const express = require('express')
const router = express.Router()
const pageHelper = require('../helpers/page')
const _ = require('lodash')
const CleanCSS = require('clean-css')

/* global WIKI */

const tmplCreateRegex = /^[0-9]+(,[0-9]+)?$/

const getPageEffectivePermissions = (req, page) => {
  return {
    comments: {
      read: WIKI.config.features.featurePageComments ? WIKI.auth.checkAccess(req.user, ['read:comments'], page) : false,
      write: WIKI.config.features.featurePageComments ? WIKI.auth.checkAccess(req.user, ['write:comments'], page) : false,
      manage: WIKI.config.features.featurePageComments ? WIKI.auth.checkAccess(req.user, ['manage:comments'], page) : false
    },
    history: {
      read: WIKI.auth.checkAccess(req.user, ['read:history'], page)
    },
    source: {
      read: WIKI.auth.checkAccess(req.user, ['read:source'], page)
    },
    pages: {
      write: WIKI.auth.checkAccess(req.user, ['write:pages'], page),
      manage: WIKI.auth.checkAccess(req.user, ['manage:pages'], page),
      delete: WIKI.auth.checkAccess(req.user, ['delete:pages'], page),
      script: WIKI.auth.checkAccess(req.user, ['write:scripts'], page),
      style: WIKI.auth.checkAccess(req.user, ['write:styles'], page)
    },
    system: {
      manage: WIKI.auth.checkAccess(req.user, ['manage:system'], page)
    }
  }
}

/**
 * Robots.txt
 */
router.get('/robots.txt', (req, res, next) => {
  res.type('text/plain')
  if (_.includes(WIKI.config.seo.robots, 'noindex')) {
    res.send('User-agent: *\nDisallow: /')
  } else {
    res.status(200).end()
  }
})

/**
 * Health Endpoint
 */
router.get('/healthz', (req, res, next) => {
  if (WIKI.models.knex.client.pool.numFree() < 1 && WIKI.models.knex.client.pool.numUsed() < 1) {
    res.status(503).json({ ok: false }).end()
  } else {
    res.status(200).json({ ok: true }).end()
  }
})

/**
 * Administration
 */
router.get(['/a', '/a/*'], (req, res, next) => {
  _.set(res.locals, 'pageMeta.title', 'Admin')
  res.render('admin')
})

/**
 * Download Page / Version
 */
router.get(['/d', '/d/*'], async (req, res, next) => {
  const pageArgs = pageHelper.parsePath(req.path, { stripExt: true })

  const versionId = (req.query.v) ? _.toSafeInteger(req.query.v) : 0

  const page = await WIKI.models.pages.getPageFromDb({
    path: pageArgs.path,
    locale: pageArgs.locale,
    userId: req.user.id,
    isPrivate: false
  })

  pageArgs.tags = _.get(page, 'tags', [])

  if (versionId > 0) {
    if (!WIKI.auth.checkAccess(req.user, ['read:history'], pageArgs)) {
      _.set(res.locals, 'pageMeta.title', 'Unauthorized')
      return res.render('unauthorized', { action: 'downloadVersion' })
    }
  } else {
    if (!WIKI.auth.checkAccess(req.user, ['read:source'], pageArgs)) {
      _.set(res.locals, 'pageMeta.title', 'Unauthorized')
      return res.render('unauthorized', { action: 'download' })
    }
  }

  if (page) {
    const fileName = _.last(page.path.split('/')) + '.' + pageHelper.getFileExtension(page.contentType)
    res.attachment(fileName)
    if (versionId > 0) {
      const pageVersion = await WIKI.models.pageHistory.getVersion({ pageId: page.id, versionId })
      res.send(pageHelper.injectPageMetadata(pageVersion))
    } else {
      res.send(pageHelper.injectPageMetadata(page))
    }
  } else {
    res.status(404).end()
  }
})

/**
 * Create/Edit document
 */
router.get(['/e', '/e/*'], async (req, res, next) => {
  const pageArgs = pageHelper.parsePath(req.path, { stripExt: true })

  if (WIKI.config.lang.namespacing && !pageArgs.explicitLocale) {
    return res.redirect(`/e/${pageArgs.locale}/${pageArgs.path}`)
  }

  // -> Set Editor Lang
  _.set(res, 'locals.siteConfig.lang', pageArgs.locale)
  _.set(res, 'locals.siteConfig.rtl', req.i18n.dir() === 'rtl')

  // -> Check for reserved path
  if (pageHelper.isReservedPath(pageArgs.path)) {
    return next(new Error('Cannot create this page because it starts with a system reserved path.'))
  }

