/*

* Copyright (c) 2000 - 2006 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description: 

 *

*/

package com.nokia.epdt.plugins.s60.securityconf;

/* java.util */

import java.util.List;

import java.util.ArrayList;

/* java.io */

import java.io.IOException;

import java.io.InputStream;

import java.io.BufferedReader;

import java.io.InputStreamReader;

import java.io.ObjectInputStream;

import java.io.ObjectOutputStream;

import java.io.OutputStream;

import java.io.PrintWriter;

/**

 * MIDP security configuration model.

 */

class SecConfModel implements SecurityConstants {

    // Emulater/real life security mode

    private boolean iEmulatedSecurityMode = false;

    private String iSelectedDomainId;

    private ProtectionDomain iUserDefinedDomain;

    private List iProtectionDomains = new ArrayList();

    private List iFunctionGroups = new ArrayList();

    /**

     * Creates MIDP security configuration model.

     * @throws IOException if it fails to load default MIDP security

     * configuration from the resources.

     */

    SecConfModel() throws IOException {

        InputStream in = openPolicyFileResource();

        try {

            PolicyFileParser.parse(in, new InitialScan());

        } finally {

            in.close();

        }

        // Create user defined domain

        iUserDefinedDomain = new ProtectionDomain(USER_DEFINED_DOMAIN);

        iProtectionDomains.add(iUserDefinedDomain);

        int n = iFunctionGroups.size();

        for (int i=0; i<n; i++) {

            String domain = (String)iFunctionGroups.get(i);

            iUserDefinedDomain.setPermission(domain,Permission.Allowed);

        }

        // Select first domain by default

        iSelectedDomainId = ((ProtectionDomain)

                             iProtectionDomains.get(0)).getIdentifier();

    }

    /**

     * Gets the protection domains known to the model, including the

     * "User defined" pseudo-domain.

     *

     * @param aIncludeHidden <code>true</code> to include hidden domains

     * @return array of protection domains

     */

    ProtectionDomain [] getProtectionDomains(boolean aIncludeHidden) {

        List domains = iProtectionDomains;

        if (!aIncludeHidden) {

            // remove hidden domains from the list

            domains = new ArrayList(iProtectionDomains);

            for (int i=domains.size()-1; i>=0; i--) {

                ProtectionDomain domain = (ProtectionDomain)domains.get(i);

                if (domain.isHidden()) domains.remove(i);

            }

        }

        return (ProtectionDomain[]) domains.toArray(

            new ProtectionDomain[domains.size()]);

    }

    /**

     * Gets currently selected protection domain.

     * @return the currently selected protection domain, <code>null</code>

     *    if none.

     */

    ProtectionDomain getSelectedDomain() {

        return findProtectionDomain(iSelectedDomainId);

    }

    /**

     * Selects a protection domain

     * @param aDomain the domain to select

     */

    void setSelectedDomain(ProtectionDomain aDomain) {

        if (aDomain == null) {

            iSelectedDomainId = null;

        } else {

            iSelectedDomainId = aDomain.getIdentifier();

        }

    }

    /**

     * Gets known function groups.

     * @return array of function group names

     */

    String[] getFunctionGroups() {

        return (String[])iFunctionGroups.toArray(

            new String[iFunctionGroups.size()]);

    }

    /**

     * Checks if we are in the "emulated security mode".

     * @return <code>true</code> if we are enforcing the same permissions

     *   for all protection domains.

     */

    boolean isEmulatedSecurityMode() {

        return iEmulatedSecurityMode;

    }

    /**

     * Turns the "emulated security mode" on or off.

     * @param aEmulatedSecurityMode <code>true</code> to enforce the same

     *   permissions for all protection domains, <code>false</code> to use

     *   default JVM secrity settings.

     */

    void setEmulatedSecurityMode(boolean aEmulatedSecurityMode) {

        iEmulatedSecurityMode = aEmulatedSecurityMode;

    }

    /**

     * Opens the policy file resource.

     * @return the input stream for the policy file resource.

     * Never returns null.

