// TODO: read all of this from terminfo

pub trait BufWrite {
    fn write_buf(&self, buf: &mut Vec<u8>);
}

#[derive(Default, Debug)]
#[must_use = "this struct does nothing unless you call write_buf"]
pub struct ClearScreen;

impl BufWrite for ClearScreen {
    fn write_buf(&self, buf: &mut Vec<u8>) {
        buf.extend_from_slice(b"\x1b[H\x1b[J");
    }
}

#[derive(Default, Debug)]
#[must_use = "this struct does nothing unless you call write_buf"]
pub struct ClearRowForward;

impl BufWrite for ClearRowForward {
    fn write_buf(&self, buf: &mut Vec<u8>) {
        buf.extend_from_slice(b"\x1b[K");
    }
}

#[derive(Default, Debug)]
#[must_use = "this struct does nothing unless you call write_buf"]
pub struct CRLF;

impl BufWrite for CRLF {
    fn write_buf(&self, buf: &mut Vec<u8>) {
        buf.extend_from_slice(b"\r\n");
    }
}

#[derive(Default, Debug)]
#[must_use = "this struct does nothing unless you call write_buf"]
pub struct MoveTo {
    row: u16,
    col: u16,
}

impl MoveTo {
    pub fn new(pos: crate::grid::Pos) -> Self {
        Self {
            row: pos.row,
            col: pos.col,
        }
    }
}

impl BufWrite for MoveTo {
    fn write_buf(&self, buf: &mut Vec<u8>) {
        if self.row == 0 && self.col == 0 {
            buf.extend_from_slice(b"\x1b[H");
        } else {
            buf.extend_from_slice(b"\x1b[");
            itoa::write(&mut *buf, self.row + 1).unwrap();
            buf.push(b';');
            itoa::write(&mut *buf, self.col + 1).unwrap();
            buf.push(b'H');
        }
    }
}

#[derive(Default, Debug)]
#[must_use = "this struct does nothing unless you call write_buf"]
pub struct ClearAttrs;

impl BufWrite for ClearAttrs {
    fn write_buf(&self, buf: &mut Vec<u8>) {
        buf.extend_from_slice(b"\x1b[m")
    }
}

#[derive(Default, Debug)]
#[must_use = "this struct does nothing unless you call write_buf"]
pub struct Attrs {
    fgcolor: Option<crate::attrs::Color>,
    bgcolor: Option<crate::attrs::Color>,
    bold: Option<bool>,
    italic: Option<bool>,
    underline: Option<bool>,
    inverse: Option<bool>,
}

impl Attrs {
    pub fn fgcolor(mut self, fgcolor: crate::attrs::Color) -> Self {
        self.fgcolor = Some(fgcolor);
        self
    }

    pub fn bgcolor(mut self, bgcolor: crate::attrs::Color) -> Self {
        self.bgcolor = Some(bgcolor);
        self
    }

    pub fn bold(mut self, bold: bool) -> Self {
        self.bold = Some(bold);
        self
    }

    pub fn italic(mut self, italic: bool) -> Self {
        self.italic = Some(italic);
        self
    }

    pub fn underline(mut self, underline: bool) -> Self {
        self.underline = Some(underline);
        self
    }

    pub fn inverse(mut self, inverse: bool) -> Self {
        self.inverse = Some(inverse);
        self
    }
}

impl BufWrite for Attrs {
    #[allow(unused_assignments)]
    fn write_buf(&self, buf: &mut Vec<u8>) {
        if self.fgcolor.is_none()
            && self.bgcolor.is_none()
            && self.bold.is_none()
            && self.italic.is_none()
            && self.underline.is_none()
            && self.inverse.is_none()
        {
            return;
        }

        buf.extend_from_slice(b"\x1b[");
        let mut first = true;

        macro_rules! write_param {
            ($i:expr) => {
                if first {
                    first = false;
                } else {
                    buf.push(b';');
                }
                itoa::write(&mut *buf, $i).unwrap();
            };
        }

        if let Some(fgcolor) = self.fgcolor {
            match fgcolor {
                crate::attrs::Color::Default => {
                    write_param!(39);
                }
                crate::attrs::Color::Idx(i) => {
                    if i < 8 {
                        write_param!(i + 30);
                    } else if i < 16 {
                        write_param!(i + 82);
                    } else {
                        write_param!(38);
                        write_param!(5);
                        write_param!(i);
                    }
                }
                crate::attrs::Color::Rgb(r, g, b) => {
                    write_param!(38);
                    write_param!(2);
                    write_param!(r);
                    write_param!(g);
                    write_param!(b);
                }
            }
        }

