# encoding: utf-8
# frozen_string_literal: true
#
# Redmine plugin for Document Management System "Features"
#
# Copyright © 2012    Daniel Munn <dan.munn@munnster.co.uk>
# Copyright © 2011-22 Karel Pičman <karel.picman@kontron.com>
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

require 'uuidtools'
require 'addressable/uri'

module RedmineDmsf
  module Webdav
    class DmsfResource < BaseResource
      include Redmine::I18n

      def initialize(path, request, response, options)
        super path, request, response, options
      end

      # name:: String - Property name
      # Returns the value of the given property
      def get_property(element)
        if element[:ns_href] == DAV_NAMESPACE
          super
        else
          get_custom_property element
        end
      end

      # name:: String - Property name
      # value:: New value
      # Set the property to the given value
      def set_property(element, value)
        # let Resource handle DAV properties
        if element[:ns_href] == DAV_NAMESPACE
          super
        else
          set_custom_property element, value
        end
      end

      # name:: Property name
      # Remove the property from the resource
      def remove_property(element)
        Redmine::Search.cache_store.delete "#{get_property_key}-#{element[:name]}"
      end

      # Gather collection of objects that denote current entities child entities
      # Used for listing directories etc, implemented basic caching because otherwise
      # Our already quite heavy usage of DB would just get silly every time we called
      # this method.
      def children
        unless @children
          @children = []
          if folder
            # Folders
            folder.dmsf_folders.visible.each do |f|
              if DmsfFolder.permissions?(f, false)
                @children.push child(f.title)
              end
            end
            # Files
            folder.dmsf_files.visible.pluck(:name).each do |name|
              @children.push child(name)
            end
          end
        end
        @children
      end

      # Does the object exist?
      # If it is either a subproject or a folder or a file, then it exists
      def exist?
        project && project.module_enabled?('dmsf') && (subproject || folder || file) &&
           (User.current.admin? || User.current.allowed_to?(:view_dmsf_folders, project))
      end

      # Is this entity a folder?
      def collection?
        folder || subproject
      end

      # Return the content type of file
      # will return inode/directory for any collections, and appropriate for File entities
      def content_type
        if file&.last_revision
          file.last_revision.detect_content_type
        else
          'inode/directory'
        end
      end

      def creation_date
        if folder
          folder.created_at
        elsif file
          file.created_at
        else
          raise NotFound
        end
      end

      def last_modified
        if folder
          folder.updated_at
        elsif file&.last_revision
          file.last_revision.updated_at
        else
          raise NotFound
        end
      end

      def etag
        ino = 2
        if file
          if file.last_revision && File.exist?(file.last_revision.disk_file)
            ino = File.stat(file.last_revision.disk_file).ino
          end
        end
        sprintf '%x-%x-%x', ino, content_length,  (last_modified ? last_modified.to_i : 0)
      end

      def content_length
        file ? file.size : 4096;
      end

      def special_type
        l(:field_folder) if folder
      end

      # Process incoming GET request
      # If instance is a collection, calls html_display (defined in base_resource.rb) which cycles through children for display
      # File will only be presented for download if user has permission to view files
      def get(request, response)
        raise Forbidden unless (!parent.exist? || !parent.folder || DmsfFolder.permissions?(parent.folder))
        if collection?
          html_display
          response['Content-Length'] = response.body.bytesize.to_s
          response['Content-Type'] = 'text/html'
        else
          raise Forbidden unless User.current.admin? || User.current.allowed_to?(:view_dmsf_files, project)
          http_if_none_match = request.get_header('HTTP_IF_NONE_MATCH')
          if http_if_none_match.present? && (http_if_none_match == etag)
            return NotModified # MS Office 2016, PROTECTED VIEW => Enable editing?
          end
          response.body = download # Rack based provider
        end
        OK
      end

