//! build

use anyhow::Result;
use clap::CommandFactory;
use clap::ValueEnum;
use clap_complete::Shell;

use std::env;
use std::fs;
use std::path::PathBuf;

// include the cli definition
pub mod cli {
    include!("src/cli/cli_args.rs");
}

const ASSET_OUT_ENV_NAME: &str = "ASSET_OUT_DIR";

/// Returns a path to a directory suitable as a target for generated
/// files.
fn out_dir(section: &str) -> Result<PathBuf> {
    println!("cargo:rerun-if-env-changed={}", ASSET_OUT_ENV_NAME);

    let outdir: PathBuf = env::var_os(ASSET_OUT_ENV_NAME)
        .unwrap_or_else(|| env::var_os("OUT_DIR")
            .expect("OUT_DIR not set")
        ).into();

    if outdir.exists() && ! outdir.is_dir() {
        return Err(anyhow::anyhow!("{:?} is not a directory", outdir));
    }
    let path = outdir.join(section);
    fs::create_dir_all(&path)?;
    Ok(path)
}

fn main() -> Result<()> {
    let mut husk = cli::CliArgs::command();

    // shell completions
    let shell_completion_path = out_dir("shell_completions")?;
    for shell in Shell::value_variants() {
        clap_complete::generate_to(*shell, &mut husk, "husk", &shell_completion_path)?;
    }

    println!("cargo:warning=shell completions written to {}", shell_completion_path.display());

    Ok(())
}