import { assert, describe, it } from "@effect/vitest"
import * as Duration from "effect/Duration"
import * as Effect from "effect/Effect"
import * as Exit from "effect/Exit"
import * as TestClock from "effect/testing/TestClock"

describe("TestClock", () => {
  it.effect("sleep - does not require passage of wall time", () =>
    Effect.gen(function*() {
      let elapsed = false
      yield* Effect.sync(() => {
        elapsed = true
      }).pipe(Effect.delay("10 hours"), Effect.forkChild)
      yield* TestClock.adjust("11 hours")
      assert.isTrue(elapsed)
    }))

  it.effect("sleep - delays effects until time is adjusted", () =>
    Effect.gen(function*() {
      let elapsed = false
      const fiber = yield* Effect.sync(() => {
        elapsed = true
      }).pipe(Effect.delay("10 hours"), Effect.forkChild)
      yield* TestClock.adjust("9 hours")
      assert.isUndefined(fiber.pollUnsafe())
      yield* TestClock.adjust("11 hours")
      assert.deepStrictEqual(fiber.pollUnsafe(), Exit.void)
      assert.isTrue(elapsed)
    }))

  it.effect("sleep - handles multiple sleeps", () =>
    Effect.gen(function*() {
      let message = ""
      yield* Effect.sync(() => {
        message += "World!"
      }).pipe(Effect.delay("3 hours"), Effect.forkScoped)
      yield* Effect.sync(() => {
        message += "Hello, "
      }).pipe(Effect.delay("1 hour"), Effect.forkScoped)
      yield* TestClock.adjust("1 hour")
      assert.strictEqual(message, "Hello, ")
      yield* TestClock.adjust("4 hours")
      assert.strictEqual(message, "Hello, World!")
    }))

  it.effect("setTime - sleep correctly handles new set time", () =>
    Effect.gen(function*() {
      let elapsed = false
      yield* Effect.sync(() => {
        elapsed = true
      }).pipe(Effect.delay("10 hours"), Effect.forkChild)
      assert.isFalse(elapsed)
      yield* TestClock.setTime(Duration.toMillis(Duration.hours(11)))
      assert.isTrue(elapsed)
    }))

  it.effect("setTime - floors nanoseconds for fractional millisecond instants", () =>
    Effect.gen(function*() {
      const testClock = yield* TestClock.make()
      yield* testClock.setTime(199023438.0000004)
      assert.strictEqual(testClock.currentTimeNanosUnsafe(), 199023438000000n)
    }))

  it("layer - can adjust when provided without an ambient Scope", () =>
    Effect.gen(function*() {
      yield* TestClock.adjust("1 second")
    }).pipe(
      Effect.provide(TestClock.layer({})),
      Effect.runPromise
    ))
})