#include <fstream>
#include <iostream>
#include <string>
#include <stdexcept>

class cell{
    private:
        int x, y;
        bool isWall;
        bool isExit;
        bool isStart;

    public:
        cell(){x=0; y=0; isWall=false; isExit=false; isStart = false;}
        cell(int x, int y, bool isWall, bool isExit, bool isStart)
            {
                this->x = x;
                this->y = y;
                this->isWall = isWall;
                this->isExit = isExit;
                this->isStart = isStart;
            }

        bool isPassable() {return !isWall;}

        void setStart(bool value) {isStart = value;}
        void setExit(bool value) {isExit = value;}
        void setX(int x) {this->x = x;}
        void setY(int y) {this->y = y;}
        void setIsWall(bool isWall) {this->isWall = isWall;}


        int  getX() {return x;}
        int  getY() {return y;}
        bool getIsWall() {return isWall;}
        bool getIsExit() {return isExit;}
        bool getIsStart() {return isStart;}

};


class maze{
    private:
        int width;
        int height;
        cell** matrix;

        cell* start;
        cell* exit;

    public:
        maze(int width, int height)
        {
            this->width = width;
            this->height = height;
            this->start = nullptr;
            this->exit = nullptr;

            matrix = new cell*[width];

            for (int x = 0; x < width; ++x) {
                matrix[x] = new cell[height];
                for (int y = 0; y < height; ++y) 
                    matrix[x][y] = cell(x, y, false, false, false);
            }
        }
        maze(int width, int height, int startX, int startY, int exitX, int exitY)
        {
            this->width = width;
            this->height = height;
            this->start = nullptr;
            this->exit = nullptr;

            matrix = new cell*[width];
            for (int x = 0; x < width; ++x) {
                matrix[x] = new cell[height];
                for (int y = 0; y < height; ++y) {
                    matrix[x][y] = cell(x, y, false, false, false);
                }
            }


            matrix[startX][startY].setStart(true);
            matrix[exitX][exitY].setExit(true);

            start = &matrix[startX][startY];
            exit = &matrix[exitX][exitY];
        }

        ~maze()
        {
        for (int i = 0; i < width; ++i) 
            delete[] matrix[i];
        delete[] matrix;
        }

        cell* getCell(int x, int y) {
            if (x < 0 || x >= width || y < 0 || y >= height)
                return nullptr;

            return &matrix[x][y];
        }
        void setCell(int x, int y, cell newCell) {
            if (x < 0 || x >= width || y < 0 || y >= height)
                return;

            matrix[x][y] = newCell;

            if (matrix[x][y].getIsStart())
                start = &matrix[x][y];

            if (matrix[x][y].getIsExit())
                exit = &matrix[x][y];
        }

        cell** getNeighbors(cell* current) { /*ДЕЛАТЬ delete[] neighbors; !!!!!!!!!!!!!!!*/
            cell** neighbors = new cell*[5];
            int count = 0;

            int x = current->getX();
            int y = current->getY();

            cell* up = getCell(x, y - 1);
            cell* down = getCell(x, y + 1);
            cell* left = getCell(x - 1, y);
            cell* right = getCell(x + 1, y);

            if (up != nullptr && up->isPassable()) {
                neighbors[count] = up;
                count++;}

            if (down != nullptr && down->isPassable()) {
                neighbors[count] = down;
                count++;}

            if (left != nullptr && left->isPassable()) {
                neighbors[count] = left;
                count++;}

            if (right != nullptr && right->isPassable()) {
                neighbors[count] = right;
                count++;}
            
            neighbors[count] = nullptr;

            return neighbors;
        }

        cell* getStart() {return start;}
        cell* getExit() {return exit;}
        int getWidth() {return width;}
        int getHeight() {return height;}        
};

class MazeBuilder {
    public:
        virtual maze* buildFromFile(const std::string& filename) = 0;
        virtual ~MazeBuilder() {}
};

class TextFileMazeBuilder : public MazeBuilder {
    public:
        maze* buildFromFile(const std::string& filename) override
        {

            std::ifstream file(filename);
            if (!file.is_open())
                throw std::runtime_error("Ошибка: Не удалось открыть файл!");

            std::string line;
            int width = 0;
            int height = 0;

            // ДОБАВИЛ: первый проход по файлу.
            // Здесь узнаём ширину и высоту лабиринта.
            while (std::getline(file, line)) {
                if (height == 0) {
                    width = line.length();
                }
                else {
                    if (line.length() != width)
                        throw std::runtime_error("Ошибка: строки лабиринта разной длины!");
                }
                height++;
            }

            if (width == 0 || height == 0) {
                throw std::runtime_error("Ошибка: файл пустой!");
            }

            file.clear();
            file.seekg(0);

            maze* labirint = new maze(width, height);
            bool hasStart = false;
            bool hasExit = false;
            int y = 0;


            while (std::getline(file, line)) {

                for (int x = 0; x < width; x++) {
                    char ch = line[x];

                    bool isWall = false;
                    bool isStart = false;
                    bool isExit = false;

                    switch(ch){
                        case '#':
                            isWall = true;
                            break;
                        case ' ':
                            isWall = false;
                            break;
                        case 'S':
                            isStart = true;

