import { describe, expect, it } from "bun:test";
import { createGeneration } from "./v3-generation.js";
import {
	bindViewHostControlEnvelope,
	bindViewToCoreRelayEnvelope,
	parseCoreToViewRelayEnvelope,
} from "./view-relay-contract.js";

describe("view relay contract", () => {
	const generation = createGeneration(7);
	const channelViewId = "view-channel";

	it("rejects messages from another generation", () => {
		const message = {
			t: "getuserfeedback:event:message",
			gen: createGeneration(8),
			payload: { kind: "ping" },
		};

		expect(
			bindViewToCoreRelayEnvelope(message, {
				generation,
				viewId: channelViewId,
			}),
		).toBeNull();
	});

	it("stamps a missing viewId on a view relay", () => {
		const message = {
			t: "getuserfeedback:event:message",
			gen: generation,
			payload: { kind: "ping" },
		};

		expect(
			bindViewToCoreRelayEnvelope(message, {
				generation,
				viewId: channelViewId,
			}),
		).toEqual({ ...message, viewId: channelViewId });
	});

	it("rejects a conflicting channel viewId", () => {
		const message = {
			t: "getuserfeedback:event:message",
			gen: generation,
			viewId: "other-view",
			payload: { kind: "ping" },
		};

		expect(
			bindViewToCoreRelayEnvelope(message, {
				generation,
				viewId: channelViewId,
			}),
		).toBeNull();
	});

	it("compares a padded message viewId after canonical trimming", () => {
		const message = {
			t: "getuserfeedback:event:message",
			gen: generation,
			viewId: `  ${channelViewId}  `,
			payload: { kind: "ping" },
		};

		expect(
			bindViewToCoreRelayEnvelope(message, {
				generation,
				viewId: channelViewId,
			}),
		).toEqual({ ...message, viewId: channelViewId });
	});

	it("rejects a whitespace-only message viewId", () => {
		const message = {
			t: "getuserfeedback:event:message",
			gen: generation,
			viewId: "   ",
			payload: { kind: "ping" },
		};

		expect(
			bindViewToCoreRelayEnvelope(message, {
				generation,
				viewId: channelViewId,
			}),
		).toBeNull();
	});

	it("rejects disallowed view message kinds", () => {
		const message = {
			t: "getuserfeedback:action:closeView",
			gen: generation,
			viewId: channelViewId,
		};

		expect(
			bindViewHostControlEnvelope(message, {
				generation,
				viewId: channelViewId,
			}),
		).toBeNull();
		expect(
			bindViewToCoreRelayEnvelope(message, {
				generation,
				viewId: channelViewId,
			}),
		).toBeNull();
	});

	it("extracts the explicit Core target and preserves RPC fields", () => {
		const message = {
			t: "getuserfeedback:rpc:response",
			gen: generation,
			viewId: channelViewId,
			rpcId: "rpc-1",
			ok: true,
			result: { value: 42 },
			futureField: { preserved: true },
		};

		expect(parseCoreToViewRelayEnvelope(message, { generation })).toEqual({
			viewId: channelViewId,
			message,
		});
	});

	it("requires an explicit Core target", () => {
		const message = {
			t: "getuserfeedback:event:message",
			gen: generation,
			payload: { kind: "broadcast" },
		};

		expect(parseCoreToViewRelayEnvelope(message, { generation })).toBeNull();
	});

	it("binds host controls to the channel identity", () => {
		const message = {
			t: "getuserfeedback:action:requestCloseView",
			gen: generation,
		};

		expect(
			bindViewHostControlEnvelope(message, {
				generation,
				viewId: channelViewId,
			}),
		).toEqual({ ...message, viewId: channelViewId });
	});

	it("rejects Core relays from another generation", () => {
		const message = {
			t: "getuserfeedback:event:message",
			gen: createGeneration(8),
			viewId: channelViewId,
			payload: { kind: "ping" },
		};

		expect(parseCoreToViewRelayEnvelope(message, { generation })).toBeNull();
	});
});