import { strictEqual, deepStrictEqual } from 'assert'
import rimraf from 'rimraf'
import { copy } from 'fs-extra'
import { Log, MemoryStorage } from '../src/log.js'
import IdentityProvider from 'orbit-db-identity-provider'
import Keystore from '../src/Keystore.js'
import LogCreator from './utils/log-creator.js'
import all from 'it-all'

// Test utils
import { config, testAPIs, startIpfs, stopIpfs } from 'orbit-db-test-utils'

const { sync: rmrf } = rimraf
const { createIdentity } = IdentityProvider
const { createLogWithSixteenEntries } = LogCreator

let ipfsd, ipfs, testIdentity, testIdentity2, testIdentity3

Object.keys(testAPIs).forEach((IPFS) => {
  describe('Log - Iterator (' + IPFS + ')', function () {
    this.timeout(config.timeout)

    const { identityKeyFixtures, signingKeyFixtures, identityKeysPath, signingKeysPath } = config

    let keystore, signingKeystore

    before(async () => {
      rmrf(identityKeysPath)
      rmrf(signingKeysPath)
      await copy(identityKeyFixtures, identityKeysPath)
      await copy(signingKeyFixtures, signingKeysPath)

      keystore = new Keystore(identityKeysPath)
      signingKeystore = new Keystore(signingKeysPath)

      testIdentity = await createIdentity({ id: 'userA', keystore, signingKeystore })
      testIdentity2 = await createIdentity({ id: 'userB', keystore, signingKeystore })
      testIdentity3 = await createIdentity({ id: 'userC', keystore, signingKeystore })
      ipfsd = await startIpfs(IPFS, config.defaultIpfsConfig)
      ipfs = ipfsd.api
    })

    after(async () => {
      await stopIpfs(ipfsd)
      rmrf(identityKeysPath)
      rmrf(signingKeysPath)

      await keystore.close()
      await signingKeystore.close()
    })

    describe('Basic iterator functionality', () => {
      let log1
      let startHash
      const hashes = []
      const logSize = 100
      const storage = MemoryStorage()

      beforeEach(async () => {
        log1 = Log(testIdentity, { logId: 'X', storage })

        for (let i = 0; i < logSize; i++) {
          const entry = await log1.append('entry' + i)
          hashes.push([entry.hash, hashes.length])
        }

        // entry67
        // startHash = 'zdpuAxCuaH2R7AYKZ6ZBeeA94v3FgmHZ8wCfDy7pLVcoc3zSo'
        startHash = hashes[67][0]
        strictEqual(startHash, hashes[67][0])
      })

      it('returns length with lte and amount', async () => {
        const amount = 10

        const it = log1.iterator({
          lte: startHash,
          amount
        })

        const result = await all(it)

        strictEqual([...result].length, 10)
      })

      it('returns entries with lte and amount', async () => {
        const amount = 10

        const it = log1.iterator({
          lte: startHash,
          amount
        })

        let i = 0
        for await (const entry of it) {
          strictEqual(entry.payload, 'entry' + (67 - i++))
        }

        strictEqual(i, amount)
      })

      it('returns length with lt and amount', async () => {
        const amount = 10

        const it = log1.iterator({
          lt: startHash,
          amount
        })

        const result = await all(it)

        strictEqual([...result].length, amount)
      })

      it('returns entries with lt and amount', async () => {
        const amount = 10

        const it = log1.iterator({
          lt: startHash,
          amount
        })

        let i = 0
        for await (const entry of it) {
          strictEqual(entry.payload, 'entry' + (66 - i++))
        }

        strictEqual(i, amount)
      })

      it('returns correct length with gt and amount', async () => {
        const amount = 5

        const it = log1.iterator({
          gt: startHash,
          amount
        })

        let i = 0
        for await (const entry of it) {
          strictEqual(entry.payload, 'entry' + (73 - i++))
        }

        strictEqual(i, amount)
      })

      it('returns length with gte and amount', async () => {
        const amount = 12

        const it = log1.iterator({
          gte: startHash,
          amount
        })

        const result = await all(it)

        strictEqual([...result].length, amount)
      })

      it('returns entries with gte and amount', async () => {
        const amount = 12

