BREP_render 0.2.1

//! Feature-schema access + the feature-schema → [`FormField`] mapping.
//!
//! The kernel OWNS the feature definitions (`feature_pipeline/schema.rs`; each
//! `features/<feat>.rs` declares its own `schema()` with an `inputParamsSchema`).
//! This module reaches that catalogue from native Rust (re-exported by the
//! kernel as [`brep_kernel::feature_schema_catalogue`]) and maps ONE feature's
//! parameter schema into the general [`FormField`] list the shared egui form
//! engine renders — the SAME `FormField`s the settings dialog uses.
//!
//! The map classifies each kernel param `type`:
//!   * `number`             → [`FieldKind::Scalar`]      (unbounded drag value)
//!   * `string`             → [`FieldKind::Text`]        (`id` is read-only)
//!   * `transform`          → three [`FieldKind::Vec3`]  (position/rotation/scale)
//!   * `boolean_operation`  → an [`FieldKind::Enum`] (operation) + a
//!                            [`FieldKind::Reference`] (tools) + a
//!                            [`FieldKind::Bool`] (mergeCoplanarFaces)
//!   * `reference_selection`→ [`FieldKind::Reference`]   (the #42 seam)
//!
//! REFERENCE-SELECTION field types (rendered as the disabled placeholder — the
//! seam for the next slice's real picker): the top-level `reference_selection`
//! params, and the `targets` list inside a `boolean_operation`. (`transform`'s
//! optional start `reference` is not surfaced here yet.)

use crate::style::{FieldKind, FormField};
use serde_json::Value;

/// The kernel-owned feature-schema catalogue (`{ version, features: [...] }`).
pub fn feature_catalogue() -> Value {
    brep_kernel::feature_schema_catalogue()
}

/// One feature's full schema entry, by its `type` / `shortName` (e.g. `"P.CU"`,
/// `"B"`). `None` if the type is not in the catalogue.
pub fn feature_schema(feature_type: &str) -> Option<Value> {
    feature_catalogue()
        .get("features")?
        .as_array()?
        .iter()
        .find(|f| {
            f.get("type").and_then(Value::as_str) == Some(feature_type)
                || f.get("shortName").and_then(Value::as_str) == Some(feature_type)
        })
        .cloned()
}

/// Human display name for a feature type: the schema `longName` (else the type
/// itself), with the feature's icon character PREPENDED. Every consumer that
/// shows a feature name (add-feature palette, history tree, context-bar offers,
/// dialogs) reads it through here, so the icon appears everywhere with no
/// per-caller wiring — see [`feature_icon`].
pub fn feature_long_name(feature_type: &str) -> String {
    let name = feature_plain_name(feature_type);
    match feature_icon(feature_type) {
        Some(glyph) => format!("{glyph} {name}"),
        None => name,
    }
}

/// The same display name WITHOUT the leading glyph — the schema `longName`, else
/// the type itself.
///
/// For the one kind of caller that draws the icon as ARTWORK rather than as a
/// character: the history tree gives the icon its own column
/// (`brep_app::panels::tree::TreeRow::glyph`), so its label must not carry the
/// glyph a second time. Everything that shows a feature name as plain text
/// keeps reading [`feature_long_name`], which is still where the icon is
/// prepended.
pub fn feature_plain_name(feature_type: &str) -> String {
    feature_schema(feature_type)
        .and_then(|f| f.get("longName").and_then(Value::as_str).map(String::from))
        .unwrap_or_else(|| feature_type.to_string())
}

/// A feature type's SHORT name (`shortName`, e.g. `P.CU`, `S`, `E`), else the
/// type code itself. This is the BASE for a new feature's id: the engine appends
/// the part history's persistent global counter to it (`P.CU` → `P.CU7`,
/// `S` → `S8`) in [`crate::history::History::next_feature_id`].
pub fn feature_short_name(feature_type: &str) -> String {
    feature_schema(feature_type)
        .and_then(|f| f.get("shortName").and_then(Value::as_str).map(String::from))
        .unwrap_or_else(|| feature_type.to_string())
}

