import { buildEvent } from './test-helpers.ts'
import { MessageQueue, insertEventIntoAscendingList, insertEventIntoDescendingList } from './utils.ts'

import type { Event } from './event.ts'

describe('inserting into a desc sorted list of events', () => {
  test('insert into an empty list', async () => {
    const list0: Event[] = []
    expect(insertEventIntoDescendingList(list0, buildEvent({ id: 'abc', created_at: 10 }))).toHaveLength(1)
  })

  test('insert in the beginning of a list', async () => {
    const list0 = [buildEvent({ created_at: 20 }), buildEvent({ created_at: 10 })]
    const list1 = insertEventIntoDescendingList(
      list0,
      buildEvent({
        id: 'abc',
        created_at: 30,
      }),
    )
    expect(list1).toHaveLength(3)
    expect(list1[0].id).toBe('abc')
  })

  test('insert in the beginning of a list with same created_at', async () => {
    const list0 = [buildEvent({ created_at: 30 }), buildEvent({ created_at: 20 }), buildEvent({ created_at: 10 })]
    const list1 = insertEventIntoDescendingList(
      list0,
      buildEvent({
        id: 'abc',
        created_at: 30,
      }),
    )
    expect(list1).toHaveLength(4)
    expect(list1[0].id).toBe('abc')
  })

  test('insert in the middle of a list', async () => {
    const list0 = [
      buildEvent({ created_at: 30 }),
      buildEvent({ created_at: 20 }),
      buildEvent({ created_at: 10 }),
      buildEvent({ created_at: 1 }),
    ]
    const list1 = insertEventIntoDescendingList(
      list0,
      buildEvent({
        id: 'abc',
        created_at: 15,
      }),
    )
    expect(list1).toHaveLength(5)
    expect(list1[2].id).toBe('abc')
  })

  test('insert in the end of a list', async () => {
    const list0 = [
      buildEvent({ created_at: 20 }),
      buildEvent({ created_at: 20 }),
      buildEvent({ created_at: 20 }),
      buildEvent({ created_at: 20 }),
      buildEvent({ created_at: 10 }),
    ]
    const list1 = insertEventIntoDescendingList(
      list0,
      buildEvent({
        id: 'abc',
        created_at: 5,
      }),
    )
    expect(list1).toHaveLength(6)
    expect(list1.slice(-1)[0].id).toBe('abc')
  })

  test('insert in the last-to-end of a list with same created_at', async () => {
    const list0: Event[] = [
      buildEvent({ created_at: 20 }),
      buildEvent({ created_at: 20 }),
      buildEvent({ created_at: 20 }),
      buildEvent({ created_at: 20 }),
      buildEvent({ created_at: 10 }),
    ]
    const list1 = insertEventIntoDescendingList(
      list0,
      buildEvent({
        id: 'abc',
        created_at: 10,
      }),
    )
    expect(list1).toHaveLength(6)
    expect(list1.slice(-2)[0].id).toBe('abc')
  })

  test('do not insert duplicates', async () => {
    const list0 = [
      buildEvent({ created_at: 20 }),
      buildEvent({ created_at: 20 }),
      buildEvent({ created_at: 10, id: 'abc' }),
    ]
    const list1 = insertEventIntoDescendingList(
      list0,
      buildEvent({
        id: 'abc',
        created_at: 10,
      }),
    )
    expect(list1).toHaveLength(3)
  })
})

describe('inserting into a asc sorted list of events', () => {
  test('insert into an empty list', async () => {
    const list0: Event[] = []
    expect(insertEventIntoAscendingList(list0, buildEvent({ id: 'abc', created_at: 10 }))).toHaveLength(1)
  })

  test('insert in the beginning of a list', async () => {
    const list0 = [buildEvent({ created_at: 10 }), buildEvent({ created_at: 20 })]
    const list1 = insertEventIntoAscendingList(
      list0,
      buildEvent({
        id: 'abc',
        created_at: 1,
      }),
    )
    expect(list1).toHaveLength(3)
    expect(list1[0].id).toBe('abc')
  })

