/*
 * Copyright 2009 The Closure Compiler Authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.javascript.jscomp;

import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Multiset;
import com.google.common.collect.Sets;
import com.google.common.collect.TreeMultiset;
import com.google.javascript.jscomp.DefinitionsRemover.Definition;
import com.google.javascript.jscomp.NodeTraversal.AbstractPostOrderCallback;
import com.google.javascript.rhino.Node;
import com.google.javascript.rhino.Token;

import java.util.Collection;
import java.util.Set;

/**
 * Tests for {@link SimpleDefinitionFinder}
 *
 */
public class SimpleDefinitionFinderTest extends CompilerTestCase {
  Set<String> found = Sets.newTreeSet();

  @Override
  protected int getNumRepetitions() {
    // run pass once.
    return 1;
  }

  @Override
  protected void tearDown() throws Exception {
    super.tearDown();
    found.clear();
  }

  public void testDefineNumber() throws Exception {
    checkDefinitionsInJs(
        "var a = 1",
        ImmutableSet.of("DEF NAME a -> NUMBER"));

    checkDefinitionsInJs(
        "a = 1",
        ImmutableSet.of("DEF NAME a -> NUMBER"));

    checkDefinitionsInJs(
        "a.b = 1",
        ImmutableSet.of("DEF GETPROP a.b -> NUMBER"));

    // getelem expressions are invisible to the definition gatherer.
    checkDefinitionsInJs(
        "a[\"b\"] = 1",
        ImmutableSet.<String>of());

    checkDefinitionsInJs(
        "f().b = 1",
        ImmutableSet.of("DEF GETPROP null -> NUMBER"));

    checkDefinitionsInJs(
        "({a : 1}); o.a",
        ImmutableSet.of("DEF STRING_KEY null -> NUMBER",
                        "USE GETPROP o.a -> [NUMBER]"));

    // TODO(johnlenz): Fix this.
    checkDefinitionsInJs(
      "({'a' : 1}); o['a']",
      ImmutableSet.<String>of("DEF STRING_KEY null -> NUMBER"));

    checkDefinitionsInJs(
      "({1 : 1}); o[1]",
      ImmutableSet.<String>of("DEF STRING_KEY null -> NUMBER"));

    checkDefinitionsInJs(
        "var a = {b : 1}; a.b",
        ImmutableSet.of("DEF NAME a -> <null>",
                        "DEF STRING_KEY null -> NUMBER",
                        "USE NAME a -> [<null>]",
                        "USE GETPROP a.b -> [NUMBER]"));
  }

  public void testDefineGet() throws Exception {
    // TODO(johnlenz): Add support for quoted properties
    checkDefinitionsInJs(
      "({get a() {}}); o.a",
      ImmutableSet.of("DEF GETTER_DEF null -> FUNCTION",
                      "USE GETPROP o.a -> [FUNCTION]"));
  }

  public void testDefineSet() throws Exception {
    // TODO(johnlenz): Add support for quoted properties
    checkDefinitionsInJs(
      "({set a(b) {}}); o.a",
      ImmutableSet.of("DEF NAME b -> <null>",
                      "DEF SETTER_DEF null -> FUNCTION",
                      "USE GETPROP o.a -> [FUNCTION]"));
  }

  public void testDefineFunction() throws Exception {
    checkDefinitionsInJs(
        "var a = function(){}",
        ImmutableSet.of("DEF NAME a -> FUNCTION"));

    checkDefinitionsInJs(
        "var a = function f(){}",
        ImmutableSet.of("DEF NAME f -> FUNCTION", "DEF NAME a -> FUNCTION"));

    checkDefinitionsInJs(
        "function a(){}",
        ImmutableSet.of("DEF NAME a -> FUNCTION"));

    checkDefinitionsInJs(
        "a = function(){}",
        ImmutableSet.of("DEF NAME a -> FUNCTION"));

    checkDefinitionsInJs(
        "a.b = function(){}",
        ImmutableSet.of("DEF GETPROP a.b -> FUNCTION"));

    // getelem expressions are invisible to the definition gatherer.
    checkDefinitionsInJs(
        "a[\"b\"] = function(){}",
        ImmutableSet.<String>of());

    checkDefinitionsInJs(
        "f().b = function(){}",
        ImmutableSet.of("DEF GETPROP null -> FUNCTION"));
  }

  public void testFunctionArgumentsBasic() throws Exception {
    checkDefinitionsInJs(
        "function f(a){return a}",
        ImmutableSet.of("DEF NAME a -> <null>",
                        "USE NAME a -> [<null>]",
                        "DEF NAME f -> FUNCTION"));

    checkDefinitionsInJs(
        "var a = 1; function f(a){return a}",
        ImmutableSet.of("DEF NAME a -> NUMBER",
                        "DEF NAME a -> <null>",
                        "USE NAME a -> [<null>, NUMBER]",
                        "DEF NAME f -> FUNCTION"));
  }

  public void testFunctionArgumentsInExterns() throws Exception {
    final String DEF = "var f = function(arg1, arg2){}";
    final String USE = "f(1, 2)";

