/*
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 1999 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "The Jakarta Project", "Tomcat", and "Apache Software
 *    Foundation" must not be used to endorse or promote products derived
 *    from this software without prior written permission. For written
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache"
 *    nor may "Apache" appear in their names without prior written
 *    permission of the Apache Group.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

package org.apache.tools.ant;

import java.io.*;
import java.util.*;
import java.text.*;

/**
 * Central representation of an Ant project. This class defines a
 * Ant project with all of it's targets and tasks. It also provides
 * the mechanism to kick off a build using a particular target name.
 * <p>
 * This class also encapsulates methods which allow Files to be refered
 * to using abstract path names which are translated to native system
 * file paths at runtime as well as defining various project properties.
 *
 * @author duncan@x180.com
 */

public class Project {

    public static final int MSG_ERR = 0;
    public static final int MSG_WARN = 1;
    public static final int MSG_INFO = 2;
    public static final int MSG_VERBOSE = 3;

    // private set of constants to represent the state
    // of a DFS of the Target dependencies
    private static final String VISITING = "VISITING";
    private static final String VISITED = "VISITED";

    private static String javaVersion;

    public static final String JAVA_1_0 = "1.0";
    public static final String JAVA_1_1 = "1.1";
    public static final String JAVA_1_2 = "1.2";
    public static final String JAVA_1_3 = "1.3";

    public static final String TOKEN_START = "@";
    public static final String TOKEN_END = "@";

    private String name;
    private PrintStream out;
    private int msgOutputLevel = MSG_INFO;

    private Hashtable properties = new Hashtable();
    private Hashtable userProperties = new Hashtable();
    private String defaultTarget;
    private Hashtable taskClassDefinitions = new Hashtable();
    private Hashtable targets = new Hashtable();
    private Hashtable filters = new Hashtable();
    private File baseDir;

    public Project(PrintStream out, int msgOutputLevel) {

        this.out = out;
        this.msgOutputLevel = msgOutputLevel;

        detectJavaVersion();

        String defs = "/org/apache/tools/ant/taskdefs/defaults.properties";

        try {
            Properties props = new Properties();
            InputStream in = this.getClass().getResourceAsStream(defs);
            props.load(in);
            in.close();

            Enumeration enum = props.propertyNames();
            while (enum.hasMoreElements()) {
                String key = (String) enum.nextElement();
                String value = props.getProperty(key);
                try {
                    Class taskClass = Class.forName(value);
                    addTaskDefinition(key, taskClass);
                } catch (ClassNotFoundException cnfe) {
                    // ignore...
                }
            }

            Properties systemP = System.getProperties();
            Enumeration e = systemP.keys();
            while (e.hasMoreElements()) {
                String name = (String) e.nextElement();
                String value = (String) systemP.get(name);
                this.setProperty(name, value);
            }
        } catch (IOException ioe) {
            String msg = "Can't load default task list";
            System.out.println(msg);
            System.exit(1);
        }
    }

    public PrintStream getOutput() {
        return this.out;
    }

    public int getOutputLevel() {
        return this.msgOutputLevel;
    }

    public void log(String msg) {
        log(msg, MSG_INFO);
    }

    public void log(String msg, int msgLevel) {
        if (msgLevel <= msgOutputLevel) {
            out.println(msg);
        }
    }

    public void log(String msg, String tag, int msgLevel) {
        if (msgLevel <= msgOutputLevel) {
            out.println("[" + tag + "] " + msg);
        }
    }

    public void setProperty(String name, String value) {
        // command line properties take precedence
        if (null != userProperties.get(name))
            return;
        log("Setting project property: " + name + " -> " +
            value, MSG_VERBOSE);
        properties.put(name, value);
    }

    public void setUserProperty(String name, String value) {
        log("Setting ro project property: " + name + " -> " +
            value, MSG_VERBOSE);
        userProperties.put(name, value);
        properties.put(name, value);
    }

    public String getProperty(String name) {
        if (name == null) return null;
        String property = (String) properties.get(name);
        return property;
    }

    public Hashtable getProperties() {
        return properties;
    }

    public void setDefaultTarget(String defaultTarget) {
        this.defaultTarget = defaultTarget;
    }

    // deprecated, use setDefault
    public String getDefaultTarget() {
        return defaultTarget;
    }

