// 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.

#include "cc/game.h"

#include "absl/memory/memory.h"

#include "absl/strings/str_cat.h"

#include "absl/strings/str_format.h"

#include "cc/logging.h"

namespace minigo {

std::ostream& operator<<(std::ostream& os, const Game::Options& options) {

os << "resign_threshold:" << options.resign_threshold

<< " resign_enabled:" << options.resign_enabled << " komi:" << options.komi

<< " ignore_repeated_moves:" << options.ignore_repeated_moves;

return os;

}

std::string Game::FormatScore(float score) {

return absl::StrFormat("%c+%.1f", score > 0 ? 'B' : 'W', std::abs(score));

}

Game::Game(std::string black_name, std::string white_name,

const Game::Options& options)

: options_(options),

black_name_(std::move(black_name)),

white_name_(std::move(white_name)) {

MG_CHECK(options_.resign_threshold < 0);

}

void Game::NewGame() {

game_over_ = false;

moves_.clear();

comment_.clear();

}

void Game::AddComment(const std::string& comment) {

if (comment_.empty()) {

comment_ = comment;

} else {

absl::StrAppend(&comment_, "\n", comment);

}

}

void Game::AddMove(Color color, Coord c, const Position::Stones& stones,

std::string comment, float Q,

const std::array<float, kNumMoves>& search_pi,

std::vector<std::string> models) {

if (!moves_.empty() && moves_.back()->color == color &&

moves_.back()->c == c) {

MG_CHECK(options_.ignore_repeated_moves)

<< "Repeated call to AddMove with same (color, coord) (" << color

<< ", " << c << ") and ignore_repeated_moves is false";

return;

}

MG_CHECK(!game_over_);

moves_.push_back(absl::make_unique<Move>());

auto* move = moves_.back().get();

move->color = color;

move->c = c;

move->Q = Q;

move->comment = std::move(comment);

move->models = std::move(models);

move->search_pi = search_pi;

move->stones = stones;

}

void Game::UndoMove() {

MG_CHECK(!moves_.empty());

moves_.pop_back();

game_over_ = false;

}

void Game::SetGameOverBecauseOfPasses(float score) {

MG_CHECK(!game_over_);

game_over_ = true;

game_over_reason_ = GameOverReason::kBothPassed;

result_ = score < 0 ? -1 : score > 0 ? 1 : 0;

result_string_ = FormatScore(score);

}

void Game::SetGameOverBecauseOfResign(Color winner) {

MG_CHECK(!game_over_);

game_over_ = true;

game_over_reason_ = GameOverReason::kOpponentResigned;

if (winner == Color::kBlack) {

result_ = 1;

result_string_ = "B+R";

} else {

result_ = -1;

result_string_ = "W+R";

}

}

void Game::SetGameOverBecauseMoveLimitReached(float score) {

MG_CHECK(!game_over_);

game_over_ = true;

game_over_reason_ = GameOverReason::kMoveLimitReached;

result_ = score < 0 ? -1 : score > 0 ? 1 : 0;

result_string_ = FormatScore(score);

}

void Game::GetStoneHistory(

int move, int num_moves,

std::vector<const Position::Stones*>* history) const {

history->clear();

history->reserve(num_moves);

MG_CHECK(move >= 0);

MG_CHECK(move < static_cast<int>(moves_.size()));

for (int i = 0; i < num_moves && move - i >= 0; ++i) {

history->push_back(&moves_[move - i]->stones);

}

}

bool Game::FindBleakestMove(int* move, float* q) const {

if (!game_over_) {

MG_LOG(ERROR) << "game isn't over";

return false;

}

if (options_.resign_enabled || moves_.empty()) {

return false;

}

// Find the move at which the game looked the bleakest from the perspective

// of the winner.

float bleakest_eval = moves_[0]->Q * result_;

size_t bleakest_move = 0;

for (size_t i = 1; i < moves_.size(); ++i) {

float eval = moves_[i]->Q * result_;

if (eval < bleakest_eval) {

bleakest_eval = eval;

bleakest_move = i;

}

}

*move = static_cast<int>(bleakest_move);

*q = bleakest_eval;

return true;

}

} // namespace minigo