const _ = require('lodash/fp')
const axios = require('axios')
const { utils: coinUtils } = require('@lamassu/coins')

const NAME = 'LN'
const SUPPORTED_COINS = ['LN', 'BTC']

const BN = require('../../../bn')

function request (graphqlQuery, token, endpoint) {
  const headers = {
    'content-type': 'application/json',
    'Authorization': `Bearer ${token}`
  }
  return axios({
    method: 'post',
    url: endpoint,
    headers: headers,
    data: graphqlQuery
  })
    .then(r => {
      if (r.error) throw r.error
      return r.data
    })
    .catch(err => {
      throw new Error(err)
    })
}

function checkCryptoCode (cryptoCode) {
  if (!SUPPORTED_COINS.includes(cryptoCode)) {
    return Promise.reject(new Error('Unsupported crypto: ' + cryptoCode))
  }

  return Promise.resolve()
}

function getTransactionsByAddress (token, endpoint, address) {
  const accountInfo = {
    'operationName': 'me',
    'query': `query me {
      me {
        defaultAccount {
          defaultWalletId
          wallets {
            id
            walletCurrency
            transactionsByAddress (address: "${address}")
              edges {
                node {
                  direction
                  settlementAmount
                  status
                }
              }
            }
          }
        }
      }
    }`,
    'variables': {}
  }
  return request(accountInfo, token, endpoint)
    .then(r => {
      return r.data.me.defaultAccount
    })
    .catch(err => {
      throw new Error(err)
    })
}

function getGaloyAccount (token, endpoint, walletId) {
  const accountInfo = {
    'operationName': 'me',
    'query': `query me($walletId: WalletId!) {
      me {
        defaultAccount {
          walletById(walletId: $walletId) {
            id
            walletCurrency
            balance
            pendingIncomingBalance
          }
        }
      }
    }`,
    'variables': { 'walletId': `${walletId}` }
  }
  return request(accountInfo, token, endpoint)
    .then(r => {
      return r.data.me.defaultAccount
    })
    .catch(err => {
      throw new Error(err)
    })
}

function isLightning (address) {
  return address.substr(0, 2) === 'ln'
}

function sendFundsOnChain (walletId, address, cryptoAtoms, token, endpoint) {
  const sendOnChain = {
    'operationName': 'onChainPaymentSend',
    'query': `mutation onChainPaymentSend($input: OnChainPaymentSendInput!) {
      onChainPaymentSend(input: $input) {
        errors {
          message
          path
        }
        status
      }
    }`,
    'variables': { 'input': { 'address': `${address}`, 'amount': `${cryptoAtoms}`, 'walletId': `${walletId}` } }
  }
  return request(sendOnChain, token, endpoint)
    .then(result => {
      return result.data.onChainPaymentSend
    })
}

function sendFundsLN (walletId, invoice, cryptoAtoms, token, endpoint) {
  const sendLnNoAmount = {
    'operationName': 'lnNoAmountInvoicePaymentSend',
    'query': `mutation lnNoAmountInvoicePaymentSend($input: LnNoAmountInvoicePaymentInput!) {
      lnNoAmountInvoicePaymentSend(input: $input) {
        errors {
          message
          path
        }
        status
      }
    }`,
    'variables': { 'input': { 'paymentRequest': `${invoice}`, 'walletId': `${walletId}`, 'amount': `${cryptoAtoms}` } }
  }
  return request(sendLnNoAmount, token, endpoint).then(result => result.data.lnNoAmountInvoicePaymentSend)
}

function sendProbeRequest (walletId, invoice, cryptoAtoms, token, endpoint) {
  const sendProbeNoAmount = {
    'operationName': 'lnNoAmountInvoiceFeeProbe',
    'query': `mutation lnNoAmountInvoiceFeeProbe($input: LnNoAmountInvoiceFeeProbeInput!) {
      lnNoAmountInvoiceFeeProbe(input: $input) {
        amount
        errors {
          message
          path
        }
      }
    }`,
    'variables': { 'input': { 'paymentRequest': `${invoice}`, 'walletId': `${walletId}`, 'amount': `${cryptoAtoms}` } }
  }
  return request(sendProbeNoAmount, token, endpoint).then(result => result.data.lnNoAmountInvoiceFeeProbe)
}

function sendCoins (account, tx, settings, operatorId) {
  const { toAddress, cryptoAtoms, cryptoCode } = tx
  const externalCryptoCode = coinUtils.getEquivalentCode(cryptoCode)
  return checkCryptoCode(cryptoCode)
    .then(() => getGaloyAccount(account.apiSecret, account.endpoint, account.walletId))
    .then(galoyAccount => {
      const wallet = galoyAccount.walletById
      if (isLightning(toAddress)) {
        return sendFundsLN(wallet.id, toAddress, cryptoAtoms, account.apiSecret, account.endpoint)
      }
      return sendFundsOnChain(wallet.id, toAddress, cryptoAtoms, account.apiSecret, account.endpoint)
    })
    .then(result => {
      switch (result.status) {
        case 'ALREADY_PAID':
          throw new Error('Transaction already exists!')
        case 'FAILURE':
          throw new Error('Transaction failed!')
        case 'SUCCESS':
          return '<galoy transaction>'
        case 'PENDING':
          return '<galoy transaction>'
        default:
          throw new Error(`Transaction failed: ${_.head(result.errors).message}`)
      }
    })
}

