rustmotion_components/

notification.rs

use rustmotion_core::css::CssStyle;
use rustmotion_core::error::Result;
use schemars::JsonSchema;
use serde::{Deserialize, Serialize};
use skia_safe::{Canvas, ColorType, ImageInfo, Paint, PaintStyle, RRect, Rect};

use rustmotion_core::engine::animator::AnimatedProperties;
use rustmotion_core::engine::layout_pass::BoxLayout;
use rustmotion_core::engine::renderer::{
    asset_cache, draw_text_with_fallback, emoji_typeface, fetch_icon_svg, paint_from_hex,
    typeface_with_fallback,
};
use rustmotion_core::schema::TimelineStep;
use rustmotion_core::traits::{PaintCtx, Painter, TimingConfig};

fn default_width() -> f32 {
    360.0
}
fn default_slide_in_at() -> f64 {
    0.5
}
fn default_slide_duration() -> f64 {
    0.15
}
fn default_stack_gap() -> f32 {
    12.0
}

#[derive(Debug, Clone, Serialize, Deserialize, JsonSchema)]
#[serde(rename_all = "snake_case")]
#[derive(Default)]
pub enum NotificationVariant {
    #[default]
    Info,
    Success,
    Warning,
    Error,
}

impl NotificationVariant {
    fn default_color(&self) -> &str {
        match self {
            NotificationVariant::Info => "#3B82F6",
            NotificationVariant::Success => "#22C55E",
            NotificationVariant::Warning => "#F59E0B",
            NotificationVariant::Error => "#EF4444",
        }
    }
}

#[derive(Debug, Serialize, Deserialize, JsonSchema)]
pub struct Notification {
    pub title: String,
    #[serde(default)]
    pub message: Option<String>,
    #[serde(default)]
    pub icon: Option<String>,
    #[serde(default)]
    pub variant: NotificationVariant,
    #[serde(default = "default_width")]
    pub width: f32,
    #[serde(default = "default_slide_in_at")]
    pub slide_in_at: f64,
    #[serde(default)]
    pub slide_out_at: Option<f64>,
    #[serde(default = "default_slide_duration")]
    pub slide_duration: f64,
    #[serde(default)]
    pub accent_color: Option<String>,
    /// Timestamps at which this notification gets pushed down one slot
    /// (i.e. when another notification appears above it).
    #[serde(default)]
    pub push_at: Vec<f64>,
    /// Gap between stacked notifications in pixels (default 12).
    #[serde(default = "default_stack_gap")]
    pub stack_gap: f32,
    /// Delay fade-in until after other notifications finish their push animation.
    /// Set to true when this notification triggers a push_at on others.
    #[serde(default)]
    pub wait_for_push: bool,
    #[serde(flatten)]
    pub timing: TimingConfig,
    #[serde(default)]
    pub style: CssStyle,
    #[serde(default)]
    pub timeline: Vec<TimelineStep>,
    #[serde(default)]
    pub stagger: Option<f32>,
}

rustmotion_core::impl_traits!(Notification {
    Animatable => animation,
    Timed => timing,
    Styled => style,
});

impl Notification {
    fn resolved_accent_color(&self) -> &str {
        self.accent_color
            .as_deref()
            .unwrap_or_else(|| self.variant.default_color())
    }

    /// Resolves `font-size` against a real per-frame viewport (`rem`/`vw`/
    /// `vh` now resolve instead of silently dropping to 0px — lot B, wave
    /// S). `em`/`%` on `font-size` itself remain approximate — see
    /// `crate::intrinsic::font_size_ctx`'s doc comment.
    fn title_font_size(&self, ctx: &PaintCtx) -> f32 {
        self.style.font_size_px_ctx(
            &crate::intrinsic::font_size_ctx(ctx.video_width as f32, ctx.video_height as f32, 0.0),
            16.0,
        )
    }

    fn message_font_size(&self, ctx: &PaintCtx) -> f32 {
        self.title_font_size(ctx) * 0.85
    }

    fn make_font(&self, bold: bool, size: f32) -> Option<skia_safe::Font> {
        let font_style = if bold {
            skia_safe::FontStyle::bold()
        } else {
            skia_safe::FontStyle::normal()
        };
        let family = self.style.font_family.as_deref().unwrap_or("Inter");
        let typeface = typeface_with_fallback(family, font_style).ok()?;
        Some(skia_safe::Font::from_typeface(typeface, size))
    }

    fn compute_opacity(&self, time: f64) -> f32 {
        // Effective start: if wait_for_push, delay by slide_duration so push animations finish first
        let effective_start = if self.wait_for_push {
            self.slide_in_at + self.slide_duration
        } else {
            self.slide_in_at
        };

        // Before fade in
        if time < effective_start {
            return 0.0;
        }

        // During fade in
        let fade_in_end = effective_start + self.slide_duration;
        if time < fade_in_end {
            let t = ((time - effective_start) / self.slide_duration) as f32;
            return (t * t * (3.0 - 2.0 * t)).clamp(0.0, 1.0); // smoothstep
        }

