var ssbRef = require('ssb-ref')

exports.new = function (baseRepo, baseBranch, headRepo, headBranch,
    title, text) {
  if (!ssbRef.isLink(baseRepo))
    throw new Error('invalid base repo id')
  if (!baseBranch || typeof baseBranch != 'string')
    throw new Error('invalid base branch')
  if (!ssbRef.isLink(headRepo))
    throw new Error('invalid head repo id')
  if (!headBranch || typeof headBranch != 'string')
    throw new Error('invalid head branch')

  var msg = {
    type: 'pull-request',
    repo: baseRepo,
    project: baseRepo,
    branch: baseBranch,
    head_repo: headRepo,
    head_branch: headBranch
  }

  if (title) {
    if (typeof title === 'string') msg.title = title
    else throw new Error('invalid title')
  }
  if (text) {
    if (typeof text === 'string') msg.text = text
    else throw new Error('invalid text')
  }

  return msg
}