/*

 * Copyright (c) 2009, 2016, 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.javac.util;

import java.nio.file.Path;

import java.util.EnumMap;

import java.util.EnumSet;

import java.util.HashMap;

import java.util.LinkedHashMap;

import java.util.Locale;

import java.util.Map;

import com.sun.tools.javac.code.Printer;

import com.sun.tools.javac.code.Symbol;

import com.sun.tools.javac.code.Symbol.*;

import com.sun.tools.javac.code.Symtab;

import com.sun.tools.javac.code.Type;

import com.sun.tools.javac.code.Type.*;

import com.sun.tools.javac.code.Types;

import static com.sun.tools.javac.code.Flags.*;

import static com.sun.tools.javac.code.TypeTag.*;

import static com.sun.tools.javac.code.Kinds.*;

import static com.sun.tools.javac.code.Kinds.Kind.*;

import static com.sun.tools.javac.util.LayoutCharacters.*;

import static com.sun.tools.javac.util.RichDiagnosticFormatter.RichConfiguration.*;

/**

 * A rich diagnostic formatter is a formatter that provides better integration

 * with javac's type system. A diagostic is first preprocessed in order to keep

 * track of each types/symbols in it; after these informations are collected,

 * the diagnostic is rendered using a standard formatter, whose type/symbol printer

 * has been replaced by a more refined version provided by this rich formatter.

 * The rich formatter currently enables three different features: (i) simple class

 * names - that is class names are displayed used a non qualified name (thus

 * omitting package info) whenever possible - (ii) where clause list - a list of

 * additional subdiagnostics that provide specific info about type-variables,

 * captured types, intersection types that occur in the diagnostic that is to be

 * formatted and (iii) type-variable disambiguation - when the diagnostic refers

 * to two different type-variables with the same name, their representation is

 * disambiguated by appending an index to the type variable name.

 *

 * <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>

 */

public class RichDiagnosticFormatter extends

        ForwardingDiagnosticFormatter<JCDiagnostic, AbstractDiagnosticFormatter> {

    final Symtab syms;

    final Types types;

    final JCDiagnostic.Factory diags;

    final JavacMessages messages;

    /* name simplifier used by this formatter */

    protected ClassNameSimplifier nameSimplifier;

    /* type/symbol printer used by this formatter */

    private RichPrinter printer;

    /* map for keeping track of a where clause associated to a given type */

    Map<WhereClauseKind, Map<Type, JCDiagnostic>> whereClauses;

    /** Get the DiagnosticFormatter instance for this context. */

    public static RichDiagnosticFormatter instance(Context context) {

        RichDiagnosticFormatter instance = context.get(RichDiagnosticFormatter.class);

        if (instance == null)

            instance = new RichDiagnosticFormatter(context);

        return instance;

    }

    protected RichDiagnosticFormatter(Context context) {

        super((AbstractDiagnosticFormatter)Log.instance(context).getDiagnosticFormatter());

        setRichPrinter(new RichPrinter());

        this.syms = Symtab.instance(context);

        this.diags = JCDiagnostic.Factory.instance(context);

        this.types = Types.instance(context);

        this.messages = JavacMessages.instance(context);

        whereClauses = new EnumMap<>(WhereClauseKind.class);

        configuration = new RichConfiguration(Options.instance(context), formatter);

        for (WhereClauseKind kind : WhereClauseKind.values())

            whereClauses.put(kind, new LinkedHashMap<Type, JCDiagnostic>());

    }

    @Override

    public String format(JCDiagnostic diag, Locale l) {

        StringBuilder sb = new StringBuilder();

        nameSimplifier = new ClassNameSimplifier();

        for (WhereClauseKind kind : WhereClauseKind.values())

            whereClauses.get(kind).clear();

        preprocessDiagnostic(diag);

        sb.append(formatter.format(diag, l));

        if (getConfiguration().isEnabled(RichFormatterFeature.WHERE_CLAUSES)) {

            List<JCDiagnostic> clauses = getWhereClauses();

            String indent = formatter.isRaw() ? "" :

                formatter.indentString(DetailsInc);

            for (JCDiagnostic d : clauses) {

                String whereClause = formatter.format(d, l);

                if (whereClause.length() > 0) {

                    sb.append('\n' + indent + whereClause);

                }

            }

        }

        return sb.toString();

    }

    @Override

    public String formatMessage(JCDiagnostic diag, Locale l) {

        nameSimplifier = new ClassNameSimplifier();

        preprocessDiagnostic(diag);

        return super.formatMessage(diag, l);

    }

    /**

     * Sets the type/symbol printer used by this formatter.

