'use strict'

const fs = require('fs')
const rheo = require('rheo')
const markdown = require('./modules/markdown.js')

const templateReader = template => () =>
  fs.createReadStream(`${__dirname}/templates/${template}.html`)
const templates = {
  layout: templateReader('layout'),
  home: templateReader('home'),
  post: templateReader('post'),
  taxon: templateReader('taxon')
}

function setTitle (siteTitle, pageTitle) {
  return rheo.template(function (s) {
    return s
      .inner('title', rheo((pageTitle ? ' · ' : '') + siteTitle))
      .inner('body header h1', rheo(siteTitle))
  })
}

function renderPostListItem (ctx) {
  return function (template, [, post]) {
    return template
      .attribute('a', 'href', () => ctx.getURL('post', post.basename))
      .inner('a', () => rheo(post.data.get('title')))
  }
}

function showPage (name) {
  return function (els) {
    return rheo(templates[name]())
  }
}

module.exports = {
  home (ctx, config, postsStream) {
    ctx.type = 'html'
    ctx.body = templates
      .layout()
      .pipe(rheo())
      .outer('main', showPage('home'))
      .inner('.posts', function (postsTemplate) {
        return postsStream.pipe(postsTemplate.map(renderPostListItem(ctx)))
      })
      .pipe(setTitle(config.site.title))
      .render()
  },

  post (ctx, config, post) {
    ctx.type = 'html'
    ctx.body = templates
      .layout()
      .pipe(rheo())
      .inner('main', showPage('post'))
      .inner('article h1', rheo(post.data.get('title')))
      .inner('article main', rheo(markdown(post.content)))
      .pipe(setTitle(config.site.title, post.data.get('title')))
      .render()
  },

  taxon (ctx, config, taxonItems) {
    ctx.type = 'html'
    ctx.body = templates
      .layout()
      .pipe(rheo())
      .inner('main', showPage('taxon'))
      .inner('h1', rheo(config.site.title))
      .inner('.posts', function (postsTemplate) {
        return taxonItems.pipe(postsTemplate.map(renderPostListItem(ctx)))
      })
      .pipe(setTitle(config.site.title))
      .render()
  }
}