use nom::{
    branch::alt,
    bytes::complete::{tag, take_till, take_till1},
    combinator::eof,
    error::Error,
    multi::fold_many0,
    sequence::{pair, tuple},
    Err, Parser,
};

enum AnsiFrag<'l> {
    Lit(&'l str),
    Special(&'l str),
}
use AnsiFrag::Special;

pub fn parse_ansi_markup(i: &str) -> Result<String, Err<Error<&str>>> {
    pair(
        fold_many0(
            alt((
                take_till1(|c| c == '<').map(AnsiFrag::Lit),
                tuple((tag("<"), take_till(|c| c == '>'), tag(">")))
                    .map(|t| AnsiFrag::Special(t.1)),
            )),
            || "".to_owned(),
            |a, r| {
                a + match r {
                    AnsiFrag::Lit(s) => &s,
                    Special(s) if s == "reset" => "\x1b[0m",
                    Special(s) if s == "bold" => "\x1b[1m",
                    Special(s) if s == "under" => "\x1b[4m",
                    Special(s) if s == "strike" => "\x1b[9m",
                    Special(s) if s == "nounder" => "\x1b[24m",
                    Special(s) if s == "black" => "\x1b[30m",
                    Special(s) if s == "red" => "\x1b[31m",
                    Special(s) if s == "green" => "\x1b[32m",
                    Special(s) if s == "yellow" => "\x1b[33m",
                    Special(s) if s == "blue" => "\x1b[34m",
                    Special(s) if s == "magenta" => "\x1b[35m",
                    Special(s) if s == "cyan" => "\x1b[36m",
                    Special(s) if s == "white" => "\x1b[37m",
                    Special(s) if s == "bgblack" => "\x1b[40m",
                    Special(s) if s == "bgred" => "\x1b[41m",
                    Special(s) if s == "bggreen" => "\x1b[42m",
                    Special(s) if s == "bgyellow" => "\x1b[43m",
                    Special(s) if s == "bgblue" => "\x1b[44m",
                    Special(s) if s == "bgmagenta" => "\x1b[45m",
                    Special(s) if s == "bgcyan" => "\x1b[46m",
                    Special(s) if s == "bgwhite" => "\x1b[47m",
                    Special(s) if s == "lt" => "<",
                    Special(r) => panic!("Unknown ansi type {}", r),
                }
            },
        ),
        eof,
    )(i)
    .map(|(_, (r, _))| r)
}

pub fn parse_ansi_markup_escape(i: &str) -> Result<String, Err<Error<&str>>> {
    parse_ansi_markup(i).map(|o| o.replace('\x1b', "\\e"))
}