    // match the attribute name
    public void setDefault(String defaultTarget) {
        this.defaultTarget = defaultTarget;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getName() {
        return name;
    }

    public void addFilter(String token, String value) {
        if (token == null) return;
        log("Setting token to filter: " + token + " -> "
            + value, MSG_VERBOSE);
        this.filters.put(token, value);
    }

    public Hashtable getFilters() {
        return filters;
    }

    // match basedir attribute in xml
    public void setBasedir(String baseD) throws BuildException {
        try {
            setBaseDir(new File(new File(baseD).getCanonicalPath()));
        } catch (IOException ioe) {
            String msg = "Can't set basedir " + baseDir + " due to " +
                ioe.getMessage();
            throw new BuildException(msg);
        }
    }

    public void setBaseDir(File baseDir) {
        this.baseDir = baseDir;
        String msg = "Project base dir set to: " + baseDir;
        log(msg, MSG_INFO);
    }

    public File getBaseDir() {
        if (baseDir == null) {
            try {
                setBasedir(".");
            } catch (BuildException ex) {
              ex.printStackTrace();
            }
        }
        return baseDir;
    }

    public static String getJavaVersion() {
        return javaVersion;
    }

    private void detectJavaVersion() {

        // Determine the Java version by looking at available classes
        // java.lang.StrictMath was introduced in JDK 1.3
        // java.lang.ThreadLocal was introduced in JDK 1.2
        // java.lang.Void was introduced in JDK 1.1
        // Count up version until a NoClassDefFoundError ends the try

        try {
            javaVersion = JAVA_1_0;
            Class.forName("java.lang.Void");
            javaVersion = JAVA_1_1;
            Class.forName("java.lang.ThreadLocal");
            javaVersion = JAVA_1_2;
            Class.forName("java.lang.StrictMath");
            javaVersion = JAVA_1_3;
            setProperty("ant.java.version", javaVersion);
        } catch (ClassNotFoundException cnfe) {
            // swallow as we've hit the max class version that
            // we have
        }

        // sanity check
        if (javaVersion == JAVA_1_0) {
            throw new BuildException("Ant cannot work on Java 1.0");
        }

        log("Detected Java Version: " + javaVersion, MSG_VERBOSE);

        log("Detected OS: " + System.getProperty("os.name"), MSG_VERBOSE);
    }

    public void addTaskDefinition(String taskName, Class taskClass) {
        String msg = " +User task: " + taskName + "     " + taskClass.getName();
        log(msg, MSG_VERBOSE);
        taskClassDefinitions.put(taskName, taskClass);
    }

    /**
     * This call expects to add a <em>new</em> Target.
     * @param target is the Target to be added to the current
     * Project.
     * @exception BuildException if the Target already exists
     * in the project.
     * @see Project#addOrReplaceTarget to replace existing Targets.
     */
    public void addTarget(Target target) {
        String name = target.getName();
        if (targets.get(name) != null) {
            throw new BuildException("Duplicate target: `"+name+"'");
        }
        addOrReplaceTarget(name, target);
    }

    /**
     * This call expects to add a <em>new</em> Target.
     * @param target is the Target to be added to the current
     * Project.
     * @param targetName is the name to use for the Target
     * @exception BuildException if the Target already exists
     * in the project.
     * @see Project#addOrReplaceTarget to replace existing Targets.
     */
     public void addTarget(String targetName, Target target)
         throws BuildException {
         if (targets.get(targetName) != null) {
             throw new BuildException("Duplicate target: `"+targetName+"'");
         }
         addOrReplaceTarget(targetName, target);
     }

    /**
     * @param target is the Target to be added or replaced in
     * the current Project.
     */
    public void addOrReplaceTarget(Target target) {
        addOrReplaceTarget(target.getName(), target);
    }

    /**
     * @param target is the Target to be added/replaced in
     * the current Project.
     * @param targetName is the name to use for the Target
     */
    public void addOrReplaceTarget(String targetName, Target target) {
        String msg = " +Target: " + targetName;
        log(msg, MSG_VERBOSE);
        target.setProject(this);
        targets.put(targetName, target);
    }

    public Task createTask(String taskType) throws BuildException {
        Class c = (Class)taskClassDefinitions.get(taskType);

