import { describe, it, expect, beforeAll, afterAll, beforeEach } from 'vitest'
import { MongoClient, Db } from 'mongodb'

const MONGO_URI = 'mongodb://adam:adam@localhost:27017/adam-acs-ttl-test?authSource=admin'
const COLLECTION_NAME = 'cwmp_exchanges'

let client: MongoClient
let db: Db
let skip = false

describe('TTL expiration integration test', () => {
  beforeAll(async () => {
    try {
      client = new MongoClient(MONGO_URI, { serverSelectionTimeoutMS: 2000 })
      await client.connect()
      db = client.db('adam-acs-ttl-test')

      // Ensure the collection exists before creating the index
      const collections = await db.listCollections({ name: COLLECTION_NAME }).toArray()
      if (collections.length === 0) {
        await db.createCollection(COLLECTION_NAME)
      }
      // Create the TTL index (as the migration would)
      const collection = db.collection(COLLECTION_NAME)
      await collection.createIndex(
        { createdAt: 1 },
        { expireAfterSeconds: 86400, name: 'idx_createdAt_ttl', background: true }
      )
    } catch {
      skip = true
    }
  })

  afterAll(async () => {
    if (skip) return
    await db.dropDatabase()
    await client.close()
  })

  beforeEach(async () => {
    if (skip) return
    await db.collection(COLLECTION_NAME).deleteMany({})
  })

  /**
   * Validates: Requirements 7.3
   *
   * Verify the TTL index is configured with expireAfterSeconds = 86400 (24 hours).
   * In a real MongoDB deployment, the TTL monitor thread runs every 60s and removes
   * documents whose createdAt field is older than 86400 seconds. For this test, we
   * verify the index configuration is correct rather than waiting for the TTL monitor.
   */
  it('should have a TTL index on createdAt with expireAfterSeconds = 86400', async () => {
    if (skip) return
    const collection = db.collection(COLLECTION_NAME)
    const indexes = await collection.indexes()

    const ttlIndex = indexes.find((idx) => idx.name === 'idx_createdAt_ttl')

    expect(ttlIndex).toBeDefined()
    expect(ttlIndex!.key).toEqual({ createdAt: 1 })
    expect(ttlIndex!.expireAfterSeconds).toBe(86400)
  })

  it('should store exchanges with createdAt set to 25 hours ago as expired candidates', async () => {
    if (skip) return
    const collection = db.collection(COLLECTION_NAME)
    const twentyFiveHoursAgo = new Date(Date.now() - 25 * 60 * 60 * 1000)

    // Insert exchanges with createdAt set 25 hours in the past
    const expiredExchanges = Array.from({ length: 5 }, (_, i) => ({
      deviceId: 'device-ttl-test',
      direction: 'CPE→ACS' as const,
      timestamp: new Date(twentyFiveHoursAgo.getTime() + i * 1000).toISOString(),
      sessionId: '10.0.0.1:54321->192.168.1.1:8080',
      cwmpMethod: 'Inform',
      rawXml: `<soap-env:Envelope><soap-env:Body><cwmp:Inform/></soap-env:Body></soap-env:Envelope>`,
      sequenceNumber: i + 1,
      createdAt: twentyFiveHoursAgo,
    }))

    await collection.insertMany(expiredExchanges)

    // Verify the documents were inserted
    const count = await collection.countDocuments({ deviceId: 'device-ttl-test' })
    expect(count).toBe(5)

    // Verify all documents have a createdAt older than 24 hours
    const docs = await collection.find({ deviceId: 'device-ttl-test' }).toArray()
    const twentyFourHoursAgo = new Date(Date.now() - 24 * 60 * 60 * 1000)

    for (const doc of docs) {
      expect(doc.createdAt).toBeInstanceOf(Date)
      expect(doc.createdAt.getTime()).toBeLessThan(twentyFourHoursAgo.getTime())
    }
  })

  it('should NOT mark recent exchanges as expired candidates', async () => {
    if (skip) return
    const collection = db.collection(COLLECTION_NAME)
    const now = new Date()

    // Insert exchanges with current createdAt (should NOT be expired)
    const recentExchanges = Array.from({ length: 3 }, (_, i) => ({
      deviceId: 'device-ttl-recent',
      direction: 'ACS→CPE' as const,
      timestamp: new Date(now.getTime() + i * 1000).toISOString(),
      sessionId: '10.0.0.1:54321->192.168.1.1:8080',
      cwmpMethod: 'GetParameterValuesResponse',
      rawXml: `<soap-env:Envelope><soap-env:Body><cwmp:GetParameterValuesResponse/></soap-env:Body></soap-env:Envelope>`,
      sequenceNumber: i + 1,
      createdAt: now,
    }))

    await collection.insertMany(recentExchanges)

    // Verify documents exist and their createdAt is within 24 hours
    const docs = await collection.find({ deviceId: 'device-ttl-recent' }).toArray()
    const twentyFourHoursAgo = new Date(Date.now() - 24 * 60 * 60 * 1000)

    expect(docs).toHaveLength(3)
    for (const doc of docs) {
      expect(doc.createdAt).toBeInstanceOf(Date)
      expect(doc.createdAt.getTime()).toBeGreaterThan(twentyFourHoursAgo.getTime())
    }
  })

  it('TTL index expireAfterSeconds should equal exactly 24 hours in seconds', async () => {
    if (skip) return
    const collection = db.collection(COLLECTION_NAME)
    const indexes = await collection.indexes()

    const ttlIndex = indexes.find((idx) => idx.name === 'idx_createdAt_ttl')
    expect(ttlIndex).toBeDefined()

    // 24 hours = 24 * 60 * 60 = 86400 seconds
    const twentyFourHoursInSeconds = 24 * 60 * 60
    expect(ttlIndex!.expireAfterSeconds).toBe(twentyFourHoursInSeconds)
  })
})