#ifndef TOOL_H
#define TOOL_H


#include <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 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; }

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

class ConeTool: public Tool {
public:
    Real radius;
    Real height;
    Real cut_radius;
    
    explicit ConeTool(Real radius = 0.5, Real height = 1, Real cut_radius = 0):
        radius(radius), height(height), cut_radius(cut_radius) { }

    Real get_radius() const override
        { return radius; }
    Real get_height(Real offset) const  override {
        Real r = fabs(radius);
        offset = fabs(offset);
        if (!(offset < r)) return INFINITY;
        Real cr = fabs(cut_radius);
        if (offset <= cr) return 0;
        Real h = fabs(height);
        if (h < precision) return 0;
        return height*(offset - cr)/(r - cr);
    }

    Real get_height_polar(Real distance, Real offset, Real angle) const override {
        if (distance < 1e-5) return 1e-5;

        offset = fabs(offset);
        angle = fabs(angle);
        Real r = fabs(radius);
        Real cr = fabs(cut_radius);
        Real h = fabs(height);
        if (h <= precision) cr = r;

        if (!(offset <= r)) return INFINITY;
        Real t2 = tan(angle)*distance; t2 *= t2;
        Real r2 = cr*cr - offset*offset;
        if (t2 <= r2) return sqrt(distance*distance + t2);
        
        if (h <= precision) return INFINITY;

        Real tt2 = tan(angle)*(distance + h); tt2 *= tt2;
        Real rr2 = radius*radius - offset*offset;
        if (!(t2 <= rr2)) return INFINITY;

        Real c = cos(angle);
        Real s = sin(angle);
        
        Real kz = (1 - cr)/h;
        Real kz2 = kz*kz;
        Real d = distance - cr/kz;
        if (d < precision) return INFINITY;
        
        Real A = kz2*c*c - s*s;
        Real B = -2*kz2*d*c;
        Real C = kz2*d*d - offset*offset;
        
        Real roots[2];
        int count = solve(roots, C, B, A);
        for(int i = 0; i < count; ++i)
            if (roots[i]*c > distance && roots[i] > distance)
                return roots[i];
        
        return INFINITY;
    }

    Shape* create_collision_shape(const Vector3 &pos, const Vector3 &dir) const override {
        return new ConeShape(pos, dir, radius, height, cut_radius);
    }
    
    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