    // function arguments are definitions when they appear in source.
    checkDefinitionsInJs(
        DEF + ";" + USE,
        ImmutableSet.of("DEF NAME f -> FUNCTION",
                        "DEF NAME arg1 -> <null>",
                        "DEF NAME arg2 -> <null>",
                        "USE NAME f -> [FUNCTION]"));

    // function arguments are NOT definitions when they appear in externs.
    checkDefinitions(
        DEF, USE,
        ImmutableSet.of("DEF NAME f -> EXTERN FUNCTION",
                        "USE NAME f -> [EXTERN FUNCTION]"));
  }

  public void testMultipleDefinition() throws Exception {
    checkDefinitionsInJs(
        "a = 1; a = 2; a",
        ImmutableSet.of("DEF NAME a -> NUMBER",
                        "USE NAME a -> [NUMBER x 2]"));

    checkDefinitionsInJs(
        "a = 1; a = 'a'; a",
        ImmutableSet.of("DEF NAME a -> NUMBER",
                        "DEF NAME a -> STRING",
                        "USE NAME a -> [NUMBER, STRING]"));

    checkDefinitionsInJs(
        "a = 1; b = 2; a = b; a",
        ImmutableSet.of("DEF NAME a -> <null>",
                        "DEF NAME a -> NUMBER",
                        "DEF NAME b -> NUMBER",
                        "USE NAME a -> [<null>, NUMBER]",
                        "USE NAME b -> [NUMBER]"));

    checkDefinitionsInJs(
        "a = 1; b = 2; c = b; c = a; c",
        ImmutableSet.of("DEF NAME a -> NUMBER",
                        "DEF NAME b -> NUMBER",
                        "DEF NAME c -> <null>",
                        "USE NAME a -> [NUMBER]",
                        "USE NAME b -> [NUMBER]",
                        "USE NAME c -> [<null> x 2]"));

    checkDefinitionsInJs(
        "function f(){} f()",
        ImmutableSet.of("DEF NAME f -> FUNCTION",
                        "USE NAME f -> [FUNCTION]"));

    checkDefinitionsInJs(
        "function f(){} f.call(null)",
        ImmutableSet.of("DEF NAME f -> FUNCTION",
                        "USE NAME f -> [FUNCTION]",
                        "USE GETPROP f.call -> [FUNCTION]"));

    checkDefinitionsInJs(
        "function f(){} f.apply(null, [])",
        ImmutableSet.of("DEF NAME f -> FUNCTION",
                        "USE NAME f -> [FUNCTION]",
                        "USE GETPROP f.apply -> [FUNCTION]"));

    checkDefinitionsInJs(
        "function f(){} f.foobar()",
        ImmutableSet.of("DEF NAME f -> FUNCTION",
                        "USE NAME f -> [FUNCTION]"));

    checkDefinitionsInJs(
        "function f(){} f(); f.call(null)",
        ImmutableSet.of("DEF NAME f -> FUNCTION",
                        "USE NAME f -> [FUNCTION]",
                        "USE GETPROP f.call -> [FUNCTION]"));

  }

  public void testDefinitionInExterns() throws Exception {
    String externs = "var a = 1";

    checkDefinitionsInExterns(
        externs,
        ImmutableSet.of("DEF NAME a -> EXTERN NUMBER"));

    checkDefinitions(
        externs,
        "var b = 1",
        ImmutableSet.of("DEF NAME a -> EXTERN NUMBER", "DEF NAME b -> NUMBER"));

    checkDefinitions(
        externs,
        "a = \"foo\"; a",
        ImmutableSet.of("DEF NAME a -> EXTERN NUMBER",
                        "DEF NAME a -> STRING",
                        "USE NAME a -> [EXTERN NUMBER, STRING]"));

    checkDefinitionsInExterns(
        "var a = {}; a.b = 10",
        ImmutableSet.of("DEF GETPROP a.b -> EXTERN NUMBER",
                        "DEF NAME a -> EXTERN <null>",
                        "USE NAME a -> [EXTERN <null>]"));

    checkDefinitionsInExterns(
        "var a = {}; a.b",
        ImmutableSet.of("DEF GETPROP a.b -> EXTERN <null>",
                        "DEF NAME a -> EXTERN <null>",
                        "USE NAME a -> [EXTERN <null>]"));

    checkDefinitions(
        "var a = {}",
        "a.b = 1",
        ImmutableSet.of("DEF GETPROP a.b -> NUMBER",
                        "DEF NAME a -> EXTERN <null>",
                        "USE NAME a -> [EXTERN <null>]"));