        // XXX
        // check for nulls, other sanity

        try {
            Object o=c.newInstance();
            Task task = null;
            if( o instanceof Task ) {
               task=(Task)o;
            } else {
                // "Generic" Bean - use the setter pattern
                // and an Adapter
                TaskAdapter taskA=new TaskAdapter();
                taskA.setProxy( o );
                task=taskA;
            }
            task.setProject(this);
            String msg = "   +Task: " + taskType;
            log (msg, MSG_VERBOSE);
            return task;
        } catch (Exception e) {
            String msg = "Could not create task of type: "
                 + taskType + " due to " + e;
            throw new BuildException(msg);
        }
    }

    public void executeTarget(String targetName) throws BuildException {

        // sanity check ourselves, if we've been asked to build nothing
        // then we should complain

        if (targetName == null) {
            String msg = "No target specified";
            throw new BuildException(msg);
        }

        // Sort the dependency tree, and run everything from the
        // beginning until we hit our targetName.
        // Sorting checks if all the targets (and dependencies)
        // exist, and if there is any cycle in the dependency
        // graph.
        Vector sortedTargets = topoSort(targetName, targets);

        int curidx = 0;
        String curtarget;

        do {
            curtarget = (String) sortedTargets.elementAt(curidx++);
            runTarget(curtarget, targets);
        } while (!curtarget.equals(targetName));
    }

    public File resolveFile(String fileName) {
        // deal with absolute files
        if (fileName.startsWith("/")) return new File( fileName );

        // Eliminate consecutive slashes after the drive spec
        if (fileName.length() >= 2 &&
            Character.isLetter(fileName.charAt(0)) &&
            fileName.charAt(1) == ':') {
            char[] ca = fileName.replace('/', '\\').toCharArray();
            char c;
            StringBuffer sb = new StringBuffer();

            for (int i = 0; i < ca.length; i++) {
                if ((ca[i] != '\\') ||
                    (ca[i] == '\\' &&
                        i > 0 &&
                        ca[i - 1] != '\\')) {
                    if (i == 0 &&
                        Character.isLetter(ca[i]) &&
                        i < ca.length - 1 &&
                        ca[i + 1] == ':') {
                        c = Character.toUpperCase(ca[i]);
                    } else {
                        c = ca[i];
                    }

                    sb.append(c);
                }
            }

            return new File(sb.toString());
        }

        File file = new File(baseDir.getAbsolutePath());
        StringTokenizer tok = new StringTokenizer(fileName, "/", false);
        while (tok.hasMoreTokens()) {
            String part = tok.nextToken();
            if (part.equals("..")) {
                file = new File(file.getParent());
            } else if (part.equals(".")) {
                // Do nothing here
            } else {
                file = new File(file, part);
            }
        }

        try {
            return new File(file.getCanonicalPath());
        }
        catch (IOException e) {
            log("IOException getting canonical path for " + file + ": " +
                e.getMessage(), MSG_ERR);
            return new File(file.getAbsolutePath());
        }
    }

    /**
        Translate a path into its native (platform specific)
        path. This should be extremely fast, code is
        borrowed from ECS project.
        <p>
        All it does is translate the : into ; and / into \
        if needed. In other words, it isn't perfect.

        @returns translated string or empty string if to_process is null or empty
        @author Jon S. Stevens <a href="mailto:jon@clearink.com">jon@clearink.com</a>
    */
    public String translatePath(String to_process) {
        if ( to_process == null || to_process.length() == 0 ) return "";

        StringBuffer bs = new StringBuffer(to_process.length() + 50);
        StringCharacterIterator sci = new StringCharacterIterator(to_process);
        String path = System.getProperty("path.separator");
        String file = System.getProperty("file.separator");
        String tmp = null;
        for (char c = sci.first(); c != CharacterIterator.DONE; c = sci.next()) {
            tmp = String.valueOf(c);

            if (tmp.equals(":")) {
                // could be a DOS drive or a Unix path separator...
                // if followed by a backslash, assume it is a drive
                c = sci.next();
                tmp = String.valueOf(c);
                bs.append( tmp.equals("\\") ? ":" : path );
                if (c == CharacterIterator.DONE) break;
            }

            if (tmp.equals(":") || tmp.equals(";"))
                tmp = path;
            else if (tmp.equals("/") || tmp.equals ("\\"))
                tmp = file;
            bs.append(tmp);
        }
        return(bs.toString());
    }