  // -> Get page data from DB
  let page = await WIKI.models.pages.getPageFromDb({
    path: pageArgs.path,
    locale: pageArgs.locale,
    userId: req.user.id,
    isPrivate: false
  })

  pageArgs.tags = _.get(page, 'tags', [])

  const injectCode = {
    css: WIKI.config.theming.injectCSS,
    head: WIKI.config.theming.injectHead,
    body: WIKI.config.theming.injectBody
  }

  if (page) {
    // -> EDIT MODE
    if (!WIKI.auth.checkAccess(req.user, ['write:pages', 'manage:pages'], pageArgs)) {
      _.set(res.locals, 'pageMeta.title', 'Unauthorized')
      return res.render('unauthorized', { action: 'edit' })
    }

    // -> Get page tags
    await page.$relatedQuery('tags')
    page.tags = _.map(page.tags, 'tag')

    // -> Beautify Script CSS
    if (!_.isEmpty(page.extra.css)) {
      page.extra.css = new CleanCSS({ format: 'beautify' }).minify(page.extra.css).styles
    }

    _.set(res.locals, 'pageMeta.title', `Edit ${page.title}`)
    _.set(res.locals, 'pageMeta.description', page.description)
    page.mode = 'update'
    page.isPublished = (page.isPublished === true || page.isPublished === 1) ? 'true' : 'false'
    page.content = Buffer.from(page.content).toString('base64')
  } else {
    // -> CREATE MODE
    if (!WIKI.auth.checkAccess(req.user, ['write:pages'], pageArgs)) {
      _.set(res.locals, 'pageMeta.title', 'Unauthorized')
      return res.render('unauthorized', { action: 'create' })
    }

    _.set(res.locals, 'pageMeta.title', `New Page`)
    page = {
      path: pageArgs.path,
      localeCode: pageArgs.locale,
      editorKey: null,
      mode: 'create',
      content: null,
      title: null,
      description: null,
      updatedAt: new Date().toISOString()
    }

    // -> From Template
    if (req.query.from && tmplCreateRegex.test(req.query.from)) {
      let tmplPageId = 0
      let tmplVersionId = 0
      if (req.query.from.indexOf(',')) {
        const q = req.query.from.split(',')
        tmplPageId = _.toSafeInteger(q[0])
        tmplVersionId = _.toSafeInteger(q[1])
      } else {
        tmplPageId = _.toSafeInteger(req.query.from)
      }

      if (tmplVersionId > 0) {
        // -> From Page Version
        const pageVersion = await WIKI.models.pageHistory.getVersion({ pageId: tmplPageId, versionId: tmplVersionId })
        if (!pageVersion) {
          _.set(res.locals, 'pageMeta.title', 'Page Not Found')
          return res.status(404).render('notfound', { action: 'template' })
        }
        if (!WIKI.auth.checkAccess(req.user, ['read:history'], { path: pageVersion.path, locale: pageVersion.locale })) {
          _.set(res.locals, 'pageMeta.title', 'Unauthorized')
          return res.render('unauthorized', { action: 'sourceVersion' })
        }
        page.content = Buffer.from(pageVersion.content).toString('base64')
        page.editorKey = pageVersion.editor
        page.title = pageVersion.title
        page.description = pageVersion.description
      } else {
        // -> From Page Live
        const pageOriginal = await WIKI.models.pages.query().findById(tmplPageId)
        if (!pageOriginal) {
          _.set(res.locals, 'pageMeta.title', 'Page Not Found')
          return res.status(404).render('notfound', { action: 'template' })
        }
        if (!WIKI.auth.checkAccess(req.user, ['read:source'], { path: pageOriginal.path, locale: pageOriginal.locale })) {
          _.set(res.locals, 'pageMeta.title', 'Unauthorized')
          return res.render('unauthorized', { action: 'source' })
        }
        page.content = Buffer.from(pageOriginal.content).toString('base64')
        page.editorKey = pageOriginal.editorKey
        page.title = pageOriginal.title
        page.description = pageOriginal.description
      }
    }
  }

  // -> Effective Permissions
  const effectivePermissions = getPageEffectivePermissions(req, pageArgs)

  res.render('editor', { page, injectCode, effectivePermissions })
})

/**
 * History
 */
router.get(['/h', '/h/*'], async (req, res, next) => {
  const pageArgs = pageHelper.parsePath(req.path, { stripExt: true })

  if (WIKI.config.lang.namespacing && !pageArgs.explicitLocale) {
    return res.redirect(`/h/${pageArgs.locale}/${pageArgs.path}`)
  }

