use mlua::FromLuaMulti;

pub enum CursorMove {
    Up(usize),
    Down(usize),
    Left(usize),
    Right(usize),
    Top,
    Bottom,
    Begin,
    End,
    Jump((usize, usize)),
    Relative((isize, isize)),
}

impl<'lua> FromLuaMulti<'lua> for CursorMove {
    fn from_lua_multi(
        values: mlua::prelude::LuaMultiValue<'lua>,
        _lua: &'lua mlua::prelude::Lua,
    ) -> mlua::prelude::LuaResult<Self> {
        let first = values
            .get(1)
            .filter(|v| v.is_integer() || v.is_number())
            .map(|v| {
                if v.is_number() {
                    v.as_number().unwrap_or(0.0)
                } else {
                    v.as_number().unwrap_or(0.0)
                }
            })
            .map(|n| n as usize);

        let second = values
            .get(2)
            .filter(|v| v.is_integer() || v.is_number())
            .map(|v| {
                if v.is_number() {
                    v.as_number().unwrap()
                } else {
                    v.as_number().unwrap()
                }
            })
            .map(|n| n as usize);

        if let Some(value) = values.get(0) {
            if value.is_string() {
                match value.as_str().unwrap().to_lowercase().as_str() {
                    "up" => return Ok(CursorMove::Up(first.unwrap_or(1))),
                    "down" => return Ok(CursorMove::Down(first.unwrap_or(1))),
                    "left" => return Ok(CursorMove::Left(first.unwrap_or(1))),
                    "right" => return Ok(CursorMove::Right(first.unwrap_or(1))),
                    "top" => return Ok(CursorMove::Top),
                    "bottom" => return Ok(CursorMove::Bottom),
                    "begin" => return Ok(CursorMove::Begin),
                    "end" => return Ok(CursorMove::End),
                    "jump" => {
                        if first.is_some() && second.is_some() {
                            return Ok(CursorMove::Jump((first.unwrap(), second.unwrap())));
                        }

                        return Err(mlua::Error::runtime("invalid row, column values"));
                    }
                    "relative" => {
                        if first.is_some() && second.is_some() {
                            return Ok(CursorMove::Jump((first.unwrap(), second.unwrap())));
                        }

                        return Err(mlua::Error::runtime("invalid row, column values"));
                    }
                    _ => {}
                }
            }
        }

        Err(mlua::Error::runtime("invalid first value"))
    }
}

#[derive(Default, Debug, Clone)]
pub struct Cursor {
    x: isize,
    y: isize,
    x_max: isize,
    y_max: isize,
}

impl Cursor {
    pub const fn new() -> Self {
        Self {
            x: 0,
            y: 0,
            x_max: 0,
            y_max: 0,
        }
    }

    pub const fn with_position(mut self, x: isize, y: isize) -> Self {
        self.x = x;
        self.y = y;
        self
    }

    pub const fn with_max(mut self, x: isize, y: isize) -> Self {
        self.x_max = x;
        self.y_max = y;
        self
    }

    pub fn x(&self) -> usize {
        self.x as usize
    }

    pub fn y(&self) -> usize {
        self.y as usize
    }

    pub fn set_x_max(&mut self, max: usize) {
        self.x_max = max as isize;
    }

    pub fn set_y_max(&mut self, max: usize) {
        self.y_max = max as isize;
    }

    pub fn move_checked(&mut self, m: CursorMove) {
        self.move_unchecked(m);
        self.correct_cursor_position();
    }

    pub fn move_unchecked(&mut self, m: CursorMove) {
        match m {
            CursorMove::Up(n) => self.y -= n as isize,
            CursorMove::Down(n) => self.y += n as isize,
            CursorMove::Left(n) => self.x -= n as isize,
            CursorMove::Right(n) => self.x += n as isize,
            CursorMove::Top => self.y = 0,
            CursorMove::Bottom => self.y = self.y_max,
            CursorMove::Begin => self.x = 0,
            CursorMove::End => self.x = self.x_max,
            CursorMove::Jump((x, y)) => {
                self.x = x as isize;
                self.y = y as isize;
            }
            CursorMove::Relative((x, y)) => {
                self.x += x;
                self.y += y;
            }
        };
    }

    pub fn correct_cursor_position(&mut self) {
        self.y = self.y.max(0).min(self.y_max);
        self.x = self.x.max(0).min(self.x_max);
    }

    pub fn is_at_start(&self) -> bool {
        self.x == 0
    }

    pub fn is_at_end(&self) -> bool {
        self.x == self.x_max
    }

    pub fn is_at_top(&self) -> bool {
        self.y == 0
    }

    pub fn is_at_bottom(&self) -> bool {
        self.y == self.y_max
    }
}