/* eslint-disable
    camelcase,
    handle-callback-err,
    no-unused-vars,
*/
// TODO: This file was created by bulk-decaffeinate.
// Fix any style issues and re-enable lint.
/*
 * decaffeinate suggestions:
 * DS101: Remove unnecessary use of Array.from
 * DS102: Remove unnecessary code created because of implicit returns
 * DS207: Consider shorter variations of null checks
 * Full docs: https://github.com/decaffeinate/decaffeinate/blob/master/docs/suggestions.md
 */
let HttpController
const UpdatesManager = require('./UpdatesManager')
const DiffManager = require('./DiffManager')
const PackManager = require('./PackManager')
const RestoreManager = require('./RestoreManager')
const logger = require('logger-sharelatex')
const HealthChecker = require('./HealthChecker')
const _ = require('underscore')

module.exports = HttpController = {
  flushDoc(req, res, next) {
    if (next == null) {
      next = function (error) {}
    }
    const { doc_id } = req.params
    const { project_id } = req.params
    logger.log({ project_id, doc_id }, 'compressing doc history')
    return UpdatesManager.processUncompressedUpdatesWithLock(
      project_id,
      doc_id,
      function (error) {
        if (error != null) {
          return next(error)
        }
        return res.sendStatus(204)
      }
    )
  },

  flushProject(req, res, next) {
    if (next == null) {
      next = function (error) {}
    }
    const { project_id } = req.params
    logger.log({ project_id }, 'compressing project history')
    return UpdatesManager.processUncompressedUpdatesForProject(
      project_id,
      function (error) {
        if (error != null) {
          return next(error)
        }
        return res.sendStatus(204)
      }
    )
  },

  flushAll(req, res, next) {
    // limit on projects to flush or -1 for all (default)
    if (next == null) {
      next = function (error) {}
    }
    const limit = req.query.limit != null ? parseInt(req.query.limit, 10) : -1
    logger.log({ limit }, 'flushing all projects')
    return UpdatesManager.flushAll(limit, function (error, result) {
      if (error != null) {
        return next(error)
      }
      const { failed, succeeded, all } = result
      const status = `${succeeded.length} succeeded, ${failed.length} failed`
      if (limit === 0) {
        return res
          .status(200)
          .send(`${status}\nwould flush:\n${all.join('\n')}\n`)
      } else if (failed.length > 0) {
        logger.log({ failed, succeeded }, 'error flushing projects')
        return res
          .status(500)
          .send(`${status}\nfailed to flush:\n${failed.join('\n')}\n`)
      } else {
        return res
          .status(200)
          .send(
            `${status}\nflushed ${succeeded.length} projects of ${all.length}\n`
          )
      }
    })
  },

  checkDanglingUpdates(req, res, next) {
    if (next == null) {
      next = function (error) {}
    }
    logger.log('checking dangling updates')
    return UpdatesManager.getDanglingUpdates(function (error, result) {
      if (error != null) {
        return next(error)
      }
      if (result.length > 0) {
        logger.log({ dangling: result }, 'found dangling updates')
        return res.status(500).send(`dangling updates:\n${result.join('\n')}\n`)
      } else {
        return res.status(200).send('no dangling updates found\n')
      }
    })
  },

  checkDoc(req, res, next) {
    if (next == null) {
      next = function (error) {}
    }
    const { doc_id } = req.params
    const { project_id } = req.params
    logger.log({ project_id, doc_id }, 'checking doc history')
    return DiffManager.getDocumentBeforeVersion(
      project_id,
      doc_id,
      1,
      function (error, document, rewoundUpdates) {
        if (error != null) {
          return next(error)
        }
        const broken = []
        for (const update of Array.from(rewoundUpdates)) {
          for (const op of Array.from(update.op)) {
            if (op.broken === true) {
              broken.push(op)
            }
          }
        }
        if (broken.length > 0) {
          return res.send(broken)
        } else {
          return res.sendStatus(204)
        }
      }
    )
  },

  getDiff(req, res, next) {
    let from, to
    if (next == null) {
      next = function (error) {}
    }
    const { doc_id } = req.params
    const { project_id } = req.params

    if (req.query.from != null) {
      from = parseInt(req.query.from, 10)
    } else {
      from = null
    }
    if (req.query.to != null) {
      to = parseInt(req.query.to, 10)
    } else {
      to = null
    }

    logger.log({ project_id, doc_id, from, to }, 'getting diff')
    return DiffManager.getDiff(project_id, doc_id, from, to, function (
      error,
      diff
    ) {
      if (error != null) {
        return next(error)
      }
      return res.json({ diff })
    })
  },

