mod build;
mod edit;

pub use build::*;
pub use edit::*;
use iris_core::util::MutDetect;

use crate::prelude::*;
use std::ops::{Deref, DerefMut};

pub struct Text {
    pub content: MutDetect<String>,
    view: TextView,
}

pub struct TextView {
    pub attrs: MutDetect<TextAttrs>,
    pub buf: MutDetect<TextBuffer>,
    // cache
    tex: Option<RenderedText>,
    width: Option<f32>,
    pub hint: Option<StrongWidget>,
}

impl TextView {
    fn is_blank(&self) -> bool {
        self.buf.is_empty()
    }

    /// The width used by the cached layout.
    pub fn wrap_width(&self) -> Option<f32> {
        self.width
    }
}

impl TextView {
    pub fn new(buf: TextBuffer, attrs: TextAttrs, hint: Option<StrongWidget>) -> Self {
        Self {
            attrs: attrs.into(),
            buf: buf.into(),
            tex: None,
            width: None,
            hint,
        }
    }

    /// region where the text should be draw
    /// does not include extra height or width from weird unicode
    pub fn region(&self) -> UiRegion {
        self.tex()
            .map(|t| t.size)
            .unwrap_or(Vec2::ZERO)
            .align(self.align)
    }

    fn render(&mut self, ctx: &mut SizeCtx) -> RenderedText {
        let width = if self.attrs.wrap {
            Some(ctx.px_size().x)
        } else {
            None
        };
        if width == self.width
            && let Some(tex) = &self.tex
            && !self.attrs.changed
            && !self.buf.changed
        {
            return tex.clone();
        }
        self.width = width;
        let tex = ctx.draw_text(&mut self.buf, &self.attrs, width);
        self.tex = Some(tex.clone());
        self.attrs.changed = false;
        self.buf.changed = false;
        tex
    }
    pub fn tex(&self) -> Option<&RenderedText> {
        self.tex.as_ref()
    }
    pub fn desired_width(&mut self, ctx: &mut SizeCtx) -> Len {
        if self.is_blank()
            && let Some(hint) = &self.hint
        {
            ctx.width(hint)
        } else {
            Len::abs(self.render(ctx).size.x)
        }
    }
    pub fn desired_height(&mut self, ctx: &mut SizeCtx) -> Len {
        if self.is_blank()
            && let Some(hint) = &self.hint
        {
            ctx.height(hint)
        } else {
            Len::abs(self.render(ctx).size.y)
        }
    }
    pub fn draw(&mut self, painter: &mut Painter) -> UiRegion {
        let tex = self.render(&mut painter.size_ctx());
        let region = tex.size.align(self.align);
        if self.is_blank()
            && let Some(hint) = &self.hint
        {
            painter.widget(hint);
        } else {
            let within = region.within(&painter.region());
            painter.glyphs(&tex, within);
        }
        region
    }

    pub fn content(&self) -> String {
        self.buf.text().to_string()
    }
}

impl Text {
    pub fn new(content: impl Into<String>) -> Self {
        let content: String = content.into();
        Self {
            view: TextView::new(TextBuffer::new(&content), TextAttrs::default(), None),
            content: content.into(),
        }
    }
    fn update_buf(&mut self, _ctx: &mut SizeCtx) {
        if self.content.changed {
            self.content.changed = false;
            self.view.buf.set_text(self.content.as_str());
        }
    }
}

impl Widget for Text {
    fn draw(&mut self, painter: &mut Painter) {
        self.update_buf(&mut painter.size_ctx());
        self.view.draw(painter);
    }

    fn desired_width(&mut self, ctx: &mut SizeCtx) -> Len {
        self.update_buf(ctx);
        self.view.desired_width(ctx)
    }

    fn desired_height(&mut self, ctx: &mut SizeCtx) -> Len {
        self.update_buf(ctx);
        self.view.desired_height(ctx)
    }
}

impl Deref for Text {
    type Target = TextAttrs;

    fn deref(&self) -> &Self::Target {
        &self.view
    }
}

impl DerefMut for Text {
    fn deref_mut(&mut self) -> &mut Self::Target {
        &mut self.view
    }
}

impl Deref for TextView {
    type Target = TextAttrs;

    fn deref(&self) -> &Self::Target {
        &self.attrs
    }
}

impl DerefMut for TextView {
    fn deref_mut(&mut self) -> &mut Self::Target {
        &mut self.attrs
    }
}