#include "game.h"

#include "hand.h"

void Game::Player::round_start() {
	// Reset contents.
	hand.clear();
	open.clear();
	pond.clear();
	riichi = false;
	
	// Notify client of round start.
	client->round_start();
}

PlayerState Game::Player::get_state() {
	Tilegroups h = open;
	h.insert(h.begin(), hand);
	
	PlayerState state = {h, pond};
	return state;
}

PlayerState Game::Player::get_state_filtered() {
	Tilegroups h = open;
	h.insert(h.begin(), hand);
	
	PlayerState state = {h, pond};
	return state;
}

Actions Game::Player::get_actions_draw() {
	Actions possible_actions;
	
	// Check if player can force a draw.
	// Check if player can tsumo.
	if(can_tsumo()) {
		possible_actions.push_back(Action(Action::Tsumo));
	}
	
	// Check if player can declare a concealed kan or extend an open pon. List all possibilities.
	
	if(!riichi) {
		// Check if player can riichi.
		if(can_riichi()) {
			possible_actions.push_back(Action(Action::Riichi));
		}
		
		// List all tiles that can be discarded.
		for(std::size_t i = 0; i < hand.size(); i++) {
			possible_actions.push_back(Action(Action::Discard, Action::Hand, i));
		}
	
	} else {
		// Only tile that can be discarded is the last drawn one.
		possible_actions.push_back(Action(Action::Discard, Action::Hand, hand.size() - 1));
	}
	
	return possible_actions;
}

Actions Game::Player::get_actions_discard(Tile tile, PlayerNum discarder) {
	Actions possible_actions;
	
	if(!riichi) {
		// Check if tile can be called for a chi. Enumerate all combinations.
		if(discarder == 3) {
			Targets targets = can_chi(tile);
			if(!targets.empty()) {
				for(Targets::iterator it = targets.begin(); it != targets.end(); it++) {
					possible_actions.push_back(Action(Action::Chi, Action::Hand, *it));
				}
			}
		}
		
		// Check if tile can be called for a pon.
		int target = can_pon(tile);
		if(target > 0) {
			possible_actions.push_back(Action(Action::Pon, Action::Hand, target + 1));
			
			// Check if tile can be called for a kan.
			if(can_kan(tile, target)) {
				possible_actions.push_back(Action(Action::Kan, Action::Hand, target + 2));
			}
		}
	}
	
	// Check if tile can be ron-ed.
	if(can_ron(tile)) {
		possible_actions.push_back(Action(Action::Ron));
	}
	
	// If any action is possible, add option to pass.
	if(possible_actions) {
		possible_actions.push_back(Action::Pass);
	}
	
	return possible_actions;
}

bool Game::Player::can_riichi() {
	if(open) {
		return false;
	}
	
	Tiles tiles = hand;
	
	tiles.sort();
	
	// Take first tile out of the set.
	Tile out = tiles.front();
	tiles.erase(tiles.begin());
	
	// Iterate over the rest of the set, exchanging the tile until a tenpai is found or all is tested.
	for(Tiles::iterator it = tiles.begin(); it != tiles.end(); it++) {
		if(Hand::tenpai(tiles)) {
			return true;
		}
		
		// TODO: Skip unnecessary tests if player got several equal tiles on hand.
		
		std::swap(*it, out);
	}
	
	return false;
}

Game::Player::Targets Game::Player::can_chi(Tile tile) {
	Targets targets;
	
	Tile::Set set = tile.get_set();
	int num = tile.get_num();
	
	// Check if tile actually can be chi-ed.
	if(set == Tile::Honor) {
		return targets;
	}
	
	bool have_above = false;
	
	// Check if we have tile below.
	Tiles::iterator it = std::find(hand.begin(), hand.end(), Tile(set, num - 1));
	if(num > 1 && it != hand.end()) {
		
		// Check if we also have tile below tile below.
		Tiles::iterator it2 = std::find(hand.begin(), hand.end(), Tile(set, num - 2));
		if(num > 2 && it2 != hand.end()) {
			targets.push_back(it2 - hand.begin()); // (T-2 T-1 T)
		}
		