        if let Some(bgcolor) = self.bgcolor {
            match bgcolor {
                crate::attrs::Color::Default => {
                    write_param!(49);
                }
                crate::attrs::Color::Idx(i) => {
                    if i < 8 {
                        write_param!(i + 40);
                    } else if i < 16 {
                        write_param!(i + 92);
                    } else {
                        write_param!(48);
                        write_param!(5);
                        write_param!(i);
                    }
                }
                crate::attrs::Color::Rgb(r, g, b) => {
                    write_param!(48);
                    write_param!(2);
                    write_param!(r);
                    write_param!(g);
                    write_param!(b);
                }
            }
        }

        if let Some(bold) = self.bold {
            if bold {
                write_param!(1);
            } else {
                write_param!(22);
            }
        }

        if let Some(italic) = self.italic {
            if italic {
                write_param!(3);
            } else {
                write_param!(23);
            }
        }

        if let Some(underline) = self.underline {
            if underline {
                write_param!(4);
            } else {
                write_param!(24);
            }
        }

        if let Some(inverse) = self.inverse {
            if inverse {
                write_param!(7);
            } else {
                write_param!(27);
            }
        }

        buf.push(b'm');
    }
}

#[derive(Debug)]
#[must_use = "this struct does nothing unless you call write_buf"]
pub struct MoveRight {
    count: u16,
}

impl MoveRight {
    pub fn new(count: u16) -> Self {
        Self { count }
    }
}

impl Default for MoveRight {
    fn default() -> Self {
        Self { count: 1 }
    }
}

impl BufWrite for MoveRight {
    fn write_buf(&self, buf: &mut Vec<u8>) {
        match self.count {
            0 => {}
            1 => buf.extend_from_slice(b"\x1b[C"),
            n => {
                buf.extend_from_slice(b"\x1b[");
                itoa::write(&mut *buf, n).unwrap();
                buf.push(b'C');
            }
        }
    }
}

#[derive(Debug)]
#[must_use = "this struct does nothing unless you call write_buf"]
pub struct EraseChar {
    count: u16,
}

impl EraseChar {
    pub fn new(count: u16) -> Self {
        Self { count }
    }
}

impl Default for EraseChar {
    fn default() -> Self {
        Self { count: 1 }
    }
}

impl BufWrite for EraseChar {
    fn write_buf(&self, buf: &mut Vec<u8>) {
        match self.count {
            0 => {}
            1 => buf.extend_from_slice(b"\x1b[X"),
            n => {
                buf.extend_from_slice(b"\x1b[");
                itoa::write(&mut *buf, n).unwrap();
                buf.push(b'X');
            }
        }
    }
}

#[derive(Default, Debug)]
#[must_use = "this struct does nothing unless you call write_buf"]
pub struct HideCursor {
    hide: bool,
}

impl HideCursor {
    pub fn new(hide: bool) -> Self {
        Self { hide }
    }
}

impl BufWrite for HideCursor {
    fn write_buf(&self, buf: &mut Vec<u8>) {
        if self.hide {
            buf.extend_from_slice(b"\x1b[?25l")
        } else {
            buf.extend_from_slice(b"\x1b[?25h")
        }
    }
}

#[derive(Debug)]
#[must_use = "this struct does nothing unless you call write_buf"]
pub struct MoveFromTo {
    from: crate::grid::Pos,
    to: crate::grid::Pos,
}

impl MoveFromTo {
    pub fn new(from: crate::grid::Pos, to: crate::grid::Pos) -> Self {
        Self { from, to }
    }
}

impl BufWrite for MoveFromTo {
    fn write_buf(&self, buf: &mut Vec<u8>) {
        if self.to.row == self.from.row + 1 && self.to.col == 0 {
            crate::term::CRLF::default().write_buf(buf);
        } else if self.from.row == self.to.row && self.from.col < self.to.col
        {
            crate::term::MoveRight::new(self.to.col - self.from.col)
                .write_buf(buf);
        } else if self.to != self.from {
            crate::term::MoveTo::new(self.to).write_buf(buf);
        }
    }
}

#[derive(Default, Debug)]
#[must_use = "this struct does nothing unless you call write_buf"]
pub struct AudibleBell;

impl BufWrite for AudibleBell {
    fn write_buf(&self, buf: &mut Vec<u8>) {
        buf.push(b'\x07');
    }
}

#[derive(Default, Debug)]
#[must_use = "this struct does nothing unless you call write_buf"]
pub struct VisualBell;

impl BufWrite for VisualBell {
    fn write_buf(&self, buf: &mut Vec<u8>) {
        buf.extend_from_slice(b"\x1bg");
    }
}