  test('insert in the beginning of a list with same created_at', async () => {
    const list0 = [buildEvent({ created_at: 10 }), buildEvent({ created_at: 20 }), buildEvent({ created_at: 30 })]
    const list1 = insertEventIntoAscendingList(
      list0,
      buildEvent({
        id: 'abc',
        created_at: 10,
      }),
    )
    expect(list1).toHaveLength(4)
    expect(list1[0].id).toBe('abc')
  })

  test('insert in the middle of a list', async () => {
    const list0 = [
      buildEvent({ created_at: 10 }),
      buildEvent({ created_at: 20 }),
      buildEvent({ created_at: 30 }),
      buildEvent({ created_at: 40 }),
    ]
    const list1 = insertEventIntoAscendingList(
      list0,
      buildEvent({
        id: 'abc',
        created_at: 25,
      }),
    )
    expect(list1).toHaveLength(5)
    expect(list1[2].id).toBe('abc')
  })

  test('insert in the end of a list', async () => {
    const list0 = [
      buildEvent({ created_at: 20 }),
      buildEvent({ created_at: 20 }),
      buildEvent({ created_at: 20 }),
      buildEvent({ created_at: 20 }),
      buildEvent({ created_at: 40 }),
    ]
    const list1 = insertEventIntoAscendingList(
      list0,
      buildEvent({
        id: 'abc',
        created_at: 50,
      }),
    )
    expect(list1).toHaveLength(6)
    expect(list1.slice(-1)[0].id).toBe('abc')
  })

  test('insert in the last-to-end of a list with same created_at', async () => {
    const list0 = [
      buildEvent({ created_at: 20 }),
      buildEvent({ created_at: 20 }),
      buildEvent({ created_at: 20 }),
      buildEvent({ created_at: 20 }),
      buildEvent({ created_at: 30 }),
    ]
    const list1 = insertEventIntoAscendingList(
      list0,
      buildEvent({
        id: 'abc',
        created_at: 30,
      }),
    )
    expect(list1).toHaveLength(6)
    expect(list1.slice(-2)[0].id).toBe('abc')
  })

  test('do not insert duplicates', async () => {
    const list0 = [
      buildEvent({ created_at: 20 }),
      buildEvent({ created_at: 20 }),
      buildEvent({ created_at: 30, id: 'abc' }),
    ]
    const list1 = insertEventIntoAscendingList(
      list0,
      buildEvent({
        id: 'abc',
        created_at: 30,
      }),
    )
    expect(list1).toHaveLength(3)
  })
})

describe('enque a message into MessageQueue', () => {
  test('enque into an empty queue', () => {
    const queue = new MessageQueue()
    queue.enqueue('node1')
    expect(queue.first!.value).toBe('node1')
  })
  test('enque into a non-empty queue', () => {
    const queue = new MessageQueue()
    queue.enqueue('node1')
    queue.enqueue('node3')
    queue.enqueue('node2')
    expect(queue.first!.value).toBe('node1')
    expect(queue.last!.value).toBe('node2')
    expect(queue.size).toBe(3)
  })
  test('dequeue from an empty queue', () => {
    const queue = new MessageQueue()
    const item1 = queue.dequeue()
    expect(item1).toBe(null)
    expect(queue.size).toBe(0)
  })
  test('dequeue from a non-empty queue', () => {
    const queue = new MessageQueue()
    queue.enqueue('node1')
    queue.enqueue('node3')
    queue.enqueue('node2')
    const item1 = queue.dequeue()
    expect(item1).toBe('node1')
    const item2 = queue.dequeue()
    expect(item2).toBe('node3')
  })
  test('dequeue more than in queue', () => {
    const queue = new MessageQueue()
    queue.enqueue('node1')
    queue.enqueue('node3')
    const item1 = queue.dequeue()
    expect(item1).toBe('node1')
    const item2 = queue.dequeue()
    expect(item2).toBe('node3')
    expect(queue.size).toBe(0)
    const item3 = queue.dequeue()
    expect(item3).toBe(null)
  })
})