#!/usr/bin/env node

function usage () {
  console.log('Usage: scripts/welcome.js <fetch-after> [--prod]')
  process.exit(1)
}

let args = process.argv.slice(2)

const useProd = args.indexOf('--prod') !== -1
const SN_API_URL = useProd ? 'https://stacker.news' : 'http://localhost:3000'
args = args.filter(arg => arg !== '--prod')
console.log('> url:', SN_API_URL)

// this is the item id of the last bio that was included in the previous post of the series
const FETCH_AFTER = args[0]
console.log('> fetch-after:', FETCH_AFTER)
if (!FETCH_AFTER) {
  usage()
}

const SN_API_KEY = process.env.SN_API_KEY
if (!SN_API_KEY) {
  console.log('SN_API_KEY must be set in environment')
  process.exit(1)
}

const LIMIT = 50

async function gql (query, variables = {}) {
  const response = await fetch(`${SN_API_URL}/api/graphql`, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json', 'x-api-key': SN_API_KEY },
    body: JSON.stringify({ query, variables })
  })

  if (response.status !== 200) {
    throw new Error(`request failed: ${response.statusText}`)
  }

  const json = await response.json()
  if (json.errors) {
    throw new Error(json.errors[0].message)
  }

  return json.data
}

async function assertSettings () {
  const { me } = await gql(`
    query me {
      me {
        id
        name
        privates {
          wildWestMode
          satsFilter
        }
      }
    }
  `)

  console.log(`> logged in as @${me.name}`)

  if (!me.privates.wildWestMode) {
    throw new Error('wild west mode must be enabled')
  }

  if (me.privates.satsFilter !== 0) {
    throw new Error('sats filter must be set to 0')
  }
}

async function fetchData () {
  return await Promise.all([
    fetchLatestWelcomePost(),
    fetchRecentBios()
  ]).then(([welcomePost, bios]) => ({ welcomePost, bios }))
}

async function fetchLatestWelcomePost () {
  const { items: { items } } = await gql(
    `query LatestWelcomePost {
      items(name: "ek", sort: "user", type: "posts", limit: 50) {
        items {
          id
          title
          text
        }
      }
    }`)

  const regex = /(Baby Stacker Corner|Tenderfoot Corner)/i
  for (const item of items) if (regex.test(item.title)) return item
  throw new Error('latest welcome post not found')
}

async function fetchRecentBios () {
  // fetch all recent bios. we assume here there won't be more than 21
  // since the last bio we already included in a post as defined by FETCH_AFTER.
  const { items: { items: bios } } = await gql(
    `query NewBios($limit: Limit!) {
      items(sort: "recent", type: "bios", limit: $limit) {
        items {
          id
          title
          createdAt
          user {
            name
            since
            nitems
            optional {
              stacked
            }
          }
        }
      }
    }`, { limit: LIMIT }
  )

  // assert that we fetched enough bios
  const newBios = bios.filter(b => Number(b.id) > FETCH_AFTER)
  if (newBios.length === bios.length) {
    throw new Error('last bio not found. increase limit')
  }
  return newBios
}

async function populate (data) {
  const { welcomePost, bios } = data
  return {
    welcomePost,
    bios: await Promise.all(
      bios.map(
        async bio => {
          bio.user.since = await util.fetchItem(bio.user.since)
          bio.user.items = await util.fetchUserItems(bio.user.name)
          bio.user.credits = util.sumBy(bio.user.items, 'credits')
          bio.user.sats = util.sumBy(bio.user.items, 'sats') - bio.user.credits
          if (bio.user.sats > 0 || bio.user.credits > 0) {
            bio.user.satstandard = bio.user.sats / (bio.user.sats + bio.user.credits)
          } else {
            bio.user.satstandard = 0
          }
          return bio
        }
      )
    )
  }
}

function printPost (data) {
  printDebug(data)
  printTitle(data)
  printAmount(data)
  printTopTenderfoots(data)
  printQuestions(data)
  printAllStackers(data)
  printSatStandardExplainer(data)
  printMemePlaceholder(data)
}

