/* Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
 * Use of this file is governed by the BSD 3-clause license that
 * can be found in the LICENSE.txt file in the project root.
 */

#pragma once

#include "antlr4-common.h"

namespace antlr4 {
namespace tree {
namespace pattern {

  /// Represents the result of matching a ParseTree against a tree pattern.
  class ANTLR4CPP_PUBLIC ParseTreeMatch {
  private:
    /// This is the backing field for getTree().
    ParseTree *_tree;

    /// This is the backing field for getPattern().
    const ParseTreePattern &_pattern;

    /// This is the backing field for getLabels().
    std::map<std::string, std::vector<ParseTree *>> _labels;

    /// This is the backing field for getMismatchedNode().
    ParseTree *_mismatchedNode;

  public:
    /// <summary>
    /// Constructs a new instance of <seealso cref="ParseTreeMatch"/> from the specified
    /// parse tree and pattern.
    /// </summary>
    /// <param name="tree"> The parse tree to match against the pattern. </param>
    /// <param name="pattern"> The parse tree pattern. </param>
    /// <param name="labels"> A mapping from label names to collections of
    /// <seealso cref="ParseTree"/> objects located by the tree pattern matching process. </param>
    /// <param name="mismatchedNode"> The first node which failed to match the tree
    /// pattern during the matching process.
    /// </param>
    /// <exception cref="IllegalArgumentException"> if {@code tree} is {@code null} </exception>
    /// <exception cref="IllegalArgumentException"> if {@code pattern} is {@code null} </exception>
    /// <exception cref="IllegalArgumentException"> if {@code labels} is {@code null} </exception>
    ParseTreeMatch(ParseTree *tree, ParseTreePattern const& pattern,
                   const std::map<std::string, std::vector<ParseTree *>> &labels, ParseTree *mismatchedNode);
    ParseTreeMatch(ParseTreeMatch const&) = default;
    virtual ~ParseTreeMatch();
    ParseTreeMatch& operator=(ParseTreeMatch const&) = default;

    /// <summary>
    /// Get the last node associated with a specific {@code label}.
    /// <p/>
    /// For example, for pattern {@code <id:ID>}, {@code get("id")} returns the
    /// node matched for that {@code ID}. If more than one node
    /// matched the specified label, only the last is returned. If there is
    /// no node associated with the label, this returns {@code null}.
    /// <p/>
    /// Pattern tags like {@code <ID>} and {@code <expr>} without labels are
    /// considered to be labeled with {@code ID} and {@code expr}, respectively.
    /// </summary>
    /// <param name="labe"> The label to check.
    /// </param>
    /// <returns> The last <seealso cref="ParseTree"/> to match a tag with the specified
    /// label, or {@code null} if no parse tree matched a tag with the label. </returns>
    virtual ParseTree* get(const std::string &label);

    /// <summary>
    /// Return all nodes matching a rule or token tag with the specified label.
    /// <p/>
    /// If the {@code label} is the name of a parser rule or token in the
    /// grammar, the resulting list will contain both the parse trees matching
    /// rule or tags explicitly labeled with the label and the complete set of
    /// parse trees matching the labeled and unlabeled tags in the pattern for
    /// the parser rule or token. For example, if {@code label} is {@code "foo"},
    /// the result will contain <em>all</em> of the following.
    ///
    /// <ul>
    /// <li>Parse tree nodes matching tags of the form {@code <foo:anyRuleName>} and
    /// {@code <foo:AnyTokenName>}.</li>
    /// <li>Parse tree nodes matching tags of the form {@code <anyLabel:foo>}.</li>
    /// <li>Parse tree nodes matching tags of the form {@code <foo>}.</li>
    /// </ul>
    /// </summary>
    /// <param name="labe"> The label.
    /// </param>
    /// <returns> A collection of all <seealso cref="ParseTree"/> nodes matching tags with
    /// the specified {@code label}. If no nodes matched the label, an empty list
    /// is returned. </returns>
    virtual std::vector<ParseTree *> getAll(const std::string &label);

    /// <summary>
    /// Return a mapping from label &rarr; [list of nodes].
    /// <p/>
    /// The map includes special entries corresponding to the names of rules and
    /// tokens referenced in tags in the original pattern. For additional
    /// information, see the description of <seealso cref="#getAll(String)"/>.
    /// </summary>
    /// <returns> A mapping from labels to parse tree nodes. If the parse tree
    /// pattern did not contain any rule or token tags, this map will be empty. </returns>
    virtual std::map<std::string, std::vector<ParseTree *>>& getLabels();

    /// <summary>
    /// Get the node at which we first detected a mismatch.
    /// </summary>
    /// <returns> the node at which we first detected a mismatch, or {@code null}
    /// if the match was successful. </returns>
    virtual ParseTree* getMismatchedNode();

    /// <summary>
    /// Gets a value indicating whether the match operation succeeded.
    /// </summary>
    /// <returns> {@code true} if the match operation succeeded; otherwise,
    /// {@code false}. </returns>
    virtual bool succeeded();

    /// <summary>
    /// Get the tree pattern we are matching against.
    /// </summary>
    /// <returns> The tree pattern we are matching against. </returns>
    virtual const ParseTreePattern& getPattern();

    /// <summary>
    /// Get the parse tree we are trying to match to a pattern.
    /// </summary>
    /// <returns> The <seealso cref="ParseTree"/> we are trying to match to a pattern. </returns>
    virtual ParseTree* getTree();

    virtual std::string toString();
  };

} // namespace pattern
} // namespace tree
} // namespace antlr4
