/*
 * FileEnvironment.java
 *
 * comments here.
 *
 * @author Michiaki Tatsubori
 *
 * @version %VERSION% %DATE%
 * @see java.lang.Object
 *
 * COPYRIGHT 1998 by Michiaki Tatsubori, ALL RIGHTS RESERVED.
 */
package io.devnulllabs.openjava.mop;

import java.io.File;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Vector;

import io.devnulllabs.openjava.ptree.ClassDeclaration;
import io.devnulllabs.openjava.ptree.ClassDeclarationList;
import io.devnulllabs.openjava.ptree.CompilationUnit;
import io.devnulllabs.openjava.ptree.ModifierList;
import io.devnulllabs.openjava.tools.DebugOut;

/**
 * The class <code>FileEnvironment</code>
 * <p>
 * For example
 *
 * <pre>
 * </pre>
 *
 *
 *
 *
 *
 * <p>
 *
 * @author Michiaki Tatsubori
 * @version 1.0
 * @since $Id: FileEnvironment.java,v 1.3 2003/11/14 13:52:02 tatsubori Exp $
 * @see java.lang.Object
 */
public class FileEnvironment extends Environment {

    private final File file;
    private String packageName;
    private String pubclassName;
    private final Vector localClasses = new Vector(); /* not implemented */

    private Vector importedClasses = new Vector();
    private Vector importedPackages = new Vector();
    private final Hashtable localClassTable = new Hashtable();

    public FileEnvironment(Environment e, String pack, String name) {
        this(e, pack, name, null);
    }

    public FileEnvironment(
        Environment e,
        String pack,
        String name,
        File file) {
        super(e);
        if (pack != null && pack.equals(""))
            pack = null;
        this.packageName = pack;
        this.pubclassName = name;
        this.file = file;
        importPackage("java.lang");
    }

    public FileEnvironment(Environment e) {
        this(e, null, null, null);
    }

    public FileEnvironment(
        Environment e,
        CompilationUnit comp_unit,
        String mainname) {
        this(e, comp_unit.getPackage(), mainname);
        setCompilationUnit(comp_unit);
    }

    public String toString() {
        StringWriter str_writer = new StringWriter();
        PrintWriter out = new PrintWriter(str_writer);

        out.println("FileEnvironment");
        out.println("\tfile : " + file);
        out.println("\tpackage : " + packageName);
        out.println("\tmain class : " + file);
        out.println("\tmain class : " + file);
        out.print("\tlocal classes : ");
        writeStringVector(out, localClasses);
        out.println();
        out.print("\timported classes : ");
        writeStringVector(out, importedClasses);
        out.println();
        out.print("\timported packages : ");
        writeStringVector(out, importedPackages);
        out.println();
        out.println("\tlocal class table : " + localClassTable);
        out.println("parent env : " + parent);

        out.flush();
        return str_writer.toString();
    }

    private static void writeStringVector(PrintWriter out, Vector v) {
        Enumeration e = v.elements();
        while (e.hasMoreElements()) {
            String str = (String) e.nextElement();
            out.print(str + " ");
        }
    }

    public File getFile() {
        return file;
    }

    /**
     * Sets the package name.
     */
    public void setPackage(String pack) {
        if (pack != null && pack.equals(""))
            pack = null;
        packageName = pack;
    }

    /**
     * Gets the package name.
     */
    public String getPackage() {
        if (packageName == "")
            return null;
        return packageName;
    }

    /**
     * Internal use only.
     *
     * @param comp_unit
     *            compilation unit to initialize this environment.
     */
    public void setCompilationUnit(CompilationUnit comp_unit) {
        packageName = comp_unit.getPackage();
        try {
            ClassDeclaration cd = comp_unit.getPublicClass();
            if (cd != null)
                pubclassName = cd.getName();
        } catch (Exception ex) {
        }

        String[] imps = comp_unit.getDeclaredImports();
        for (int i = 0; i < imps.length; ++i) {
            if (CompilationUnit.isOnDemandImport(imps[i])) {
                String imppack = CompilationUnit.trimOnDemand(imps[i]);
                this.importPackage(imppack);
            } else {
                this.importClass(imps[i]);
            }
        }

        ClassDeclarationList classdecls = comp_unit.getClassDeclarations();
        for (int i = 0; i < classdecls.size(); ++i) {
            ClassDeclaration cdecl = classdecls.get(i);
            if (cdecl.getModifiers().contains(ModifierList.PUBLIC))
                continue;
            this.recordLocalClassName(cdecl.getName());
        }

