import { expect, test } from "vitest"

import { computed, signal } from "#Source/reactor/index.ts"

/**
 * @description 这个测试文件应该与 https://github.com/stackblitz/alien-signals/blob/master/tests/computed.spec.ts 保持同步。
 */

test("should correctly propagate changes through computed signals", () => {
  /**
   * @description Src
   * |
   * c1
   * |
   * c2
   * |
   * c3
   */
  const src = signal(() => 0)
  const c1 = computed(() => src.get() % 2)
  const c2 = computed(() => c1.get())
  const c3 = computed(() => c2.get())

  expect(c3.get()).toBe(0)
  src.set(1)
  expect(c2.get()).toBe(1)
  src.set(3)
  expect(c3.get()).toBe(1)
})

test("should propagate updated source value through chained computations", () => {
  /**
   * @description Src / \ a c
   *
   *      |     |
   *
   * B | \ / d
   */
  const src = signal(() => 0)
  const a = computed(() => src.get())
  const b = computed(() => a.get() % 2)
  const c = computed(() => src.get())
  const d = computed(() => b.get() + c.get())

  expect(d.get()).toBe(0)
  src.set(2)
  expect(d.get()).toBe(2)
})

test("should handle flags are indirectly updated during resolve pending", () => {
  /**
   * @description A
   * |
   * b
   * /\
   * c   |
   * \ /
   * d
   */
  const a = signal(() => false)
  const b = computed(() => a.get())
  const c = computed(() => {
    b.get()
    return 0
  })
  const d = computed(() => {
    c.get()
    return b.get()
  })

  expect(d.get()).toBe(false)
  a.set(true)
  expect(d.get()).toBe(true)
})

test("should not update if the signal value is reverted", () => {
  /**
   * @description Src
   * |
   * c1
   */
  const src = signal(() => 0)
  let c1RunTimes = 0
  const c1 = computed(() => {
    c1RunTimes = c1RunTimes + 1
    return src.get()
  })

  expect(c1.get()).toBe(0)
  expect(c1RunTimes).toBe(1)
  src.set(1)
  src.set(0)
  expect(c1.get()).toBe(0)
  expect(c1RunTimes).toBe(1)
})