//! Infer COLMAP cameras from a folder of images using only their headers (size + EXIF).
//!
//! Run with:
//! ```text
//! cargo run --example infer_camera -- ../images
//! ```
//! If no path is given it defaults to `../images` (the South Building sample set).

use std::path::PathBuf;

use colmap::image::{infer_shared_cameras_in_dir, read_exif, read_image_size};

fn main() -> colmap::Result<()> {
    let dir: PathBuf = std::env::args()
        .nth(1)
        .map(PathBuf::from)
        .unwrap_or_else(|| PathBuf::from(concat!(env!("CARGO_MANIFEST_DIR"), "/../images")));

    println!("Scanning {}", dir.display());

    let images = colmap::image::list_images_in_dir(&dir)?;
    println!("Found {} images\n", images.len());

    if let Some(first) = images.first() {
        let (w, h) = read_image_size(first)?;
        println!("First image: {}", first.file_name().unwrap().to_string_lossy());
        println!("  size: {w} x {h}");
        if let Some(exif) = read_exif(first)? {
            println!("  make/model: {:?} / {:?}", exif.make, exif.model);
            println!("  focal length: {:?} mm", exif.focal_length_mm);
            println!(
                "  focal-plane res: {:?} (unit {:?})",
                exif.focal_plane_x_resolution, exif.focal_plane_resolution_unit
            );
        }
        let cam = colmap::image::infer_camera_from_image(first, 1)?;
        println!(
            "  inferred camera: {} {}x{} params={:?} prior_focal={}",
            cam.model_name(),
            cam.width,
            cam.height,
            cam.params,
            cam.has_prior_focal_length
        );
    }

    let (cameras, assignment) = infer_shared_cameras_in_dir(&dir)?;
    println!(
        "\nDeduplicated to {} camera(s) across {} images.",
        cameras.len(),
        assignment.len()
    );
    Ok(())
}