import { expect, test, vi } from "vitest"

import { ExpirationManager } from "#Source/timer/index.ts"

test("RemainingManager getRemaining only returns seconds for active expirations", () => {
  vi.useFakeTimers()
  vi.setSystemTime(new Date(2_026, 0, 1, 0, 0, 0))

  try {
    const expirationManager = new ExpirationManager<"alpha" | "beta" | "gamma">({
      enableRemainingManager: false,
    })

    expirationManager.upsertExpiration("alpha", Date.now() + 2_500)
    expirationManager.upsertExpiration("beta", Date.now() - 1)
    expirationManager.upsertExpiration("gamma", Date.now() + 2_500)
    expirationManager.removeExpiration("gamma")

    expect(expirationManager.remainingManager.getRemaining("alpha")).toBe(3)
    expect(expirationManager.remainingManager.getRemaining("beta")).toBeUndefined()
    expect(expirationManager.remainingManager.getRemaining("gamma")).toBeUndefined()

    expirationManager.terminate()
  } finally {
    vi.clearAllTimers()
    vi.useRealTimers()
  }
})

test("RemainingManager getRemainingSnapshot only includes active expirations", () => {
  vi.useFakeTimers()
  vi.setSystemTime(new Date(2_026, 0, 1, 0, 0, 0))

  try {
    const expirationManager = new ExpirationManager<"alpha" | "beta" | "gamma">({
      enableRemainingManager: false,
    })

    expirationManager.upsertExpiration("alpha", Date.now() + 1_500)
    expirationManager.upsertExpiration("beta", Date.now() - 1)
    expirationManager.upsertExpiration("gamma", Date.now() + 1_500)
    expirationManager.removeExpiration("gamma")

    expect(expirationManager.remainingManager.getRemainingSnapshot()).toEqual({ alpha: 2 })

    expirationManager.terminate()
  } finally {
    vi.clearAllTimers()
    vi.useRealTimers()
  }
})

test("RemainingManager emit only publishes changed snapshots", () => {
  vi.useFakeTimers()
  vi.setSystemTime(new Date(2_026, 0, 1, 0, 0, 0))

  try {
    const expirationManager = new ExpirationManager<"alpha">({
      enableRemainingManager: false,
    })
    const remainingSnapshots: Array<{ alpha?: number | undefined }> = []

    expirationManager.remainingManager.event.subscribe("remaining", (remaining): void => {
      remainingSnapshots.push({ ...remaining })
    })

    expirationManager.upsertExpiration("alpha", Date.now() + 2_500)
    expirationManager.remainingManager.emit()
    vi.advanceTimersByTime(1_000)
    expirationManager.remainingManager.emit()

    expect(remainingSnapshots).toEqual([{ alpha: 3 }, { alpha: 2 }])

    expirationManager.terminate()
  } finally {
    vi.clearAllTimers()
    vi.useRealTimers()
  }
})

test("RemainingManager start enables interval-driven updates", () => {
  vi.useFakeTimers()
  vi.setSystemTime(new Date(2_026, 0, 1, 0, 0, 0))

  try {
    const expirationManager = new ExpirationManager<"alpha">({
      enableRemainingManager: false,
    })
    const remainingSnapshots: Array<{ alpha?: number | undefined }> = []

    expirationManager.remainingManager.event.subscribe("remaining", (remaining): void => {
      remainingSnapshots.push({ ...remaining })
    })

    expirationManager.upsertExpiration("alpha", Date.now() + 2_500)
    vi.advanceTimersByTime(1_000)

    expect(remainingSnapshots).toEqual([{ alpha: 3 }])

    expirationManager.remainingManager.start()
    vi.advanceTimersByTime(1_000)

    expect(remainingSnapshots).toEqual([{ alpha: 3 }, { alpha: 1 }])

    expirationManager.terminate()
  } finally {
    vi.clearAllTimers()
    vi.useRealTimers()
  }
})