      # Process incoming MKCOL request
      # Create a DmsfFolder at location requested, only if parent is a folder (or root)
      # Ensure item is only functional if project is enabled for dmsf
      def make_collection
        if request.body.read.to_s.empty?
          raise NotFound unless project && project.module_enabled?('dmsf')
          raise Forbidden unless User.current.admin? || User.current.allowed_to?(:folder_manipulation, project)
          raise Forbidden unless (!parent.exist? || !parent.folder || DmsfFolder.permissions?(parent.folder, false))
          f = DmsfFolder.new
          f.title = basename
          f.dmsf_folder_id = parent.folder&.id
          f.project = project
          f.user = User.current
          f.save ? Created : Conflict
        else
          UnsupportedMediaType
        end
      end

      # Process incoming DELETE request
      # <instance> should be of entity to be deleted, we simply follow the Dmsf entity method
      # for deletion and return of appropriate status based on outcome.
      def delete
        if file
          raise Forbidden unless User.current.admin? || User.current.allowed_to?(:file_delete, project)
          raise Forbidden unless (!parent.exist? || !parent.folder || DmsfFolder.permissions?(parent.folder, false))
          raise Locked if file.locked_for_user?
          pattern = Setting.plugin_redmine_dmsf['dmsf_webdav_disable_versioning']
          if pattern.present? && basename.match(pattern)
            # Files that are not versioned should be destroyed
            destroy = true
          elsif file.last_revision.size == 0
            # Zero-sized files should be destroyed
            destroy = true
          else
            destroy = false
          end
          if file.delete(destroy)
            DmsfMailer.deliver_files_deleted project, [file]
            NoContent
          else
            Conflict
          end
        elsif folder
          raise Locked if folder.locked?
          # To fullfil Litmus requirements to not delete folder if fragments are in the URL
          uri = URI(uri_encode(request.get_header('REQUEST_URI')))
          raise BadRequest if uri.fragment.present?
          raise Forbidden unless User.current.admin? || User.current.allowed_to?(:folder_manipulation, project)
          raise Forbidden unless DmsfFolder.permissions?(folder, false)
          folder.delete(false) ? NoContent : Conflict
        else
          MethodNotAllowed
        end
      end