     * @throws IOException if resource is not found

     */

    private InputStream openPolicyFileResource() throws IOException {

        InputStream in = getClass().getResourceAsStream(POLICY_FILE_NAME);

        if (in != null) return in;

        throw new IOException(POLICY_FILE_NAME);

    }

    /**

     * Finds ProtectionDomain object for the specified identifier.

     * @param aId the domain identifier

     * @return ProtectionDomain object if found, null otherwise.

     */

    private ProtectionDomain findProtectionDomain(String aId) {

        int n = iProtectionDomains.size();

        for (int i=0; i<n; i++) {

            ProtectionDomain d = (ProtectionDomain)iProtectionDomains.get(i);

            if (d.getIdentifier().equals(aId)) {

                return d;

            }

        }

        return null;

    }

    /**

     * Writes policy file to the output stream

     * @param aStream the stream to write to

     * @throws IOException if an I/O error occurs

     */

    void writePolicyFile(OutputStream aStream) throws IOException {

        InputStream in = openPolicyFileResource();

        try {

            PrintWriter out = new PrintWriter(aStream, false);

            try {

                if (!iEmulatedSecurityMode) {

                    // Just copy the original file

                    BufferedReader reader = new BufferedReader(

                        new InputStreamReader(in));

                    String line = null;

                    while ((line = reader.readLine()) != null) {

                        out.println(line);

                    }

                } else {

                    // Save modified version of the original file

                    out.println("# This is a generated file.");

                    out.println();

                    PolicyFileParser.parse(in, new PolicyFileWriter(out));

                }

            } finally {

                out.flush();

            }

        } finally {

            in.close();

        }

    }

    /**

     * Saves the state of the model to the output stream

     * @param aStream the stream to write to

     * @throws IOException if an I/O error occurs

     */

    void save(OutputStream aStream) throws IOException {

        ObjectOutputStream out = new ObjectOutputStream(aStream);

        out.writeBoolean(iEmulatedSecurityMode);

        out.writeObject(iSelectedDomainId);

        out.writeObject(iUserDefinedDomain);

    }

    /**

     * Loads the state of the model from the input stream

     * @param aStream the stream to read from

     * @throws IOException if an I/O error occurs

     * @throws ClassNotFoundException if deserialization error occurs

     */

    void load(InputStream aStream) throws IOException, ClassNotFoundException {

        ObjectInputStream in = new ObjectInputStream(aStream);

        boolean emulatedSecurityMode = in.readBoolean();

        String selectedDomainId = (String)in.readObject();

        ProtectionDomain userDomain = (ProtectionDomain)in.readObject();

        // Verify and store deserialized values

        iEmulatedSecurityMode = emulatedSecurityMode;

        if (findProtectionDomain(selectedDomainId) != null) {

            iSelectedDomainId = selectedDomainId;

        }

        if (userDomain.isUserDefined()) {

            // User defined domain is always the last one

            iProtectionDomains.set(iProtectionDomains.size()-1,userDomain);

            iUserDefinedDomain = userDomain;

        }

    }

    /**

     * This handler scans the policy file to collect information about

     * domains, function groups and bindings.

     */

    private class InitialScan implements PolicyFileParser.Handler {

        private String iProtectionDomain;

        private String iFunctionGroup;

        public void handleFormatDecl(String aFormatVersion) {}

        public void handleEmptyLine() {}

        public void handleDecl(String aLine) {}

        public void handleProtectionDomainDecl(String aDomain) {

            ProtectionDomain domain = findProtectionDomain(aDomain);

            if (domain == null) {

                domain = new ProtectionDomain(aDomain);

                iProtectionDomains.add(domain);

            }

        }

        public void handleFunctionGroupDecl(String aGroupName) {

            iFunctionGroups.add(aGroupName);

        }

        public void handleDomainBindingsDecl(String aProtectionDomain) {

            iProtectionDomain = aProtectionDomain;

        }

        public void handleFunctionGroupBindingDecl(String aFunctionGroup) {

            iFunctionGroup = aFunctionGroup;

