/*

 * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package com.sun.tools.sjavac;

import java.io.File;

import java.net.URI;

import java.util.ArrayList;

import java.util.Collections;

import java.util.HashMap;

import java.util.HashSet;

import java.util.Iterator;

import java.util.List;

import java.util.Map;

import java.util.Set;

/**

 * The Package class maintains meta information about a package.

 * For example its sources, dependents,its pubapi and its artifacts.

 *

 * It might look odd that we track dependents/pubapi/artifacts on

 * a package level, but it makes sense since recompiling a full package

 * takes as long as recompiling a single java file in that package,

 * if you take into account the startup time of the jvm.

 *

 * Also the dependency information will be much smaller (good for the javac_state file size)

 * and it simplifies tracking artifact generation, you do not always know from which

 * source a class file was generated, but you always know which package it belongs to.

 *

 * It is also educational to see package dependencies triggering recompilation of

 * other packages. Even though the recompilation was perhaps not necessary,

 * the visible recompilation of the dependent packages indicates how much circular

 * dependencies your code has.

 *

 * <p><b>This is NOT part of any supported API.

 * If you write code that depends on this, you do so at your own

 * risk.  This code and its internal interfaces are subject to change

 * or deletion without notice.</b></p>

 */

public class Package implements Comparable<Package> {

    // The module this package belongs to. (There is a legacy module with an empty string name,

    // used for all legacy sources.)

    private Module mod;

    // Name of this package, module:pkg

    // ex1 jdk.base:java.lang

    // ex2 :java.lang (when in legacy mode)

    private String name;

    // The directory path to the package. If the package belongs to a module,

    // then that module's file system name is part of the path.

    private String dirname;

    // This package depends on these packages.

    // This package has the following dependents, that depend on this package.

    // This is the public api of this package.

    // Map from source file name to Source info object.

    // This package generated these artifacts.

    public Package(Module m, String n) {

        int c = n.indexOf(":");

        assert(c != -1);

        String mn = n.substring(0,c);

        assert(m.name().equals(m.name()));

        name = n;

        dirname = n.replace('.', File.separatorChar);

        if (m.name().length() > 0) {

            // There is a module here, prefix the module dir name to the path.

            dirname = m.dirname()+File.separatorChar+dirname;

        }

    }

    public Module mod() { return mod; }

    public String name() { return name; }

    public String dirname() { return dirname; }

    public Map<String,Source> sources() { return sources; }

    public Map<String,File> artifacts() { return artifacts; }

    public List<String> pubapi() { return pubapi; }

    public Set<String> dependencies() { return dependencies; }

    public Set<String> dependents() { return dependents; }

    @Override

    public boolean equals(Object o) {

        return (o instanceof Package) && name.equals(((Package)o).name);

    }

    @Override

    public int hashCode() {

        return name.hashCode();

    }

    @Override

    public int compareTo(Package o) {

        return name.compareTo(o.name);

    }

    public void addSource(Source s) {

        sources.put(s.file().getPath(), s);

    }

    public void addDependency(String d) {

        dependencies.add(d);

    }

    public void addDependent(String d) {

        dependents.add(d);

    }

    public void addPubapi(String p) {

        pubapi.add(p);

    }

    /**

     * Check if we have knowledge in the javac state that

     * describe the results of compiling this package before.

     */

    public boolean existsInJavacState() {

        return artifacts.size() > 0 || pubapi.size() > 0;

    }

    public static List<String> pubapiToList(String ps)

    {

        String[] lines = ps.split("\n");

        for (String l : lines) {

            r.add(l);

        }

        return r;

    }

    public boolean hasPubapiChanged(List<String> ps) {

        Iterator<String> i = ps.iterator();

        Iterator<String> j = pubapi.iterator();

        int line = 0;

        while (i.hasNext() && j.hasNext()) {

            String is = i.next();

            String js = j.next();

            if (!is.equals(js)) {

                Log.debug("Change in pubapi for package "+name+" line "+line);

                Log.debug("Old: "+js);

                Log.debug("New: "+is);

                return true;

            }

            line++;

        }

        if ((i.hasNext() && !j.hasNext() ) ||

            (!i.hasNext() && j.hasNext())) {

            Log.debug("Change in pubapi for package "+name);

            if (i.hasNext()) {

                Log.debug("New has more lines!");

            } else {

                Log.debug("Old has more lines!");

            }

            return true;

        }

        return false;

    }

    public void setPubapi(List<String> ps) {

        pubapi = ps;

    }

    public void setDependencies(Set<String> ds) {

        dependencies = ds;

    }

    public void save(StringBuilder b) {

        b.append("P ").append(name).append("\n");

        Source.saveSources(sources, b);

        saveDependencies(b);

        savePubapi(b);

        saveArtifacts(b);

    }

    static public Package load(Module module, String l) {

        String name = l.substring(2);

        return new Package(module, name);

    }

    public void loadDependency(String l) {

        String n = l.substring(2);

        addDependency(n);

    }

    public void loadPubapi(String l) {

        String pi = l.substring(2);

        addPubapi(pi);

    }

    public void saveDependencies(StringBuilder b) {

        for (String key : dependencies) {

            sorted_dependencies.add(key);

        }

        Collections.sort(sorted_dependencies);

        for (String a : sorted_dependencies) {

            b.append("D "+a+"\n");

        }

    }

    public void savePubapi(StringBuilder b) {

        for (String l : pubapi) {

            b.append("I "+l+"\n");

        }

    }

    public static void savePackages(Map<String,Package> packages, StringBuilder b) {

        for (String key : packages.keySet() ) {

            sorted_packages.add(key);

        }

        Collections.sort(sorted_packages);

        for (String s : sorted_packages) {

            Package p = packages.get(s);

            p.save(b);

        }

    }

    public void addArtifact(String a) {

        artifacts.put(a, new File(a));

    }

    public void addArtifact(File f) {

        artifacts.put(f.getPath(), f);

    }

    public void addArtifacts(Set<URI> as) {

        for (URI u : as) {

            addArtifact(new File(u));

        }

    }

    public void setArtifacts(Set<URI> as) {

        assert(!artifacts.isEmpty());

        addArtifacts(as);

    }

    public void loadArtifact(String l) {

        // Find next space after "A ".

        int dp = l.indexOf(' ',2);

        String fn = l.substring(2,dp);

        long last_modified = Long.parseLong(l.substring(dp+1));

        File f = new File(fn);

        if (f.exists() && f.lastModified() != last_modified) {

            // Hmm, the artifact on disk does not have the same last modified

            // timestamp as the information from the build database.

            // We no longer trust the artifact on disk. Delete it.

            // The smart javac wrapper will then rebuild the artifact.

            Log.debug("Removing "+f.getPath()+" since its timestamp does not match javac_state.");

            f.delete();

        }

        artifacts.put(f.getPath(), f);

    }

    public void saveArtifacts(StringBuilder b) {

        for (File f : artifacts.values()) {

            sorted_artifacts.add(f);

        }

        Collections.sort(sorted_artifacts);

        for (File f : sorted_artifacts) {

            // The last modified information is only used

            // to detect tampering with the output dir.

            // If the outputdir has been modified, not by javac,

            // then a mismatch will be detected in the last modified

            // timestamps stored in the build database compared

            // to the timestamps on disk and the artifact will be deleted.

            b.append("A "+f.getPath()+" "+f.lastModified()+"\n");

        }

    }

    /**

     * Always clean out a tainted package before it is recompiled.

     */

    public void deleteArtifacts() {

        for (File a : artifacts.values()) {

            a.delete();

        }

    }

}