function printDebug ({ welcomePost }) {
  console.log(`> latest welcome post: ${welcomePost.title}\n`)
}

function printTitle ({ welcomePost }) {
  const nr = welcomePostNr(welcomePost)
  console.log(`# Tenderfoot Corner #${nr + 1}\n`)
}

function welcomePostNr (welcomePost) {
  return Number(welcomePost.title.match(/\d+/)[0])
}

function printAmount ({ welcomePost, bios }) {
  const nr = welcomePostNr(welcomePost)
  console.log(`${bios.length} new stackers have found their way to Stacker News since [#${nr}](${util.itemLink(welcomePost.id)})!\n`)
}

function printTopTenderfoots ({ bios }) {
  console.log('Top 10 Tenderfoots:\n')
  console.log('| nym | items | sats/ccs stacked | sat standard |')
  console.log('| --- | ----- | ---------------- | ------------ |')

  const topTenderfoots = bios
    .sort((a, b) => (b.user.sats + b.user.credits) - (a.user.sats + a.user.credits))
    .slice(0, 10)

  for (const bio of topTenderfoots) {
    const { user } = bio
    console.log(`| **@${user.name}** | ${user.nitems} | ${user.sats}/${user.credits} | ${user.satstandard.toFixed(2)} |`)
  }

  console.log()
}

function printQuestions () {
  console.log('Questions for the new stackers:\n')
  console.log('1. How did you find out about SN?')
  console.log('2. How difficult was it to get started? Any feedback?')
  console.log('3. How much experience do you have with lightning?')
  console.log('4. Have you read the [FAQ](https://stacker.news/faq) already?')
  console.log('5. Have you realized that you need to attach a wallet to receive sats?')
  console.log('6. Do you understand the difference between cowboy credits (CCs) and sats?')
  console.log('7. How were your first weeks on SN?\n')
}

async function printAllStackers ({ bios }) {
  console.log('All new stackers:\n')
  console.log('| nym | bio (stacking since) | items | sats/ccs stacked | sat standard |')
  console.log('| --- | -------------------- | ----- | ---------------- | ------------ |')

  for (const bio of bios) {
    const { user } = bio

    const bioCreatedAt = util.formatDate(bio.createdAt)
    let col2 = util.dateLink(bio)
    if (Number(bio.id) !== user.since.id) {
      const sinceCreatedAt = util.formatDate(user.since.createdAt)
      // stacking since might not be the same item as the bio
      // but it can still have been created on the same day
      if (bioCreatedAt !== sinceCreatedAt) {
        col2 += ` (${util.dateLink(user.since)})`
      }
    }
    console.log(`| @${user.name} | ${col2} | ${user.nitems} | ${user.sats}/${user.credits} | ${user.satstandard.toFixed(2)} |`)
  }

  console.log()
}

function printSatStandardExplainer () {
  console.log('_sat standard = ratio of received sats vs credits (`sats/(sats+credits)`)_\n')
}

function printMemePlaceholder () {
  console.log('<<< INSERT MEME HERE >>>')
  console.log('inspiration: https://imgflip.com/memetemplates?sort=top-new')
}

const util = {
  formatDate (date) {
    return new Date(date).toLocaleDateString('en-US', { month: 'short', day: 'numeric' })
  },
  sumBy (arr, key) {
    return arr.reduce((acc, item) => acc + item[key], 0)
  },
  itemLink (id) {
    return `https://stacker.news/items/${id}`
  },
  dateLink (item) {
    return `[${this.formatDate(item.createdAt)}](${this.itemLink(item.id)})`
  },
  async fetchItem (id) {
    const data = await gql(`
      query Item($id: ID!) {
        item(id: $id) {
          id
          createdAt
        }
      }`, { id }
    )
    return data.item
  },
  async fetchUserItems (name) {
    const data = await gql(`
      query UserItems($name: String!) {
        items(sort: "user", type: "all", limit: 999, name: $name) {
          items {
            id
            createdAt
            sats
            credits
          }
        }
      }`, { name }
    )
    return data.items.items
  }
}

assertSettings()
  .then(fetchData)
  .then(populate)
  .then(printPost)
  .catch(console.error)