        const it = log1.iterator({
          gte: startHash,
          amount
        })

        let i = 0
        for await (const entry of it) {
          strictEqual(entry.payload, 'entry' + (79 - i++))
        }

        strictEqual(i, amount)
      })

      it('iterates with lt and gt', async () => {
        const expectedHashes = hashes.slice().slice(0, 12).map(e => e[0])
        const it = log1.iterator({
          gt: expectedHashes[0],
          lt: expectedHashes[expectedHashes.length - 1]
        })
        const result = await all(it)
        const hashes_ = await Promise.all([...result.reverse()].map(e => e.hash))

        strictEqual(hashes_.length, 10)

        let i = 0
        for (const h of hashes_) {
          strictEqual(expectedHashes[i + 1], h)
          i++
        }
        strictEqual(i, 10)
      })

      it('iterates with lt and gte', async () => {
        const expectedHashes = hashes.slice().slice(0, 26).map(e => e[0])
        const it = log1.iterator({
          gte: expectedHashes[0],
          lt: expectedHashes[expectedHashes.length - 1]
        })
        const result = await all(it)
        const hashes_ = await Promise.all([...result].map(e => e.hash))

        strictEqual(hashes_.length, 25)
        strictEqual(hashes_.indexOf(expectedHashes[0]), 24)
        strictEqual(hashes_.indexOf(expectedHashes[expectedHashes.length - 1]), -1)
        strictEqual(hashes_.indexOf(expectedHashes[expectedHashes.length - 2]), 0)

        let i = 0
        for (const h of hashes_) {
          strictEqual(expectedHashes[expectedHashes.length - 2 - i], h)
          i++
        }
        strictEqual(i, 25)
      })

      it('iterates with lte and gt', async () => {
        const expectedHashes = hashes.slice().slice(0, 5).map(e => e[0])
        const it = log1.iterator({
          gt: expectedHashes[0],
          lte: expectedHashes[expectedHashes.length - 1]
        })
        const result = await all(it)
        const hashes_ = await Promise.all([...result].map(e => e.hash))

        strictEqual(hashes_.length, 4)
        strictEqual(hashes_.indexOf(expectedHashes[0]), -1)
        strictEqual(hashes_.indexOf(expectedHashes[expectedHashes.length - 1]), 0)
        strictEqual(hashes_.indexOf(expectedHashes[expectedHashes.length - 2]), 1)
        strictEqual(hashes_.indexOf(expectedHashes[expectedHashes.length - 3]), 2)
        strictEqual(hashes_.indexOf(expectedHashes[expectedHashes.length - 4]), 3)
      })

      it('iterates with lte and gte', async () => {
        const expectedHashes = hashes.slice().slice(0, 10).map(e => e[0])
        const it = log1.iterator({
          gte: expectedHashes[0],
          lte: expectedHashes[expectedHashes.length - 1]
        })
        const result = await all(it)
        const hashes_ = await Promise.all([...result].map(e => e.hash))

        strictEqual(hashes_.length, 10)
        strictEqual(hashes_.indexOf(expectedHashes[0]), 9)
        strictEqual(hashes_.indexOf(expectedHashes[expectedHashes.length - 1]), 0)

        let i = 0
        for (const h of hashes_) {
          strictEqual(expectedHashes[expectedHashes.length - 1 - i], h)
          i++
        }
        strictEqual(i, 10)
      })

      it('iterates the full log by default', async () => {
        const expectedHashes = hashes.slice().map(e => e[0])
        const it = log1.iterator({})
        const result = await all(it)
        const hashes_ = await Promise.all([...result].map(e => e.hash))

        strictEqual(hashes_.length, logSize)

        let i = 0
        for (const h of hashes_) {
          strictEqual(expectedHashes[expectedHashes.length - 1 - i], h)
          i++
        }

        strictEqual(i, logSize)
      })

      it('iterates the full log with gte and lte and amount', async () => {
        const expectedHashes = hashes.slice().map(e => e[0])
        const it = log1.iterator({
          gte: expectedHashes[0],
          lte: expectedHashes[expectedHashes.length - 1],
          amount: logSize
        })
        const result = await all(it)
        const hashes_ = await Promise.all([...result].map(e => e.hash))