      # Process incoming MOVE request
      # Behavioural differences between collection and single entity
      def move(dest_path, overwrite)
        dest = ResourceProxy.new(dest_path, @request, @response, @options.merge(user: @user))
        return PreconditionFailed if !dest.resource.is_a?(DmsfResource) || dest.resource.project.nil?
        parent = dest.resource.parent
        raise Forbidden unless dest.resource.project.module_enabled?(:dmsf)
        if !parent.exist? || (!User.current.admin? && (!DmsfFolder.permissions?(folder, false) ||
            !DmsfFolder.permissions?(parent.folder, false)))
          raise Forbidden
        end
        if collection?
          if dest.exist?
            if overwrite
              if folder
                (dest.collection?)&.delete true
              end
            else
              return PreconditionFailed
            end
          end
          if !User.current.admin? && (!User.current.allowed_to?(:folder_manipulation, project) ||
              !User.current.allowed_to?(:folder_manipulation, dest.resource.project))
            raise Forbidden
          end
          unless folder
            return MethodNotAllowed # Moving sub-project not enabled
          end
          raise Locked if folder.locked_for_user?
          # Change the title
          folder.title = dest.resource.basename
          return PreconditionFailed unless folder.save
          # Move to a new destination
          folder.move_to(dest.resource.project, parent.folder) ? Created : PreconditionFailed
        else
          if !User.current.admin? && (!User.current.allowed_to?(:file_manipulation, project) ||
              !User.current.allowed_to?(:file_manipulation, dest.resource.project))
            raise Forbidden
          end
          raise Locked if file.locked_for_user?
          if dest.exist? && (!dest.collection?)
            return PreconditionFailed unless overwrite
            if dest.resource.file.last_revision.size == 0 || reuse_version_for_locked_file(dest.resource.file)
              # Last revision in the destination has zero size so reuse that revision
              new_revision = dest.resource.file.last_revision
            else
              # Create a new revison by cloning the last revision in the destination
              new_revision = dest.resource.file.last_revision.clone
              new_revision.increase_version DmsfFileRevision::PATCH_VERSION
            end
            # The file on disk must be renamed from .tmp to the correct filetype or else Xapian won't know how to index.
            # Copy file.last_revision.disk_file to new_revision.disk_file
            new_revision.size = file.last_revision.size
            new_revision.disk_filename = new_revision.new_storage_filename
            File.open(file.last_revision.disk_file, 'rb') do |f|
              new_revision.copy_file_content f
            end
            # Save
            new_revision.save && dest.resource.file.save
            # Delete (and destroy) the file that should have been renamed and return what should have been returned in case of a copy
            file.delete(true) ? Created : PreconditionFailed
          else
            return PreconditionFailed unless exist? && file
            if (project == dest.resource.project) && dest.resource.basename.match(/.\.tmp$/i)
              Rails.logger.info "WebDAV MOVE: #{file.name} -> #{dest.resource.basename}, possible MSOffice rename to .tmp when saving."
              # Renaming the file to X.tmp, might be Office that is saving a file. Keep the original file.
              file.copy_to_filename dest.resource.project, parent&.folder, dest.resource.basename
              Created
            else
              if (project == dest.resource.project) && (file.last_revision.size == 0)
                # Moving a zero sized file within the same project, just update the dmsf_folder
                file.dmsf_folder = parent&.folder
              else
                return InternalServerError unless file.move_to(dest.resource.project, parent&.folder)
              end
              # Update Revision and names of file [We can link to old physical resource, as it's not changed]
              if file.last_revision
                file.last_revision.name = dest.resource.basename
                file.last_revision.title = DmsfFileRevision.filename_to_title(dest.resource.basename)
              end
              file.name = dest.resource.basename
              # Save Changes
              if file.last_revision.save && file.save
                dest.exist? ? NoContent : Created
              else
                PreconditionFailed
              end
            end
          end
        end
      end

      # Process incoming COPY request
      # Behavioural differences between collection and single entity
      def copy(dest, overwrite, depth)
        dest = ResourceProxy.new(dest, @request, @response, @options.merge(user: @user))
        return PreconditionFailed unless dest.resource.project
        parent = dest.resource.parent
        raise Forbidden unless (!parent.exist? || !parent.folder || DmsfFolder.permissions?(parent.folder, false))
        return Conflict unless dest.parent.exist?
        res = Created
        if dest.exist?
          return Locked if dest.lockdiscovery.present?
          if overwrite
            dest.delete
            res = NoContent
          else
            return PreconditionFailed
          end
        end
        return PreconditionFailed unless parent.exist? && parent.folder
        if collection?
          # Permission check if they can manipulate folders and view folders
          # Can they:
          #  Manipulate folders on destination project :folder_manipulation
          #  View folders on destination project       :view_dmsf_folders
          #  View files on the source project          :view_dmsf_files
          #  View fodlers on the source project        :view_dmsf_folders
          raise Forbidden unless User.current.admin? ||
             (User.current.allowed_to?(:folder_manipulation, dest.resource.project) &&
              User.current.allowed_to?(:view_dmsf_folders, dest.resource.project) &&
              User.current.allowed_to?(:view_dmsf_files, project) &&
              User.current.allowed_to?(:view_dmsf_folders, project))
          raise Forbidden unless DmsfFolder.permissions?(folder, false)
          folder.title = dest.resource.basename
          new_folder = folder.copy_to(dest.resource.project, parent.folder)
          return PreconditionFailed if new_folder.nil? || new_folder.id.nil?
          Created
        else
          # Permission check if they can manipulate folders and view folders
          # Can they:
          #  Manipulate files on destination project   :file_manipulation
          #  View files on destination project         :view_dmsf_files
          #  View files on the source project          :view_dmsf_files
          raise Forbidden unless User.current.admin? ||
             (User.current.allowed_to?(:file_manipulation, dest.resource.project) &&
              User.current.allowed_to?(:view_dmsf_files, dest.resource.project) &&
              User.current.allowed_to?(:view_dmsf_files, project))
          return PreconditionFailed unless exist? && file
          new_file = file.copy_to(dest.resource.project, parent&.folder)
          return InternalServerError unless (new_file && new_file.last_revision)
          # Update Revision and names of file (We can link to old physical resource, as it's not changed)
          new_file.last_revision.name = dest.resource.basename
          new_file.name = dest.resource.basename
          # Save Changes
          (new_file.last_revision.save && new_file.save) ? res : PreconditionFailed
        end
      end

