import {
  assertEquals,
  assertRejects,
  assertThrows,
} from "https://deno.land/std@0.224.0/assert/mod.ts";
import { DependencyManager } from "./dependency-manager.ts";

// Test case for registering a module
Deno.test("DependencyManager: register a module", () => {
  const manager = new DependencyManager();
  const provider = () => "dependency";
  manager.register("identifier", provider);
  assertEquals(
    manager.resolve("identifier"),
    Promise.resolve("dependency"),
  );
});

// Test case for resolving a module
Deno.test("DependencyManager: resolve a module", async () => {
  const manager = new DependencyManager();
  const provider = () => "dependency";
  manager.register("identifier", provider);
  const result = await manager.resolve("identifier");
  assertEquals(result, "dependency");
});

// Test case for resolving an async module
Deno.test("DependencyManager: resolve an async module", async () => {
  const manager = new DependencyManager();
  const provider = () => {
    return new Promise((resolve) =>
      setTimeout(() => resolve("dependency"), 100)
    );
  };
  manager.register("identifier", provider);
  const result = await manager.resolve("identifier");
  assertEquals(result, "dependency");
});

// Test case for handling circular dependencies
Deno.test("DependencyManager: circular dependency detection", async () => {
  const manager = new DependencyManager();
  const providerA = async () => await manager.resolve("B");
  const providerB = async () => await manager.resolve("A");

  manager.register("A", providerA);
  manager.register("B", providerB);

  await assertRejects(
    () => manager.resolve("A"),
    Error,
    "Circular dependency detected for module A.",
  );
});

// Test case for handling duplicate module registration
Deno.test("DependencyManager: duplicate module registration", () => {
  const manager = new DependencyManager();
  const provider = () => "dependency";
  manager.register("identifier", provider);
  assertThrows(
    () => manager.register("identifier", provider),
    Error,
    "Module identifier is already registered.",
  );
});

// Test case for handling unresolved modules
Deno.test("DependencyManager: resolve an unregistered module", async () => {
  const manager = new DependencyManager();
  await assertRejects(
    () => manager.resolve("unregistered-identifier"),
    Error,
    "Module unregistered-identifier is not registered.",
  );
});