//! Check the model is a model and not an LFS pointer.
//!
//! `models/keypoints/*.onnx` is stored in Git LFS (see `.gitattributes`). A
//! clone made without git-lfs, or with `GIT_LFS_SKIP_SMUDGE` set, leaves a
//! ~130-byte text pointer at that path instead of the weights, and
//! `include_bytes!` would embed it without complaint. Same guard as
//! `dr-segment`'s, for the same failure.

use std::path::Path;

const MODELS: &[&str] = &[
    "../../models/keypoints/xfeat-1024.onnx",
    "../../models/keypoints/xfeat-768.onnx",
];

fn main() {
    for m in MODELS {
        println!("cargo:rerun-if-changed={m}");
    }
    println!("cargo:rerun-if-changed=build.rs");

    if std::env::var_os("CARGO_FEATURE_EMBEDDED_MODEL").is_none() {
        return;
    }

    for model in MODELS.iter().copied() {
        check(model);
    }
}

fn check(model: &str) {
    let path = Path::new(model);
    let Ok(bytes) = std::fs::read(path) else {
        panic!(
            "\n\n{model} is missing.\n\
             It ships in Git LFS. Run `git lfs install && git lfs pull`, or build \
             with `--no-default-features` for a geometry-only build.\n"
        );
    };

    if bytes.starts_with(b"version https://git-lfs.github.com/spec/") {
        panic!(
            "\n\n{model} is a Git LFS pointer, not the model.\n\
             Run `git lfs install && git lfs pull`, or build with \
             `--no-default-features` for a geometry-only build.\n"
        );
    }
}