import { describe, expect, it } from "@suaveplan/testing/runner";
import { flatTransform, makeSurface } from "../__fixtures__/fixtures.js";
import type {
    Control,
    ControlNode,
    Group,
} from "../types/control-node.types.js";
import { walkSurface } from "./walk.js";

function group(id: string, children: ReadonlyArray<ControlNode>): Group {
    return {
        type: "group",
        id,
        layout: { kind: "absolute" },
        transform: flatTransform(),
        children,
    };
}

function control(id: string): Control {
    return { type: "control", id, kind: "knob", transform: flatTransform() };
}

describe("walkSurface", () => {
    it("visits a single-root surface once with empty parent stack", {
        timeout: 5000,
    }, () => {
        const root = group("root", []);
        const visited: Array<{ id: string; parents: string[] }> = [];
        walkSurface(makeSurface(root), (node, parents) =>
            visited.push({ id: node.id, parents: parents.map((p) => p.id) })
        );
        expect(visited).toEqual([{ id: "root", parents: [] }]);
    });

    it("visits root → A → [B, C → [D]] → E in DFS pre-order", {
        timeout: 5000,
    }, () => {
        const tree = group("root", [
            group("A", [control("B"), group("C", [control("D")])]),
            control("E"),
        ]);
        const ids: string[] = [];
        walkSurface(makeSurface(tree), (n) => ids.push(n.id));
        expect(ids).toEqual(["root", "A", "B", "C", "D", "E"]);
    });

    it("passes the root-first parent stack to every visit", {
        timeout: 5000,
    }, () => {
        const tree = group("root", [group("A", [control("B")])]);
        const stacks = new Map<string, string[]>();
        walkSurface(makeSurface(tree), (node, parents) => {
            stacks.set(
                node.id,
                parents.map((p) => p.id)
            );
        });
        expect(stacks.get("root")).toEqual([]);
        expect(stacks.get("A")).toEqual(["root"]);
        expect(stacks.get("B")).toEqual(["root", "A"]);
    });

    it("visits nine nodes when a group contains two groups with three controls each", {
        timeout: 5000,
    }, () => {
        const tree = group("root", [
            group("g1", [control("c1"), control("c2"), control("c3")]),
            group("g2", [control("c4"), control("c5"), control("c6")]),
        ]);
        let count = 0;
        walkSurface(makeSurface(tree), () => {
            count += 1;
        });
        expect(count).toBe(9);
    });
});