/// The icon character for a feature type, if one exists. Every kernel
/// feature type has a FreeCAD-inspired monoline glyph in the font's Private-Use
/// block U+E030-E059 (edited as `BREP_app/assets/glyphs/*.svg`, which are also
/// the source of the inline SVG icon catalog — see `BREP_app/src/icons.rs`;
/// `every_feature_type_has_catalogued_artwork` there checks each of these
/// codepoints actually HAS a glyph, which this module's own test cannot). The font is
/// installed as family `"brep_icons"` at the HEAD of egui's fallback chain
/// ([`crate`]-side `fonts.rs`), so a bare returned `char` renders as the icon.
///
/// Matches the SAME alias set the kernel dispatch does (short codes AND the
/// long-/class-name strings saved files carry — e.g. `"CHAMFER"`, the misspelt
/// `"DATIUM"`, `"PUSH FACE"`), uppercased, so a type loaded from disk resolves.
pub fn feature_icon(kind: &str) -> Option<char> {
    let cp: u32 = match kind.trim().to_ascii_uppercase().as_str() {
        "D" | "DATUM" | "DATIUM" => 0xE030,
        "P" | "PLANE" => 0xE031,
        "P.CU" | "CUBE" => 0xE032,
        "P.CY" | "CYLINDER" => 0xE033,
        "P.CO" | "CONE" => 0xE034,
        "P.S" | "SPHERE" => 0xE035,
        "P.T" | "TORUS" => 0xE036,
        "P.PY" | "PYRAMID" => 0xE037,
        "IMPORT3D" => 0xE038,
        "S" | "SKETCH" => 0xE039,
        "SP" | "SPLINE" => 0xE03A,
        "PORT" => 0xE03B,
        "HX" | "HELIX" => 0xE03C,
        "E" | "EXTRUDE" => 0xE03D,
        "B" | "BOOLEAN" => 0xE03E,
        "F" | "FILLET" => 0xE03F,
        "CH" | "CHAMFER" => 0xE040,
        "O.S" | "OFFSET SHELL" | "OFFSETSHELL" => 0xE041,
        "O.F" | "OFFSET FACE" | "OFFSETFACE" => 0xE042,
        "PF" | "PUSHFACE" | "PUSH FACE" => 0xE043,
        "DF" | "DELETE FACE" | "DELETEFACE" => 0xE044,
        "THK" | "THICKEN" => 0xE045,
        "SM.TAB" => 0xE046,
        "SM.CF" => 0xE047,
        "SM.F" => 0xE048,
        "SM.HEM" => 0xE049,
        "SM.FILLET" | "SM.CFIL" => 0xE04A,
        "SM.CHAMFER" | "SM.CCHM" => 0xE04B,
        "SM.CUTOUT" => 0xE04C,
        "LOFT" => 0xE04D,
        "M" | "MIRROR" => 0xE04E,
        "SPL" | "SPLIT" => 0xE04F,
        "R" | "REVOLVE" => 0xE050,
        "RIB" => 0xE051,
        "SW" | "SWEEP" => 0xE052,
        "SWP" | "PATH SWEEP" | "PATHSWEEP" => 0xE053,
        "H" | "HOLE" => 0xE054,
        "TU" | "TUBE" => 0xE055,
        "XFORM" | "TRANSFORM" => 0xE056,
        "PATTERN" => 0xE057,
        "ACOMP" | "ASSEMBLY COMPONENT" => 0xE058,
        "SM.UNFOLD" => 0xE059,
        _ => return None,
    };
    char::from_u32(cp)
}

/// A feature type's DEFAULT `inputParams`, built from its schema: one entry per
/// `inputParamsSchema` param seeded with that param's `default_value` (missing →
/// `null`). The caller assigns the unique `id` afterwards (the schema's `id`
/// default is `null`). Additive, engine-owned, and reusable by any "add feature"
/// path so a new feature's params always track the kernel schema. Unknown types
/// yield an empty object.
pub fn feature_default_params(feature_type: &str) -> Value {
    let mut params = serde_json::Map::new();
    if let Some(props) = feature_schema(feature_type)
        .as_ref()
        .and_then(|s| s.get("inputParamsSchema"))
        .and_then(Value::as_object)
    {
        for (name, spec) in props {
            let default = spec.get("default_value").cloned().unwrap_or(Value::Null);
            params.insert(name.clone(), default);
        }
    }
    Value::Object(params)
}

