//
// Test our fractional crate / module...
//
// Georg Hopp <georg@steffers.org>
//
// Copyright © 2019 Georg Hopp
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.
//
use std::convert::{TryFrom, TryInto, Into};
use std::f64::consts::PI as FPI;
use std::fmt::{Debug, Display};
use std::marker::Send;
use std::num::TryFromIntError;
use std::ops::{Add,Sub,Neg,Mul,Div};
use std::sync::mpsc;
use std::thread;
use std::time::{Duration, Instant};

use fractional::continuous::Continuous;
use fractional::easel::{ Coordinate, Coordinates, Drawable, Line, Polyline
                       , Polygon, Canvas, Fillable };
use fractional::fractional::{Fractional, from_vector};
use fractional::trigonometry::Trig;
use fractional::vector::Vector;
use fractional::transform::{TMatrix, Transformable};

use fractional::xcb::{XcbEasel, XcbCanvas};

use fractional::geometry::{Camera,DirectLight,Polyeder,Primitives};

fn mean(v: &Vec<i64>) -> Result<Fractional, TryFromIntError> {
    let r = v.iter().fold(0, |acc, x| acc + x);
    let l = i64::try_from(v.len())?;
    Ok(Fractional(r, l))
}

fn common_fractional() {
    let a = vec![3, 6, 1, 9];
    let b = from_vector(&a);
    let c = mean(&a).unwrap(); // This might fail if the len of the
                               // vector (usize) does not fit into i32.
    let cr :f64 = c.try_into().unwrap();

    println!("         [i32] : {:?}", a);
    println!("  [Fractional] : {:?}", b);
    println!(" mean of [i32] : {}"  , c);
    println!("        as f64 : {}"  , cr);
    println!("  again as f64 : {}"  , TryInto::<f64>::try_into(c).unwrap());
}

fn continuous() {
    let d = Fractional(45, 16);
    let e = Fractional(16, 45);

    let dc :Continuous = (&d).into();
    let ec :Continuous = (&e).into();

    println!("cont frac of d : {} => {:?}", d, dc);
    println!("cont frac of e : {} => {:?}", e, ec);
    println!("   reverted dc : {:?} {}", dc, Into::<Fractional>::into(&dc));
    println!("   reverted ec : {:?} {}", ec, Into::<Fractional>::into(&ec));
}

fn sqrt() {
    let f       = Fractional(-9, 4);
    let fr :f64 = f.try_into().unwrap();
    let sq      = f.sqrt();
    let _sq     = fr.sqrt();

    println!("{:>14} : {:?} / {}", format!("sqrt {}", f), sq, _sq);

    for f in [ Fractional(9, 4)
             , Fractional(45, 16)
             , Fractional(16, 45)
             , Fractional(9, 3) ].iter() {
        let fr  :f64 = (*f).try_into().unwrap();
        let sq       = f.sqrt().unwrap();
        let sqr :f64 = sq.try_into().unwrap();
        let _sqr     = fr.sqrt();

        println!("{:>14} : {} {} / {}", format!("sqrt {}", f), sq, sqr, _sqr);
    }
}

fn pi() {
    let pi              = Fractional::pi();
    let pir :f64        = pi.try_into().unwrap();
    let pit :(i32, i32) = pi.try_into().unwrap();
    let pi2r :f64       = (pi * pi).try_into().unwrap();

    println!("        Rust π : {}"     , FPI);
    println!("             π : {} {}"  , pi, pir);
    println!("    π as tuple : {:?}"   , pit);
    println!("       Rust π² : {}"     , FPI * FPI);
    println!("            π² : {} {}"  , pi * pi, pi2r);
}

fn _sin() {
    for d in [ 0, 30, 45, 90, 135, 180, 225, 270, 315
             , 9, 17, 31, 73, 89, 123, 213, 312, 876 ].iter() {
        let s       = Fractional::sin(*d as i32);
        let sr :f64 = s.try_into().unwrap();
        let _s      = f64::sin(*d as f64 * FPI / 180.0);

        println!("{:>14} : {} {} / {}", format!("sin {}", d), s, sr, _s);
    }
}

fn _tan() {
    for d in [ 0, 30, 45, 90, 135, 180, 225, 270, 315
             , 9, 17, 31, 73, 89, 123, 213, 312, 876 ].iter() {
        let t       = Fractional::tan(*d as i32);
        let tr :f64 = t.try_into().unwrap();
        let _t      = f64::tan(*d as f64 * FPI / 180.0);

