use std::convert::Infallible;
use std::io::{self, IsTerminal};
use std::rc::Rc;
use std::time::Instant;

use avril_core::{Extension, Op};

use avril_ext_stdio::Stdio;

/// Whether inspected values written to this stream should be colored.
pub fn colors(stderr: bool) -> bool {
    let terminal = if stderr {
        io::stderr().is_terminal()
    } else {
        io::stdout().is_terminal()
    };
    terminal && std::env::var_os("NO_COLOR").is_none_or(|value| value.is_empty())
}

pub fn init(stdio: Rc<Stdio>) -> Extension {
    let clear = stdio.clone();
    let start = Instant::now();
    Extension {
        name: "ext:console",
        dependencies: &[],
        ops: vec![
            Op::new("op_console_print", move |(stderr, text): (bool, String)| {
                stdio.print(stderr, text)
            }),
            Op::new("op_console_clear", move |_: ()| {
                if io::stdout().is_terminal() {
                    clear.print(false, "\x1b[1;1H\x1b[0J".into())?;
                }
                Ok::<_, io::Error>(())
            }),
            Op::new("op_console_colors", |stderr: bool| {
                Ok::<_, Infallible>(colors(stderr))
            }),
            Op::new("op_console_now", move |_: ()| {
                Ok::<_, io::Error>(start.elapsed().as_secs_f64() * 1000.0)
            }),
        ],
        modules: &[
            (
                "ext:console/main.js",
                include_str!(concat!(env!("OUT_DIR"), "/main.js")),
            ),
            (
                "ext:console/inspect.js",
                include_str!(concat!(env!("OUT_DIR"), "/inspect.js")),
            ),
            (
                "ext:console/format.js",
                include_str!(concat!(env!("OUT_DIR"), "/format.js")),
            ),
            (
                "ext:console/table.js",
                include_str!(concat!(env!("OUT_DIR"), "/table.js")),
            ),
        ],
        entry_point: Some("ext:console/main.js"),
    }
}