     * @param printer the rich printer to be set

     */

    protected void setRichPrinter(RichPrinter printer) {

        this.printer = printer;

        formatter.setPrinter(printer);

    }

    /**

     * Returns the type/symbol printer used by this formatter.

     * @return type/symbol rich printer

     */

    protected RichPrinter getRichPrinter() {

        return printer;

    }

    /**

     * Preprocess a given diagnostic by looking both into its arguments and into

     * its subdiagnostics (if any). This preprocessing is responsible for

     * generating info corresponding to features like where clauses, name

     * simplification, etc.

     *

     * @param diag the diagnostic to be preprocessed

     */

    protected void preprocessDiagnostic(JCDiagnostic diag) {

        for (Object o : diag.getArgs()) {

            if (o != null) {

                preprocessArgument(o);

            }

        }

        if (diag.isMultiline()) {

            for (JCDiagnostic d : diag.getSubdiagnostics())

                preprocessDiagnostic(d);

        }

    }

    /**

     * Preprocess a diagnostic argument. A type/symbol argument is

     * preprocessed by specialized type/symbol preprocessors.

     *

     * @param arg the argument to be translated

     */

    protected void preprocessArgument(Object arg) {

        if (arg instanceof Type) {

            preprocessType((Type)arg);

        }

        else if (arg instanceof Symbol) {

            preprocessSymbol((Symbol)arg);

        }

        else if (arg instanceof JCDiagnostic) {

            preprocessDiagnostic((JCDiagnostic)arg);

        }

        else if (arg instanceof Iterable<?> && !(arg instanceof Path)) {

            for (Object o : (Iterable<?>)arg) {

                preprocessArgument(o);

            }

        }

    }

    /**

     * Build a list of multiline diagnostics containing detailed info about

     * type-variables, captured types, and intersection types

     *

     * @return where clause list

     */

    protected List<JCDiagnostic> getWhereClauses() {

        List<JCDiagnostic> clauses = List.nil();

        for (WhereClauseKind kind : WhereClauseKind.values()) {

            List<JCDiagnostic> lines = List.nil();

            for (Map.Entry<Type, JCDiagnostic> entry : whereClauses.get(kind).entrySet()) {

                lines = lines.prepend(entry.getValue());

            }

            if (!lines.isEmpty()) {

                String key = kind.key();

                if (lines.size() > 1)

                    key += ".1";

                JCDiagnostic d = diags.fragment(key, whereClauses.get(kind).keySet());

                d = new JCDiagnostic.MultilineDiagnostic(d, lines.reverse());

                clauses = clauses.prepend(d);

            }

        }

        return clauses.reverse();

    }

    private int indexOf(Type type, WhereClauseKind kind) {

        int index = 1;

        for (Type t : whereClauses.get(kind).keySet()) {

            if (t.tsym == type.tsym) {

                return index;

            }

            if (kind != WhereClauseKind.TYPEVAR ||

                    t.toString().equals(type.toString())) {

                index++;

            }

        }

        return -1;

    }

    private boolean unique(TypeVar typevar) {

        typevar = (TypeVar) typevar.stripMetadata();

        int found = 0;

        for (Type t : whereClauses.get(WhereClauseKind.TYPEVAR).keySet()) {

            if (t.stripMetadata().toString().equals(typevar.toString())) {

                found++;

            }

        }

        if (found < 1)

            throw new AssertionError("Missing type variable in where clause: " + typevar);

        return found == 1;