  _.set(res, 'locals.siteConfig.lang', pageArgs.locale)
  _.set(res, 'locals.siteConfig.rtl', req.i18n.dir() === 'rtl')

  const page = await WIKI.models.pages.getPageFromDb({
    path: pageArgs.path,
    locale: pageArgs.locale,
    userId: req.user.id,
    isPrivate: false
  })

  if (!page) {
    _.set(res.locals, 'pageMeta.title', 'Page Not Found')
    return res.status(404).render('notfound', { action: 'history' })
  }

  pageArgs.tags = _.get(page, 'tags', [])

  if (!WIKI.auth.checkAccess(req.user, ['read:history'], pageArgs)) {
    _.set(res.locals, 'pageMeta.title', 'Unauthorized')
    return res.render('unauthorized', { action: 'history' })
  }

  if (page) {
    _.set(res.locals, 'pageMeta.title', page.title)
    _.set(res.locals, 'pageMeta.description', page.description)

    // -> Effective Permissions
    const effectivePermissions = getPageEffectivePermissions(req, pageArgs)

    res.render('history', { page, effectivePermissions })
  } else {
    res.redirect(`/${pageArgs.path}`)
  }
})

/**
 * Page ID redirection
 */
router.get(['/i', '/i/:id'], async (req, res, next) => {
  const pageId = _.toSafeInteger(req.params.id)
  if (pageId <= 0) {
    return res.redirect('/')
  }

  const page = await WIKI.models.pages.query().column(['path', 'localeCode', 'isPrivate', 'privateNS']).findById(pageId)
  if (!page) {
    _.set(res.locals, 'pageMeta.title', 'Page Not Found')
    return res.status(404).render('notfound', { action: 'view' })
  }

  if (!WIKI.auth.checkAccess(req.user, ['read:pages'], {
    locale: page.localeCode,
    path: page.path,
    private: page.isPrivate,
    privateNS: page.privateNS,
    explicitLocale: false,
    tags: page.tags
  })) {
    _.set(res.locals, 'pageMeta.title', 'Unauthorized')
    return res.render('unauthorized', { action: 'view' })
  }

  if (WIKI.config.lang.namespacing) {
    return res.redirect(`/${page.localeCode}/${page.path}`)
  } else {
    return res.redirect(`/${page.path}`)
  }
})

/**
 * Profile
 */
router.get(['/p', '/p/*'], (req, res, next) => {
  if (!req.user || req.user.id < 1 || req.user.id === 2) {
    return res.render('unauthorized', { action: 'view' })
  }

  _.set(res.locals, 'pageMeta.title', 'User Profile')
  res.render('profile')
})

/**
 * Source
 */
router.get(['/s', '/s/*'], async (req, res, next) => {
  const pageArgs = pageHelper.parsePath(req.path, { stripExt: true })
  const versionId = (req.query.v) ? _.toSafeInteger(req.query.v) : 0

  const page = await WIKI.models.pages.getPageFromDb({
    path: pageArgs.path,
    locale: pageArgs.locale,
    userId: req.user.id,
    isPrivate: false
  })

  pageArgs.tags = _.get(page, 'tags', [])

  if (WIKI.config.lang.namespacing && !pageArgs.explicitLocale) {
    return res.redirect(`/s/${pageArgs.locale}/${pageArgs.path}`)
  }

  _.set(res, 'locals.siteConfig.lang', pageArgs.locale)
  _.set(res, 'locals.siteConfig.rtl', req.i18n.dir() === 'rtl')

  if (versionId > 0) {
    if (!WIKI.auth.checkAccess(req.user, ['read:history'], pageArgs)) {
      _.set(res.locals, 'pageMeta.title', 'Unauthorized')
      return res.render('unauthorized', { action: 'sourceVersion' })
    }
  } else {
    if (!WIKI.auth.checkAccess(req.user, ['read:source'], pageArgs)) {
      _.set(res.locals, 'pageMeta.title', 'Unauthorized')
      return res.render('unauthorized', { action: 'source' })
    }
  }

  if (page) {
    if (versionId > 0) {
      const pageVersion = await WIKI.models.pageHistory.getVersion({ pageId: page.id, versionId })
      _.set(res.locals, 'pageMeta.title', pageVersion.title)
      _.set(res.locals, 'pageMeta.description', pageVersion.description)
      res.render('source', {
        page: {
          ...page,
          ...pageVersion
        }
      })
    } else {
      _.set(res.locals, 'pageMeta.title', page.title)
      _.set(res.locals, 'pageMeta.description', page.description)

      // -> Effective Permissions
      const effectivePermissions = getPageEffectivePermissions(req, pageArgs)

      res.render('source', { page, effectivePermissions })
    }
  } else {
    res.redirect(`/${pageArgs.path}`)
  }
})

/**
 * Tags
 */
router.get(['/t', '/t/*'], (req, res, next) => {
  _.set(res.locals, 'pageMeta.title', 'Tags')
  res.render('tags')
})