  getUpdates(req, res, next) {
    let before, min_count
    if (next == null) {
      next = function (error) {}
    }
    const { project_id } = req.params

    if (req.query.before != null) {
      before = parseInt(req.query.before, 10)
    }
    if (req.query.min_count != null) {
      min_count = parseInt(req.query.min_count, 10)
    }

    return UpdatesManager.getSummarizedProjectUpdates(
      project_id,
      { before, min_count },
      function (error, updates, nextBeforeTimestamp) {
        if (error != null) {
          return next(error)
        }
        return res.json({
          updates,
          nextBeforeTimestamp
        })
      }
    )
  },

  exportProject(req, res, next) {
    // The project history can be huge:
    //  - updates can weight MBs for insert/delete of full doc
    //  - multiple updates form a pack
    // Flush updates per pack onto the wire.
    const { project_id } = req.params
    logger.log({ project_id }, 'exporting project history')
    UpdatesManager.exportProject(project_id, function (
      err,
      { updates, userIds },
      confirmWrite
    ) {
      const abortStreaming = req.aborted || res.finished || res.destroyed
      if (abortStreaming) {
        // Tell the producer to stop emitting data
        if (confirmWrite) confirmWrite(new Error('stop'))
        return
      }
      const hasStartedStreamingResponse = res.headersSent
      if (err) {
        logger.error({ project_id, err }, 'export failed')
        if (!hasStartedStreamingResponse) {
          // Generate a nice 500
          return next(err)
        } else {
          // Stop streaming
          return res.destroy()
        }
      }
      // Compose the response incrementally
      const isFirstWrite = !hasStartedStreamingResponse
      const isLastWrite = updates.length === 0
      if (isFirstWrite) {
        // The first write will emit the 200 status, headers and start of the
        //  response payload (open array)
        res.setHeader('Content-Type', 'application/json')
        res.setHeader('Trailer', 'X-User-Ids')
        res.writeHead(200)
        res.write('[')
      }
      if (!isFirstWrite && !isLastWrite) {
        // Starting from the 2nd non-empty write, emit a continuing comma.
        // write 1: [updates1
        // write 2: ,updates2
        // write 3: ,updates3
        // write N: ]
        res.write(',')
      }

      // Every write will emit a blob onto the response stream:
      // '[update1,update2,...]'
      //   ^^^^^^^^^^^^^^^^^^^
      res.write(JSON.stringify(updates).slice(1, -1), confirmWrite)

      if (isLastWrite) {
        // The last write will have no updates and will finish the response
        //  payload (close array) and emit the userIds as trailer.
        res.addTrailers({ 'X-User-Ids': JSON.stringify(userIds) })
        res.end(']')
      }
    })
  },

  restore(req, res, next) {
    if (next == null) {
      next = function (error) {}
    }
    let { doc_id, project_id, version } = req.params
    const user_id = req.headers['x-user-id']
    version = parseInt(version, 10)
    return RestoreManager.restoreToBeforeVersion(
      project_id,
      doc_id,
      version,
      user_id,
      function (error) {
        if (error != null) {
          return next(error)
        }
        return res.sendStatus(204)
      }
    )
  },

  pushDocHistory(req, res, next) {
    if (next == null) {
      next = function (error) {}
    }
    const { project_id } = req.params
    const { doc_id } = req.params
    logger.log({ project_id, doc_id }, 'pushing all finalised changes to s3')
    return PackManager.pushOldPacks(project_id, doc_id, function (error) {
      if (error != null) {
        return next(error)
      }
      return res.sendStatus(204)
    })
  },

  pullDocHistory(req, res, next) {
    if (next == null) {
      next = function (error) {}
    }
    const { project_id } = req.params
    const { doc_id } = req.params
    logger.log({ project_id, doc_id }, 'pulling all packs from s3')
    return PackManager.pullOldPacks(project_id, doc_id, function (error) {
      if (error != null) {
        return next(error)
      }
      return res.sendStatus(204)
    })
  },

  healthCheck(req, res) {
    return HealthChecker.check(function (err) {
      if (err != null) {
        logger.err({ err }, 'error performing health check')
        return res.sendStatus(500)
      } else {
        return res.sendStatus(200)
      }
    })
  },

  checkLock(req, res) {
    return HealthChecker.checkLock(function (err) {
      if (err != null) {
        logger.err({ err }, 'error performing lock check')
        return res.sendStatus(500)
      } else {
        return res.sendStatus(200)
      }
    })
  }
}