use std::fmt;

use crate::bitmap::MapPoint;

#[derive(Debug, Copy, Clone)]
pub enum Brush {
    Line {
        size: u8,
        start: Option<MapPoint>,
        extend: bool,
    },
    Circle {
        size: u8,
    },
    RectSelect {
        start: MapPoint,
        end: MapPoint,
    },
    Fill,
    Custom {
        size: u8,
    },
}

impl Brush {
    pub fn grow(&mut self) -> Result<(), BrushError> {
        match self {
            Brush::Line { ref mut size, .. } => *size += 1,
            Brush::Circle { ref mut size, .. } => *size += 1,
            Brush::Custom { ref mut size, .. } => *size += 1,
            _ => return Err(BrushError::CannotIncreaseSize),
        }
        Ok(())
    }
    pub fn shrink(&mut self) -> Result<(), BrushError> {
        match self {
            Brush::Line { ref mut size, .. } => *size += size.saturating_sub(1),
            Brush::Circle { ref mut size, .. } => *size += size.saturating_sub(1),
            Brush::Custom { ref mut size, .. } => *size += size.saturating_sub(1),
            _ => return Err(BrushError::CannotIncreaseSize),
        }
        Ok(())
    }
    pub fn new() -> Self {
        Brush::Circle { size: 0 }
    }
    pub fn line(size: u8, extend: bool) -> Self {
        Brush::Line {
            size,
            start: None,
            extend,
        }
    }
    pub fn is_line(&self) -> bool {
        matches!(self, Self::Line { .. })
    }
}

impl fmt::Display for Brush {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            Brush::Line { extend, .. } => write!(f, "LINE{}", if *extend { "+" } else { "" }),
            Brush::Circle { .. } => write!(f, "CIRCLE"),
            Brush::RectSelect { .. } => write!(f, "SELECT"),
            Brush::Fill => write!(f, "FILL"),
            Brush::Custom { .. } => write!(f, "CUSTOM"),
        }
    }
}

pub enum BrushError {
    CannotIncreaseSize,
}