    /**
     * Convienence method to copy a file from a source to a destination.
     * No filtering is performed.
     *
     * @throws IOException
     */
    public void copyFile(String sourceFile, String destFile) throws IOException {
        copyFile(new File(sourceFile), new File(destFile), false);
    }

    /**
     * Convienence method to copy a file from a source to a destination
     * specifying if token filtering must be used.
     *
     * @throws IOException
     */
    public void copyFile(String sourceFile, String destFile, boolean filtering)
        throws IOException
    {
        copyFile(new File(sourceFile), new File(destFile), filtering);
    }

    /**
     * Convienence method to copy a file from a source to a destination.
     * No filtering is performed.
     *
     * @throws IOException
     */
    public void copyFile(File sourceFile, File destFile) throws IOException {
        copyFile(sourceFile, destFile, false);
    }

    /**
     * Convienence method to copy a file from a source to a destination
     * specifying if token filtering must be used.
     *
     * @throws IOException
     */
    public void copyFile(File sourceFile, File destFile, boolean filtering)
        throws IOException
    {

        if (destFile.lastModified() < sourceFile.lastModified()) {
            log("Copy: " + sourceFile.getAbsolutePath() + " > "
                    + destFile.getAbsolutePath(), MSG_VERBOSE);

            // ensure that parent dir of dest file exists!
            // not using getParentFile method to stay 1.1 compat
            File parent = new File(destFile.getParent());
            if (!parent.exists()) {
                parent.mkdirs();
            }

            if (filtering) {
                BufferedReader in = new BufferedReader(new FileReader(sourceFile));
                BufferedWriter out = new BufferedWriter(new FileWriter(destFile));

                int length;
                String newline = null;
                String line = in.readLine();
                while (line != null) {
                    if (line.length() == 0) {
                        out.newLine();
                    } else {
                        newline = replace(line, filters);
                        out.write(newline);
                        out.newLine();
                    }
                    line = in.readLine();
                }

                out.close();
                in.close();
            } else {
                FileInputStream in = new FileInputStream(sourceFile);
                FileOutputStream out = new FileOutputStream(destFile);

                byte[] buffer = new byte[8 * 1024];
                int count = 0;
                do {
                    out.write(buffer, 0, count);
                    count = in.read(buffer, 0, buffer.length);
                } while (count != -1);

                in.close();
                out.close();
            }
        }
    }

    /**
     * Does replacement on the given string using the given token table.
     *
     * @returns the string with the token replaced.
     */
    private String replace(String s, Hashtable tokens) {
        int index = s.indexOf(TOKEN_START);

        if (index > -1) {
            try {
                StringBuffer b = new StringBuffer();
                int i = 0;
                String token = null;
                String value = null;

                do {
                    token = s.substring(index + TOKEN_START.length(), s.indexOf(TOKEN_END, index + TOKEN_START.length() + 1));
                    b.append(s.substring(i, index));
                    if (tokens.containsKey(token)) {
                        value = (String) tokens.get(token);
                        log("Replacing: " + TOKEN_START + token + TOKEN_END + " -> " + value, MSG_VERBOSE);
                        b.append(value);
                    } else {
                        b.append(TOKEN_START);
                        b.append(token);
                        b.append(TOKEN_END);
                    }
                    i = index + TOKEN_START.length() + token.length() + TOKEN_END.length();
                } while ((index = s.indexOf(TOKEN_START, i)) > -1);

                b.append(s.substring(i));
                return b.toString();
            } catch (StringIndexOutOfBoundsException e) {
                return s;
            }
        } else {
            return s;
        }
    }

    /**
     * returns the boolean equivalent of a string, which is considered true
     * if either "on", "true", or "yes" is found, ignoring case.
     */
    public static boolean toBoolean(String s) {
        return (s.equalsIgnoreCase("on") ||
                s.equalsIgnoreCase("true") ||
                s.equalsIgnoreCase("yes"));
    }

    // Given a string defining a target name, and a Hashtable
    // containing the "name to Target" mapping, pick out the
    // Target and execute it.
    private final void runTarget(String target, Hashtable targets)
        throws BuildException {
        Target t = (Target)targets.get(target);
        if (t == null) {
            throw new RuntimeException("Unexpected missing target `"+target+
                                       "' in this project.");
        }
        log("Executing Target: "+target, MSG_INFO);
        t.execute();
    }

