facett-graph 0.1.10

//! **facett-graph** — the graph (node/edge) viewer component, on
//! [`facett_core`]. Build a [`Scene`] from a labelled edge list (the common
//! shape: a graph query, a dataflow DAG) and draw it. Source-agnostic — the
//! caller turns its Arrow/Cypher/whatever into edges first.

use std::collections::{BTreeMap, HashMap};

pub use facett_core::{Edge, Facet, FacetCaps, Layout, Node, Scene, Theme, draw, hash_color, set_theme, theme};

mod depgraph;
pub use depgraph::{DepEdge, DepGraphView, DepNode, draw_arrow};

/// Build a [`Scene`] from a labelled edge list — each row is
/// `(src_id, dst_id, src_label, dst_label)`. Distinct ids become nodes, coloured
/// per label (FNV-hashed). The reusable "graph from edges" adapter korp's Graph
/// and Pipelines views both want.
pub fn scene_from_labeled_edges<I>(rows: I) -> Scene
where
    I: IntoIterator<Item = (i64, i64, String, String)>,
{
    let mut scene = Scene::new();
    let mut idx: HashMap<i64, usize> = HashMap::new();
    for (s, d, sl, dl) in rows {
        let si = *idx.entry(s).or_insert_with(|| scene.node(sl.clone(), hash_color(&sl)));
        let di = *idx.entry(d).or_insert_with(|| scene.node(dl.clone(), hash_color(&dl)));
        scene.edge(si, di);
    }
    scene
}

/// A simple graph-view widget: a [`Scene`] + a [`Layout`]. Implements [`Facet`],
/// so it drops into a `FacetDeck` and exposes `state_json` for free.
pub struct GraphView {
    pub scene: Scene,
    pub layout: Layout,
    pub empty_hint: String,
    pub title: String,
}

impl GraphView {
    pub fn new(scene: Scene) -> Self {
        Self { scene, layout: Layout::default(), empty_hint: "empty".into(), title: "graph".into() }
    }
    pub fn empty_hint(mut self, hint: impl Into<String>) -> Self {
        self.empty_hint = hint.into();
        self
    }
    pub fn with_title(mut self, title: impl Into<String>) -> Self {
        self.title = title.into();
        self
    }
    pub fn show(&self, ui: &mut egui::Ui) {
        draw(ui, &self.scene, self.layout, &self.empty_hint);
    }
    /// Per-label node counts (for the introspection).
    pub fn label_counts(&self) -> BTreeMap<String, usize> {
        let mut m = BTreeMap::new();
        for n in &self.scene.nodes {
            *m.entry(n.label.clone()).or_insert(0) += 1;
        }
        m
    }
}

impl GraphView {
    /// The copyable text: every node label, one per line (the graph carries no
    /// per-node selection, so this is the whole scene's label list).
    pub fn copy_text(&self) -> Option<String> {
        if self.scene.nodes.is_empty() {
            return None;
        }
        Some(self.scene.nodes.iter().map(|n| n.label.clone()).collect::<Vec<_>>().join("\n"))
    }
}

// ── typed copy (§16) — read-only: the scene's node labels as Text ─────────────
impl facett_core::clip::CopySource for GraphView {
    fn copy_kinds(&self) -> &[facett_core::clip::ClipKind] {
        use facett_core::clip::ClipKind;
        &[ClipKind::Text]
    }
    fn copy_payload(&self) -> Option<facett_core::clip::ClipPayload> {
        self.copy_text().map(facett_core::clip::ClipPayload::Text)
    }
}

impl Facet for GraphView {
    fn title(&self) -> &str {
        &self.title
    }
    fn copy(&mut self) -> Option<String> {
        use facett_core::clip::CopySource as _;
        self.copy_payload().map(|p| p.as_text())
    }
    fn ui(&mut self, ui: &mut egui::Ui) {
        self.show(ui);
        // ── render-lane emit: this Facet::ui path RAN ─────────────────────────
        #[cfg(feature = "testmatrix")]
        facett_core::testmatrix::emit(
            "facett-graph::GraphView::ui",
            "ui_render",
            !self.scene.nodes.is_empty() || !self.empty_hint.is_empty(),
            &format!("nodes={} edges={}", self.scene.nodes.len(), self.scene.edges.len()),
        );
    }
    fn state_json(&self) -> serde_json::Value {
        serde_json::json!({
            "nodes": self.scene.nodes.len(),
            "edges": self.scene.edges.len(),
            "labels": self.label_counts(),
        })
    }
    /// Painted via [`draw`], which reads the active [`Theme`] (edges/labels/empty
    /// hint) from the context; its canvas takes the host's `available_size`.
    fn caps(&self) -> FacetCaps {
        FacetCaps::NONE.themeable().resizable().copyable()
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn typed_copy_is_the_node_label_list() {
        use facett_core::clip::{ClipKind, CopySource};
        let scene = scene_from_labeled_edges(vec![(1, 2, "Person".into(), "Company".into())]);
        let mut g = GraphView::new(scene);
        let p = g.copy_payload().expect("a populated scene copies");
        assert_eq!(p.kind(), ClipKind::Text);
        assert!(p.as_text().contains("Person") && p.as_text().contains("Company"));
        assert_eq!(<GraphView as Facet>::copy(&mut g), Some(p.as_text()));
    }

    #[test]
    fn builds_scene_from_labeled_edges() {
        let scene = scene_from_labeled_edges(vec![
            (1, 2, "Person".into(), "Company".into()),
            (1, 3, "Person".into(), "Address".into()),
        ]);
        assert_eq!(scene.nodes.len(), 3, "1, 2, 3 distinct");
        assert_eq!(scene.edges.len(), 2);
        assert_eq!(scene.nodes[0].label, "Person");
    }
}