#ifndef TOOL_H

#define TOOL_H

#include <cassert></cassert>

#include "raster.h"

#include "shape.h"

class Tool {

public:

    virtual ~Tool() { }

    virtual Real get_radius() const = 0; // must be >= 0

    virtual Real get_height(Real offset) const = 0; // must be >= 0

    virtual void calc_collision(

        Real plane_k,

        Real &tool_height,

        Real &collision_height,

        Real &collision_offset ) const = 0;

    virtual Real get_height_polar(Real distance, Real offset, Real angle) const { // must be >= distance

        // not exact solution, only for small angles

        if (distance < 1e-5) return 1e-5;

        Vector2 v(offset, tan(angle)*distance);

        return sqrt(distance*distance + v.y*v.y) + get_height(v.len());

    }

    virtual Shape* create_collision_shape(const Vector3 &pos, const Vector3 &dir) const = 0;

    virtual void draw(const Vector3 &pos, const Vector3 &dir) const = 0;

};

class FlatTool: public Tool {

public:

    Real radius;

    explicit FlatTool(Real radius = 0.5):

        radius(radius) { }

    Real get_radius() const override

        { return radius; }

    Real get_height(Real offset) const  override

        { return fabs(offset) <= fabs(radius) ? 0 : INFINITY; }

    void calc_collision(

        Real plane_k,

        Real &tool_height,

        Real &collision_height,

        Real &collision_offset

    ) const override

    {

        tool_height = 0;

        collision_height = 0;

        collision_offset = 0;

        if (plane_k <= 1e-5) return;

        tool_height = collision_height = radius*plane_k;

        collision_offset = radius;

    }

    Real get_height_polar(Real distance, Real offset, Real angle) const override {

        if (distance < 1e-5) return 1e-5;

        if (!(fabs(offset) <= fabs(radius))) return INFINITY;

        Real t2 = tan(angle)*distance; t2 *= t2;

        Real r2 = radius*radius - offset*offset;

        return t2 <= r2 ? sqrt(distance*distance + t2) : INFINITY;

    }

    Shape* create_collision_shape(const Vector3 &pos, const Vector3 &dir) const override {

        return new CilinderShape(radius, pos, dir);

    }

    void draw(const Vector3 &pos, const Vector3 &dir) const override;

};

class ToolPainter: public Painter {

public:

    const Tool *tool;

    Vector2 scale;

    Real distance;

    explicit ToolPainter(const Tool *tool = 0, const Vector2 scale = Vector2(1, 1)):

        tool(tool), scale(scale), distance() { }

    Real get_min_height() const override

        { return distance; }

    Vector2 get_radius_xy() const override {

        if (!tool) return Vector2();

        Vector2 rxy = get_tool_radius_xy();

        return Vector2(rxy.x/scale.x, rxy.y/scale.y);

    }

    Real get_height_xy(const Vector2 &offset) const override {

        if (!tool) return INFINITY;

        return get_tool_height_xy(Vector2(offset.x*scale.x, offset.y*scale.y));

    }

    virtual Vector2 get_tool_radius_xy() const = 0;

    virtual Real get_tool_height_xy(const Vector2 &offset) const = 0;

};

class FlatToolPainter: public ToolPainter {

    using ToolPainter::ToolPainter; // parent constructors

    Vector2 get_tool_radius_xy() const override {

        Real r = tool->get_radius();

        return Vector2(r, r);

    }

    Real get_tool_height_xy(const Vector2 &offset) const override

        { return distance + tool->get_height(offset.len()); }

};

class PolarToolPainter: public ToolPainter {

public:

    int coord;

    explicit PolarToolPainter(const Tool *tool = 0, const Vector2 scale = Vector2(1, 1), int coord = 0):

        ToolPainter(tool, scale), coord(coord) { }

    Vector2 get_tool_radius_xy() const override {

        assert(coord > 0 && coord < 2);

        Real r = tool->get_radius();

        Vector2 rxy(r, r);

        rxy.c[coord] = distance > 1e-5 ? rxy.c[coord]/distance : INFINITY;

        return rxy;

    }

    Real get_tool_height_xy(const Vector2 &offset) const override {

        if (!tool) return INFINITY;

        assert(coord > 0 && coord < 2);

        return tool->get_height_polar(distance, offset.c[1-coord], offset.c[coord]);

    }

};

#endif