var pull = require('pull-stream')
var paramap = require('pull-paramap')
var asyncMemo = require('asyncmemo')
var Issues = require('ssb-issues')
var ssbGit = require('ssb-git-repo')

function readNext(fn) {
  var next
  return function (end, cb) {
    if (next) return next(end, cb)
    fn(function (err, _next) {
      if (err) return cb(err)
      next = _next
      next(null, cb)
    })
  }
}

module.exports = {
  name: 'pull-requests',
  version: '1.0.0',
  manifest: {
    get: 'async',
    list: 'source'
  },
  schemas: require('./lib/schemas'),
  init: function (sbot) {

    var issues = Issues.init(sbot)
    var getMsg = asyncMemo(sbot.get)
    var getRepo = asyncMemo(function (id, cb) {
      getMsg(id, function (err, msg) {
        if (err) return cb(err)
        ssbGit.getRepo(sbot, {key: id, value: msg}, {live: true}, cb)
      })
    })

    var getPullReq = asyncMemo(function (id, cb) {
      issues.get(id, function (err, issue) {
        if (err) return cb(err)
        var c = issue.msg.value.content
        issue.baseRepo = c.repo
        issue.baseBranch = c.branch
        issue.headRepo = c.head_repo
        issue.headBranch = c.head_branch
        cb(null, issue)
      })
    })

    function listPullReqs(opts) {
      opts = opts || {}
      opts.type = 'pull-request'
      return pull(
        sbot.messagesByType(opts),
        pull.filter(function (msg) {
          return (!opts.repo || opts.repo == msg.value.content.repo)
            && (!opts.author || opts.author == msg.value.author)
        }),
        paramap(function (msg, cb) {
          getPullReq(msg.key, cb)
        }, 8),
        pull.filter(opts.open != null && function (pr) {
          return pr.open == opts.open
        })
      )
    }

    return {
      get: getPullReq,
      list: listPullReqs
    }
  }
}