git ssb

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const pull = require('pull-stream')
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const sort = require('ssb-sort')
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const isPoll = require('../../isPoll')
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const isPosition = require('../../isPosition')
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const { ERROR_POSITION_TYPE } = require('../../types')
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const results = require('../../position/sync/chooseOneResults')
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module.exports = function (server) {
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  return function get (key, cb) {
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    server.get(key, (err, value) => {
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      if (err) return cb(err)
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      var poll = { key, value }
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      if (!isPoll(poll)) return cb(new Error('scuttle-poll could not fetch, key provided was not a valid poll key'))
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      pull(
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        createBacklinkStream(key),
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        pull.collect(msgs => {
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          cb(null, decoratedPoll(poll, msgs))
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        })
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      )
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    })
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  }
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  function createBacklinkStream (key) {
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    var filterQuery = {
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      $filter: {
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        dest: key
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      }
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    }
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    return server.backlinks.read({
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      query: [filterQuery],
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      index: 'DTA' // use asserted timestamps
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    })
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  }
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}
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function decoratedPoll (rawPoll, msgs) {
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  const { title, body } = rawPoll.value.content
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  const poll = Object.assign({}, rawPoll, {
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    title,
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    body,
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    positions: [],
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    results: {},
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    errors: []
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  })
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  // filter position message into 'positions' and 'errors'
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  // TODO schema checks right position shape, but needs to add e.g. acceptible position ranges based on poll
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  // TODO add missingContext warnings
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  msgs = sort(msgs)
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  const type = poll.value.content.pollDetails.type
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  msgs.forEach(msg => {
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    if (isPosition[type](msg)) {
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      poll.positions.push(msg)
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      return
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    }
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    if (isPosition(msg)) {
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      poll.errors.push({
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        type: ERROR_POSITION_TYPE,
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        message: `Position responses need to be off the ${type} type for this poll`,
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        position: msg
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      })
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    }
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  })
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  poll.results = results(poll.positions)
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  return poll
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}
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