ukebox 0.9.1

use std::fmt;
use std::str::FromStr;

use clap;
use clap::ArgEnum;

use crate::{Interval, Note, Semitones};

// Using clap's `arg_enum` macro allows the specification of all Tuning
// variants as `possible_values` for the CLI `--tuning` option.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, ArgEnum)]
#[clap(rename_all = "UPPER")]
pub enum Tuning {
    C,
    D,
    G,
}

impl Tuning {
    pub fn get_semitones(self) -> Semitones {
        match self {
            Self::C => 0,
            Self::D => 2,
            Self::G => 7,
        }
    }

    pub fn get_interval(self) -> Interval {
        match self {
            Self::C => Interval::PerfectUnison,
            Self::D => Interval::MajorSecond,
            Self::G => Interval::PerfectFifth,
        }
    }

    pub fn roots(self) -> impl Iterator<Item = Note> + 'static {
        let interval = self.get_interval();

        ["G", "C", "E", "A"]
            .iter()
            .map(move |c| Note::from_str(c).unwrap() + interval)
    }
}

impl fmt::Display for Tuning {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        let s = match self {
            Tuning::C => "C",
            Tuning::D => "D",
            Tuning::G => "G",
        };

        write!(f, "{}", s)
    }
}