		// Check if we have tile above.
		it2 = std::find(hand.begin(), hand.end(), Tile(set, num + 1));
		if(num < 9 && it2 != hand.end()) {
			targets.push_back(it - hand.begin()); // (T-1 T T+1)
			have_above = true;
			it = it2;
		}
	}
	
	// Check if we have tile above.
	if(have_above || (it = std::find(hand.begin(), hand.end(), Tile(set, num + 1))) != hand.end()) {
		// Check if we have tile above tile above.
		Tiles::iterator it2 = std::find(hand.begin(), hand.end(), Tile(set, num + 2));
		if(num < 8 && it2 != hand.end()) {
			targets.push_back(it - hand.begin()); // (T T+1 T+2)
		}
	}
	
	return targets;
}

int Game::Player::can_pon(Tile tile) {
	Tiles::iterator it = std::find(hand.begin(), hand.end(), tile);
	if(it + 1 < hand.end() && it[1] == tile) {
		return it - hand.begin();
	}
	
	return -1;
}

//Game::Player::Targets Game::Player::can_kan() {
//	return Targets(); // TODO
//}

bool Game::Player::can_kan(Tile tile, int target) {
	if(std::size_t(target + 2) < hand.size() && hand[target + 2] == tile) {
		return true;
	}
	return false;
}

bool Game::Player::can_tsumo() {
	Tiles tiles = hand;
	tiles.sort();
	return Hand::agari(tiles);
}

bool Game::Player::can_ron(Tile tile) {
	Tiles tiles = hand;
	tiles.push_back(tile);
	tiles.sort();
	return Hand::agari(tiles);
}

void Game::Player::draw(Tile tile) {
	hand.push_back(tile);
}

void Game::Player::discard(int target) {
	Tile tile = hand[target];
	hand.erase(hand.begin() + target);
	hand.sort();
	pond.push_back(tile);
}

Tile Game::Player::last_discard() {
	return pond.back();
}

Tile Game::Player::claim() {
	Tile& t = pond.back();
	t.invisible = true;
	return t;
}

void Game::Player::make_chi(Tile tile, int target) {
	Tiles chi;
	
	tile.rotated = true;
	chi.push_back(tile);
	
	Tile::Set set = tile.get_set();
	int num = tile.get_num();
	
	Tiles::iterator it = hand.begin();
	
	switch(hand[target].get_num() - num) {
		case -2:
			it = std::find(it, hand.end(), Tile(set, num - 2));
			chi.push_back(*it);
			it = hand.erase(it);
		
		case -1:
			it = std::find(it, hand.end(), Tile(set, num - 1));
			chi.push_back(*it);
			it = hand.erase(it);
			
		case 1:
			if(chi.size() == 3) {
				break;
			}
			
			it = std::find(it, hand.end(), Tile(set, num + 1));
			chi.push_back(*it);
			it = hand.erase(it);
			
			if(chi.size() == 3) {
				break;
			}
			
			it = std::find(it, hand.end(), Tile(set, num + 2));
			chi.push_back(*it);
			hand.erase(it);
	}
	
	open.push_back(chi);
}

void Game::Player::make_pon(Tile tile, int target, PlayerNum discarder) {
	Tiles pon;
	
	tile.rotated = true;
	
	if(discarder == 3) {
		pon.push_back(tile);
	}
	
	pon.push_back(hand[target]);
	hand.del(target);
	
	if(discarder == 2) {
		pon.push_back(tile);
	}
	
	pon.push_back(hand[target]);
	hand.del(target);
	
	if(discarder == 1) {
		pon.push_back(tile);
	}
	
	open.push_back(pon);
}

void Game::Player::make_kan(Tile tile, int target, PlayerNum discarder) {
	Tiles kan;
	
	tile.rotated = true;
	
	if(discarder == 3) {
		kan.push_back(tile);
	}
	
	kan.push_back(hand[target]);
	hand.del(target);
	
	if(discarder == 2) {
		kan.push_back(tile);
	}
	
	kan.push_back(hand[target]);
	hand.del(target);
	
	kan.push_back(hand[target]);
	hand.del(target);
	
	if(discarder == 1) {
		kan.push_back(tile);
	}
	
	open.push_back(kan);
}