use sha2::{Digest, Sha256};
use std::env;
use std::fs;
use std::path::PathBuf;

fn main() {
    let manifest_dir = env::var("CARGO_MANIFEST_DIR").unwrap();
    let src_dir = PathBuf::from(&manifest_dir).join("src");

    let mut hasher = Sha256::new();
    hash_dir(&src_dir, &mut hasher);
    let digest = hasher.finalize();
    let hash_hex = format!("{:x}", digest);
    println!("cargo:rustc-env=BUILD_SRC_HASH={}", hash_hex);

    let out_dir = PathBuf::from(env::var("OUT_DIR").unwrap());
    fs::write(out_dir.join("build_hash.txt"), format!("{}\n", hash_hex)).unwrap();

    // 嵌入 RSA 公钥（用于 selfhosted 验签）
    let pubkey_path = PathBuf::from(&manifest_dir).join("embedded").join("pubkey.pem");
    if let Ok(pubkey) = fs::read_to_string(&pubkey_path) {
        let trimmed = pubkey.trim();
        if !trimmed.is_empty() {
            println!("cargo:rustc-env=CRAFTLABS_SELFHOSTED_PUBKEY={}", trimmed);
        }
    }
    println!("cargo:rerun-if-changed=embedded/pubkey.pem");
}

fn hash_dir(dir: &PathBuf, hasher: &mut Sha256) {
    if let Ok(entries) = fs::read_dir(dir) {
        let mut paths: Vec<_> = entries.filter_map(|e| e.ok()).collect();
        paths.sort_by_key(|e| e.file_name());
        for entry in paths {
            let path = entry.path();
            if path.is_dir() {
                hash_dir(&path, hasher);
            } else if path.extension().map_or(false, |ext| ext == "rs") {
                if let Ok(content) = fs::read(&path) {
                    hasher.update(&content);
                }
            }
        }
    }
}