build.rs

use std::path::PathBuf;
use std::process::Command;

fn main() {
    println!("cargo:rerun-if-changed=deepmem-version.txt");
    println!("cargo:rerun-if-changed=.git/HEAD");
    emit_git_head_ref_rerun_hint();

    let deepmem_version = std::fs::read_to_string("deepmem-version.txt")
        .map(|s| s.trim().to_string())
        .unwrap_or_else(|_| "unknown".into());
    let git_sha = git_output(&["rev-parse", "--short", "HEAD"]).unwrap_or_else(|| "unknown".into());
    let git_dirty = git_output(&["status", "--porcelain"])
        .map(|s| if s.trim().is_empty() { "false" } else { "true" })
        .unwrap_or("unknown");

    println!(
        "cargo:rustc-env=WX_CLI_DISPLAY_VERSION=deepmem-{}-{deepmem_version}",
        env!("CARGO_PKG_VERSION")
    );
    println!("cargo:rustc-env=WX_CLI_GIT_SHA={git_sha}");
    println!("cargo:rustc-env=WX_CLI_GIT_DIRTY={git_dirty}");
}

fn emit_git_head_ref_rerun_hint() {
    let Some(git_dir) = git_dir() else {
        return;
    };
    let head_path = git_dir.join("HEAD");
    let Ok(head) = std::fs::read_to_string(&head_path) else {
        return;
    };
    let Some(head_ref) = head.trim().strip_prefix("ref: ") else {
        return;
    };
    println!(
        "cargo:rerun-if-changed={}",
        git_dir.join(head_ref).display()
    );
}

fn git_dir() -> Option<PathBuf> {
    let git_path = PathBuf::from(".git");
    if git_path.is_dir() {
        return Some(git_path);
    }

    let git_file = std::fs::read_to_string(&git_path).ok()?;
    let git_dir = git_file.trim().strip_prefix("gitdir: ")?.trim();
    let git_dir = PathBuf::from(git_dir);
    if git_dir.is_absolute() {
        Some(git_dir)
    } else {
        Some(
            git_path
                .parent()
                .unwrap_or_else(|| std::path::Path::new("."))
                .join(git_dir),
        )
    }
}

fn git_output(args: &[&str]) -> Option<String> {
    let out = Command::new("git").args(args).output().ok()?;
    if !out.status.success() {
        return None;
    }
    Some(String::from_utf8_lossy(&out.stdout).trim().to_string())
}