                            if (hasStart)
                                throw std::runtime_error("Ошибка: в лабиринте больше одного старта!");

                            hasStart = true;
                            break;
                        case 'E':
                            isExit = true;

                            if (hasExit)
                                throw std::runtime_error("Ошибка: в лабиринте больше одного выхода!");
                            hasExit = true;
                            break;
                        default:
                            throw std::runtime_error("Ошибка: неизвестный символ в файле!");
                            break;
                    }

                    cell current(x, y, isWall, isExit, isStart);
                    labirint->setCell(x, y, current);
                }

                y++;
            }
            file.close();
            if (!hasStart)
                throw std::runtime_error("Ошибка: в лабиринте нет старта!");
            if (!hasExit)
                throw std::runtime_error("Ошибка: в лабиринте нет выхода!");
            return labirint;

        }

        // прочитать символы
        // создать клетки
        // вернуть готовый Maze
    }
};


class PathFindingStrategy {
    public:
        virtual cell** findPath(maze* m, cell* start, cell* exit) = 0;
        virtual ~PathFindingStrategy() {}
};

class PathBuilder {
    public:
        static cell** buildPath(cell* start, cell* exit, cell*** parent) {
            int length = 0;
            cell* current = exit;

            while (current != nullptr) {
                length++;
                if (current == start)
                    break;
                current = parent[current->getX()][current->getY()];
            }

            cell** path = new cell*[length + 1];
            current = exit;

            for (int i = length - 1; i >= 0; i--) {
                path[i] = current;
                if (current == start)
                    break;
                current = parent[current->getX()][current->getY()];
            }
            path[length] = nullptr;
            return path;
        }
};

class BFSStrategy : public PathFindingStrategy {
    public:
        cell** findPath(maze* m, cell* start, cell* exit) override {
            int width = m->getWidth();
            int height = m->getHeight();
            bool** visited = new bool*[width];
            cell*** parent = new cell**[width];

            for (int x = 0; x < width; x++) {
                visited[x] = new bool[height];
                parent[x] = new cell*[height];

                for (int y = 0; y < height; y++) {
                    visited[x][y] = false;
                    parent[x][y] = nullptr;
                }
            }

            cell** deque = new cell*[width * height];
            int head = 0;
            int tail = 0;

            deque[tail] = start;
            tail++;
            visited[start->getX()][start->getY()] = true;
            bool found = false;

            while (head < tail) {
                cell* current = deque[head];
                head++;

                if (current == exit) { //сравниваются указатели
                    found = true;
                    break;
                }

                cell** neighbors = m->getNeighbors(current);

                for (int i = 0; neighbors[i] != nullptr; i++) {
                    cell* next = neighbors[i];

                    int nx = next->getX();
                    int ny = next->getY();

                    if (!visited[nx][ny]) {
                        visited[nx][ny] = true;
                        parent[nx][ny] = current;

                        deque[tail] = next;
                        tail++;
                    }
                }
                delete[] neighbors;
            }

            cell** path;
            
            if (found) {
                path = PathBuilder::buildPath(start, exit, parent);
            } 
            else {
                path = new cell*[1];
                path[0] = nullptr;
            }

            delete[] deque;

            for (int x = 0; x < width; x++) {
                delete[] visited[x];
                delete[] parent[x];
            }
            delete[] visited;
            delete[] parent;
            return path;
        }
};

class DFSStrategy : public PathFindingStrategy {
    public:
        cell** findPath(maze* m, cell* start, cell* exit) override {
            int width = m->getWidth();
            int height = m->getHeight();
            bool** visited = new bool*[width];
            cell*** parent = new cell**[width];

            
            cell** stack = new cell*[width * height];
            int top = 0;
            for (int x = 0; x < width; x++) {
                visited[x] = new bool[height];
                parent[x] = new cell*[height];

                for (int y = 0; y < height; y++) {
                    visited[x][y] = false;
                    parent[x][y] = nullptr;
                }
            }

            stack[top] = start;
            top++;
            visited[start->getX()][start->getY()] = true;
            bool found = false;

            while (top > 0) {
                top--;
                cell* current = stack[top];

                if (current == exit) { //сравниваются указатели
                    found = true;
                    break;
                }

                cell** neighbors = m->getNeighbors(current);

                for (int i = 0; neighbors[i] != nullptr; i++) {
                    cell* next = neighbors[i];

                    int nx = next->getX();
                    int ny = next->getY();

                    if (!visited[nx][ny]) {
                        visited[nx][ny] = true;
                        parent[nx][ny] = current;

                        stack[top] = next;
                        top++;
                    }
                }
                delete[] neighbors;
            }

            cell** path;
            
            if (found) {
                path = PathBuilder::buildPath(start, exit, parent);
            } 
            else {
                path = new cell*[1];
                path[0] = nullptr;
            }

            delete[] stack;

            for (int x = 0; x < width; x++) {
                delete[] visited[x];
                delete[] parent[x];
            }
            delete[] visited;
            delete[] parent;
            return path;
        }
};

class AStarStrategy : public PathFindingStrategy {
    public:
        cell** findPath(maze* m, cell* start, cell* exit) override {
            // здесь будет алгоритм A*
        }
};


int main(){

}