mikronova/draupnir

crates/draupnir-build-thing/src/main.rs

//! `draupnir-build-thing` — the recipe's door.
//!
//! * `--list` — every declared variant and what builds it.
//! * `toml` — the emitted `.nornir/build-variants.toml` on stdout.
//! * `emit` — REGENERATE `<repo>/.nornir/build-variants.toml` from the code
//!   (the repo root is found from this crate's manifest dir; `emit <root>`
//!   names another).
//!
//! It owns no build knowledge (LAW 5): every answer comes from the recipe's own
//! `variants()`.

use std::path::PathBuf;
use std::process::ExitCode;

use draupnir_build_thing::{emit::repo_root, DraupnirBuildThing};
use nornir_build_thing::plugin::BuildThing;

fn main() -> ExitCode {
    let args: Vec<String> = std::env::args().skip(1).collect();
    match args.first().map(String::as_str) {
        Some("--list") => {
            let set = DraupnirBuildThing.variants();
            for v in &set.variants {
                let what = if v.kind.is_cargo() {
                    v.command_line()
                } else {
                    format!(
                        "(typ {}: built by the {} builder, runs no cargo)",
                        v.kind.as_str(),
                        v.kind.as_str()
                    )
                };
                println!("{:<28} {what}", v.name);
            }
            ExitCode::SUCCESS
        }
        Some("toml") => match draupnir_build_thing::emitted_toml() {
            Ok(t) => {
                print!("{t}");
                ExitCode::SUCCESS
            }
            Err(e) => {
                eprintln!("draupnir-build-thing: {e:#}");
                ExitCode::FAILURE
            }
        },
        Some("emit") => {
            let root = args.get(1).map(PathBuf::from).unwrap_or_else(repo_root);
            match draupnir_build_thing::write_emitted(&root) {
                Ok(p) => {
                    println!("emitted {}", p.display());
                    ExitCode::SUCCESS
                }
                Err(e) => {
                    eprintln!("draupnir-build-thing: {e:#}");
                    ExitCode::FAILURE
                }
            }
        }
        _ => {
            eprintln!("usage: draupnir-build-thing --list | toml | emit [<repo-root>]");
            ExitCode::FAILURE
        }
    }
}