import assert from "node:assert/strict";
import * as lib from "@clusterio/lib";
import { HostConnection } from "@clusterio/controller";

function makeSave(instanceId, name) {
	return new lib.SaveDetails(instanceId, "file", name, 0, 0, false, false, 0, false);
}

// Mock saves datastore backed by a Map keyed on SaveDetails.id.
class MockSaves {
	constructor(saves = []) {
		this.saves = new Map(saves.map(s => [s.id, s]));
	}

	get(id) { return this.saves.get(id); }

	values() { return this.saves.values(); }

	setMany(saves) { for (const s of saves) { this.saves.set(s.id, s); } }

	deleteMany(saves) { for (const s of saves) { this.saves.delete(s.id); } }
}

// Mock instances manager where instance id -> assigned host id.
function makeInstances(assignments) {
	return {
		get(id) {
			if (!assignments.has(id)) {
				return undefined;
			}
			const host = assignments.get(id);
			return { config: { get: name => (name === "instance.assigned_host" ? host : undefined) } };
		},
	};
}

describe("controller/src/HostConnection", function() {
	describe(".handleInstanceSaveDetailsUpdatesEvent()", function() {
		// Instance 1 is on host 10, instance 2 is on host 20.
		const assignments = new Map([[1, 10], [2, 20]]);

		function run(hostId, saves, event) {
			const saveStore = new MockSaves(saves);
			const ctx = {
				id: hostId,
				_controller: { instances: makeInstances(assignments), saves: saveStore },
			};
			HostConnection.prototype.handleInstanceSaveDetailsUpdatesEvent.call(ctx, event);
			return saveStore;
		}

		it("applies updates for an instance assigned to this host", async function() {
			const store = run(10, [], new lib.InstanceSaveDetailsUpdatesEvent([makeSave(1, "a.zip")], 1));
			assert.deepEqual([...store.values()].map(s => s.id), ["1/a.zip"]);
		});

		it("sweeps missing saves for an instance assigned to this host", async function() {
			const store = run(10, [makeSave(1, "old.zip")], new lib.InstanceSaveDetailsUpdatesEvent([], 1));
			assert.deepEqual([...store.values()], []);
		});

		it("ignores injected saves for an instance on another host", async function() {
			const store = run(30, [], new lib.InstanceSaveDetailsUpdatesEvent([makeSave(1, "HACKED.zip")]));
			assert.deepEqual([...store.values()], [], "foreign save must not be stored");
		});

		it("ignores a wipe of an instance on another host", async function() {
			const existing = makeSave(1, "keep.zip");
			const store = run(30, [existing], new lib.InstanceSaveDetailsUpdatesEvent([], 1));
			assert.deepEqual([...store.values()].map(s => s.id), ["1/keep.zip"], "existing save must survive");
		});

		it("ignores updates for a nonexistent instance", async function() {
			const store = run(30, [], new lib.InstanceSaveDetailsUpdatesEvent([makeSave(999, "x.zip")]));
			assert.deepEqual([...store.values()], []);
		});
	});
});