/**
 * View document / asset
 */
router.get('/*', async (req, res, next) => {
  const stripExt = _.some(WIKI.data.pageExtensions, ext => _.endsWith(req.path, `.${ext}`))
  const pageArgs = pageHelper.parsePath(req.path, { stripExt })
  const isPage = (stripExt || pageArgs.path.indexOf('.') === -1)

  if (isPage) {
    if (WIKI.config.lang.namespacing && !pageArgs.explicitLocale) {
      return res.redirect(`/${pageArgs.locale}/${pageArgs.path}`)
    }

    req.i18n.changeLanguage(pageArgs.locale)

    try {
      // -> Get Page from cache
      const page = await WIKI.models.pages.getPage({
        path: pageArgs.path,
        locale: pageArgs.locale,
        userId: req.user.id,
        isPrivate: false
      })
      pageArgs.tags = _.get(page, 'tags', [])

      // -> Check User Access
      if (!WIKI.auth.checkAccess(req.user, ['read:pages'], pageArgs)) {
        if (req.user.id === 2) {
          res.cookie('loginRedirect', req.path, {
            maxAge: 15 * 60 * 1000
          })
        }
        if (pageArgs.path === 'home' && req.user.id === 2) {
          return res.redirect('/login')
        }
        _.set(res.locals, 'pageMeta.title', 'Unauthorized')
        return res.status(403).render('unauthorized', {
          action: 'view'
        })
      }

      _.set(res, 'locals.siteConfig.lang', pageArgs.locale)
      _.set(res, 'locals.siteConfig.rtl', req.i18n.dir() === 'rtl')

      if (page) {
        _.set(res.locals, 'pageMeta.title', page.title)
        _.set(res.locals, 'pageMeta.description', page.description)

        // -> Build sidebar navigation
        let sdi = 1
        const sidebar = (await WIKI.models.navigation.getTree({ cache: true, locale: pageArgs.locale, groups: req.user.groups })).map(n => ({
          i: `sdi-${sdi++}`,
          k: n.kind,
          l: n.label,
          c: n.icon,
          y: n.targetType,
          t: n.target
        }))

        // -> Build theme code injection
        const injectCode = {
          css: WIKI.config.theming.injectCSS,
          head: WIKI.config.theming.injectHead,
          body: WIKI.config.theming.injectBody
        }

        if (!_.isEmpty(page.extra.css)) {
          injectCode.css = `${injectCode.css}\n${page.extra.css}`
        }

        if (!_.isEmpty(page.extra.js)) {
          injectCode.body = `${injectCode.body}\n${page.extra.js}`
        }

        if (req.query.legacy || req.get('user-agent').indexOf('Trident') >= 0) {
          // -> Convert page TOC
          if (_.isString(page.toc)) {
            page.toc = JSON.parse(page.toc)
          }

          // -> Render legacy view
          res.render('legacy/page', {
            page,
            sidebar,
            injectCode,
            isAuthenticated: req.user && req.user.id !== 2
          })
        } else {
          // -> Convert page TOC
          if (!_.isString(page.toc)) {
            page.toc = JSON.stringify(page.toc)
          }

          // -> Inject comments variables
          if (WIKI.config.features.featurePageComments && WIKI.data.commentProvider.codeTemplate) {
            [
              { key: 'pageUrl', value: `${WIKI.config.host}/i/${page.id}` },
              { key: 'pageId', value: page.id }
            ].forEach((cfg) => {
              WIKI.data.commentProvider.head = _.replace(WIKI.data.commentProvider.head, new RegExp(`{{${cfg.key}}}`, 'g'), cfg.value)
              WIKI.data.commentProvider.body = _.replace(WIKI.data.commentProvider.body, new RegExp(`{{${cfg.key}}}`, 'g'), cfg.value)
              WIKI.data.commentProvider.main = _.replace(WIKI.data.commentProvider.main, new RegExp(`{{${cfg.key}}}`, 'g'), cfg.value)
            })
          }

          // -> Effective Permissions
          const effectivePermissions = getPageEffectivePermissions(req, pageArgs)

          // -> Render view
          res.render('page', {
            page,
            sidebar,
            injectCode,
            comments: WIKI.data.commentProvider,
            effectivePermissions
          })
        }
      } else if (pageArgs.path === 'home') {
        _.set(res.locals, 'pageMeta.title', 'Welcome')
        res.render('welcome', { locale: pageArgs.locale })
      } else {
        _.set(res.locals, 'pageMeta.title', 'Page Not Found')
        if (WIKI.auth.checkAccess(req.user, ['write:pages'], pageArgs)) {
          res.status(404).render('new', { path: pageArgs.path, locale: pageArgs.locale })
        } else {
          res.status(404).render('notfound', { action: 'view' })
        }
      }
    } catch (err) {
      next(err)
    }
  } else {
    if (!WIKI.auth.checkAccess(req.user, ['read:assets'], pageArgs)) {
      return res.sendStatus(403)
    }

    await WIKI.models.assets.getAsset(pageArgs.path, res)
  }
})

module.exports = router