        println!("{:>14} : {} {} / {}", format!("tan {}", d), t, tr, _t);
    }
}

fn _cos() {
    for d in [ 0, 30, 45, 90, 135, 180, 225, 270, 315
             , 9, 17, 31, 73, 89, 123, 213, 312, 876 ].iter() {
        let c       = Fractional::cos(*d as i32);
        let cr :f64 = c.try_into().unwrap();
        let _c      = f64::cos(*d as f64 * FPI / 180.0);

        println!("{:>14} : {} {} / {}", format!("cos {}", d), c, cr, _c);
    }
}

fn _vector1() {
    let v1 = Vector(1.into(), 2.into(), 3.into());
    let v2 = Vector(2.into(), 2.into(), 3.into());
    let s :Fractional = 3.into();

    _vector(v1, v2, s);
}

fn _vector2() {
    let v1 = Vector(1.0, 2.0, 3.0);
    let v2 = Vector(2.0, 2.0, 3.0);
    let s = 3.0;

    _vector(v1, v2, s);
}

fn _vector<T>(v1 :Vector<T>, v2 :Vector<T>, s :T)
    where T: Add<Output = T> + Sub<Output = T> + Neg<Output = T>
           + Mul<Output = T> + Div<Output = T> + Trig + Copy + Display {
    println!("{:>14} : {}", "Vector v1", v1);
    println!("{:>14} : {}", "Vector v2", v2);
    println!("{:>14} : {}", "magnitude v1", v1.mag());
    println!("{:>14} : {}", "-v1", -v1);
    println!("{:>14} : {}", "v1 + v1", v1 + v1);
    println!("{:>14} : {}", "v1 - v1", v1 - v1);
    println!("{:>14} : {}", "v2 - v1", v2 - v1);
    println!("{:>14} : {}", format!("v1 * {}", s), v1.mul(&s));
    println!("{:>14} : {}", "norm v1", v1.norm());
    println!("{:>14} : {}", "magnitude norm v1", v1.norm().mag());
    println!("{:>14} : {}", "magnitude v1", v1.mag());
    println!("{:>14} : {}", "norm * magnitude", v1.norm().mul(&v1.mag()));
    println!("{:>14} : {}", "distance v1 v2", v1.distance(v2));
    println!("{:>14} : {}", "distance v2 v1", v2.distance(v1));
    println!("{:>14} : {}", "v1 dot v2", v1.dot(v2));
    println!("{:>14} : {}", "v2 dot v1", v2.dot(v1));
    println!("{:>14} : {}", "v1 * v2", v1 * v2);
    println!("{:>14} : {}", "v2 * v1", v2 * v1);
}

fn _transform1() {
    let v  = Vector(Fractional(1,1), Fractional(1,1), Fractional(1,1));
    let v1 = Vector(Fractional(1,1), Fractional(2,1), Fractional(3,1));
    let v2 = Vector(Fractional(1,1), Fractional(1,1), Fractional(0,1));
    let v3 = Vector(Fractional(1,1), Fractional(0,1), Fractional(1,1));

    _transform(v, v1, v2, v3);
}

fn _transform2() {
    let v  = Vector(1.0, 1.0, 1.0);
    let v1 = Vector(1.0, 2.0, 3.0);
    let v2 = Vector(1.0, 1.0, 0.0);
    let v3 = Vector(1.0, 0.0, 1.0);

    _transform(v, v1, v2, v3);
}

fn _transform<T>(v :Vector<T>, v1 :Vector<T>, v2 :Vector<T>, v3 :Vector<T>)
    where T: Add<Output = T> + Sub<Output = T> + Neg<Output = T>
           + Mul<Output = T> + Div<Output = T> + Trig
           + Debug + From<i32> + Copy + Display {

    println!("{:>14} : {}", "Vector v1", v1);
    println!( "{:>14} : {}", "translate v1"
            , v.transform(&TMatrix::translate(v)));
    println!();

    fn _rot<T>( o :&str , n :&str , v :&Vector<T>
              , fs :&[&dyn Fn(i32) -> TMatrix<T>] )
        where T: Add<Output = T> + Sub<Output = T> + Neg<Output = T>
               + Mul<Output = T> + Div<Output = T> + Trig
               + Debug + From<i32> + Copy + Display {

