// Copyright 2018 Google LLC

//

// 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.

#ifndef CC_SGF_H_

#define CC_SGF_H_

#include <iostream>

#include <memory>

#include <string>

#include <utility>

#include <vector>

#include "absl/strings/string_view.h"

#include "absl/types/span.h"

#include "cc/color.h"

#include "cc/coord.h"

#include "cc/move.h"

namespace minigo {

namespace sgf {

constexpr char kProgramIdentifier[] = "Minigo";

// Abstract syntax tree for an SGF file.

// The Ast class just holds the structure and contents of the tree and doesn't

// infer any meaning from the property IDs or values.

class Ast {

public:

struct Property {

std::string ToString() const;

absl::string_view id;

std::vector<absl::string_view> values;

};

struct Node {

std::string ToString() const;

const Property* FindProperty(absl::string_view id) const;

std::vector<Property> properties;

};

struct Tree {

std::string ToString() const;

std::vector<Node> nodes;

std::vector<Tree> children;

};

// Parses the SGF file.

__attribute__((warn_unused_result)) bool Parse(std::string contents);

// Returns a non-empty string containing error information if the most recent

// call to Parse returned false.

const std::string& error() const { return error_; }

const std::vector<Tree>& trees() const { return trees_; }

private:

std::string error_;

std::vector<Tree> trees_;

std::string contents_;

};

// A single move with a (possibly empty) comment.

struct MoveWithComment {

MoveWithComment() = default;

MoveWithComment(Move move, std::string comment)

: move(move), comment(std::move(comment)) {}

MoveWithComment(Color color, Coord c, std::string comment)

: move(color, c), comment(std::move(comment)) {}

// MoveWithComment is convertible to a Move for ease of use.

operator Move() const { return move; }

Move move;

std::string comment;

bool operator==(const MoveWithComment& other) const {

return move == other.move && comment == other.comment;

}

};

std::ostream& operator<<(std::ostream& ios, const MoveWithComment& move);

struct CreateSgfOptions {

std::string black_name = kProgramIdentifier;

std::string white_name = kProgramIdentifier;

std::string ruleset = "Chinese";

float komi = 7.5;

std::string result;

};

// Returns a valid SGF file for the given move sequence.

std::string CreateSgfString(absl::Span<const MoveWithComment> moves,

const CreateSgfOptions& options);

// Extracts the main line series of moves from a SGF AST tree.

std::vector<Move> GetMainLineMoves(const Ast::Tree& tree);

// Extracts the main line series of moves from the first tree in an SGF file.

// Returns an empty vector if the AST has no trees.

inline std::vector<Move> GetMainLineMoves(const Ast& ast) {

if (ast.trees().empty()) {

return {};

}

return GetMainLineMoves(ast.trees()[0]);

}

} // namespace sgf

} // namespace minigo

#endif // CC_SGF_H_