/**
*******************************************************************************
* Copyright (C) 2004, International Business Machines Corporation and         *
* others. All Rights Reserved.                                                *
*******************************************************************************
*/

/**
 * Compare two API files (generated by GatherAPIData) and generate a report
 * on the differences.
 * 
 * Sample invocation:
 * java -old: icu4j28.api.zip -new: icu4j30.api -html -out: icu4j_compare_28_30.html
 */

package com.ibm.icu.dev.tool.docs;

import java.io.*;
import java.util.*;
import java.util.zip.*;

public class ReportAPI {
    APIData oldData;
    APIData newData;
    boolean html;
    String outputFile;

    TreeSet added;
    TreeSet removed;
    ArrayList changed;

    static final class APIData {
	private int version;
	private String name;
	private String base;
	private TreeSet set;
	
	static APIData read(BufferedReader br) {
	    try {
		APIData data = new APIData();

		data.version = Integer.parseInt(APIInfo.readToken(br)); // version
		data.name = APIInfo.readToken(br);
		data.base = APIInfo.readToken(br); // base
		br.readLine();
	    
		data.set = new TreeSet(APIInfo.defaultComparator());
		for (APIInfo info = new APIInfo(); info.read(br); info = new APIInfo()) {
		    data.set.add(info);
		}
		return data;
	    }
	    catch (IOException e) {
		RuntimeException re = new RuntimeException("error reading api data");
		re.initCause(e);
		throw re;
	    }
	}

	static APIData read(String fileName) {
	    try {
		InputStream is;
		if (fileName.endsWith(".zip")) {
		    ZipFile zf = new ZipFile(fileName);
		    Enumeration entryEnum = zf.entries();
		    if (entryEnum.hasMoreElements()) {
			ZipEntry entry = (ZipEntry)entryEnum.nextElement();
			is = zf.getInputStream(entry);
			// we only handle one!!!
		    } else {
			throw new IOException("zip file is empty");
		    }
		} else {
		    File f = new File(fileName);
		    is = new FileInputStream(f);
		    if (fileName.endsWith(".gz")) {
			is = new GZIPInputStream(is);
		    }
		}
		InputStreamReader isr = new InputStreamReader(is);
		return read(new BufferedReader(isr));
	    }
	    catch (IOException e) {
		RuntimeException re = new RuntimeException("error getting info stream: " + fileName);
		re.initCause(e);
		throw re;
	    }
	}
    }
	
    static final class DeltaInfo extends APIInfo {
        private APIInfo added;
        private APIInfo removed;

        DeltaInfo(APIInfo added, APIInfo removed) {
            this.added = added;
            this.removed = removed;
        }

        public int getVal(int typ) {
            return added.getVal(typ);
        }

        public String get(int typ, boolean brief) {
            return added.get(typ, brief);
        }
    }

    public static void main(String[] args) {
	String oldFile = null;
	String newFile = null;
	String outFile = null;
	boolean html = false;

	for (int i = 0; i < args.length; ++i) {
	    String arg = args[i];
	    if (arg.equals("-old:")) {
		oldFile = args[++i];
	    } else if (arg.equals("-new:")) {
		newFile = args[++i];
	    } else if (arg.equals("-out:")) {
		outFile = args[++i];
	    } else if (arg.equals("-html")) {
		html = true;
	    }
	}

	new ReportAPI(oldFile, newFile).writeReport(outFile, html);
    }

    ReportAPI(String oldFile, String newFile) {
	oldData = APIData.read(oldFile);
	newData = APIData.read(newFile);

	// writing comparison info
	removed = (TreeSet)oldData.set.clone();
	removed.removeAll(newData.set);

	added = (TreeSet)newData.set.clone();
	added.removeAll(oldData.set);

	changed = new ArrayList();
	Iterator ai = added.iterator();
	Iterator ri = removed.iterator();
	Comparator c = APIInfo.changedComparator();
	APIInfo a = null, r = null;
	while (ai.hasNext() && ri.hasNext()) {
	    if (a == null) a = (APIInfo)ai.next();
	    if (r == null) r = (APIInfo)ri.next();
	    int result = c.compare(a, r);
	    if (result < 0) {
		a = null;
	    } else if (result > 0) {
		r = null;
	    } else {
		changed.add(new DeltaInfo(a, r));
		a = null; ai.remove();
		r = null; ri.remove();
	    }
	}

	added = stripAndResort(added);
	removed = stripAndResort(removed);
    }

    private boolean writeReport(String outFile, boolean html) {
        OutputStream os = System.out;
        if (outFile != null) {
            try {
                os = new FileOutputStream(outFile);
            }
            catch (FileNotFoundException e) {
                RuntimeException re = new RuntimeException(e.getMessage());
                re.initCause(e);
                throw re;
            }
        }

        PrintWriter pw = null;
	try {
	    pw = new PrintWriter(new BufferedWriter(new OutputStreamWriter(os, "UTF-8")));
	}
	catch (UnsupportedEncodingException e) {
	    throw new InternalError(); // UTF-8 should always be supported
	}