        // Check fade out
        if let Some(slide_out_at) = self.slide_out_at {
            if time >= slide_out_at {
                let fade_out_end = slide_out_at + self.slide_duration;
                if time >= fade_out_end {
                    return 0.0;
                }
                let t = ((time - slide_out_at) / self.slide_duration) as f32;
                return (1.0 - t * t * (3.0 - 2.0 * t)).clamp(0.0, 1.0);
            }
        }

        // Fully visible
        1.0
    }

    fn render_icon_svg(
        &self,
        canvas: &Canvas,
        icon_id: &str,
        color: &str,
        x: f32,
        y: f32,
        size: f32,
    ) -> Result<()> {
        let icon_w = size.round() as u32;
        let icon_h = size.round() as u32;
        let cache_key = format!("icon:{}:{}:{}x{}", icon_id, color, icon_w, icon_h);

        let cache = asset_cache();
        let img = if let Some(cached) = cache.get(&cache_key) {
            cached.clone()
        } else if let Ok(svg_data) = fetch_icon_svg(icon_id, color, icon_w, icon_h) {
            let opt = usvg::Options::default();
            if let Ok(tree) = usvg::Tree::from_data(&svg_data, &opt) {
                let svg_size = tree.size();
                if let Some(mut pixmap) = tiny_skia::Pixmap::new(icon_w, icon_h) {
                    let sx = icon_w as f32 / svg_size.width();
                    let sy = icon_h as f32 / svg_size.height();
                    resvg::render(
                        &tree,
                        tiny_skia::Transform::from_scale(sx, sy),
                        &mut pixmap.as_mut(),
                    );
                    let img_data = skia_safe::Data::new_copy(pixmap.data());
                    let info = ImageInfo::new(
                        (icon_w as i32, icon_h as i32),
                        ColorType::RGBA8888,
                        skia_safe::AlphaType::Premul,
                        None,
                    );
                    if let Some(decoded) =
                        skia_safe::images::raster_from_data(&info, img_data, icon_w as usize * 4)
                    {
                        cache.insert(cache_key, decoded.clone());
                        decoded
                    } else {
                        return Ok(());
                    }
                } else {
                    return Ok(());
                }
            } else {
                return Ok(());
            }
        } else {
            return Ok(());
        };

        let dst = Rect::from_xywh(x, y, size, size);
        canvas.draw_image_rect(img, None, dst, &Paint::default());
        Ok(())
    }
}

impl Notification {
    fn paint(
        &self,
        canvas: &Canvas,
        layout_w: f32,
        layout_h: f32,
        time: f64,
        ctx: &PaintCtx,
    ) -> Result<()> {
        let w = layout_w;
        let h = layout_h;
        let opacity = self.compute_opacity(time);

        if opacity <= 0.0 {
            return Ok(());
        }

        // Resolve the title font before any canvas.save() so an early return
        // on font failure keeps save/restore balanced.
        let Some(title_font) = self.make_font(true, self.title_font_size(ctx)) else {
            return Ok(());
        };

        // Stack offset: count how many push_at timestamps have passed,
        // each one shifts this notification down by one slot with animation.
        let slot_size = h + self.stack_gap;
        let mut stack_y = 0.0_f32;
        let transition_dur = self.slide_duration;
        for &push_time in &self.push_at {
            if time >= push_time {
                let t = ((time - push_time) / transition_dur).clamp(0.0, 1.0) as f32;
                let eased = t * t * (3.0 - 2.0 * t); // smoothstep
                stack_y += slot_size * eased;
            }
        }

        canvas.save();
        if stack_y > 0.0 {
            canvas.translate((0.0, stack_y));
        }
        if opacity < 1.0 {
            let mut layer_paint = Paint::default();
            layer_paint.set_alpha_f(opacity);
            canvas.save_layer(&skia_safe::canvas::SaveLayerRec::default().paint(&layer_paint));
        }

        let bg_color = self.style.background_color_str().unwrap_or("#1E293B");
        let radius = self.style.border_radius_px_or(12.0);
        let accent_color = self.resolved_accent_color();
        let accent_width = 4.0;

        // Background rounded rect
        let bg_rect = Rect::from_xywh(0.0, 0.0, w, h);
        let bg_rrect = RRect::new_rect_xy(bg_rect, radius, radius);
        let mut bg_paint = paint_from_hex(bg_color);
        bg_paint.set_style(PaintStyle::Fill);
        bg_paint.set_anti_alias(true);
        canvas.draw_rrect(bg_rrect, &bg_paint);

        // Left accent stripe
        let accent_rect = Rect::from_xywh(0.0, 0.0, accent_width, h);
        let accent_rrect = RRect::new_rect_radii(
            accent_rect,
            &[
                (radius, radius).into(),
                (0.0, 0.0).into(),
                (0.0, 0.0).into(),
                (radius, radius).into(),
            ],
        );
        let mut accent_paint = paint_from_hex(accent_color);
        accent_paint.set_style(PaintStyle::Fill);
        accent_paint.set_anti_alias(true);
        canvas.draw_rrect(accent_rrect, &accent_paint);