/// The boolean operation choices (a fixed kernel enum — the schema stores only a
/// default operation, not the variant set, so the known set rides here).
const BOOLEAN_OPS: &[&str] = &["NONE", "UNION", "SUBTRACT", "INTERSECT"];

/// Map a feature type's `inputParamsSchema` into the general form fields, in
/// schema (insertion) order — the kernel builds schemas with serde_json's
/// `preserve_order`, so grouped fields stay contiguous for the group headers.
pub fn feature_form_fields(feature_type: &str) -> Vec<FormField> {
    let Some(schema) = feature_schema(feature_type) else {
        return Vec::new();
    };
    form_fields_from_schema(&schema)
}

/// Map ANY schema entry carrying an `inputParamsSchema` object into form fields
/// — the shared engine behind [`feature_form_fields`] AND the assembly
/// constraint dialogs (whose schemas come from the kernel's
/// `constraint_schema_catalogue`, same shape, different catalogue). One mapping,
/// two catalogues (the schema-driven-dialog principle).
pub fn form_fields_from_schema(schema: &Value) -> Vec<FormField> {
    let Some(params) = schema
        .get("inputParamsSchema")
        .and_then(Value::as_object)
    else {
        return Vec::new();
    };

    let mut fields = Vec::new();
    for (name, spec) in params {
        let ty = spec.get("type").and_then(Value::as_str).unwrap_or("");
        match ty {
            "number" => fields.push(FormField {
                path: vec![name.clone()],
                label: prettify(name),
                group: "Parameters".into(),
                kind: FieldKind::Scalar { step: 0.5 },
            }),
            "string" => fields.push(FormField {
                path: vec![name.clone()],
                label: prettify(name),
                group: "Parameters".into(),
                // The `id` is the feature's identity; editing it must cascade to
                // references, so it is shown read-only for now.
                kind: FieldKind::Text {
                    read_only: name == "id",
                },
            }),
            "transform" => {
                // TWO transform param shapes share the `transform` schema type,
                // discriminated by the schema's own `default_value` (the shape a
                // fresh feature is seeded with, so it can never lie):
                //   * the ACOMP rigid instance pose `{translate, rotateEulerDeg}`
                //     (assemblies spec §2.2 — no scale, degrees, intrinsic XYZ);
                //   * the legacy `{position, rotationEuler, scale}` triple every
                //     modeling feature uses.
                // The mapping lives HERE (the form-engine altitude) so no dialog
                // ever special-cases a feature type.
                let is_rigid_pose = spec
                    .get("default_value")
                    .map(|d| d.get("translate").is_some() || d.get("rotateEulerDeg").is_some())
                    .unwrap_or(false);
                if is_rigid_pose {
                    fields.push(vec3_field(name, "translate", "Translate", 0.5));
                    fields.push(vec3_field(name, "rotateEulerDeg", "Rotation (deg)", 1.0));
                } else {
                    fields.push(vec3_field(name, "position", "Position", 0.5));
                    fields.push(vec3_field(name, "rotationEuler", "Rotation (deg)", 1.0));
                    fields.push(vec3_field(name, "scale", "Scale", 0.1));
                }
            }
            "boolean" => {
                // A plain checkbox param (e.g. ACOMP `isFixed`, constraint
                // `reverse`/`opposeNormals`/`exteriorAngle`). Label from the
                // schema's `label` when present, else the prettified key.
                fields.push(FormField {
                    path: vec![name.clone()],
                    label: field_label(spec, name),
                    group: "Parameters".into(),
                    kind: FieldKind::Bool,
                });
            }
            "boolean_operation" => {
                fields.push(FormField {
                    path: vec![name.clone(), "operation".into()],
                    label: "Operation".into(),
                    group: "Boolean".into(),
                    kind: FieldKind::Enum {
                        variants: BOOLEAN_OPS.iter().map(|s| s.to_string()).collect(),
                    },
                });
                fields.push(FormField {
                    path: vec![name.clone(), "targets".into()],
                    label: "Tool solids".into(),
                    group: "Boolean".into(),
                    kind: FieldKind::Reference {
