use ecs::Component;

use crate::color::Color;
use crate::data_types::dimens::Dimens;
use crate::texture::{Id as TextureId, Texture};

#[derive(Debug, Clone, Component)]
pub struct Material
{
    ambient: Option<Color<f32>>,
    diffuse: Option<Color<f32>>,
    specular: Option<Color<f32>>,
    ambient_map: TextureId,
    diffuse_map: TextureId,
    specular_map: TextureId,
    textures: Vec<Texture>,
    shininess: f32,
}

impl Material
{
    #[must_use]
    pub fn ambient(&self) -> Option<&Color<f32>>
    {
        self.ambient.as_ref()
    }

    #[must_use]
    pub fn diffuse(&self) -> Option<&Color<f32>>
    {
        self.diffuse.as_ref()
    }

    #[must_use]
    pub fn specular(&self) -> Option<&Color<f32>>
    {
        self.specular.as_ref()
    }

    #[must_use]
    pub fn ambient_map(&self) -> &TextureId
    {
        &self.ambient_map
    }

    #[must_use]
    pub fn diffuse_map(&self) -> &TextureId
    {
        &self.diffuse_map
    }

    #[must_use]
    pub fn specular_map(&self) -> &TextureId
    {
        &self.specular_map
    }

    #[must_use]
    pub fn textures(&self) -> &[Texture]
    {
        &self.textures
    }

    #[must_use]
    pub fn shininess(&self) -> f32
    {
        self.shininess
    }
}

/// [`Material`] builder.
#[derive(Debug, Clone)]
pub struct Builder
{
    ambient: Option<Color<f32>>,
    diffuse: Option<Color<f32>>,
    specular: Option<Color<f32>>,
    ambient_map: Option<TextureId>,
    diffuse_map: Option<TextureId>,
    specular_map: Option<TextureId>,
    textures: Vec<Texture>,
    shininess: f32,
}

impl Builder
{
    #[must_use]
    pub fn new() -> Self
    {
        Self {
            ambient: None,
            diffuse: None,
            specular: None,
            ambient_map: None,
            diffuse_map: None,
            specular_map: None,
            textures: Vec::new(),
            shininess: 32.0,
        }
    }

    #[must_use]
    pub fn ambient(mut self, ambient: Color<f32>) -> Self
    {
        self.ambient = Some(ambient);

        self
    }

    #[must_use]
    pub fn diffuse(mut self, diffuse: Color<f32>) -> Self
    {
        self.diffuse = Some(diffuse);

        self
    }

    #[must_use]
    pub fn specular(mut self, specular: Color<f32>) -> Self
    {
        self.specular = Some(specular);

        self
    }

    #[must_use]
    pub fn ambient_map(mut self, ambient_map: TextureId) -> Self
    {
        self.ambient_map = Some(ambient_map);

        self
    }

    #[must_use]
    pub fn diffuse_map(mut self, diffuse_map: TextureId) -> Self
    {
        self.diffuse_map = Some(diffuse_map);

        self
    }

    #[must_use]
    pub fn specular_map(mut self, specular_map: TextureId) -> Self
    {
        self.specular_map = Some(specular_map);

        self
    }

    #[must_use]
    pub fn textures(mut self, textures: impl IntoIterator<Item = Texture>) -> Self
    {
        self.textures = textures.into_iter().collect();

        self
    }

    #[must_use]
    pub fn shininess(mut self, shininess: f32) -> Self
    {
        self.shininess = shininess;

        self
    }

    /// Builds a new [`Material`].
    ///
    /// # Panics
    /// Will panic if no ambient map, diffuse map or specular map is set.
    #[must_use]
    pub fn build(mut self) -> Material
    {
        let ambient_map = self.ambient_map.unwrap_or_else(|| {
            let texture = create_1x1_white_texture();
            let texture_id = texture.id();

            self.textures.push(texture);

            texture_id
        });

        let diffuse_map = self.diffuse_map.unwrap_or_else(|| {
            let texture = create_1x1_white_texture();
            let texture_id = texture.id();

            self.textures.push(texture);

            texture_id
        });

        let specular_map = self.specular_map.unwrap_or_else(|| {
            let texture = create_1x1_white_texture();
            let texture_id = texture.id();

            self.textures.push(texture);

            texture_id
        });

        Material {
            ambient: self.ambient.clone(),
            diffuse: self.diffuse.clone(),
            specular: self.specular.clone(),
            ambient_map,
            diffuse_map,
            specular_map,
            textures: self.textures,
            shininess: self.shininess,
        }
    }
}

impl Default for Builder
{
    fn default() -> Self
    {
        Self::new()
    }
}

fn create_1x1_white_texture() -> Texture
{
    Texture::new_from_color(&Dimens { width: 1, height: 1 }, &Color::WHITE_U8)
}