        strictEqual(hashes_.length, logSize)

        let i = 0
        for (const h of hashes_) {
          strictEqual(expectedHashes[expectedHashes.length - 1 - i], h)
          i++
        }

        strictEqual(i, logSize)
      })

      it('returns length with gt and default amount', async () => {
        const it = log1.iterator({
          gt: startHash
        })

        const result = await all(it)

        strictEqual([...result].length, 32)
      })

      it('returns entries with gt and default amount', async () => {
        const it = log1.iterator({
          gt: startHash
        })

        let i = 0
        for await (const entry of it) {
          strictEqual(entry.payload, 'entry' + (logSize - 1 - i++))
        }

        strictEqual(i, 32)
      })

      it('returns length with gte and default amount', async () => {
        const it = await log1.iterator({
          gte: startHash
        })

        const result = await all(it)

        strictEqual([...result].length, 33)
      })

      it('returns entries with gte and default amount', async () => {
        const it = log1.iterator({
          gte: startHash
        })

        let i = 0
        for await (const entry of it) {
          strictEqual(entry.payload, 'entry' + (logSize - 1 - i++))
        }

        strictEqual(i, 33)
      })

      it('returns length with lt and default amount value', async () => {
        const it = log1.iterator({
          lt: startHash
        })

        const result = await all(it)

        strictEqual([...result].length, 67)
      })

      it('returns entries with lt and default amount value', async () => {
        const it = log1.iterator({
          lt: startHash
        })

        let i = 0
        for await (const entry of it) {
          strictEqual(entry.payload, 'entry' + (66 - i++))
        }
        strictEqual(i, 67)
      })

      it('returns length with lte and default amount value', async () => {
        const it = log1.iterator({
          lte: startHash
        })

        const result = await all(it)

        strictEqual([...result].length, 68)
      })

      it('returns entries with lte and default amount value', async () => {
        const it = log1.iterator({
          lte: startHash
        })

        let i = 0
        for await (const entry of it) {
          strictEqual(entry.payload, 'entry' + (67 - i++))
        }

        strictEqual(i, 68)
      })

      it('returns zero entries when amount is 0', async () => {
        const it = log1.iterator({
          amount: 0
        })

        let i = 0
        for await (const entry of it) { // eslint-disable-line no-unused-vars
          i++
        }

        strictEqual(i, 0)
      })
    })

    describe('Iteration over forked/joined logs', () => {
      let fixture, identities

      before(async () => {
        identities = [testIdentity3, testIdentity2, testIdentity3, testIdentity]
        fixture = await createLogWithSixteenEntries(Log, ipfs, identities)
      })

      it('returns the full length from all heads', async () => {
        const it = fixture.log.iterator({
          lte: fixture.log.heads()
        })

        const result = await all(it)

        strictEqual([...result].length, 16)
      })

      it('returns partial entries from all heads', async () => {
        const it = fixture.log.iterator({
          lte: fixture.log.heads(),
          amount: 6
        })

        const result = await all(it)

        deepStrictEqual([...result].map(e => e.payload),
          ['entryA10', 'entryA9', 'entryA8', 'entryA7', 'entryC0', 'entryA6'])
      })

      it('returns partial logs from single heads #1', async () => {
        const it = fixture.log.iterator({
          lte: [fixture.log.heads()[0]]
        })

        const result = await all(it)

        strictEqual([...result].length, 10)
      })

      it('returns partial logs from single heads #2', async () => {
        const it = fixture.log.iterator({
          lte: [fixture.log.heads()[1]]
        })

        const result = await all(it)

        strictEqual([...result].length, 11)
      })

      it('throws error if lte not a string or array of entries', async () => {
        let errMsg

        try {
          const it = fixture.log.iterator({
            lte: false
          })
          await all(it)
        } catch (e) {
          errMsg = e.message
        }

        strictEqual(errMsg, 'lte must be a string or an array of Entries')
      })

      it('throws error if lt not a string or array of entries', async () => {
        let errMsg

        try {
          const it = fixture.log.iterator({
            lt: {}
          })
          await all(it)
        } catch (e) {
          errMsg = e.message
        }

        strictEqual(errMsg, 'lt must be a string or an array of Entries')
      })
    })
  })
})