'use strict'

const assert = require('assert')
const mapSeries = require('p-map-series')
const rmrf = require('rimraf')
const OrbitDB = require('../src/OrbitDB')
const config = require('./utils/config')
const startIpfs = require('./utils/start-ipfs')

const dbPath = './orbitdb/tests/persistency'
const ipfsPath = './orbitdb/tests/persistency/ipfs'

describe('orbit-db - Persistency', function() {
  this.timeout(config.timeout)

  const entryCount = 100

  let ipfs, orbitdb1, db, address

  before(async () => {
    config.daemon1.repo = ipfsPath
    rmrf.sync(config.daemon1.repo)
    rmrf.sync(dbPath)
    ipfs = await startIpfs(config.daemon1)
    orbitdb1 = new OrbitDB(ipfs, dbPath + '/1')
  })

  after(async () => {
    if(orbitdb1) 
      await orbitdb1.stop()

    if (ipfs)
      await ipfs.stop()
  })

  describe('load', function() {
    beforeEach(async () => {
      const dbName = new Date().getTime().toString()
      const entryArr = []

      for (let i = 0; i < entryCount; i ++)
        entryArr.push(i)

      db = await orbitdb1.eventlog(dbName)
      address = db.address.toString()
      await mapSeries(entryArr, (i) => db.add('hello' + i))
      await db.close()
      db = null
    })

    afterEach(async () => {
      await db.drop()
    })

    it('loads database from local cache', async () => {
      db = await orbitdb1.eventlog(address)
      await db.load()
      const items = db.iterator({ limit: -1 }).collect()
      assert.equal(items.length, entryCount)
      assert.equal(items[0].payload.value, 'hello0')
      assert.equal(items[items.length - 1].payload.value, 'hello99')
    })

    it('loads database partially', async () => {
      const amount = 33
      db = await orbitdb1.eventlog(address)
      await db.load(amount)
      const items = db.iterator({ limit: -1 }).collect()
      assert.equal(items.length, amount)
      assert.equal(items[0].payload.value, 'hello' + (entryCount - amount))
      assert.equal(items[items.length - 1].payload.value, 'hello99')
    })

    it('loading a database emits \'ready\' event', async () => {
      db = await orbitdb1.eventlog(address)
      return new Promise(async (resolve) => {
        db.events.on('ready', () => {
          const items = db.iterator({ limit: -1 }).collect()
          assert.equal(items.length, entryCount)
          assert.equal(items[0].payload.value, 'hello0')
          assert.equal(items[items.length - 1].payload.value, 'hello99')
          resolve()
        })
        await db.load()
      })
    })

    it('loading a database emits \'load.progress\' event', async () => {
      db = await orbitdb1.eventlog(address)
      return new Promise(async (resolve, reject) => {
        let count = 0
        db.events.on('load.progress', (address, hash, entry, progress, total) => {
          count ++
          try {
            assert.equal(address, db.address.toString())
            assert.equal(total, entryCount)
            assert.equal(progress, count)
            assert.notEqual(hash, null)
            assert.notEqual(entry, null)
            if (progress === entryCount && count === entryCount) {
              setTimeout(() => {
                resolve()
              }, 200)
            }
          } catch (e) {
            reject(e)
          }
        })
        // Start loading the database
        await db.load()
      })
    })
  })

  describe('load from empty snapshot', function() {
    it('loads database from an empty snapshot', async () => {
      db = await orbitdb1.eventlog('empty-snapshot')
      address = db.address.toString()
      await db.saveSnapshot()
      await db.close()

      db = await orbitdb1.open(address)
      await db.loadFromSnapshot()
      const items = db.iterator({ limit: -1 }).collect()
      assert.equal(items.length, 0)
    })
  })

  describe('load from snapshot', function() {
    beforeEach(async () => {
      const dbName = new Date().getTime().toString()
      const entryArr = []

      for (let i = 0; i < entryCount; i ++)
        entryArr.push(i)

      db = await orbitdb1.eventlog(dbName)
      address = db.address.toString()
      await mapSeries(entryArr, (i) => db.add('hello' + i))
      await db.saveSnapshot()
      await db.close()
      db = null
    })

    afterEach(async () => {
      await db.drop()
    })

    it('loads database from snapshot', async () => {
      db = await orbitdb1.eventlog(address)
      await db.loadFromSnapshot()
      const items = db.iterator({ limit: -1 }).collect()
      assert.equal(items.length, entryCount)
      assert.equal(items[0].payload.value, 'hello0')
      assert.equal(items[entryCount - 1].payload.value, 'hello99')
    })

    it('throws an error when trying to load a missing snapshot', async () => {
      db = await orbitdb1.eventlog(address)
      await db.drop()
      db = null
      db = await orbitdb1.eventlog(address)

      let err
      try {
        await db.loadFromSnapshot()
      } catch (e) {
        err = e.toString()
      }
      assert.equal(err, `Error: Snapshot for ${address} not found!`)
    })

    it('loading a database emits \'ready\' event', async () => {
      db = await orbitdb1.eventlog(address)
      return new Promise(async (resolve) => {
        db.events.on('ready', () => {
          const items = db.iterator({ limit: -1 }).collect()
          assert.equal(items.length, entryCount)
          assert.equal(items[0].payload.value, 'hello0')
          assert.equal(items[entryCount - 1].payload.value, 'hello99')
          resolve()
        })
        await db.loadFromSnapshot()
      })
    })

    it('loading a database emits \'load.progress\' event', async () => {
      db = await orbitdb1.eventlog(address)
      return new Promise(async (resolve, reject) => {
        let count = 0
        db.events.on('load.progress', (address, hash, entry, progress, total) => {
          count ++
          try {
            assert.equal(address, db.address.toString())
            assert.equal(total, entryCount)
            assert.equal(progress, count)
            assert.notEqual(hash, null)
            assert.notEqual(entry, null)
            if (progress === entryCount && count === entryCount) {
              resolve()
            }
          } catch (e) {
            reject(e)
          }
        })
        // Start loading the database
        await db.loadFromSnapshot()
      })
    })
  })
})