    }

    /**
     * Looks a class object up.
     *
     * @param name
     *            the name of the fully-qualified name of the class looked for
     */
    public OJClass lookupClass(String name) {
        OJClass clazz = (OJClass) localClassTable.get(name);
        if (clazz != null)
            return clazz;
        try {
            clazz = OJClass.forName(name);
        } catch (OJClassNotFoundException e) {
            return null;
        }
        return clazz;
    }

    /**
     * Records a class object.
     *
     * @param name
     *            the fully-qualified name of the class
     * @param clazz
     *            the class object associated with that name
     */
    public void record(String name, OJClass clazz) {
        DebugOut.println("Fenv#record(): " + name + " " + clazz);
        localClassTable.put(name, clazz);
    }

    /**
     * Imports a class.
     *
     * @param name
     *            the fully-qualified name of the imported class
     * @return false if the given name is already registered or if it is an
     *         ambiguous name.
     */
    public boolean importClass(String qualified_name) {
        DebugOut.println("FileEnvironment#importClass() : " + qualified_name);
        String simple_name = toSimpleName(qualified_name);
        if (isAlreadyImportedClass(qualified_name)
            || isCrashingClassName(simple_name)) {
            return false;
        } else {
            importedClasses.addElement(qualified_name);
            return true;
        }
    }

    /**
     * Imports a package.
     *
     * @param name
     *            the fully-qualified name of the imported package
     */
    public void importPackage(String name) {
        DebugOut.println("FileEnvironment#importPackage() : " + name);
        importedPackages.addElement(name);
    }

    /**
     * Obtains the fully-qualified name of the given class name.
     *
     * @param name
     *            a simple class name or a fully-qualified class name
     * @return the fully-qualified name of the class
     */
    public String toQualifiedName(String name) {
        if (name == null || isPrimitiveType(name) || isQualifiedName(name)) {
            return name;
        }

        if (name.endsWith("[]")) {
            String stripped = name.substring(0, name.length() - 2);
            return toQualifiedName(stripped) + "[]";
        }

        String sname = name;

        if ((file != null && file.getName().endsWith(sname + ".oj"))
            || localClasses.indexOf(sname) != -1) {
            String pack = getPackage();
            if (pack == null)
                return sname;
            return pack + "." + sname;
        }

        String qname;

        qname = searchImportedClasses(sname);
        if (qname != null)
            return qname;

        qname = searchImportedPackages(sname);
        if (qname != null)
            return qname;

        return sname;
    }

    /**
     * Register a simple name as a local class
     */
    public void recordLocalClassName(String name) {
        DebugOut.println(
            "FileEnvironment#recordLocalClassName() : " + toSimpleName(name));
        localClasses.addElement(toSimpleName(name));
    }

    private static final boolean isPrimitiveType(String name) {
        if (name == null)
            return false;
        return (
            name.equals("boolean")
                || name.equals("byte")
                || name.equals("char")
                || name.equals("double")
                || name.equals("float")
                || name.equals("int")
                || name.equals("long")
                || name.equals("short")
                || name.equals("void"));
    }

    private String searchImportedClasses(String simple_name) {
        String tail = "." + simple_name;
        for (int i = 0, size = importedClasses.size(); i < size; ++i) {
            String qname = (String) importedClasses.elementAt(i);
            if (qname.endsWith(tail))
                return qname;
        }
        return null;
    }

    private boolean isAlreadyImportedClass(String qualified_name) {
        for (int i = 0, size = importedClasses.size(); i < size; ++i) {
            String qname = (String) importedClasses.elementAt(i);
            if (qname.equals(qualified_name))
                return true;
        }
        return false;
    }

    private boolean isCrashingClassName(String simple_name) {
        return (searchImportedClasses(simple_name) != null);
    }

    private String searchImportedPackages(String simple_name) {
        String found;

        String packname = getPackage();
        if (packname == null || packname.equals("")) {
            found = simple_name;
        } else {
            found = packname + "." + simple_name;
        }
        if (theClassExists(found))
            return found;

        found = null;

        /* the qualified name found last should be taken */
        for (int i = 0, size = importedPackages.size(); i < size; ++i) {
            packname = (String) importedPackages.elementAt(i);
            String qname = packname + "." + simple_name;
            if (theClassExists(qname))
                found = qname;
        }

        /* this returns the qualified name found last. */
        return found;
    }

    /*
     * The use of Class.forName() costs too much time.
     */
    private boolean theClassExists(String class_name) {
        return (lookupClass(class_name) != null);
    }

    /**
     * binds a name to the class type.
     *
     * @param name
     *            the fully-qualified name of the class
     * @param clazz
     *            the class object associated with that name
     */
    public void bindVariable(String name, OJClass clazz) {
        System.err.println("error : illegal binding on FileEnvironment");
    }

    public OJClass lookupBind(String name) {
        return null;
    }

}