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

#[derive(Clone, Copy, PartialEq, Eq, Hash, Debug, Serialize, Deserialize)]
pub enum Ship {
    Battleship,
    Carrier,
    Cruiser,
    Destroyer,
    Submarine
}

impl fmt::Display for Ship {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        use Ship::*;
        
        f.write_str(
            match self {
                &Battleship => "Battleship",
                &Carrier => "Carrier",
                &Cruiser => "Cruiser",
                &Destroyer => "Destroyer",
                &Submarine => "Submarine"
            }
        )
    }
}

impl str::FromStr for Ship {
    type Err = String;
    fn from_str(s: &str) -> Result<Self, Self::Err> {
        use Ship::*;
        
        match s {
            "Battleship" => Ok(Battleship),
            "Carrier" => Ok(Carrier),
            "Cruiser" => Ok(Cruiser),
            "Destroyer" => Ok(Destroyer),
            "Submarine" => Ok(Submarine),
            _ => Err(String::from("ship type is not known"))
        }
    }
}

impl Ship {
    pub fn length(&self) -> u16 {
        use Ship::*;
        
        match self {
            &Battleship => 4,
            &Carrier => 5,
            &Cruiser => 3,
            &Destroyer => 2,
            &Submarine => 3
        }
    }

    pub fn all_types() -> Vec<Ship> {
        use Ship::*;
        
        vec!(
            Battleship,
            Carrier,
            Cruiser,
            Destroyer,
            Submarine
        )
    }
}