const RedisManager = require('./RedisManager')
const ProjectHistoryRedisManager = require('./ProjectHistoryRedisManager')
const DocumentManager = require('./DocumentManager')
const HistoryManager = require('./HistoryManager')
const logger = require('@overleaf/logger')
const Metrics = require('./Metrics')
const Errors = require('./Errors')
const { callbackifyAll } = require('@overleaf/promise-utils')

async function flushProjectWithLocks(projectId) {
  const timer = new Metrics.Timer('projectManager.flushProjectWithLocks')
  const docIds = await RedisManager.promises.getDocIdsInProject(projectId)

  logger.debug({ projectId, docIds }, 'flushing docs')
  const errors = []
  for (const docId of docIds) {
    try {
      await DocumentManager.promises.flushDocIfLoadedWithLock(projectId, docId)
    } catch (error) {
      if (error instanceof Errors.NotFoundError) {
        logger.warn(
          { err: error, projectId, docId },
          'found deleted doc when flushing'
        )
      } else {
        logger.error({ err: error, projectId, docId }, 'error flushing doc')
        errors.push(error)
      }
    }
  }

  timer.done()
  if (errors.length > 0) {
    throw new Error('Errors flushing docs. See log for details')
  }
}

async function flushAndDeleteProjectWithLocks(projectId, options) {
  const timer = new Metrics.Timer(
    'projectManager.flushAndDeleteProjectWithLocks'
  )

  const docIds = await RedisManager.promises.getDocIdsInProject(projectId)

  logger.debug({ projectId, docIds }, 'deleting docs')
  const errors = []
  for (const docId of docIds) {
    try {
      await DocumentManager.promises.flushAndDeleteDocWithLock(
        projectId,
        docId,
        {}
      )
    } catch (error) {
      logger.error({ err: error, projectId, docId }, 'error deleting doc')
      errors.push(error)
    }
  }

  // When deleting the project here we want to ensure that project
  // history is completely flushed because the project may be
  // deleted in web after this call completes, and so further
  // attempts to flush would fail after that.
  await HistoryManager.promises.flushProjectChanges(projectId, options)
  timer.done()
  if (errors.length > 0) {
    throw new Error('Errors deleting docs. See log for details')
  }
}

async function queueFlushAndDeleteProject(projectId) {
  await RedisManager.promises.queueFlushAndDeleteProject(projectId)
  Metrics.inc('queued-delete')
}

async function getProjectDocsTimestamps(projectId, callback) {
  const docIds = await RedisManager.promises.getDocIdsInProject(projectId)
  if (docIds.length === 0) {
    return []
  }

  const timestamps = await RedisManager.promises.getDocTimestamps(docIds)
  return timestamps
}

async function getProjectDocsAndFlushIfOld(
  projectId,
  projectStateHash,
  excludeVersions
) {
  const timer = new Metrics.Timer('projectManager.getProjectDocsAndFlushIfOld')

  const projectStateChanged =
    await RedisManager.promises.checkOrSetProjectState(
      projectId,
      projectStateHash
    )

  // we can't return docs if project structure has changed
  if (projectStateChanged) {
    timer.done()
    throw new Errors.ProjectStateChangedError('project state changed')
  }

  // project structure hasn't changed, return doc content from redis
  const docs = []
  const docIds = await RedisManager.promises.getDocIdsInProject(projectId)
  for (const docId of docIds) {
    const { lines, version } =
      await DocumentManager.promises.getDocAndFlushIfOldWithLock(
        projectId,
        docId
      )
    docs.push({ _id: docId, lines, v: version })
  }

  timer.done()
  return docs
}

async function getProjectRanges(projectId) {
  const docIds = await RedisManager.promises.getDocIdsInProject(projectId)
  const docs = []
  for (const docId of docIds) {
    const ranges = await RedisManager.promises.getDocRanges(docId)
    docs.push({ id: docId, ranges })
  }
  return docs
}

async function clearProjectState(projectId) {
  await RedisManager.promises.clearProjectState(projectId)
}

async function updateProjectWithLocks(
  projectId,
  projectHistoryId,
  userId,
  updates,
  projectVersion,
  source
) {
  const timer = new Metrics.Timer('projectManager.updateProject')

  let projectSubversion = 0 // project versions can have multiple operations
  let projectOpsLength = 0

  for (const update of updates) {
    update.version = `${projectVersion}.${projectSubversion++}`
    switch (update.type) {
      case 'add-doc':
        projectOpsLength =
          await ProjectHistoryRedisManager.promises.queueAddEntity(
            projectId,
            projectHistoryId,
            'doc',
            update.id,
            userId,
            update,
            source
          )
        break
      case 'rename-doc':
        if (!update.newPathname) {
          // an empty newPathname signifies a delete, so there is no need to
          // update the pathname in redis
          projectOpsLength =
            await ProjectHistoryRedisManager.promises.queueRenameEntity(
              projectId,
              projectHistoryId,
              'doc',
              update.id,
              userId,
              update,
              source
            )
        } else {
          // rename the doc in redis before queuing the update
          await DocumentManager.promises.renameDocWithLock(
            projectId,
            update.id,
            userId,
            update,
            projectHistoryId
          )
          projectOpsLength =
            await ProjectHistoryRedisManager.promises.queueRenameEntity(
              projectId,
              projectHistoryId,
              'doc',
              update.id,
              userId,
              update,
              source
            )
        }
        break
      case 'add-file':
        projectOpsLength =
          await ProjectHistoryRedisManager.promises.queueAddEntity(
            projectId,
            projectHistoryId,
            'file',
            update.id,
            userId,
            update,
            source
          )
        break
      case 'rename-file':
        projectOpsLength =
          await ProjectHistoryRedisManager.promises.queueRenameEntity(
            projectId,
            projectHistoryId,
            'file',
            update.id,
            userId,
            update,
            source
          )
        break
      default:
        throw new Error(`Unknown update type: ${update.type}`)
    }
  }

  if (
    HistoryManager.shouldFlushHistoryOps(
      projectId,
      projectOpsLength,
      updates.length
    )
  ) {
    HistoryManager.flushProjectChangesAsync(projectId)
  }

  timer.done()
}

const ProjectManager = {
  flushProjectWithLocks,
  flushAndDeleteProjectWithLocks,
  queueFlushAndDeleteProject,
  getProjectDocsTimestamps,
  getProjectDocsAndFlushIfOld,
  getProjectRanges,
  clearProjectState,
  updateProjectWithLocks,
}

module.exports = {
  ...callbackifyAll(ProjectManager),
  promises: ProjectManager,
}