shelly 0.2.2

use std::fs;
use std::path;

use anyhow::{Result, anyhow};
use clap::Clap;

use shelly::config::{Config, SupportedLanguage, Target};
use shelly::elixir;

/// Generate dynamic, scripting language projects with dependencies for
/// quick CLI feedback loops.
#[derive(Clap)]
#[clap(version = "1.0", author = "Alex M. <alex41290@gmail.com>")]
struct Opts {
    /// Path to create project
    #[clap(default_value = ".")]
    path: String,

    /// Drop into REPL after building
    #[clap(short, long)]
    shell: bool,

    /// A target is a language and dependencies pairing
    #[clap(short, long)]
    target: Option<String>,

    #[clap(short, long)]
    config: Option<String>,
}

const DEFAULT_CONFIG: &'static str = include_str!("./templates/shelly.yml");

fn main() -> Result<()> {
    let opts: Opts = Opts::parse();

    let config_file = if let Some(cfg) = opts.config {
        fs::read_to_string(cfg)?
    } else {
        let home_path = path::PathBuf::from(std::env::var("HOME")?);
        let path = home_path.join(".config").join("shelly");

        if path.clone().join("shelly.yml").as_path().exists() {
            fs::read_to_string(path.clone().join("shelly.yml"))?
        } else {
            fs::create_dir_all(path.clone())?;
            fs::write(path.join("shelly.yml"), DEFAULT_CONFIG)?;
            String::from(DEFAULT_CONFIG)
        }
    };

    let config: Config = serde_yaml::from_str(config_file.as_str())?;

    let target_name = if let Some(t) = opts.target {
        t
    } else {
        config.default_target
    };
    let target = config
        .targets
        .get(&target_name)
        .expect("Target not specified in `shelly.yml` file");
    let Target { language, deps } = target;

    match language {
        SupportedLanguage::elixir => {
            elixir::write_project(opts.path, deps.clone())?;
            elixir::run(opts.shell)?;
            Ok(())
        }
        SupportedLanguage::node => Err(anyhow!("Language 'node' not supported yet")),
        SupportedLanguage::rust => Err(anyhow!("Language 'rust' not supported yet")),
    }
}