//! Detect the faces in a JPEG and read each one's eyes (docs/faces.md §17).
//!
//! The thing worth looking at is whether the eye boxes land on eyes and
//! whether soft ones are refused — so with `--dump DIR` the crops the
//! classifiers were shown are written out as PPMs, one per eye and one per
//! head framing, named by image and face, and every line carries the
//! numbers the readability floors are set from.
//!
//!   cargo run -p dr-face --features inference --example eyes -- \
//!       DET.onnx 2D106DET.onnx OCEC.onnx SGC.onnx [--dump DIR] photo.jpg [photo.jpg ...]
//!
//! All four models must have had their dynamic dims pinned first; see
//! `tools/fix-face-model-shapes.sh`.

use std::path::{Path, PathBuf};
use std::time::Instant;

use dr_face::{align, DetectOptions, Detector, EyeModels, Pixels};

fn main() {
    env_logger::init();

    let mut args: Vec<String> = std::env::args().skip(1).collect();
    let dump = args.iter().position(|a| a == "--dump").map(|i| {
        args.remove(i);
        PathBuf::from(args.remove(i))
    });
    if args.len() < 5 {
        eprintln!(
            "usage: eyes DET.onnx 2D106DET.onnx OCEC.onnx SGC.onnx [--dump DIR] IMAGE.jpg [IMAGE.jpg ...]"
        );
        std::process::exit(2);
    }
    if let Some(d) = &dump {
        std::fs::create_dir_all(d).expect("dump dir");
    }

    let t = Instant::now();
    let mut detector = Detector::from_path(&args[0]).expect("load detector");
    let mut models = EyeModels::from_paths(&args[1], &args[2], &args[3]).expect("load eye models");
    println!("loaded the models in {:?}", t.elapsed());

    let opts = DetectOptions::default();
    for path in &args[4..] {
        let (rgb, w, h) = match load_jpeg(path) {
            Ok(v) => v,
            Err(e) => {
                println!("{path}: {e}");
                continue;
            }
        };
        let dets = detector.detect(&rgb, w, h, &opts).expect("detect");
        println!("\n{path}  ({w}×{h})  {} face(s)", dets.len());

        let stem = Path::new(path)
            .file_stem()
            .map(|s| s.to_string_lossy().into_owned())
            .unwrap_or_default();

        for (i, d) in dets.iter().enumerate() {
            let px = Pixels::RgbF32(&rgb);
            let t = Instant::now();
            let reading = models
                .read(px, w, h, d.bbox, &d.landmarks)
                .expect("read eyes");
            let ms = t.elapsed().as_secs_f64() * 1e3;
            let Some((r, lm)) = reading else {
                println!("  [{i}] nothing to cut, skipped");
                continue;
            };
            println!(
                "  [{i}] conf {:.2}  box {:.0}×{:.0}  right {:.3} ({:.0}px, sharp {:.3})  left {:.3} ({:.0}px, sharp {:.3})  sunglasses {:.3}  → {:?}  ({ms:.1} ms)",
                d.confidence,
                d.width(),
                d.height(),
                r.right.open,
                r.right.px,
                r.right.sharpness,
                r.left.open,
                r.left.px,
                r.left.sharpness,
                r.sunglasses,
                r.state(),
            );
            if let Some(dir) = &dump {
                // The same crops `EyeModels::read` cut, cut again for the
                // sheet from the landmarks it handed back: the reading itself
                // carries numbers, not pixels.
                for (name, contour) in [("right", lm.right_eye()), ("left", lm.left_eye())] {
                    if let Some(patch) =
                        align::eye_box(&contour).and_then(|b| align::eye_patch(px, w, h, b))
                    {
                        write_ppm(
                            &dir.join(format!("{stem}-{i}-{name}.ppm")),
                            patch.pixels(),
                            align::EYE_PATCH_WIDTH,
                            align::EYE_PATCH_HEIGHT,
                        );
                    }
                }
                if let Some(head) = align::head_views(px, w, h, &d.landmarks) {
                    for (n, view) in head.views().enumerate() {
                        write_ppm(
                            &dir.join(format!("{stem}-{i}-head{n}.ppm")),
                            view,
                            align::SUNGLASSES_EDGE,
                            align::SUNGLASSES_EDGE,
                        );
                    }
                }
            }
        }
    }
}

fn write_ppm(path: &Path, rgb: &[f32], w: usize, h: usize) {
    let mut out = format!("P6\n{w} {h}\n255\n").into_bytes();
    out.extend(
        rgb.iter()
            .map(|v| (v.clamp(0.0, 1.0) * 255.0).round() as u8),
    );
    std::fs::write(path, out).expect("write ppm");
}

/// Decode to the tightly packed `f32` RGB `0.0..=1.0` the crate expects.
fn load_jpeg(path: &str) -> Result<(Vec<f32>, usize, usize), String> {
    let bytes = std::fs::read(path).map_err(|e| e.to_string())?;
    let mut dec = zune_jpeg::JpegDecoder::new(&bytes);
    let px = dec.decode().map_err(|e| e.to_string())?;
    let info = dec.info().ok_or("no jpeg header")?;
    let (w, h) = (info.width as usize, info.height as usize);

    let rgb: Vec<f32> = match px.len() / (w * h) {
        3 => px.iter().map(|&v| v as f32 / 255.0).collect(),
        1 => px
            .iter()
            .flat_map(|&v| {
                let g = v as f32 / 255.0;
                [g, g, g]
            })
            .collect(),
        n => return Err(format!("{n} components per pixel, expected 1 or 3")),
    };
    Ok((rgb, w, h))
}