test("RemainingManager stop disables interval-driven updates", () => {
  vi.useFakeTimers()
  vi.setSystemTime(new Date(2_026, 0, 1, 0, 0, 0))

  try {
    const expirationManager = new ExpirationManager<"alpha">({
      enableRemainingManager: true,
    })
    const remainingSnapshots: Array<{ alpha?: number | undefined }> = []

    expirationManager.remainingManager.event.subscribe("remaining", (remaining): void => {
      remainingSnapshots.push({ ...remaining })
    })

    expirationManager.upsertExpiration("alpha", Date.now() + 3_500)
    vi.advanceTimersByTime(1_000)

    expect(remainingSnapshots).toEqual([{ alpha: 4 }, { alpha: 3 }])

    expirationManager.remainingManager.stop()
    vi.advanceTimersByTime(1_000)

    expect(remainingSnapshots).toEqual([{ alpha: 4 }, { alpha: 3 }])

    expirationManager.terminate()
  } finally {
    vi.clearAllTimers()
    vi.useRealTimers()
  }
})

test("RemainingManager pause suspends interval-driven updates", () => {
  vi.useFakeTimers()
  vi.setSystemTime(new Date(2_026, 0, 1, 0, 0, 0))

  try {
    const expirationManager = new ExpirationManager<"alpha">({
      enableRemainingManager: true,
    })
    const remainingSnapshots: Array<{ alpha?: number | undefined }> = []

    expirationManager.remainingManager.event.subscribe("remaining", (remaining): void => {
      remainingSnapshots.push({ ...remaining })
    })

    expirationManager.upsertExpiration("alpha", Date.now() + 3_500)
    vi.advanceTimersByTime(1_000)
    expirationManager.remainingManager.pause()
    vi.advanceTimersByTime(1_000)

    expect(remainingSnapshots).toEqual([{ alpha: 4 }, { alpha: 3 }])

    expirationManager.terminate()
  } finally {
    vi.clearAllTimers()
    vi.useRealTimers()
  }
})

test("RemainingManager resume restarts interval-driven updates after pause", () => {
  vi.useFakeTimers()
  vi.setSystemTime(new Date(2_026, 0, 1, 0, 0, 0))

  try {
    const expirationManager = new ExpirationManager<"alpha">({
      enableRemainingManager: true,
    })
    const remainingSnapshots: Array<{ alpha?: number | undefined }> = []

    expirationManager.remainingManager.event.subscribe("remaining", (remaining): void => {
      remainingSnapshots.push({ ...remaining })
    })

    expirationManager.upsertExpiration("alpha", Date.now() + 3_500)
    expirationManager.remainingManager.pause()
    vi.advanceTimersByTime(1_000)
    expirationManager.remainingManager.resume()
    vi.advanceTimersByTime(1_000)

    expect(remainingSnapshots).toEqual([{ alpha: 4 }, { alpha: 2 }])

    expirationManager.terminate()
  } finally {
    vi.clearAllTimers()
    vi.useRealTimers()
  }
})

test("RemainingManager terminate stops future emissions", () => {
  vi.useFakeTimers()
  vi.setSystemTime(new Date(2_026, 0, 1, 0, 0, 0))

  try {
    const expirationManager = new ExpirationManager<"alpha">({
      enableRemainingManager: true,
    })
    const remainingSnapshots: Array<{ alpha?: number | undefined }> = []

    expirationManager.remainingManager.event.subscribe("remaining", (remaining): void => {
      remainingSnapshots.push({ ...remaining })
    })

    expirationManager.upsertExpiration("alpha", Date.now() + 3_500)
    expirationManager.remainingManager.terminate()
    vi.advanceTimersByTime(2_000)
    expirationManager.remainingManager.emit()

    expect(remainingSnapshots).toEqual([{ alpha: 4 }])

    expirationManager.terminate()
  } finally {
    vi.clearAllTimers()
    vi.useRealTimers()
  }
})