                        filter: vec!["SOLID".into()],
                        multiple: true,
                    },
                });
                fields.push(FormField {
                    path: vec![name.clone(), "mergeCoplanarFaces".into()],
                    label: "Merge coplanar faces".into(),
                    group: "Boolean".into(),
                    kind: FieldKind::Bool,
                });
            }
            "button" => {
                // An action button (e.g. Edit Sketch): binds to no value. Its
                // `key` (the schema key) identifies the click to the host. The
                // caption is the schema `label` (falling back to the key).
                let label = spec
                    .get("label")
                    .and_then(Value::as_str)
                    .map(String::from)
                    .unwrap_or_else(|| prettify(name));
                fields.push(FormField {
                    path: vec![name.clone()],
                    label: label.clone(),
                    group: "Parameters".into(),
                    kind: FieldKind::Button { label },
                });
            }
            "reference_selection" => {
                let filter = spec
                    .get("selectionFilter")
                    .and_then(Value::as_array)
                    .map(|a| {
                        a.iter()
                            .filter_map(|v| v.as_str().map(String::from))
                            .collect()
                    })
                    .unwrap_or_default();
                let multiple = spec
                    .get("multiple")
                    .and_then(Value::as_bool)
                    .unwrap_or(false);
                // `"References"` is a SEMANTIC TAG, not a rendered wrapper: the
                // history tree inlines this group (each reference renders as its
                // own self-titled node — no "References" parent), and the context
                // bar keys on it to find a feature's PRE-FILL fields (top-level
                // `reference_selection`s, vs a boolean-op `targets` in `Boolean`;
                // WHETHER a feature is offered is the kernel predicate's call —
                // `feature_pipeline::context_offer`).
                fields.push(FormField {
                    path: vec![name.clone()],
                    label: prettify(name),
                    group: "References".into(),
                    kind: FieldKind::Reference { filter, multiple },
                });
            }
            "options" => {
                // A single-choice enum: render as a dropdown of the schema's
                // `options`, using the field's `label` when present (e.g.
                // flangeLengthReference → "Length reference", inset → "Flange
                // position") else the prettified key.
                let variants = spec
                    .get("options")
                    .and_then(Value::as_array)
                    .map(|a| {
                        a.iter()
                            .filter_map(|v| v.as_str().map(String::from))
                            .collect()
                    })
                    .unwrap_or_default();
                fields.push(FormField {
                    path: vec![name.clone()],
                    label: field_label(spec, name),
                    group: "Parameters".into(),
                    kind: FieldKind::Enum { variants },
                });
            }
            // Unmapped kernel param types (vec3-array/etc. arrive as more
            // features are wired) are skipped rather than mis-rendered.
            _ => {}
        }
    }
    fields
}

fn vec3_field(param: &str, sub: &str, label: &str, step: f64) -> FormField {
    FormField {
        path: vec![param.to_string(), sub.to_string()],
        label: label.to_string(),
        group: "Transform".into(),
        kind: FieldKind::Vec3 { step },
    }
}

/// A field's display label: the schema `label` when set, else the prettified key.
fn field_label(spec: &Value, name: &str) -> String {
    spec.get("label")
        .and_then(Value::as_str)
        .map(String::from)
        .unwrap_or_else(|| prettify(name))
}

/// `sizeX` → `Size X`, `rotationEuler` → `Rotation euler`, `id` → `Id`.
fn prettify(key: &str) -> String {
    let mut out = String::new();
    for (i, ch) in key.chars().enumerate() {
        if i == 0 {
            out.extend(ch.to_uppercase());
        } else if ch.is_ascii_uppercase() {
            out.push(' ');
            out.extend(ch.to_lowercase());
        } else {
            out.push(ch);
        }
    }
    out
}

