use crate::*;
use crate::ratatui::prelude::Position;
use unicode_width::{UnicodeWidthStr, UnicodeWidthChar};

/// Displays an owned [str]-like with fixed maximum width.
///
/// Width is computed using [unicode_width].
pub struct TrimString<T: AsRef<str>>(pub u16, pub T);

impl<'a, T: AsRef<str>> TrimString<T> {
    fn as_ref (&self) -> TrimStringRef<'_, T> {
        TrimStringRef(self.0, &self.1)
    }
}
impl<'a, T: AsRef<str>> Content<TuiOut> for TrimString<T> {
    fn layout (&self, to: [u16; 4]) -> [u16;4] {
        Content::layout(&self.as_ref(), to)
    }
    fn render (&self, to: &mut TuiOut) {
        Content::render(&self.as_ref(), to)
    }
}

/// Displays a borrowed [str]-like with fixed maximum width
///
/// Width is computed using [unicode_width].
pub struct TrimStringRef<'a, T: AsRef<str>>(pub u16, pub &'a T);

impl<T: AsRef<str>> Content<TuiOut> for TrimStringRef<'_, T> {
    fn layout (&self, to: [u16; 4]) -> [u16;4] {
        [to.x(), to.y(), to.w().min(self.0).min(self.1.as_ref().width() as u16), to.h()]
    }
    fn render (&self, target: &mut TuiOut) {
        let area = target.area();
        let mut width: u16 = 1;
        let mut chars = self.1.as_ref().chars();
        while let Some(c) = chars.next() {
            if width > self.0 || width > area.w() {
                break
            }
            if let Some(cell) = target.buffer.cell_mut(Position {
                x: area.x() + width - 1,
                y: area.y()
            }) {
                cell.set_char(c);
            }
            width += c.width().unwrap_or(0) as u16;
        }
    }
}