#pragma once
#include <new>
#include <utility>
#include <string>


/** @struct{Point}
 * @property float x : width value
 * @property float y : height value
 * @property float z : Depth value
 * @property int first_edge : offset of the first edge in memory for a point
 * @property int e_count : number of edges for a point
 */
struct Point {
    std::string name;
    float x, y, z;
    int first_edge = -1;
    int e_count = 0;
    bool is_active = false;
};


/** Edge
 * @brief Stores the end point and weight of the edge
 * @param end_point Index of the point this edge goes to. 
 * @param e_weight Weight of the edge.
 */
struct Edge {
    int end_point;
    float e_weight;
    int next_edge_index = -1;
};

/** @class Graph
 * @brief Defines the default values for the private variables 
 * @property all_points The buffer that stores all of the points in the graph
 * @property all_edges The buffer that stores all the edges in the graph
 * @property next_possible_edge The offset to the next possible edge memory location
 * @property p_capacity The total number of points able to be stored
 * @property e_capacity The total number of edges able to be stored
 */
class Graph {
private:
    Point* all_points = nullptr;
    Edge* all_edges = nullptr;

    int next_free_point = -1;
    size_t num_points = 0;

    int next_free_edge = -1;
    size_t num_edges = 0;
    
    size_t next_possible_edge = 0;
    size_t p_capacity = 0;
    size_t e_capacity = 0;


public:

    /** Constructor
	 * @brief Creates a new Graph object
	 * @param max_points Maximum number of points in the Graph
	 * @param max_edges Maximum number of edges in the GRAPH (not the point)
	 */
    Graph(size_t maxPoints, size_t maxEdges) noexcept;


    /** Deconstructor
	 * @brief Deletes all_points and all_edges from memory
	 */
    ~Graph();
    
    /** Move Constructor
	 * @brief Instructions to move the current graph object from one memory location to another without copying. 
     * @param new_location The new memory location to move the graph to. 
	 */
    Graph(Graph&& new_location) noexcept;
    
    /** Getter Function: get_points
     * @brief Gets the memory address of all of the points on given graph
     * 
     * @returns The address of the first Point in the graph
     */
    Point* get_points() noexcept;

    /** Getter Function: get_p_edges
	 * @brief Gets the address of the first edge for Point P at index p_index
	 * 
	 * @param p_index The index (int) of the point
	 * @returns Edge* : the address of the first edge for p_index
	 * */
    Edge* get_p_edges(int p_index) noexcept;

    /** add_point
     * @brief Adds a point onto the graph
     * 
     * @param name The name of the point.
     * @param x The width value
     * @param y The heighth value
     * @param z The depth value
     * @returns The memory location of the point
     */
    Point* add_point(std::string name, float x, float y, float z) noexcept;

    /** delete_point
     * @brief Removes a point from the graph
     * 
     * @param p_index The index of the point to be deleted
     * @returns True on successful deletion
     */
    bool delete_point(int p_index) noexcept;

    /** add_edge
	 * @brief Adds an edge between two points
	 * 
	 * @param e_start : the index of the starting point
	 * @param e_end : the index of the ending point
	 * 
     * @returns A pointer to the newly added edge
	 **/
    Edge* add_edge(int e_start, int e_end, float weight) noexcept;

   
    /** delete_edge
     * @brief Deletes on edge from Point A to Point B.
     * 
     * This function uses a tombstone method to decide if a point is active or just sitting in available memory
     * @param e_start The index of the starting point.
     * @param e_end The index of the ending point.
     * 
     * @return true if the edge was found and deleted
     */
    bool delete_edge(int e_start, int e_end) noexcept;
    
    //Preventing mem-spikes by preventing copying and enforcing deletions.
    Graph(const Graph&) = delete;
    Graph& operator=(const Graph&) = delete;
};