      # Lock Check
      # Check for the existence of locks
      def lock_check(args = {})
        entity = file || folder
        if entity
          refresh = args && (!args[:scope]) && (!args[:type])
          args ||= {}
          args[:method] = @request.request_method.downcase
          http_if = request.get_header('HTTP_IF')
          if http_if.present?
            no_lock = http_if.include?('<DAV:no-lock>')
            not_no_lock = http_if.include?('Not <DAV:no-lock>')
            # Invalid lock token
            if /\(<([a-f0-9]+-[a-f0-9]+-[a-f0-9]+-[a-f0-9]+-[a-f0-9]+)>/.match(http_if)
              raise PreconditionFailed unless entity.locked?
              if $1 != entity.lock.first.uuid
                raise Locked if entity.locked_for_user?(args)
              end
            else
              if ((!no_lock || not_no_lock) && entity.locked_for_user?(args))
                raise Locked
              else
                raise PreconditionFailed
              end
            end
            # Invalid etag
            if /^\(<([a-f0-9]+-[a-f0-9]+-[a-f0-9]+-[a-f0-9]+-[a-f0-9]+)> \[([a-f0-9]+-[a-f0-9]+-[a-f0-9]+)\]/.match(http_if)
              if $2 != etag
                raise PreconditionFailed
              else
                return  # lock & etag
              end
            end
            # no-lock
            return if no_lock
          end
          if entity.locked_for_user?(args) && !refresh
            if http_if.present?
              case args[:method]
              when 'put'
                return
              when 'proppatch'
                return
              end
            end
            raise Locked
          end
        end
      end

      # Lock
      def lock(args)
        unless parent&.exist?
          e = Dav4rack::LockFailure.new
          e.add_failure @path, Conflict
          raise e
        end
        unless exist?
          return super(args)
        end
        lock_check args
        entity = file || folder
        unless entity
          e = Dav4rack::LockFailure.new
          e.add_failure @path, MethodNotAllowed
          raise e
        end
        begin
          # If scope and type are not defined, the only thing we can
          # logically assume is that the lock is being refreshed (office loves
          # to do this for example, so we do a few checks, try to find the lock
          # and ultimately extend it, otherwise we return Conflict for any failure
          refresh = args && (!args[:scope]) && (!args[:type]) # Perhaps a lock refresh
          if refresh
            http_if = request.get_header('HTTP_IF')
            if http_if.blank?
              e = Dav4rack::LockFailure.new
              e.add_failure @path, Conflict
              raise e
            end
            l = nil
            if /([a-f0-9]{8}-[a-f0-9]{4}-4[a-f0-9]{3}-[89aAbB][a-f0-9]{3}-[a-f0-9]{12})/.match(http_if)
              l = DmsfLock.find_by(uuid: $1)
            end
            unless l
              e = Dav4rack::LockFailure.new
              e.add_failure @path, Conflict
              raise e
            end
            l.expires_at = Time.current + 1.week
            l.save!
            @response['Lock-Token'] = l.uuid
            return [1.weeks.to_i, l.uuid]
          end
          scope = "scope_#{(args[:scope] || 'exclusive')}".to_sym
          type = "type_#{(args[:type] || 'write')}".to_sym
          # l should be the instance of the lock we've just created
          l = entity.lock!(scope, type, Time.current + 1.weeks, args[:owner])
          @response['Lock-Token'] = l.uuid
          [1.week.to_i, l.uuid]
        rescue RedmineDmsf::Errors::DmsfLockError => exception
          e = Dav4rack::LockFailure.new(exception.message)
          e.add_failure @path, Conflict
          raise e
        end
      end

