use geom::Angle;
use serde_derive::{Deserialize, Serialize};
use std::fmt;

// Copy could be reconsidered, but eh
#[derive(Debug, Clone, Copy, PartialEq, Serialize, Deserialize)]
pub enum Color {
    RGBA(f32, f32, f32, f32),
    // (The texture ID to pass to the shader, (texture width, height)). Tiles seamlessly through
    // all of map-space.
    TileTexture(f32, (f64, f64)),
    // Stretches the entire texture to fit the entire polygon. Rotates from the center of the
    // polygon. Not sure what this means for anything but circles right now. Have to manually
    // fiddle with the original orientation to fix y inversion.
    StretchTexture(f32, Angle),
    // A polygon with UV coordinates for each point must be used.
    CustomUVTexture(f32),
    Hatching,
}

impl fmt::Display for Color {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        match self {
            Color::RGBA(r, g, b, a) => write!(f, "Color(r={}, g={}, b={}, a={})", r, g, b, a),
            Color::TileTexture(id, (w, h)) => {
                write!(f, "Color::TileTexture({}, width={}, height={})", id, w, h)
            }
            Color::StretchTexture(id, angle) => {
                write!(f, "Color::StretchTexture({}, {})", id, angle)
            }
            Color::CustomUVTexture(id) => write!(f, "Color::CustomUVTexture({})", id),
            Color::Hatching => write!(f, "Color::Hatching"),
        }
    }
}

impl Color {
    pub const BLACK: Color = Color::rgb_f(0.0, 0.0, 0.0);
    pub const WHITE: Color = Color::rgb_f(1.0, 1.0, 1.0);
    pub const RED: Color = Color::rgb_f(1.0, 0.0, 0.0);
    pub const GREEN: Color = Color::rgb_f(0.0, 1.0, 0.0);
    pub const BLUE: Color = Color::rgb_f(0.0, 0.0, 1.0);
    pub const CYAN: Color = Color::rgb_f(0.0, 1.0, 1.0);
    pub const YELLOW: Color = Color::rgb_f(1.0, 1.0, 0.0);
    pub const PURPLE: Color = Color::rgb_f(0.5, 0.0, 0.5);
    pub const PINK: Color = Color::rgb_f(1.0, 0.41, 0.71);
    pub const ORANGE: Color = Color::rgb_f(1.0, 0.55, 0.0);

    // TODO should assert stuff about the inputs

    // TODO Once f32 can be used in const fn, make these const fn too and clean up call sites
    // dividing by 255.0. https://github.com/rust-lang/rust/issues/57241
    pub fn rgb(r: usize, g: usize, b: usize) -> Color {
        Color::rgba(r, g, b, 1.0)
    }

    pub const fn rgb_f(r: f32, g: f32, b: f32) -> Color {
        Color::RGBA(r, g, b, 1.0)
    }

    pub fn rgba(r: usize, g: usize, b: usize, a: f32) -> Color {
        Color::RGBA(
            (r as f32) / 255.0,
            (g as f32) / 255.0,
            (b as f32) / 255.0,
            a,
        )
    }

    pub const fn rgba_f(r: f32, g: f32, b: f32, a: f32) -> Color {
        Color::RGBA(r, g, b, a)
    }

    pub const fn grey(f: f32) -> Color {
        Color::RGBA(f, f, f, 1.0)
    }

    pub fn alpha(&self, a: f32) -> Color {
        match self {
            Color::RGBA(r, g, b, _) => Color::RGBA(*r, *g, *b, a),
            _ => unreachable!(),
        }
    }

    pub fn from_hex(raw: &str) -> Color {
        // Skip the leading '#'
        let r = usize::from_str_radix(&raw[1..3], 16).unwrap();
        let g = usize::from_str_radix(&raw[3..5], 16).unwrap();
        let b = usize::from_str_radix(&raw[5..7], 16).unwrap();
        Color::rgb(r, g, b)
    }

    pub fn rotate(&self, angle: Angle) -> Color {
        match self {
            Color::StretchTexture(id, _) => Color::StretchTexture(*id, angle),
            _ => unreachable!(),
        }
    }
}