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 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
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 *
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 * software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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package org.hsqldb.lib;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.net.MalformedURLException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.Properties;
import java.util.Set;
import java.util.HashSet;
import java.util.StringTokenizer;
import java.util.regex.Pattern;

/* $Id: RCData.java 5968 2019-04-27 12:55:27Z fredt $ */

/**
 * Manages all the details we need to connect up to JDBC database(s),
 * in a declarative way.
 * <P>
 * The file <CODE>src/org/hsqldb/sample/SqlFileEmbedder.java</CODE>
 * in the HSQLDB distribution provides an example of how to use RCData for your
 * own programs.
 *
 * @see <A href="../../../../util-guide/sqltool-chapt.html#sqltool_auth-sect"
 *      target="guide">
 *     The RC File section of the HyperSQL Utilities Guide</A>
 * @see org.hsqldb.sample.SqlFileEmbedder
 * @author Blaine Simpson (blaine dot simpson at admc dot com)
 */
public class RCData {

    public static final String DEFAULT_JDBC_DRIVER   = "org.hsqldb.jdbc.JDBCDriver";
    private String             defaultJdbcDriverName = DEFAULT_JDBC_DRIVER;

    public void setDefaultJdbcDriver(String defaultJdbcDriverName) {
        this.defaultJdbcDriverName = defaultJdbcDriverName;
    }

    public String getDefaultJdbcDriverName() {
        return defaultJdbcDriverName;
    }

    /**
     * DISABLED DUE TO SECURITY CONCERNS.
     * Just for testing and debugging.
     *
     * N.b. this echoes passwords!
    public void report() {
        System.err.println("urlid: " + id + ", url: " + url + ", username: "
                           + username + ", password: " + password);
    }
     */

    public String toString() {
        return "id: " + angleBracketNull(id)
          + ", url: " + angleBracketNull(url)
          + ", username: " + angleBracketNull(username)
          + ", password: <" + (password == null ? "NULL" : "PRESENT") + ">"
          + ", ti: " + angleBracketNull(ti)
          + ", driver: " + angleBracketNull(driver)
          + ", truststore: " + angleBracketNull(truststore)
          + ", libpath: " + angleBracketNull(libpath);
    }

    private static String angleBracketNull(final String s) {
        return s == null ? "<NULL>" : s;
    }


    /**
     * Creates a RCDataObject by looking up the given key in the
     * given authentication file.
     *
     * @param file File containing the authentication information.
     * @param dbKey Key to look up in the file.
     *              If null, then will echo all urlids in the file to stdout.
     *              (A rather ill-conceived design).
     * @throws Exception any exception
     */
    public RCData(File file, String dbKey) throws Exception {
        // This set is so we can catch duplicates.
        Set<String> idPatterns = new HashSet<String>();

        if (file == null) {
            throw new IllegalArgumentException("RC file name not specified");
        }

        if (!file.canRead()) {
            throw new IOException("Please set up authentication file '" + file
                                  + "'");
        }

        // System.err.println("Using RC file '" + file + "'");
        StringTokenizer tokenizer = null;
        boolean         loadingStanza   = false;
        String          s;
        String[]        tokens;
        String          keyword, value;
        int             linenum = 0;
        BufferedReader  br      = new BufferedReader(new FileReader(file));

        try {
        while ((s = br.readLine()) != null) {
            ++linenum;

            s = s.trim();

            if (s.length() == 0) {
                continue;
            }

            if (s.charAt(0) == '#') {
                continue;
            }

            tokenizer = new StringTokenizer(s);

            if (tokenizer.countTokens() == 1) {
                keyword = tokenizer.nextToken();
                value   = "";
            } else if (tokenizer.countTokens() > 1) {
                keyword = tokenizer.nextToken();
                value   = tokenizer.nextToken("").trim();
            } else {
                throw new Exception("Corrupt line " + linenum + " in '" + file
                                    + "':  " + s);
            }

            if (keyword.equals("urlid")) {
                tokens = value.split("\\s*,\\s*", -1);
                for (int i = 0; i < tokens.length; i++) {
                    if (idPatterns.contains(tokens[i]))
                        throw new Exception("ID Pattern '" + tokens[i]
                          + "' repeated at line " + linenum + " in '"
                          + file + "'");
                    idPatterns.add(tokens[i]);
                    if (dbKey == null) {
                        System.out.println(tokens[i]);
                        continue;
                    }
                    loadingStanza =
                      Pattern.compile(tokens[i]).matcher(dbKey).matches();
                    if (id == null && loadingStanza) id = dbKey;
                }

                continue;
            }
            if (dbKey == null) continue;

            if (loadingStanza) {
                if (keyword.equals("url")) {
                    url = value;
                } else if (keyword.equals("username")) {
                    username = value;
                } else if (keyword.equals("driver")) {
                    driver = value;
                } else if (keyword.equals("charset")) {
                    charset = value;
                } else if (keyword.equals("truststore")) {
                    truststore = value;
                } else if (keyword.equals("password")) {
                    password = value;
                } else if (keyword.equals("transiso")) {
                    ti = value;
                } else if (keyword.equals("libpath")) {
                    libpath = value;
                } else {
                    throw new Exception("Bad line " + linenum + " in '" + file
                                        + "':  " + s);
                }
            }
        }
        } finally {
            try  {
                br.close();
            } catch (IOException ioe) {
                // Can only report on so many errors at one time
            }
            br = null;  // Encourage GC
        }


