use crate::core::image::HostImage;
use crate::core::material::CreateMaterial;
use crate::{Arena, ArenaUpload, FileLoc, utils::TextureParameterDictionary};
use anyhow::Result;
use anyhow::anyhow;
use shared::Ptr;
use shared::core::material::Material;
use shared::materials::MixMaterial;
use std::collections::HashMap;
use std::sync::Arc;

impl CreateMaterial for MixMaterial {
    fn create(
        parameters: &TextureParameterDictionary,
        _normal_map: Option<Arc<HostImage>>,
        named_materials: &HashMap<String, Material>,
        loc: &FileLoc,
        arena: &Arena,
    ) -> Result<Material> {
        let names = parameters.get_string_array("materials")?;
        let [a, b]: [String; 2] = names
            .try_into()
            .map_err(|_| anyhow!("{loc}: must provide two values for \"string materials\""))?;

        let mut resolve = |n: &str| -> Result<Ptr<Material>> {
            let m = named_materials
                .get(n)
                .ok_or_else(|| anyhow!("{loc}: {n}: named material not found"))?;
            Ok(arena.alloc(*m))
        };

        let materials = [resolve(&a)?, resolve(&b)?];
        let amount = parameters.get_float_texture("amount", 0.5)?;

        let mix_mat = MixMaterial {
            materials,
            amount: arena.upload(amount),
        };
        Ok(Material::Mix(mix_mat))
    }
}