/**
 * Defines a mesh, ready to be OpenGL-rendered
 **/

#pragma once

#include <vector>
#include <unordered_map>
#include <cstddef>  // size_t
#include "common_structures.hpp"

class Mesh {
    public:
        Mesh();

        /// Adds a fresh vertice at `pt`, and returns its ID for further use
        size_t add_vertice(const Point& pt);
        size_t add_vertice(const Point& pt, const Point& normal);

        /// Creates a new face out of the three given point IDs
        void add_face(const Face& face);
        void add_face(size_t f1, size_t f2, size_t f3);

        /// Center manipulation
        const Point& get_center() const;
        void set_center(const Point& pt);
        void translate(const Point& tr); ///< Translate by the vector `tr`

        /** Translates the vertices to make (0, 0, 0) the mesh's barycenter.
         * If `keep_position == true`, this also sets the center to the
         * previous barycenter.
         */
        void normalize_center(bool keep_position=false);

        /// Get the normal vector for vertice `vert_id`
        const Point& get_normal(size_t vert_id);

        /// Gets the various vertices
        const std::vector<Point>& get_vertices() const;

        /// Gets the various faces
        const std::vector<Face>& get_faces() const;

        const Color& get_color() const { return color; }
        void set_color(const Color& _color) { color = _color; }

    private: //struct
        struct NormalVect {
            NormalVect(const Point& vect, bool manual=false)
                : vect(vect), dirty(false), manual(manual) {}
            NormalVect()
                : vect(Point(0., 0., 0.)), dirty(true), manual(false) {}
            Point vect;
            bool dirty;
            bool manual;
        };

    private: //meth
        size_t inner_add_vertice(const Point& pt, const NormalVect& normal);
        void compute_normal(size_t vert);

    private:
        std::vector<Point> vertices;
        std::vector<NormalVect> normals;
        std::vector<Face> faces;
        std::vector<std::vector<size_t> > faces_with_vert;

        Point center;
        Color color;
};