      # Unlock
      # Token based unlock (authenticated) will ensure that a correct token is sent, further ensuring
      # ownership of token before permitting unlock
      def unlock(token)
        unless exist?
          return super(token)
        end
        if token.nil? || token.empty? || (token == '<(null)>') || User.current.anonymous?
          BadRequest
        else
          if token =~ /([a-f0-9]{8}-[a-f0-9]{4}-4[a-f0-9]{3}-[89aAbB][a-f0-9]{3}-[a-f0-9]{12})/
            token = $1
          else
            return BadRequest
          end
          l = DmsfLock.find_by_uuid(token)
          unless l
            return NoContent
          end
          # Additional case: if a user tries to unlock the file instead of the folder that's locked
          # This should throw forbidden as only the lock at level initiated should be unlocked
          entity = file || folder
          return NoContent unless entity&.locked?
          l_entity = l.file || l.folder
          if l_entity != entity
            Forbidden
          else
            entity.unlock!
            NoContent
          end
        end
      end

      # HTTP POST request.
      # Forbidden, as method should not be utilized.
      def post(request, response)
        raise Forbidden
      end

      # HTTP PUT request.
      def put(request, response)
        raise BadRequest if collection?
        raise Forbidden unless User.current.admin? || User.current.allowed_to?(:file_manipulation, project)
        raise Forbidden unless (!parent.exist? || !parent.folder || DmsfFolder.permissions?(parent.folder, false))
        # Ignore file name patterns given in the plugin settings
        pattern = Setting.plugin_redmine_dmsf['dmsf_webdav_ignore']
        pattern = /^(\._|\.DS_Store$|Thumbs.db$)/ if pattern.blank?
        if basename.match(pattern)
          Rails.logger.info "#{basename} ignored"
          return NoContent
        end
        reuse_revision = false
        if exist? # We're over-writing something, so ultimately a new revision
          f = file
          # Disable versioning for file name patterns given in the plugin settings.
          pattern = Setting.plugin_redmine_dmsf['dmsf_webdav_disable_versioning']
          if pattern.present? && basename.match(pattern)
            Rails.logger.info "Versioning disabled for #{basename}"
            reuse_revision = true
          end
          if reuse_version_for_locked_file(file)
            reuse_revision = true
          end
          last_revision = file.last_revision
          if last_revision.size == 0 || reuse_revision
            new_revision = last_revision
            reuse_revision = true
          else
            if last_revision
              new_revision = last_revision.dup
              new_revision.source_revision = last_revision
            else
              new_revision = DmsfFileRevision.new
            end
            # Custom fields
            last_revision.custom_field_values.each_with_index do |custom_value, i|
              new_revision.custom_field_values[i].value = custom_value
            end
          end
        else
          f = DmsfFile.new
          f.project_id = project.id
          f.name = basename
          f.dmsf_folder = parent.folder
          f.notification = !Setting.plugin_redmine_dmsf['dmsf_default_notifications'].blank?
          new_revision = DmsfFileRevision.new
          new_revision.minor_version = 0
          new_revision.major_version = 0
          new_revision.title = DmsfFileRevision.filename_to_title(basename)
        end

        new_revision.dmsf_file = f
        new_revision.user = User.current
        new_revision.name = basename
        new_revision.increase_version(DmsfFileRevision::PATCH_VERSION) unless reuse_revision
        new_revision.mime_type = Redmine::MimeType.of(new_revision.name)