	String title = "ICU4J API Comparison: " + oldData.name + " with " + newData.name;
	String info = "Contents generated by ReportAPI tool.";
	String copyright = "Copyright (C) 2004, International Business Machines Corporation, All Rights Reserved.";
		
	if (html) {
	    pw.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
	    pw.println("<html>");
	    pw.println("<head>");
	    pw.println("<meta http-equiv=\"Content-Type\" content=\"text/html; charset=utf-8\">");
	    pw.println("<title>" + title + "</title>");
	    pw.println("</head>");
	    pw.println("<body>");

	    pw.println("<h1>" + title + "</h1>");

	    pw.println();
	    pw.println("<hr/>");
	    pw.println("<h2>Removed from " + oldData.name +"</h2>");
	    if (removed.size() > 0) {
		printResults(removed, pw, true, false);
	    } else {
		pw.println("<p>(no API removed)</p>");
	    }

	    pw.println();
	    pw.println("<hr/>");
	    pw.println("<h2>Changed in " + newData.name + " (old, new)</h2>");
	    if (changed.size() > 0) {
		printResults(changed, pw, true, true);
	    } else {
		pw.println("<p>(no API changed)</p>");
	    }

	    pw.println();
	    pw.println("<hr/>");
	    pw.println("<h2>Added in " + newData.name + "</h2>");
	    if (added.size() > 0) {
		printResults(added, pw, true, false);
	    } else {
		pw.println("<p>(no API added)</p>");
	    }

	    pw.println("<hr/>");
	    pw.println("<p><i>" + info + "<br/>" + copyright + "</i></p>");
	    pw.println("</body>");
	    pw.println("</html>");
	} else {
	    pw.println(title);
	    pw.println();
	    pw.println();

	    pw.println("=== Removed from " + oldData.name + " ===");
	    if (removed.size() > 0) {
		printResults(removed, pw, false, false);
	    } else {
		pw.println("(no API removed)");
	    }

	    pw.println();
	    pw.println();
	    pw.println("=== Changed in " + newData.name + " (old, new) ===");
	    if (changed.size() > 0) {
		printResults(changed, pw, false, true);
	    } else {
		pw.println("(no API changed)");
	    }

	    pw.println();
	    pw.println();
	    pw.println("=== Added in " + newData.name + " ===");
	    if (added.size() > 0) {
		printResults(added, pw, false, false);
	    } else {
		pw.println("(no API added)");
	    }

	    pw.println();
	    pw.println("================");
	    pw.println(info);
	    pw.println(copyright);
	}
	pw.close();

        return false;
    }

    private static void printResults(Collection c, PrintWriter pw, boolean html, boolean isChangedAPIs) {
        Iterator iter = c.iterator();
        String pack = null;
        String clas = null;
        while (iter.hasNext()) {
            APIInfo info = (APIInfo)iter.next();

	    String packageName = info.getPackageName();
	    if (!packageName.equals(pack)) {
		if (html) {
		    if (clas != null) {
			pw.println("</ul>");
		    }
		    if (pack != null) {
			pw.println("</ul>");
		    }
		    pw.println();
		    pw.println("<h3>Package " + packageName + "</h3>");
		    pw.print("<ul>");
		} else {
		    if (pack != null) {
			pw.println();
		    }
		    pw.println();
		    pw.println("Package " + packageName + ":");
		}
		pw.println();
                        
		pack = packageName;
		clas = null;
	    }

	    if (!info.isClass()) {
		String className = info.getClassName();
		if (!className.equals(clas)) {
		    if (html) {
			if (clas != null) {
			    pw.println("</ul>");
			}
			pw.println("<li>" + className);
			pw.println("<ul>");
		    } else {
			pw.println(className);
		    }
		    clas = className;
		}
		pw.print("    ");
	    }

	    if (html) {
		pw.print("<li>");
		if (info instanceof DeltaInfo) {
		    DeltaInfo dinfo = (DeltaInfo)info;
		    dinfo.removed.print(pw, isChangedAPIs);
		    pw.println("</br>");
		    dinfo.added.print(pw, isChangedAPIs);
		} else {
		    info.print(pw, isChangedAPIs);
		}
		pw.println("</li>");
	    } else {
		if (info instanceof DeltaInfo) {
		    DeltaInfo dinfo = (DeltaInfo)info;
		    dinfo.removed.println(pw, isChangedAPIs);
		    dinfo.added.println(pw, isChangedAPIs);
		} else {
		    info.println(pw, isChangedAPIs);
		}
	    }
	}

        if (html) {
	    if (clas != null) {
		pw.println("</ul>");
	    }
	    if (pack != null) {
		pw.println("</ul>");
	    }
        }
	pw.println();
    }

    private static TreeSet stripAndResort(TreeSet t) {
        stripClassInfo(t);
        TreeSet r = new TreeSet(APIInfo.classFirstComparator());
        r.addAll(t);
        return r;
    }

    private static void stripClassInfo(Collection c) {
        // c is sorted with class info first
        Iterator iter = c.iterator();
        String cname = null;
        while (iter.hasNext()) {
            APIInfo info = (APIInfo)iter.next();
            String className = info.getClassName();
            if (cname != null) {
                if (cname.equals(className)) {
                    iter.remove();
                    continue;
                }
                cname = null;
            } 
            if (info.isClass()) {
                cname = info.getName();
            }
        }
    }
}