wearte_derive 0.0.2

// Based on https://github.com/dtolnay/cargo-expand

use prettyprint::{PagingMode, PrettyPrinter};

use std::env;
use std::ffi::OsString;
use std::fs;
use std::io::{self, Write};
use std::path::PathBuf;
use std::process::{Command, Stdio};

use wearte_config::PrintOption;

pub fn log(s: &str, path: String, option: &PrintOption) {
    if definitely_not_nightly() {
        logger(s, path, option);
    } else {
        writeln!(io::stdout(), "{}", s).unwrap();
    }
}

fn logger(s: &str, path: String, option: &PrintOption) {
    let rustfmt =
        which_rustfmt().expect("Install rustfmt by running `rustup component add rustfmt`.");

    let mut builder = tempfile::Builder::new();
    builder.prefix("wearte");
    let outdir = builder.tempdir().expect("failed to create tmp file");
    let outfile_path = outdir.path().join("expanded");
    fs::write(&outfile_path, s).expect("correct write to file");

    // Ignore any errors.
    let _status = Command::new(rustfmt)
        .arg(&outfile_path)
        .stderr(Stdio::null())
        .status();

    let s = fs::read_to_string(&outfile_path).unwrap();
    let mut builder = PrettyPrinter::default();
    builder.header(true);
    builder.grid(false);
    builder.line_numbers(option.number_line.unwrap_or(false));
    builder.language("rust");
    builder.paging_mode(PagingMode::Never);

    let printer = if let Some(theme) = option.theme {
        builder.theme(theme);
        let printer = builder.build().unwrap();
        let themes = printer.get_themes();
        if themes.get(theme).is_none() {
            let msg: Vec<String> = themes.keys().map(|x| format!("{:?}", x)).collect();
            eprintln!("Themes: {}", msg.join(",\n        "));
        }
        printer
    } else {
        builder.theme(DEFAULT_THEME);
        builder.build().unwrap()
    };

    // Ignore any errors.
    let _ = printer.string_with_header(s, path);
}

fn cargo_binary() -> OsString {
    env::var_os("CARGO").unwrap_or_else(|| "cargo".to_owned().into())
}

fn definitely_not_nightly() -> bool {
    let mut cmd = Command::new(cargo_binary());
    cmd.arg("--version");

    let output = match cmd.output() {
        Ok(output) => output,
        Err(_) => return false,
    };

    let version = match String::from_utf8(output.stdout) {
        Ok(version) => version,
        Err(_) => return false,
    };

    version.starts_with("cargo 1") && !version.contains("nightly")
}

fn which_rustfmt() -> Option<PathBuf> {
    match env::var_os("RUSTFMT") {
        Some(which) => {
            if which.is_empty() {
                None
            } else {
                Some(PathBuf::from(which))
            }
        }
        None => toolchain_find::find_installed_component("rustfmt"),
    }
}

static DEFAULT_THEME: &str = "zenburn";