        // Content area
        let h_pad = 16.0;
        let v_pad = 16.0;
        let icon_size = self.title_font_size(ctx) * 1.5;
        let mut content_x = accent_width + h_pad;

        // Icon
        if let Some(icon_id) = &self.icon {
            let icon_y = (h - icon_size) / 2.0;
            self.render_icon_svg(canvas, icon_id, accent_color, content_x, icon_y, icon_size)?;
            content_x += icon_size + 12.0;
        }

        // Title
        let title_fs = self.title_font_size(ctx);
        let emoji_font_title =
            emoji_typeface().map(|tf| skia_safe::Font::from_typeface(tf, title_fs));
        let title_color = self.style.color_str_or("#FFFFFF");
        let mut title_paint = paint_from_hex(title_color);
        title_paint.set_anti_alias(true);

        let (_, title_metrics) = title_font.metrics();
        let title_y = v_pad + (-title_metrics.ascent);

        draw_text_with_fallback(
            canvas,
            &self.title,
            &title_font,
            &emoji_font_title,
            0.0,
            content_x,
            title_y,
            &title_paint,
        );

        // Message
        if let Some(message) = &self.message {
            let msg_fs = self.message_font_size(ctx);
            if let Some(msg_font) = self.make_font(false, msg_fs) {
                let emoji_font_msg =
                    emoji_typeface().map(|tf| skia_safe::Font::from_typeface(tf, msg_fs));
                let mut msg_paint = paint_from_hex("#9CA3AF");
                msg_paint.set_anti_alias(true);

                let (_, msg_metrics) = msg_font.metrics();
                let msg_y = title_y + 4.0 + title_fs * 0.3 + (-msg_metrics.ascent);

                draw_text_with_fallback(
                    canvas,
                    message,
                    &msg_font,
                    &emoji_font_msg,
                    0.0,
                    content_x,
                    msg_y,
                    &msg_paint,
                );
            }
        }

        if opacity < 1.0 {
            canvas.restore();
        }
        canvas.restore();
        Ok(())
    }
}

impl Painter for Notification {
    fn paint_content(
        &self,
        canvas: &Canvas,
        layout: &BoxLayout,
        _props: &AnimatedProperties,
        ctx: &PaintCtx,
    ) {
        let _ = self.paint(canvas, layout.width, layout.height, ctx.time, ctx);
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use rustmotion_core::css::CssStyle;
    use rustmotion_core::css::Length;

    fn test_ctx() -> PaintCtx {
        PaintCtx {
            time: 1.0,
            scenario_time: 1.0,
            scene_duration: 2.0,
            frame_index: 30,
            fps: 30,
            video_width: 400,
            video_height: 200,
            stagger_offset: 0.0,
        }
    }

    // ─── Lot B, wave S: relative `font-size` units ─────────────────────────

    #[test]
    fn rem_font_size_paints_visible_ink() {
        // Reproduction: `font-size: "2rem"` used to resolve to 0px via the
        // context-free `font_size_px_or`.
        let notification = Notification {
            title: "Hello".to_string(),
            message: None,
            icon: None,
            variant: NotificationVariant::Info,
            width: default_width(),
            slide_in_at: 0.0,
            slide_out_at: None,
            slide_duration: default_slide_duration(),
            accent_color: None,
            push_at: Vec::new(),
            stack_gap: default_stack_gap(),
            wait_for_push: false,
            timing: Default::default(),
            style: CssStyle {
                font_size: Some(Length::String("2rem".into())),
                ..Default::default()
            },
            timeline: Vec::new(),
            stagger: None,
        };
        const W: i32 = 400;
        const H: i32 = 200;
        let mut surface = skia_safe::surfaces::raster_n32_premul((W, H)).expect("raster surface");
        {
            let canvas = surface.canvas();
            notification
                .paint(canvas, 360.0, 100.0, 1.0, &test_ctx())
                .expect("paint succeeds");
        }
        let snapshot = surface.image_snapshot();
        let info = skia_safe::ImageInfo::new(
            (W, H),
            skia_safe::ColorType::RGBA8888,
            skia_safe::AlphaType::Premul,
            None,
        );
        let mut buf = vec![0u8; (W * H * 4) as usize];
        let ok = snapshot.read_pixels(
            &info,
            &mut buf,
            (W * 4) as usize,
            skia_safe::IPoint::new(0, 0),
            skia_safe::image::CachingHint::Disallow,
        );
        assert!(ok, "pixel read should succeed");
        // Title text is white (#FFFFFF default) on a dark #1E293B card —
        // probe for near-white ink specifically.
        let text_ink = buf
            .chunks_exact(4)
            .filter(|p| p[3] > 0 && p[0] > 200 && p[1] > 200 && p[2] > 200)
            .count();
        assert!(
            text_ink > 10,
            "notification at font-size: 2rem must paint visible text, got {text_ink} pixels"
        );
    }
}