    }

    //where

    /**

     * This enum defines all posssible kinds of where clauses that can be

     * attached by a rich diagnostic formatter to a given diagnostic

     */

    enum WhereClauseKind {

        /** where clause regarding a type variable */

        TYPEVAR("where.description.typevar"),

        /** where clause regarding a captured type */

        CAPTURED("where.description.captured"),

        /** where clause regarding an intersection type */

        INTERSECTION("where.description.intersection");

        /** resource key for this where clause kind */

        private final String key;

        WhereClauseKind(String key) {

            this.key = key;

        }

        String key() {

            return key;

        }

    }

    // <editor-fold defaultstate="collapsed" desc="name simplifier">

    /**

     * A name simplifier keeps track of class names usages in order to determine

     * whether a class name can be compacted or not. Short names are not used

     * if a conflict is detected, e.g. when two classes with the same simple

     * name belong to different packages - in this case the formatter reverts

     * to fullnames as compact names might lead to a confusing diagnostic.

     */

    protected class ClassNameSimplifier {

        /* table for keeping track of all short name usages */

        Map<Name, List<Symbol>> nameClashes = new HashMap<>();

        /**

         * Add a name usage to the simplifier's internal cache

         */

        protected void addUsage(Symbol sym) {

            Name n = sym.getSimpleName();

            List<Symbol> conflicts = nameClashes.get(n);

            if (conflicts == null) {

                conflicts = List.nil();

            }

            if (!conflicts.contains(sym))

                nameClashes.put(n, conflicts.append(sym));

        }

        public String simplify(Symbol s) {

            String name = s.getQualifiedName().toString();

            if (!s.type.isCompound() && !s.type.isPrimitive()) {

                List<Symbol> conflicts = nameClashes.get(s.getSimpleName());

                if (conflicts == null ||

                    (conflicts.size() == 1 &&

                    conflicts.contains(s))) {

                    List<Name> l = List.nil();

                    Symbol s2 = s;

                    while (s2.type.hasTag(CLASS) &&

                            s2.type.getEnclosingType().hasTag(CLASS) &&

                            s2.owner.kind == TYP) {

                        l = l.prepend(s2.getSimpleName());

                        s2 = s2.owner;

                    }

                    l = l.prepend(s2.getSimpleName());

                    StringBuilder buf = new StringBuilder();

                    String sep = "";

                    for (Name n2 : l) {

                        buf.append(sep);

                        buf.append(n2);

                        sep = ".";

                    }

                    name = buf.toString();

                }

            }

            return name;

        }

    }

    // </editor-fold>

    // <editor-fold defaultstate="collapsed" desc="rich printer">

    /**

     * Enhanced type/symbol printer that provides support for features like simple names

     * and type variable disambiguation. This enriched printer exploits the info

     * discovered during type/symbol preprocessing. This printer is set on the delegate

     * formatter so that rich type/symbol info can be properly rendered.

     */

    protected class RichPrinter extends Printer {

        @Override

        public String localize(Locale locale, String key, Object... args) {

            return formatter.localize(locale, key, args);

        }

        @Override

        public String capturedVarId(CapturedType t, Locale locale) {

            return indexOf(t, WhereClauseKind.CAPTURED) + "";

        }

        @Override

        public String visitType(Type t, Locale locale) {

            String s = super.visitType(t, locale);

            if (t == syms.botType)

                s = localize(locale, "compiler.misc.type.null");

            return s;

        }

        @Override

        public String visitCapturedType(CapturedType t, Locale locale) {

            if (getConfiguration().isEnabled(RichFormatterFeature.WHERE_CLAUSES)) {

                return localize(locale,

                    "compiler.misc.captured.type",

                    indexOf(t, WhereClauseKind.CAPTURED));

            }

            else

                return super.visitCapturedType(t, locale);

        }

        @Override

        public String visitClassType(ClassType t, Locale locale) {

            if (t.isCompound() &&

                    getConfiguration().isEnabled(RichFormatterFeature.WHERE_CLAUSES)) {

                return localize(locale,

                        "compiler.misc.intersection.type",

                        indexOf(t, WhereClauseKind.INTERSECTION));