        //System.err.println(idPatterns.size() + " patterns: " + idPatterns);
        if (dbKey == null) {
            return;
        }

        if (libpath != null) {
            throw new IllegalArgumentException(
                "Sorry, 'libpath' not supported yet");
        }

        if (id == null)
            throw new IllegalArgumentException(
                "No match for '" + dbKey + "' in file '" + file + "'");
    }

    /**
     * Convenience constructor for backward compatibility.
     *
     * @see #RCData(String,String,String,String,String,String,String,String)
     */
    public RCData(String id, String url, String username, String password,
                  String driver, String charset,
                  String truststore) throws Exception {
        this(id, url, username, password, driver, charset, truststore, null);
    }

    /**
     * Wrapper for unset Transaction Isolation.
     */
    public RCData(String id, String url, String username, String password,
                  String driver, String charset, String truststore,
                  String libpath) throws Exception {
        this(id, url, username, password, driver, charset, truststore,
                libpath, null);
    }

    /**
     * Creates a new <code>RCData</code> object.
     *
     * <P>
     * The parameters driver, charset, truststore, and libpath are optional.
     * Setting these parameters to <code>NULL</code> will set them to their
     * default values.
     *
     * @param id The identifier for these connection settings
     * @param url The URL of the database to connect to
     * @param username The username to log in as
     * @param password The password of the username
     * @param driver The JDBC driver to use
     * @param charset The character set to use
     * @param truststore The trust store to use
     * @param libpath The JDBC library to add to CLASSPATH
     * @param ti The transaction level
     * @throws Exception if the a non-optional parameter is set to <code>NULL</code>
     */
    public RCData(String id, String url, String username, String password,
                  String driver, String charset, String truststore,
                  String libpath, String ti) throws Exception {

        this.id         = id;
        this.url        = url;
        this.username   = username;
        this.password   = password;
        this.ti         = ti;
        this.driver     = driver;
        this.charset    = charset;
        this.truststore = truststore;
        this.libpath    = libpath;

        if (libpath != null) {
            throw new IllegalArgumentException(
                "Sorry, 'libpath' not supported yet");
        }

        // We now require only id to be set by this constructor.
        // This allows using programs to add settings to an RC object partially
        // populated by RC file.
        // Will not find out about missing 'url' until try to actually connect.
        if (id == null) {
            throw new Exception("id was not set");
        }
    }

    /* Purposefully not using JavaBean paradigm so that these fields can
     * be used as a traditional, public DO */
    public String id;
    public String url;
    public String username;
    public String password;
    public String ti;
    public String driver;
    public String charset;
    public String truststore;
    public String libpath;

    /**
     * Gets a JDBC Connection using the data of this RCData object.
     *
     * @return New JDBC Connection
     * @throws ClassNotFoundException on class not found
     * @throws SQLException on database access error
     * @throws MalformedURLException on malformed URL
     */
    public Connection getConnection()
    throws ClassNotFoundException, SQLException, MalformedURLException {
        return getConnection(null, null);
    }

    /**
     * Gets a JDBC Connection using the data of this RCData object with
     * specified override elements
     *
     * @param curDriverIn driver
     * @param curTrustStoreIn trusted store
     * @return New JDBC Connection
     * @throws ClassNotFoundException on class not found
     * @throws MalformedURLException on malformed URL
     * @throws SQLException on database access error
     */
    public Connection getConnection(String curDriverIn, String curTrustStoreIn)
                                    throws ClassNotFoundException,
                                           MalformedURLException,
                                           SQLException {

        // Local vars to satisfy compiler warnings
        String curDriver = null;
        String curTrustStore = null;

        Properties sysProps = System.getProperties();

        if (curDriverIn == null) {

            // If explicit driver not specified
            curDriver = ((driver == null) ? DEFAULT_JDBC_DRIVER
                                          : driver);
        } else {
            curDriver = expandSysPropVars(curDriverIn);
        }

        if (curTrustStoreIn == null) {
            if (truststore != null) {
                curTrustStore = expandSysPropVars(truststore);
            }
        } else {
            curTrustStore = expandSysPropVars(curTrustStoreIn);
        }

        if (curTrustStore == null) {
            sysProps.remove("javax.net.ssl.trustStore");
        } else {
            sysProps.put("javax.net.ssl.trustStore", curTrustStore);
        }

