'use strict'

const send = require('koa-send')
const streamify = require('stream-array')
const responders = require('./responders')

function toArrayStream (iterator) {
  return streamify(Array.from(iterator.entries()))
}

function home (config, posts) {
  const postsStream = toArrayStream(posts)
  return async function (ctx, next) {
    responders.home(ctx, config, postsStream)
  }
}

function post (config, posts) {
  return async function (ctx, next) {
    ctx.assert(posts.has(ctx.params.filename), 404, 'Post not found')
    const post = posts.get(ctx.params.filename)

    responders.post(ctx, config, post)
  }
}

function taxonGenerator (config, term, items) {
  return async function (ctx, next) {
    const value = ctx.params.value
    ctx.assert(items.has(ctx.params.value), 404, `${term} ${value} not found`)

    const taxonItems = toArrayStream(items.get(value))

    responders.taxon(ctx, config, taxonItems)
  }
}

const prefix = /^\/static\//
async function serveFiles (ctx) {
  if (prefix.test(ctx.path)) {
    await send(ctx, ctx.path.replace(prefix, ''), {
      root: './static'
    })
  }
}

module.exports = {
  home,
  post,
  taxonGenerator,
  serveFiles
}