    /**
     * Topologically sort a set of Targets.
     * @param root is the (String) name of the root Target. The sort is
     * created in such a way that the sequence of Targets uptil the root
     * target is the minimum possible such sequence.
     * @param targets is a Hashtable representing a "name to Target" mapping
     * @return a Vector of Strings with the names of the targets in
     * sorted order.
     * @exception BuildException if there is a cyclic dependency among the
     * Targets, or if a Target does not exist.
     */
    private final Vector topoSort(String root, Hashtable targets)
        throws BuildException {
        Vector ret = new Vector();
        Hashtable state = new Hashtable();
        Stack visiting = new Stack();

        // We first run a DFS based sort using the root as the starting node.
        // This creates the minimum sequence of Targets to the root node.
        // We then do a sort on any remaining unVISITED targets.
        // This is unnecessary for doing our build, but it catches
        // circular dependencies or missing Targets on the entire
        // dependency tree, not just on the Targets that depend on the
        // build Target.

        tsort(root, targets, state, visiting, ret);
        log("Build sequence for target `"+root+"' is "+ret, MSG_VERBOSE);
        for (Enumeration en=targets.keys(); en.hasMoreElements();) {
            String curTarget = (String)(en.nextElement());
            String st = (String) state.get(curTarget);
            if (st == null) {
                tsort(curTarget, targets, state, visiting, ret);
            }
            else if (st == VISITING) {
                throw new RuntimeException("Unexpected node in visiting state: "+curTarget);
            }
        }
        log("Complete build sequence is "+ret, MSG_VERBOSE);
        return ret;
    }

    // one step in a recursive DFS traversal of the Target dependency tree.
    // - The Hashtable "state" contains the state (VISITED or VISITING or null)
    // of all the target names.
    // - The Stack "visiting" contains a stack of target names that are
    // currently on the DFS stack. (NB: the target names in "visiting" are
    // exactly the target names in "state" that are in the VISITING state.)
    // 1. Set the current target to the VISITING state, and push it onto
    // the "visiting" stack.
    // 2. Throw a BuildException if any child of the current node is
    // in the VISITING state (implies there is a cycle.) It uses the
    // "visiting" Stack to construct the cycle.
    // 3. If any children have not been VISITED, tsort() the child.
    // 4. Add the current target to the Vector "ret" after the children
    //   have been visited. Move the current target to the VISITED state.
    //   "ret" now contains the sorted sequence of Targets upto the current
    //   Target.

    private final void tsort(String root, Hashtable targets,
                             Hashtable state, Stack visiting,
                             Vector ret)
        throws BuildException {
        state.put(root, VISITING);
        visiting.push(root);

        Target target = (Target)(targets.get(root));

        // Make sure we exist
        if (target == null) {
            StringBuffer sb = new StringBuffer("Target `");
            sb.append(root);
            sb.append("' does not exist in this project. ");
            visiting.pop();
            if (!visiting.empty()) {
                String parent = (String)visiting.peek();
                sb.append("It is used from target `");
                sb.append(parent);
                sb.append("'.");
            }

            throw new BuildException(new String(sb));
        }

        for (Enumeration en=target.getDependencies(); en.hasMoreElements();) {
            String cur = (String) en.nextElement();
            String m=(String)state.get(cur);
            if (m == null) {
                // Not been visited
                tsort(cur, targets, state, visiting, ret);
            }
            else if (m == VISITING) {
                // Currently visiting this node, so have a cycle
                throw makeCircularException(cur, visiting);
            }
        }

        String p = (String) visiting.pop();
        if (root != p) {
            throw new RuntimeException("Unexpected internal error: expected to pop "+root+" but got "+p);
        }
        state.put(root, VISITED);
        ret.addElement(root);
    }

    private static BuildException makeCircularException(String end, Stack stk) {
        StringBuffer sb = new StringBuffer("Circular dependency: ");
        sb.append(end);
        String c;
        do {
            c = (String)stk.pop();
            sb.append(" <- ");
            sb.append(c);
        } while(!c.equals(end));
        return new BuildException(new String(sb));
    }
}