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

    #[test]
    fn catalogue_is_reachable_from_native_rust() {
        let cat = feature_catalogue();
        assert!(cat.get("features").and_then(Value::as_array).is_some());
        assert!(feature_schema("P.CU").is_some());
        assert!(feature_schema("P.CY").is_some());
        assert!(feature_schema("B").is_some());
        // Glyph is prepended; the name still ends with the schema longName.
        assert!(feature_long_name("P.CU").ends_with("Primitive Cube"));
        assert!(feature_long_name("P.CU").starts_with(feature_icon("P.CU").unwrap()));
    }

    #[test]
    fn every_catalogue_feature_type_has_an_icon() {
        // The palette + history tree prefix every feature with its glyph, so a
        // missing mapping would leave a bare feature with no icon. Guard the
        // whole catalogue against a future feature landing without a glyph.
        let cat = feature_catalogue();
        for feature in cat["features"].as_array().expect("features") {
            let ty = feature["type"].as_str().expect("type");
            assert!(
                feature_icon(ty).is_some(),
                "feature type {ty} has no icon (add one under BREP_app/assets/glyphs/ + features::feature_icon)"
            );
        }
        // Alias resolution: the long-name / misspelt strings saved files use.
        assert_eq!(feature_icon("CHAMFER"), feature_icon("CH"));
        assert_eq!(feature_icon("DATIUM"), feature_icon("D"));
        assert_eq!(feature_icon("push face"), feature_icon("PF"));
        assert!(feature_icon("NOPE").is_none());
    }

    #[test]
    fn short_name_is_the_schema_code_or_the_type_fallback() {
        // The base for a new feature's id: the schema shortName (incl. dotted
        // primitive codes), falling back to the type code for an unknown type.
        assert_eq!(feature_short_name("P.CU"), "P.CU");
        assert_eq!(feature_short_name("P.S"), "P.S");
        assert_eq!(feature_short_name("S"), "S");
        assert_eq!(feature_short_name("E"), "E");
        assert_eq!(feature_short_name("NOPE"), "NOPE");
    }

    #[test]
    fn cube_form_fields_map_types_correctly() {
        let fields = feature_form_fields("P.CU");
        // id (read-only Text), sizeX/Y/Z (Scalar), transform → 3× Vec3,
        // boolean → Enum + Reference + Bool.
        let by_key = |k: &str| fields.iter().find(|f| f.key() == k).cloned();

        assert!(matches!(
            by_key("id").unwrap().kind,
            FieldKind::Text { read_only: true }
        ));
        assert!(matches!(
            by_key("sizeX").unwrap().kind,
            FieldKind::Scalar { .. }
        ));
        // transform expands into three Vec3 sub-fields on nested paths.
        let position = fields
            .iter()
            .find(|f| f.path == ["transform", "position"])
            .expect("transform.position vec3");
        assert!(matches!(position.kind, FieldKind::Vec3 { .. }));
        assert_eq!(
            fields
                .iter()
                .filter(|f| matches!(f.kind, FieldKind::Vec3 { .. }))
                .count(),
            3
        );
        // boolean_operation expands: operation Enum, targets Reference, merge Bool.
        let op = fields
            .iter()
            .find(|f| f.path == ["boolean", "operation"])
            .expect("boolean.operation");
        assert!(matches!(op.kind, FieldKind::Enum { .. }));
        let targets = fields
            .iter()
            .find(|f| f.path == ["boolean", "targets"])
            .expect("boolean.targets");
        assert!(matches!(targets.kind, FieldKind::Reference { multiple: true, .. }));
    }