function probeLN (account, cryptoCode, invoice) {
  const probeHardLimits = [100, 500, 1000]
  const promises = probeHardLimits.map(limit => {
    return sendProbeRequest(account.walletId, invoice, limit, account.apiSecret, account.endpoint)
      .then(r => _.isEmpty(r.errors))
  })
  return Promise.all(promises)
    .then(results => _.zipObject(probeHardLimits, results))
}

function newOnChainAddress (walletId, token, endpoint) {
  const createOnChainAddress = {
    'operationName': 'onChainAddressCreate',
    'query': `mutation onChainAddressCreate($input: OnChainAddressCreateInput!) {
      onChainAddressCreate(input: $input) {
        address
        errors {
          message
          path
        }
      }
    }`,
    'variables': { 'input': { 'walletId': `${walletId}` } }
  }
  return request(createOnChainAddress, token, endpoint)
    .then(result => {
      return result.data.onChainAddressCreate.address
    })
}

function newInvoice (walletId, cryptoAtoms, token, endpoint) {
  const createInvoice = {
    'operationName': 'lnInvoiceCreate',
    'query': `mutation lnInvoiceCreate($input: LnInvoiceCreateInput!) {
      lnInvoiceCreate(input: $input) {
        errors {
          message
          path
        }
        invoice {
          paymentRequest
        }
      }
    }`,
    'variables': { 'input': { 'walletId': `${walletId}`, 'amount': `${cryptoAtoms}` } }
  }
  return request(createInvoice, token, endpoint)
    .then(result => {
      return result.data.lnInvoiceCreate.invoice.paymentRequest
    })
}

function balance (account, cryptoCode, settings, operatorId) {
  return checkCryptoCode(cryptoCode)
    .then(() => getGaloyAccount(account.apiSecret, account.endpoint))
    .then(galoyAccount => {
      const wallet = galoyAccount.walletByid
      return new BN(wallet.balance || 0)
    })
}

function newAddress (account, info, tx, settings, operatorId) {
  const { cryptoAtoms, cryptoCode } = tx
  return checkCryptoCode(cryptoCode)
    .then(() => getGaloyAccount(account.apiSecret, account.endpoint))
    .then(galoyAccount => {
      const wallet = galoyAccount.walletById
      const promises = [
        newOnChainAddress(wallet.id, account.apiSecret, account.endpoint),
        newInvoice(wallet.id, cryptoAtoms, account.apiSecret, account.endpoint)
      ]
      return Promise.all(promises)
    })
    .then(([onChainAddress, invoice]) => {
      return `bitcoin:${onChainAddress}?amount=${cryptoAtoms}&lightning=${invoice}`
    })
}

function getStatus (account, tx, requested, settings, operatorId) {
  const { toAddress, cryptoAtoms, cryptoCode } = tx
  const getBalance = _.reduce((acc, value) => {
    acc[value.node.status] = acc[value.node.status].plus(new BN(value.node.settlementAmount))
    return acc
  }, { SUCCESS: new BN(0), PENDING: new BN(0), FAILURE: new BN(0) })

  const externalCryptoCode = coinUtils.getEquivalentCode(cryptoCode)
  return checkCryptoCode(cryptoCode)
    .then(() => {
      const address = coinUtils.parseUrl(cryptoCode, account.environment, toAddress)
      // Consider all LN transactions successful
      if (isLightning(address)) {
        return { receivedCryptoAtoms: cryptoAtoms, status: 'confirmed' }
      }
      // On-chain and intra-ledger transactions
      return getTransactionsByAddress(account.apiSecret, account.endpoint, address)
        .then(accountInfo => {
          const transactions =
            _.find(wallet => wallet.walletCurrency === externalCryptoCode &&
              wallet.id === accountInfo.defaultWalletId &&
              wallet.id === account.walletId)(accountInfo.wallets).transactions.edges
          const { SUCCESS: confirmed, PENDING: pending } = getBalance(transactions)
          if (confirmed.gte(requested)) return { receivedCryptoAtoms: confirmed, status: 'confirmed' }
          if (pending.gte(requested)) return { receivedCryptoAtoms: pending, status: 'authorized' }
          if (pending.gt(0)) return { receivedCryptoAtoms: pending, status: 'insufficientFunds' }
          return { receivedCryptoAtoms: pending, status: 'notSeen' }
        })
    })
}

function newFunding (account, cryptoCode, settings, operatorId) {
  const externalCryptoCode = coinUtils.getEquivalentCode(cryptoCode)
  // Regular BTC address
  return checkCryptoCode(cryptoCode)
    .then(() => getGaloyAccount(account.apiSecret, account.endpoint))
    .then(galoyAccount => {
      const wallet = galoyAccount.walletById
      return newOnChainAddress(wallet.id, account.apiSecret, account.endpoint)
        .then(onChainAddress => [onChainAddress, wallet.balance, wallet.pendingIncomingBalance])
    })
    .then(([onChainAddress, balance, pendingIncomingBalance]) => {
      return {
        fundingPendingBalance: new BN(pendingIncomingBalance),
        fundingConfirmedBalance: new BN(balance),
        fundingAddress: onChainAddress
      }
    })
}

function cryptoNetwork (account, cryptoCode, settings, operatorId) {
  return checkCryptoCode(cryptoCode)
    .then(() => account.environment === 'test' ? 'test' : 'main')
}

function checkBlockchainStatus (cryptoCode) {
  return checkCryptoCode(cryptoCode)
    .then(() => Promise.resolve('ready'))
}

module.exports = {
  NAME,
  balance,
  sendCoins,
  newAddress,
  getStatus,
  newFunding,
  cryptoNetwork,
  checkBlockchainStatus,
  sendProbeRequest,
  probeLN
}