Overleaf/services/web/app/coffee/Features/LinkedFiles/ProjectFileAgent.coffee

FileWriter = require('../../infrastructure/FileWriter')
AuthorizationManager = require('../Authorization/AuthorizationManager')
ProjectLocator = require('../Project/ProjectLocator')
DocstoreManager = require('../Docstore/DocstoreManager')
FileStoreHandler = require('../FileStore/FileStoreHandler')
FileWriter = require('../../infrastructure/FileWriter')
_ = require "underscore"
Settings = require 'settings-sharelatex'


AccessDeniedError = (message) ->
	error = new Error(message)
	error.name = 'AccessDenied'
	error.__proto__ = AccessDeniedError.prototype
	return error
AccessDeniedError.prototype.__proto__ = Error.prototype


BadEntityTypeError = (message) ->
	error = new Error(message)
	error.name = 'BadEntityType'
	error.__proto__ = BadEntityTypeError.prototype
	return error
BadEntityTypeError.prototype.__proto__ = Error.prototype


BadDataError = (message) ->
	error = new Error(message)
	error.name = 'BadData'
	error.__proto__ = BadDataError.prototype
	return error
BadDataError.prototype.__proto__ = Error.prototype


FileNotFoundError = (message) ->
	error = new Error(message)
	error.name = 'BadData'
	error.__proto__ = FileNotFoundError.prototype
	return error
FileNotFoundError.prototype.__proto__ = Error.prototype


module.exports = ProjectFileAgent =

	sanitizeData: (data) ->
		return data

	_validate: (data) ->
		return (
			!!data.source_project_id &&
			!!data.source_entity_path &&
			!!data.source_project_display_name
		)

	writeIncomingFileToDisk:
		(project_id, data, current_user_id, callback = (error, fsPath) ->) ->
			callback = _.once(callback)
			if !ProjectFileAgent._validate(data)
				return callback(new BadDataError())
			{source_project_id, source_entity_path} = data
			AuthorizationManager.canUserReadProject current_user_id, source_project_id,
				null, (err, canRead) ->
					return callback(err) if err?
					return callback(new AccessDeniedError()) if !canRead
					ProjectLocator.findElementByPath {
						project_id: source_project_id,
						path: source_entity_path
					}, (err, entity, type) ->
						# return callback(err) if err?  # also applies when file not found
						if err?
							if err.toString().match(/^not found.*/)
								err = new FileNotFoundError()
							return callback(err)
						ProjectFileAgent._writeEntityToDisk source_project_id, entity._id, type, callback

	_writeEntityToDisk: (project_id, entity_id, type, callback=(err, location)->) ->
		callback = _.once(callback)
		if type == 'doc'
			DocstoreManager.getDoc project_id, entity_id, (err, lines) ->
				return callback(err) if err?
				FileWriter.writeLinesToDisk entity_id, lines, callback
		else if type == 'file'
			FileStoreHandler.getFileStream project_id, entity_id, null, (err, fileStream) ->
				return callback(err) if err?
				FileWriter.writeStreamToDisk entity_id, fileStream, callback
		else
			callback(new BadEntityTypeError())

	handleError: (error, req, res, next) ->
		if error instanceof AccessDeniedError
			res.status(403).send("You do not have access to this project")
		else if error instanceof BadDataError
			res.status(400).send("The submitted data is not valid")
		else if error instanceof BadEntityTypeError
			res.status(400).send("The file is the wrong type")
		else if error instanceof FileNotFoundError
			res.status(404).send("File not found")
		else
			next(error)
		next()