        for d in [ 30, 45, 60, 90, 120, 135, 150, 180
                 , 210, 225, 240, 270, 300, 315, 330 ].iter() {
            let mi = fs.iter().map(|f| f(*d as i32));
            println!( "{:>14} : {}"
                    , format!("{} {} {}", o, d, n)
                    , v.transform(&TMatrix::combine(mi)) );
        }
    }

    println!("{:>14} : {}", "Vector v2", v2);
    _rot("rot_x", "v2", &v2, &[&TMatrix::rotate_x]);
    println!();
    _rot("rot_y", "v2", &v2, &[&TMatrix::rotate_y]);
    println!();
    _rot("rot_xy", "v2", &v2, &[&TMatrix::rotate_x, &TMatrix::rotate_y]);
    println!();
    println!("{:>14} : {}", "Vector v3", v3);
    _rot("rot_z", "v3", &v3, &[&TMatrix::rotate_z]);
    println!();

    for d in [ 30, 45, 60, 90, 120, 135, 150, 180
             , 210, 225, 240, 270, 300, 315, 330 ].iter() {
        println!( "{:>14} : {}"
                , format!("rot_v {} v2", d)
                , v2.transform(&TMatrix::rotate_v(&v, *d as i32)) );
    }
}

fn _line() {
    let a = (Coordinate(0, 1, 0.0), Coordinate(6, 4, 0.0));
    let b = (Coordinate(0, 4, 0.0), Coordinate(6, 1, 0.0));
    let c = (Coordinate(1, 0, 0.0), Coordinate(6, 8, 0.0));
    let d = (Coordinate(1, 8, 0.0), Coordinate(6, 0, 0.0));

    for i in [a, b, c, d].iter() {
        println!("{:>14} : {}", Line(i.0, i.1), Line(i.0, i.1).plot());
        println!("{:>14} : {}", Line(i.1, i.0), Line(i.1, i.0).plot());
    }

    println!();
    let pl = Polyline(
        Coordinates(vec!(a.0, a.1, b.0, b.1, c.0, c.1, d.0, d.1)));
    println!("{:>14} : {}", pl, pl.plot());

    println!();
    let pg = Polygon(
        Coordinates(vec!( Coordinate(  0, -10, 0.0)
                        , Coordinate( 10,  10, 0.0)
                        , Coordinate(-10,  10, 0.0) )));
    println!("{:>14} : {}", pg, pg.plot());

    let i = Vector(Fractional(  0,1), Fractional(-30,1), Fractional(0,1));
    let j = Vector(Fractional( 30,1), Fractional( 30,1), Fractional(0,1));
    let k = Vector(Fractional(-30,1), Fractional( 30,1), Fractional(0,1));

    let rot :TMatrix<Fractional> = TMatrix::rotate_z(20);
    let Vector(ix, iy, _) = i.transform(&rot);
    let Vector(jx, jy, _) = j.transform(&rot);
    let Vector(kx, ky, _) = k.transform(&rot);

    fn to_i32(x :Fractional) -> i32 {
        let Fractional(n, d) = x;
        (n / d + if (n % d).abs() < (n / 2).abs() { 0 } else { 1 }) as i32
    }

    println!();
    let pg = Polygon(
        Coordinates(vec!( Coordinate(to_i32(ix) + 100, to_i32(iy) + 100, 0.0)
                        , Coordinate(to_i32(jx) + 100, to_i32(jy) + 100, 0.0)
                        , Coordinate(to_i32(kx) + 100, to_i32(ky) + 100, 0.0) )));
    println!("{:>14} : {}", pg, pg.plot());

    let i = Vector(  0.0, -30.0, 0.0);
    let j = Vector( 30.0,  30.0, 0.0);
    let k = Vector(-30.0,  30.0, 0.0);

    let rot :TMatrix<f64> = TMatrix::rotate_z(20);
    let Vector(ix, iy, _) = i.transform(&rot);
    let Vector(jx, jy, _) = j.transform(&rot);
    let Vector(kx, ky, _) = k.transform(&rot);

    fn to_i32_2(x :f64) -> i32 {
        x.round() as i32
    }

    println!();
    let pg = Polygon(
        Coordinates(vec!( Coordinate(to_i32_2(ix) + 100, to_i32_2(iy) + 100, 0.0)
                        , Coordinate(to_i32_2(jx) + 100, to_i32_2(jy) + 100, 0.0)
                        , Coordinate(to_i32_2(kx) + 100, to_i32_2(ky) + 100, 0.0) )));
    println!("{:>14} : {}", pg, pg.plot());
}