    checkDefinitions(
        "var a = {}",
        "a.b",
        ImmutableSet.of("DEF NAME a -> EXTERN <null>",
                        "USE NAME a -> [EXTERN <null>]"));

    checkDefinitionsInExterns(
        externs,
        ImmutableSet.of("DEF NAME a -> EXTERN NUMBER"));
  }

  public void testObjectLitInExterns() {
    checkDefinitions(
        "var goog = {};" +
        "/** @type {number} */ goog.HYBRID;" +
        "/** @enum */ goog.Enum = {HYBRID: 0, ROADMAP: 1};",
        "goog.HYBRID; goog.Enum.ROADMAP;",
        ImmutableSet.of(
            "DEF GETPROP goog.Enum -> EXTERN <null>",
            "DEF GETPROP goog.HYBRID -> EXTERN <null>",
            "DEF NAME goog -> EXTERN <null>",
            "DEF STRING_KEY null -> EXTERN NUMBER",
            "USE GETPROP goog.Enum -> [EXTERN <null>]",
            "USE GETPROP goog.Enum.ROADMAP -> [EXTERN NUMBER]",
            "USE GETPROP goog.HYBRID -> [EXTERN <null>, EXTERN NUMBER]",
            "USE NAME goog -> [EXTERN <null>]"));
  }

  public void testCallInExterns() {
    checkDefinitionsInExterns(
        "var goog = {};" +
        "/** @constructor */ goog.Response = function() {};" +
        "goog.Response.prototype.get;" +
        "goog.Response.prototype.get().get;",
        ImmutableSet.of(
            "DEF GETPROP goog.Response -> EXTERN FUNCTION",
            "DEF GETPROP goog.Response.prototype.get -> EXTERN <null>",
            "DEF GETPROP null -> EXTERN <null>",
            "DEF NAME goog -> EXTERN <null>",
            "USE GETPROP goog.Response -> [EXTERN FUNCTION]",
            "USE GETPROP goog.Response.prototype.get -> [EXTERN <null> x 2]",
            "USE NAME goog -> [EXTERN <null>]"));
  }

  void checkDefinitionsInExterns(String externs, Set<String> expected) {
    checkDefinitions(externs, "", expected);
  }

  void checkDefinitionsInJs(String js, Set<String> expected) {
    checkDefinitions("", js, expected);
  }

  void checkDefinitions(String externs, String source, Set<String> expected) {
    testSame(externs, source, null);
    assertEquals(expected, found);
    found.clear();
  }

  @Override
  protected CompilerPass getProcessor(Compiler compiler) {
    return new SimpleDefinitionEnumerator(compiler);
  }

  /**
   * Run SimpleDefinitionFinder, then gather a list of definitions.
   */
  private class SimpleDefinitionEnumerator
      extends AbstractPostOrderCallback implements CompilerPass {
    private final SimpleDefinitionFinder passUnderTest;
    private final Compiler compiler;

    SimpleDefinitionEnumerator(Compiler compiler) {
      this.passUnderTest = new SimpleDefinitionFinder(compiler);
      this.compiler = compiler;
    }

    @Override
    public void process(Node externs, Node root) {
      passUnderTest.process(externs, root);
      NodeTraversal.traverse(compiler, externs, this);
      NodeTraversal.traverse(compiler, root, this);

      for (DefinitionSite defSite : passUnderTest.getDefinitionSites()) {
        Node node = defSite.node;
        Definition definition = defSite.definition;
        StringBuilder sb = new StringBuilder();
        sb.append("DEF ");
        sb.append(Token.name(node.getType()));
        sb.append(" ");
        sb.append(node.getQualifiedName());
        sb.append(" -> ");

        if (definition.isExtern()) {
          sb.append("EXTERN ");
        }

        Node rValue = definition.getRValue();
        if (rValue != null) {
          sb.append(Token.name(rValue.getType()));
        } else {
          sb.append("<null>");
        }

        found.add(sb.toString());
      }

    }

    @Override
    public void visit(NodeTraversal traversal, Node node, Node parent) {
      Collection<Definition> defs =
          passUnderTest.getDefinitionsReferencedAt(node);
      if (defs != null) {
        StringBuilder sb = new StringBuilder();
        sb.append("USE ");
        sb.append(Token.name(node.getType()));
        sb.append(" ");
        sb.append(node.getQualifiedName());
        sb.append(" -> ");
        Multiset<String> defstrs = TreeMultiset.create();
        for (Definition def : defs) {
          String defstr;

          Node rValue = def.getRValue();
          if (rValue != null) {
            defstr = Token.name(rValue.getType());
          } else {
            defstr = "<null>";
          }

          if (def.isExtern()) {
            defstr = "EXTERN " + defstr;
          }

          defstrs.add(defstr);
        }

        sb.append(defstrs.toString());
        found.add(sb.toString());
      }
    }
  }
}