    #[test]
    fn flange_options_and_boolean_fields_render() {
        // Regression: `options` and plain `boolean` schema fields fell into the
        // `_ => {}` catch-all and were silently skipped, so the flange's
        // length-reference / position dropdowns (and Reverse-direction toggle)
        // never appeared in the dialog.
        let fields = feature_form_fields("SM.F");
        let by_key = |k: &str| fields.iter().find(|f| f.key() == k).cloned();

        let length_ref = by_key("flangeLengthReference").expect("flangeLengthReference renders");
        assert_eq!(length_ref.label, "Length reference");
        if let FieldKind::Enum { variants } = &length_ref.kind {
            assert!(variants.iter().any(|v| v.as_str() == "Inner Virtual Sharp"));
            assert!(variants.iter().any(|v| v.as_str() == "Outer Virtual Sharp"));
            assert!(variants.iter().any(|v| v.as_str() == "Tangent to Bend"));
        } else {
            panic!("flangeLengthReference should render as an Enum dropdown");
        }

        let inset = by_key("inset").expect("inset (Flange position) renders");
        assert_eq!(inset.label, "Flange position");
        assert!(matches!(inset.kind, FieldKind::Enum { .. }));

        // plain `boolean` now renders too, with its schema label.
        let reverse = by_key("useOppositeCenterline").expect("useOppositeCenterline renders");
        assert_eq!(reverse.label, "Reverse direction");
        assert!(matches!(reverse.kind, FieldKind::Bool));
    }

    #[test]
    fn default_params_seed_from_schema_defaults() {
        // A primitive's defaults are COMPLETE (build-ready) straight from schema.
        let cube = feature_default_params("P.CU");
        assert_eq!(cube["sizeX"], 10.0);
        assert_eq!(cube["sizeY"], 10.0);
        assert_eq!(cube["transform"]["scale"], serde_json::json!([1, 1, 1]));
        assert_eq!(cube["boolean"]["operation"], "NONE");
        // The `id` default is null — the caller assigns a unique one.
        assert_eq!(cube["id"], Value::Null);
        // A feature whose reference default is null still yields the key.
        let boolean = feature_default_params("B");
        assert!(boolean.as_object().unwrap().contains_key("targetSolid"));
        assert_eq!(boolean["boolean"]["operation"], "UNION");
        // Unknown types → empty object (no panic).
        assert_eq!(feature_default_params("NOPE"), serde_json::json!({}));
    }

    #[test]
    fn boolean_feature_target_is_a_reference_field() {
        let fields = feature_form_fields("B");
        let target = fields
            .iter()
            .find(|f| f.key() == "targetSolid")
            .expect("targetSolid field");
        match &target.kind {
            FieldKind::Reference { filter, multiple } => {
                assert_eq!(filter, &["SOLID".to_string()]);
                assert!(!multiple);
            }
            other => panic!("targetSolid should be a Reference, got {other:?}"),
        }
    }

    #[test]
    fn sketch_feature_maps_button_fields() {
        // The SKETCH schema's `editSketch` (`type:"button"`)
        // become `FieldKind::Button` fields carrying the schema label + their key.
        let fields = feature_form_fields("S");
        let edit = fields
            .iter()
            .find(|f| f.key() == "editSketch")
            .expect("editSketch button field");
        assert!(
            matches!(&edit.kind, FieldKind::Button { label } if label == "Edit Sketch"),
            "editSketch should be Button('Edit Sketch'), got {:?}",
            edit.kind
        );
        assert_eq!(edit.path, ["editSketch"], "button binds to its own key");
        // `dumpSketchDiagnostics` was a debug button whose hint promised a download
        // it never performed — it wrote to a JS global / stderr and showed the user
        // nothing. It is gone from the schema; the engine-side
        // `sketch_diagnostics_dump_json` it called stays as the developer API.
        assert!(
            fields.iter().all(|f| f.key() != "dumpSketchDiagnostics"),
            "the dead Dump Diagnostics button must not come back"
        );
    }