fn _democanvas<T>( xcb         :&XcbEasel
                 , title       :&'static str
                 , tx          :mpsc::Sender<i32>
                 , _triangle   :Polyeder<T>
                 , tetrahedron :Polyeder<T>
                 , cube        :Polyeder<T>
                 , light       :DirectLight<T> )
    where T: 'static + Add<Output = T> + Sub<Output = T> + Neg<Output = T>
           + Mul<Output = T> + Div<Output = T>
           + Debug + Copy + Trig + Send + From<i32> + PartialOrd {

    let mut canvas = xcb.canvas(151, 151).unwrap();
    let camera     = Camera::<T>::new(&canvas, 45); // the orig. view angle
                                                    // was 50.

    canvas.set_title(title);
    <XcbCanvas as Canvas<T>>::init_events(&canvas);
    <XcbCanvas as Canvas<T>>::start_events(&canvas, tx.clone());

    thread::spawn(move || {
        let     start = Instant::now();
        let     step  = Duration::from_millis(25);
        let mut last  = Instant::now();

        let t = TMatrix::translate(Vector(0.into() , 0.into() , 150.into()));

        loop {
            let deg = ((start.elapsed() / 25).as_millis() % 360) as i32;

            let rz = TMatrix::rotate_z(deg);
            let rx = TMatrix::rotate_x(-deg*2);
            let ry = TMatrix::rotate_y(-deg*2);

            let rot1 = TMatrix::combine(vec!(rz, rx, t));
            let rot2 = TMatrix::combine(vec!(rz, ry, t));

            let objects = vec!( (tetrahedron.transform(&rot1), 0xFFFF00)
                              , (       cube.transform(&rot2), 0x0000FF) );
            //let objects = vec!( (       cube.transform(&rot2), 0x0000FF) );
            //let objects = vec!( (tetrahedron.transform(&rot1), 0xFFFF00) );
            //let objects = vec!( (triangle.transform(&rot1), 0xFFFF00) );

            <XcbCanvas as Canvas<T>>::clear(&mut canvas);

            for (o, color) in objects {
                for (pg, c) in o.project(&camera, &light, color) {
                    //canvas.draw(&pg, Coordinate(0, 0, 0.into()), c);
                    (&pg).fill(&mut canvas, c);
                    //(&pg).debug();
                    //println!("\n");
                }
            }

            let passed = Instant::now() - last;
            let f      = (passed.as_nanos() / step.as_nanos()) as u32;

            if f > 1 {
                println!("{} !!! Detected frame drop", title);
            }

            last = last + step*(f + 1);
            <XcbCanvas as Canvas<T>>::put_text( &canvas
                                              , Coordinate(10, 15, 0.into())
                                              , &format!( "sleep: {:?}"
                                              , last - Instant::now() ));
            <XcbCanvas as Canvas<T>>::show(&canvas);
            thread::sleep(last - Instant::now());
        }
    });
}

fn main() {
    common_fractional();
    println!();
    continuous();
    println!();
    sqrt();
    println!();
    pi();
    println!();
    _sin();
    println!();
    _cos();
    println!();
    _tan();
    println!();
    _vector1();
    println!();
    _vector2();
    println!();
    _transform1();
    println!();
    _transform2();
    println!();
    _line();

    let xcb = XcbEasel::new().unwrap();
    let (tx, rx) = mpsc::channel();

    _democanvas( &xcb, "Something...(f64)", tx.clone()
               , Polyeder::triangle(60.0)
               , Polyeder::tetrahedron(80.0)
               , Polyeder::cube(55.0)
               , DirectLight::new(Vector(0.0, 0.0, 1.0)) );
    /*
    _democanvas( &xcb, "Something...(Fractional)", tx.clone()
               , Polyeder::triangle(Fractional(60,1))
               , Polyeder::tetrahedron(Fractional(80,1))
               , Polyeder::cube(Fractional(55,1))
               , DirectLight::new(Vector( Fractional(0,1)
                                        , Fractional(0,1)
                                        , Fractional(1,1) )) );
    */

    for x in rx {
        match x {
            1 => break,
            _ => {},
        }
    }
}