//! TRACES: FR-DEV-3g
//! Learned demosaic and denoise on the raw mosaic (docs/dev/denoise.md).
//!
//! A network trained on the library's own base-ISO raws with the 6D's
//! measured noise added takes the repaired, normalised mosaic and a σ for
//! every photosite, and returns linear camera RGB at full resolution — the
//! texture the classical demosaic would have produced, with the noise gone.
//! It replaces the demosaic box; nothing downstream changes (§2).
//!
//! - [`noise`] says how noisy each photosite is, from the best source the
//!   frame has.
//! - [`tile`] runs a fixed-shape network over a whole frame, exactly.
//! - [`onnx`] is that network under the inference engine.
//!
//! The input must already have been through the app's hot-pixel pass
//! (`dr_gpu::Demosaicer::repair_hot_pixels`): the noise model was fitted
//! with what that pass removes left out.

pub mod noise;
#[cfg(feature = "onnx")]
pub mod onnx;
pub mod tile;

use dr_decode::RawImage;

pub use noise::{NoiseModel, Source};
pub use tile::{TileNet, HALO};

#[derive(Debug, thiserror::Error)]
pub enum DenoiseError {
    #[error("the network cannot take this photograph: {0}")]
    Unsupported(String),
    #[error("the denoise model misbehaved: {0}")]
    Model(String),
    #[error("could not read the denoise model: {0}")]
    ModelRead(#[from] std::io::Error),
    #[cfg(feature = "onnx")]
    #[error(transparent)]
    Engine(#[from] dr_inference_engine::Error),
    #[cfg(feature = "onnx")]
    #[error(transparent)]
    Ort(#[from] ort::Error),
}

/// Whether the learned stage can take this frame at all: a Bayer mosaic.
/// X-Trans needs its own model (§9); a linear DNG has no photosites.
pub fn eligible(raw: &RawImage) -> bool {
    raw.samples_per_pixel == 1 && tile::rggb_offset(raw.cfa_pattern).is_some()
}

/// The active area of `raw`, denoised and demosaiced: `crop.height ×
/// crop.width` interleaved RGB, linear camera space, normalised black 0 and
/// white 1 per photosite as the classical demosaic normalises.
///
/// `raw` must be hot-pixel repaired. `None` when `progress` stopped it.
pub fn denoise(
    raw: &RawImage,
    noise: &NoiseModel,
    net: &mut dyn TileNet,
    progress: &mut dyn FnMut(usize, usize) -> bool,
) -> Result<Option<Vec<f32>>, DenoiseError> {
    if !eligible(raw) {
        return Err(DenoiseError::Unsupported(format!(
            "{:?} with {} samples per photosite",
            raw.cfa_pattern, raw.samples_per_pixel
        )));
    }
    let active = noise::active(raw);
    let (h, w) = (active.h, active.w);
    tile::run_tiled(
        net,
        h,
        w,
        raw.cfa_pattern,
        &|y, x| active.at(y, x),
        &|c, v| noise.sigma(c, v),
        progress,
    )
}