (config.memory) {
            return;
        }
        deleteDb("openClose");
        Connection conn;
        conn = getConnection("jdbc:h2:" + getBaseDir() + "/openClose;FILE_LOCK=FS");
        assertThrows(ErrorCode.DATABASE_ALREADY_OPEN_1,
                () -> getConnection("jdbc:h2:" + getBaseDir() + "/openClose;FILE_LOCK=FS;OPEN_NEW=TRUE"));
        conn.close();
    }

    private void testErrorMessageWrongSplit() throws Exception {
        if (config.memory || config.reopen) {
            return;
        }
        String fn = getBaseDir() + "/openClose2" + Constants.SUFFIX_MV_FILE;
        FileUtils.delete("split:" + fn);
        Connection conn;
        String url = getURL("jdbc:h2:split:18:" + getBaseDir() + "/openClose2", true);
        conn = DriverManager.getConnection(url);
        conn.createStatement().execute("create table test(id int, name varchar) " +
                "as select 1, space(1000000)");
        conn.close();
        FileChannel c = FileUtils.open(fn+".1.part", "rw");
        c.position(c.size() * 2 - 1);
        c.write(ByteBuffer.wrap(new byte[1]));
        c.close();
        assertThrows(ErrorCode.IO_EXCEPTION_1, () -> getConnection(url));
        FileUtils.delete("split:" + fn);
    }

    private void testCloseDelay() throws Exception {
        deleteDb("openClose");
        String url = getURL("openClose;DB_CLOSE_DELAY=1", true);
        String user = getUser(), password = getPassword();
        Connection conn = DriverManager.getConnection(url, user, password);
        conn.close();
        Thread.sleep(950);
        long time = System.nanoTime();
        while (System.nanoTime() - time < TimeUnit.MILLISECONDS.toNanos(100)) {
            conn = DriverManager.getConnection(url, user, password);
            conn.close();
        }
        conn = DriverManager.getConnection(url, user, password);
        conn.createStatement().execute("SHUTDOWN");
        conn.close();
    }

    private void testBackup() throws SQLException {
        if (config.memory) {
            return;
        }
        deleteDb("openClose");
        String url = getURL("openClose", true);
        org.h2.Driver.load();
        Connection conn = DriverManager.getConnection(url, "sa", "abc def");
        Statement stat = conn.createStatement();
        stat.execute("CREATE TABLE TEST(C CLOB)");
        stat.execute("INSERT INTO TEST VALUES(SPACE(10000))");
        stat.execute("BACKUP TO '" + getBaseDir() + "/test.zip'");
        conn.close();
        deleteDb("openClose");
        Restore.execute(getBaseDir() + "/test.zip", getBaseDir(), null);
        conn = DriverManager.getConnection(url, "sa", "abc def");
        stat = conn.createStatement();
        ResultSet rs = stat.executeQuery("SELECT * FROM TEST");
        rs.next();
        assertEquals(10000, rs.getString(1).length());
        assertFalse(rs.next());
        conn.close();
        FileUtils.delete(getBaseDir() + "/test.zip");
    }

    private void testReconnectFast() throws SQLException {
        if (config.memory) {
            return;
        }

        deleteDb("openClose");
        String user = getUser(), password = getPassword();
        String url = getURL("openClose;DATABASE_EVENT_LISTENER='" +
                MyDatabaseEventListener.class.getName() + "'", true);
        Connection conn = DriverManager.getConnection(url, user, password);
        Statement stat = conn.createStatement();
        stat.execute("CREATE TABLE TEST(ID IDENTITY, NAME VARCHAR)");
        stat.execute("SET MAX_MEMORY_UNDO 100000");
        stat.execute("CREATE INDEX IDXNAME ON TEST(NAME)");
        stat.execute("INSERT INTO TEST SELECT X, X || ' Data' " +
                "FROM SYSTEM_RANGE(1, 1000)");
        stat.close();
        conn.close();
        conn = DriverManager.getConnection(url, user, password);
        stat = conn.createStatement();
        ResultSet rs = stat.executeQuery("SELECT * FROM SYSTEM_RANGE(1, 1)");
        if (rs.next()) {
            rs.getString(1);
        }
        rs.close();
        stat.close();
        conn.close();
        conn = DriverManager.getConnection(url, user, password);
        stat = conn.createStatement();
        // stat.execute("SET DB_CLOSE_DELAY 0");
        stat.executeUpdate("SHUTDOWN");
        stat.close();
        conn.close();
    }

    private void testCase() throws Exception {
        if (config.memory) {
            return;
        }

        org.h2.Driver.load();
        deleteDb("openClose");
        final String url = getURL("openClose;FILE_LOCK=NO", true);
        final String user = getUser(), password = getPassword();
        Connection conn = DriverManager.getConnection(url, user, password);
        conn.createStatement().execute("drop table employee if exists");
        conn.createStatement().execute(
                "create table employee(id int primary key, name varchar, salary int)");
        conn.close();
        // previously using getSize(200, 1000);
        // but for Ubuntu, the default ulimit is 1024,
        // which breaks the test
        int len = getSize(10, 50);
        Task[] tasks = new Task[len];
        for (int i = 0; i < len; i++) {
            tasks[i] = new Task() {
                @Override
                public void call() throws SQLException {
                    Connection c = DriverManager.getConnection(url, user, password);
                    PreparedStatement prep = c
                            .prepareStatement("insert into employee values(?, ?, 0)");
                    int id = getNextId();
                    prep.setInt(1, id);
                    prep.setString(2, "employee " + id);
                    prep.execute();
                    c.close();
                }
            };
            tasks[i].execute();
        }
        // for(int i=0; i<len; i++) {
        // threads[i].start();
        // }
        for (int i = 0; i < len; i++) {
            tasks[i].get();
        }
        conn = DriverManager.getConnection(url, user, password);
        ResultSet rs = conn.createStatement().executeQuery(
                "select count(*) from employee");
        rs.next();
        assertEquals(len, rs.getInt(1));
        conn.close();
    }

    synchronized int getNextId() {
        return nextId++;
    }

    private void test1_1() throws IOException {
        Path old = Paths.get(getBaseDir()).resolve("db" + Constants.SUFFIX_OLD_DATABASE_FILE);
        Files.createFile(old);
        try {
            assertThrows(ErrorCode.FILE_VERSION_ERROR_1,
                    () -> DriverManager.getConnection("jdbc:h2:" + getBaseDir() + "/db"));
        } finally {
            Files.deleteIfExists(old);
        }
    }


    /**
     * A database event listener used in this test.
     */
    public static final class MyDatabaseEventListener implements DatabaseEventListener {

        @Override
        public void exceptionThrown(SQLException e, String sql) {
            throw new AssertionError("unexpected: " + e + " sql: " + sql);
        }

        @Override
        public void setProgress(int state, String name, long current, long max) {
            String stateName;
            switch (state) {
            case STATE_SCAN_FILE:
                stateName = "Scan " + name + " " + current + "/" + max;
                if (current > 0) {
                    throw new AssertionError("unexpected: " + stateName);
                }
                break;
            case STATE_STATEMENT_START:
                break;
            case STATE_CREATE_INDEX:
                stateName = "Create Index " + name + " " + current + "/" + max;
                if (!"SYS:SYS_ID".equals(name)) {
                    throw new AssertionError("unexpected: " + stateName);
                }
                break;
            case STATE_RECOVER:
                stateName = "Recover " + current + "/" + max;
                break;
            default:
                stateName = "?";
            }
            // System.out.println(": " + stateName);
        }

    }

}