    #[test]
    fn acomp_form_fields_map_rigid_pose_and_is_fixed() {
        // The ACOMP schema's `transform` default is the RIGID POSE shape
        // `{translate, rotateEulerDeg}` — the form mapping must bind those two
        // nested paths (NOT the legacy position/rotationEuler/scale triple), and
        // its `isFixed` boolean must surface as a checkbox (dialog-visible per
        // the insert-flow contract).
        let fields = feature_form_fields("ACOMP");
        let translate = fields
            .iter()
            .find(|f| f.path == ["transform", "translate"])
            .expect("transform.translate vec3");
        assert!(matches!(translate.kind, FieldKind::Vec3 { .. }));
        let rotate = fields
            .iter()
            .find(|f| f.path == ["transform", "rotateEulerDeg"])
            .expect("transform.rotateEulerDeg vec3");
        assert!(matches!(rotate.kind, FieldKind::Vec3 { .. }));
        assert!(
            !fields.iter().any(|f| f.path == ["transform", "scale"]),
            "a rigid pose has no scale row"
        );
        let fixed = fields
            .iter()
            .find(|f| f.key() == "isFixed")
            .expect("isFixed checkbox");
        assert!(matches!(fixed.kind, FieldKind::Bool));
        assert_eq!(fixed.label, "Fixed", "schema label wins over the prettified key");
        // The legacy shape is untouched: a cube still maps the full triple.
        let cube = feature_form_fields("P.CU");
        assert!(cube.iter().any(|f| f.path == ["transform", "scale"]));
    }

    #[test]
    fn constraint_schemas_map_through_the_shared_field_engine() {
        // The nine assembly-constraint schemas share the feature-schema shape, so
        // `form_fields_from_schema` renders them with the SAME mapping: elements →
        // Reference (filter + multiplicity from the schema), numbers → Scalar,
        // booleans → Bool, id → read-only Text.
        let catalogue = brep_kernel::constraint_schema_catalogue();
        let distance = catalogue
            .as_array()
            .unwrap()
            .iter()
            .find(|s| s.get("type").and_then(Value::as_str) == Some("distance"))
            .expect("distance schema in the catalogue");
        let fields = form_fields_from_schema(distance);
        let elements = fields
            .iter()
            .find(|f| f.key() == "elements")
            .expect("elements reference field");
        match &elements.kind {
            FieldKind::Reference { filter, multiple } => {
                assert_eq!(filter, &["FACE".to_string(), "VERTEX".into(), "EDGE".into()]);
                assert!(multiple, "two-element constraints take a list");
            }
            other => panic!("elements should be a Reference, got {other:?}"),
        }
        assert!(matches!(
            fields.iter().find(|f| f.key() == "distance").unwrap().kind,
            FieldKind::Scalar { .. }
        ));
        assert!(matches!(
            fields.iter().find(|f| f.key() == "opposeNormals").unwrap().kind,
            FieldKind::Bool
        ));
        assert!(matches!(
            fields.iter().find(|f| f.key() == "id").unwrap().kind,
            FieldKind::Text { read_only: true }
        ));
    }

    #[test]
    fn reference_selection_field_is_a_self_titled_references_tagged_node() {
        // The history tree renders a `reference_selection` field as its OWN
        // top-level-under-the-feature node (no "References" wrapper): the node
        // title is the field's LABEL and it carries the Select button. This pins
        // the descriptor contract that the tree's inlining relies on — the field's
        // `label` is the prettified param name ("Sketch plane"), and its `group`
        // stays `"References"` as the semantic tag (tree inline marker + the
        // context bar's primary-reference discriminator).
        let sketch_plane = feature_form_fields("S")
            .into_iter()
            .find(|f| f.key() == "sketchPlane")
            .expect("sketch has a sketchPlane reference_selection field");
        assert_eq!(sketch_plane.label, "Sketch plane", "node title = field label");
        assert_eq!(sketch_plane.group, "References", "kept as a semantic tag");
        assert_eq!(sketch_plane.path, ["sketchPlane"], "a top-level (primary) reference");
        match &sketch_plane.kind {
            FieldKind::Reference { filter, multiple } => {
                assert_eq!(filter, &["PLANE".to_string(), "FACE".to_string()]);
                assert!(!multiple, "the sketch plane is a single reference");
            }
            other => panic!("sketchPlane should be a Reference, got {other:?}"),
        }
    }
}