use cosmic_text::{Family, Metrics};

use crate::prelude::*;

pub struct Text {
    pub content: String,
    pub attrs: TextAttrs,
    buf: TextBuffer,
}

impl Text {
    pub fn font_size(mut self, size: impl UiNum) -> Self {
        self.attrs.font_size = size.to_f32();
        self.attrs.line_height = self.attrs.font_size * 1.1;
        self
    }
    pub fn color(mut self, color: UiColor) -> Self {
        self.attrs.color = color;
        self
    }
    pub fn family(mut self, family: Family<'static>) -> Self {
        self.attrs.family = family;
        self
    }
    pub fn line_height(mut self, height: f32) -> Self {
        self.attrs.line_height = height;
        self
    }
    pub fn new(content: impl Into<String>) -> Self {
        let attrs = TextAttrs::default();
        Self {
            content: content.into(),
            buf: TextBuffer::new_empty(Metrics::new(attrs.font_size, attrs.line_height)),
            attrs,
        }
    }
}

impl Widget for Text {
    fn draw(&mut self, painter: &mut Painter) {
        let (handle, offset) = painter.render_text(&mut self.buf, &self.content, &self.attrs);
        let dims = handle.size();
        let size = offset.size(&handle);
        let mut region = painter.region().center().expand(size);
        region.top_left.offset += offset.top_left;
        region.bot_right.offset = region.top_left.offset + dims;
        painter.draw_texture_at(&handle, region);
        // TODO: when on_update is added to painter,
        // reuse TextureHandle
    }

    fn get_size(&mut self, ctx: &mut SizeCtx) -> Vec2 {
        let (handle, offset) =
            ctx.text
                .draw(&mut self.buf, &self.content, &self.attrs, ctx.textures);
        offset.size(&handle)
    }
}

pub fn text(content: impl Into<String>) -> Text {
    Text::new(content)
}