            }

            else

                return super.visitClassType(t, locale);

        }

        @Override

        protected String className(ClassType t, boolean longform, Locale locale) {

            Symbol sym = t.tsym;

            if (sym.name.length() == 0 ||

                    !getConfiguration().isEnabled(RichFormatterFeature.SIMPLE_NAMES)) {

                return super.className(t, longform, locale);

            }

            else if (longform)

                return nameSimplifier.simplify(sym).toString();

            else

                return sym.name.toString();

        }

        @Override

        public String visitTypeVar(TypeVar t, Locale locale) {

            if (unique(t) ||

                    !getConfiguration().isEnabled(RichFormatterFeature.UNIQUE_TYPEVAR_NAMES)) {

                return t.toString();

            }

            else {

                return localize(locale,

                        "compiler.misc.type.var",

                        t.toString(), indexOf(t, WhereClauseKind.TYPEVAR));

            }

        }

        @Override

        public String visitClassSymbol(ClassSymbol s, Locale locale) {

            if (s.type.isCompound()) {

                return visit(s.type, locale);

            }

            String name = nameSimplifier.simplify(s);

            if (name.length() == 0 ||

                    !getConfiguration().isEnabled(RichFormatterFeature.SIMPLE_NAMES)) {

                return super.visitClassSymbol(s, locale);

            }

            else {

                return name;

            }

        }

        @Override

        public String visitMethodSymbol(MethodSymbol s, Locale locale) {

            String ownerName = visit(s.owner, locale);

            if (s.isStaticOrInstanceInit()) {

               return ownerName;

            } else {

                String ms = (s.name == s.name.table.names.init)

                    ? ownerName

                    : s.name.toString();

                if (s.type != null) {

                    if (s.type.hasTag(FORALL)) {

                        ms = "<" + visitTypes(s.type.getTypeArguments(), locale) + ">" + ms;

                    }

                    ms += "(" + printMethodArgs(

                            s.type.getParameterTypes(),

                            (s.flags() & VARARGS) != 0,

                            locale) + ")";

                }

                return ms;

            }

        }

    }

    // </editor-fold>

    // <editor-fold defaultstate="collapsed" desc="type scanner">

    /**

     * Preprocess a given type looking for (i) additional info (where clauses) to be

     * added to the main diagnostic (ii) names to be compacted.

     */

    protected void preprocessType(Type t) {

        typePreprocessor.visit(t);

    }

    //where

    protected Types.UnaryVisitor<Void> typePreprocessor =

            new Types.UnaryVisitor<Void>() {

        public Void visit(List<Type> ts) {

            for (Type t : ts)

                visit(t);

            return null;

        }

        @Override

        public Void visitForAll(ForAll t, Void ignored) {

            visit(t.tvars);

            visit(t.qtype);

            return null;

        }

        @Override

        public Void visitMethodType(MethodType t, Void ignored) {

            visit(t.argtypes);

            visit(t.restype);

            return null;

        }

        @Override

        public Void visitErrorType(ErrorType t, Void ignored) {

            Type ot = t.getOriginalType();

            if (ot != null)

                visit(ot);

            return null;

        }

        @Override

        public Void visitArrayType(ArrayType t, Void ignored) {

            visit(t.elemtype);

            return null;

        }

        @Override

        public Void visitWildcardType(WildcardType t, Void ignored) {

            visit(t.type);

            return null;

        }

        public Void visitType(Type t, Void ignored) {

            return null;

        }

        @Override

        public Void visitCapturedType(CapturedType t, Void ignored) {

            if (indexOf(t, WhereClauseKind.CAPTURED) == -1) {

                String suffix = t.lower == syms.botType ? ".1" : "";

                JCDiagnostic d = diags.fragment("where.captured"+ suffix, t, t.bound, t.lower, t.wildcard);

                whereClauses.get(WhereClauseKind.CAPTURED).put(t, d);

                visit(t.wildcard);

                visit(t.lower);

                visit(t.bound);

            }

            return null;

        }

        @Override