        String urlString = null;
        if (url == null) {
            throw new MalformedURLException(
              "url string is required to establish a connection, but is null"
              );
        }

        try {
            urlString = expandSysPropVars(url);
        } catch (IllegalArgumentException iae) {
            throw new MalformedURLException(iae.toString() + " for URL '"
                                            + url + "'");
        }

        String userString = null;

        if (username != null) try {
            userString = expandSysPropVars(username);
        } catch (IllegalArgumentException iae) {
            throw new MalformedURLException(iae.toString()
                                            + " for user name '" + username
                                            + "'");
        }

        String passwordString = null;

        if (password != null) try {
            passwordString = expandSysPropVars(password);
        } catch (IllegalArgumentException iae) {
            throw new MalformedURLException(iae.toString()
                                            + " for password");
        }

        Class.forName(curDriver);
        // This is not necessary for jdbc:odbc or if class loaded by a
        // service resource file.  Consider checking for that.

        Connection c = (userString == null)
                     ? DriverManager.getConnection(urlString)
                     : DriverManager.getConnection(urlString, userString,
                                                   passwordString);
        if (ti != null) RCData.setTI(c, ti);
        // Would like to verify the setting made by checking
        // c.getTransactionIsolation().  Unfortunately, the spec allows for
        // databases to substitute levels according to some rules, and it's
        // impossible to know what to expect since custom levels are permitted.
        // Debug:
        // System.err.println("TI set to " + ti + "\nPOST: "
        // + SqlTool.tiToString(c.getTransactionIsolation()));

        return c;
    }

    /**
     * Returns a copy of the given String with System property names in the
     * format <code>${system.property}</code> replaced by the corresponding Java
     * System Properties.
     */
    public static String expandSysPropVars(String inString) {

        String outString = inString;
        int    varOffset, varEnd;
        String varVal, varName;

        while (true) {

            // Recursive substitution for ${x} variables.
            varOffset = outString.indexOf("${");

            if (varOffset < 0) {
                break;
            }

            varEnd = outString.indexOf('}', varOffset + 2);

            if (varEnd < 0) {
                break;
            }

            varName = outString.substring(varOffset + 2, varEnd);

            if (varName.length() < 1) {
                throw new IllegalArgumentException("Bad variable setting");
            }

            varVal = System.getProperty(varName);

            if (varVal == null) {
                throw new IllegalArgumentException(
                    "No Java system property with name '" + varName + "'");
            }

            outString = outString.substring(0, varOffset) + varVal
                        + outString.substring(varEnd + 1);
        }

        return outString;
    }

    /**
     * Set Transaction Isolation level on the specified JDBC Connection
     */
    public static void setTI(Connection c, String tiString)
            throws SQLException {
        int i = -1;
        if (tiString.equals("TRANSACTION_READ_UNCOMMITTED"))
            i = Connection.TRANSACTION_READ_UNCOMMITTED;
        if (tiString.equals("TRANSACTION_READ_COMMITTED"))
            i = Connection.TRANSACTION_READ_COMMITTED;
        if (tiString.equals("TRANSACTION_REPEATABLE_READ"))
            i = Connection.TRANSACTION_REPEATABLE_READ;
        if (tiString.equals("TRANSACTION_SERIALIZABLE"))
            i = Connection.TRANSACTION_SERIALIZABLE;
        if (tiString.equals("TRANSACTION_NONE"))
            i = Connection.TRANSACTION_NONE;
        if (i < 0) {
            throw new SQLException(
                    "Trans. isol. value not supported by "
                    + RCData.class.getName() + ": " + tiString);
        }
        c.setTransactionIsolation(i);
    }

    /**
     * Return a String representation for the given numerical
     * java.sql.Connection Transaction level.
     * <P>
     * Database implementations are free to provide their own transaction
     * isolation levels, so you can't depend upon this method to much.
     *
     * @param ti Transaction levle
     * @return The string representation
     */
    public static String tiToString(int ti) {
        switch (ti) {
            case Connection.TRANSACTION_READ_UNCOMMITTED:
                return "TRANSACTION_READ_UNCOMMITTED";
            case Connection.TRANSACTION_READ_COMMITTED:
                return "TRANSACTION_READ_COMMITTED";
            case Connection.TRANSACTION_REPEATABLE_READ:
                return "TRANSACTION_REPEATABLE_READ";
            case Connection.TRANSACTION_SERIALIZABLE:
                return "TRANSACTION_SERIALIZABLE";
            case Connection.TRANSACTION_NONE:
                return "TRANSACTION_NONE";
        }
        return "Custom Transaction Isolation numerical value: " + ti;
    }
}