        }

        public void handlePermission(Permission aPermission) {

            ProtectionDomain domain = findProtectionDomain(iProtectionDomain);

            if (domain != null && iFunctionGroup != null) {

                if (WILDCARD.equals(iFunctionGroup)) {

                    int n = iFunctionGroups.size();

                    for (int i=0; i<n; i++) {

                        domain.setPermission((String)iFunctionGroups.get(i),

                                             aPermission);

                    }

                } else {

                    domain.setPermission(iFunctionGroup, aPermission);

                }

            }

        }

        public void handleEndFunctionGroupBinding() {

            iFunctionGroup = null;

        }

        public void handleEndDomainBindings() {

            iProtectionDomain = null;

        }

    }

    /**

     * This handler writes a modified version of the policy file.

     * Must only be used in the "emulated" security mode.

     */

    private class PolicyFileWriter implements PolicyFileParser.Handler {

        private PrintWriter iWriter;

        private ProtectionDomain iEmulatedDomain;

        private String iProtectionDomain;

        PolicyFileWriter(PrintWriter aWriter) {

            if (!isEmulatedSecurityMode()) throw new IllegalStateException();

            iWriter = aWriter;

            iEmulatedDomain = getSelectedDomain();

        }

        private void printDecl(String aKeyword, String aValue) {

            iWriter.print('\t');

            iWriter.print(aKeyword);

            iWriter.print(' ');

            // For some reason, strings enclosed in square brackets (such as

            // [UNTRUSTED] or [*]) are not quoted. That may have some special

            // meaning to the phone software.

            int len = aValue.length();

            if (len >= 2 &&

                aValue.charAt(0) == '[' &&

                aValue.charAt(len-1) == ']') {

                iWriter.println(aValue);

            } else {

                iWriter.print('"');

                iWriter.print(aValue);

                iWriter.println('"');

            }

        }

        // PolicyFileParser.Handler interface

        public void handleFormatDecl(String aFormatVersion) {

            iWriter.print(FORMAT_VERSION_KEYWORD);

            iWriter.print(" ");

            iWriter.println(aFormatVersion);

        }

        public void handleEmptyLine() {

            if (iProtectionDomain == null) {

                iWriter.println();

            }

        }

        public void handleDecl(String aLine) {

            if (iProtectionDomain == null) {

                iWriter.println(aLine);

            }

        }

        public void handleProtectionDomainDecl(String aProtectionDomain) {

            printDecl(DOMAIN_KEYWORD, aProtectionDomain);

        }

        public void handleFunctionGroupDecl(String aGroupName) {

            iWriter.print('\t');

            iWriter.print(FUNCTION_GROUP_KEYWORD);

            iWriter.print(" \"");

            iWriter.print(aGroupName);

            iWriter.println('"');

        }

        public void handleDomainBindingsDecl(String aProtectionDomain) {

            printDecl(DOMAIN_BINDINGS_KEYWORD, aProtectionDomain);

            iWriter.println();

            iProtectionDomain = aProtectionDomain;

        }

        public void handleFunctionGroupBindingDecl(String aFunctionGroup) {}

        public void handlePermission(Permission aPermission) {}

        public void handleEndFunctionGroupBinding() {}

        public void handleEndDomainBindings() {

            int n = iFunctionGroups.size();

            for (int i=0; i<n; i++) {

                String group = (String)iFunctionGroups.get(i);

                Permission p = iEmulatedDomain.getPermission(group);

                if (!p.isDenied()) {

                    iWriter.print('\t');

                    printDecl(FUNCTION_GROUP_BINDING_KEYWORD, group);

                    iWriter.println();

                    p.print(iWriter);

                    iWriter.print("\t\t");

                    iWriter.println(END_FUNCTION_GROUP_BINDING_KEYWORD);

                    iWriter.println();

                }

            }

            iWriter.print('\t');

            iWriter.println(END_DOMAIN_BINDINGS_KEYWORD);

            iProtectionDomain = null;

        }

    }

}