        # Phusion passenger does not have a method "length" in its model
        # however, includes a size method - so we instead use reflection
        # to determine best approach to problem
        if request.body.respond_to?(:length)
          new_revision.size = request.body.length
        elsif request.body.respond_to?(:size)
          new_revision.size = request.body.size
        else
          new_revision.size = request.content_length # Bad Guess
        end

        # Ignore 1b files sent for authentication
        if Setting.plugin_redmine_dmsf['dmsf_webdav_ignore_1b_file_for_authentication'].present? && (new_revision.size == 1)
          Rails.logger.warn "1b file '#{basename}' sent for authentication ignored"
          return NoContent
        end

        unless new_revision.valid?
          Rails.logger.error new_revision.errors.full_messages.to_sentence
          raise UnprocessableEntity
        end

        unless f.save
          Rails.logger.error f.errors.full_messages.to_sentence
          raise UnprocessableEntity
        end

        new_revision.disk_filename = new_revision.new_storage_filename unless reuse_revision

        if new_revision.save
          new_revision.copy_file_content request.body
          # Digest
          sha = Digest::SHA256.new
          if request.body.respond_to?(:read)
            while (buffer = request.body.read(8192))
              sha.update buffer
            end
          else
            sha.update request.body
          end
          new_revision.digest = sha.hexdigest
          new_revision.save
          # Notifications
          DmsfMailer.deliver_files_updated project, [f]
        else
          Rails.logger.error new_revision.errors.full_messages.to_sentence
          raise InternalServerError
        end

        Created
      end

      # array of lock info hashes
      # required keys are :time, :token, :depth
      # other valid keys are :scope, :type, :root and :owner
      def lockdiscovery
        entity = file || folder
        return [] unless entity&.locked?
        if entity.dmsf_folder&.locked?
          entity.lock.reverse[0].folder.locks # longwinded way of getting base items locks
        else
          entity.lock false
        end
      end

      # returns an array of activelock ox elements
      def lockdiscovery_xml
        x = Nokogiri::XML::DocumentFragment.parse ''
        Nokogiri::XML::Builder.with(x) do |doc|
          doc.lockdiscovery {
            lockdiscovery.each do |lock|
              next if lock.expired?
              doc.activelock {
                doc.locktype { doc.write }
                doc.lockscope {
                  if lock.lock_scope == :scope_exclusive
                    doc.exclusive
                  else
                    doc.shared
                  end
                }
                doc.depth lock.folder.nil? ? '0' : 'infinity'
                doc.owner lock.user.to_s
                if lock.expires_at.nil?
                  doc.timeout 'Infinite'
                else
                  doc.timeout "Second-#{(lock.expires_at.to_i - Time.current.to_i)}"
                end
                lock_entity = lock.folder || lock.file
                lock_path = +"#{request.scheme}://#{request.host}:#{request.port}#{path_prefix}#{Addressable::URI.escape(lock_entity.project.identifier)}/"
                lock_path << lock_entity.dmsf_path.map { |e| Addressable::URI.escape(e.respond_to?('name') ? e.name : e.title) }.join('/')
                lock_path << '/' if lock_entity.is_a?(DmsfFolder) && lock_path[-1,1] != '/'
                doc.lockroot { doc.href lock_path }
                if (lock.user.id == User.current.id) || User.current.allowed_to?(:force_file_unlock, project)
                  doc.locktoken { doc.href lock.uuid }
                end
              }
            end
          }
        end
        x
      end

      private

      # Prepare file for download using Rack functionality:
      # Download (see RedmineDmsf::Webdav::Download) extends Rack::File to allow single-file
      # implementation of service for request, which allows for us to pipe a single file through
      # also best-utilising Dav4rack's implementation.
      def download
        raise NotFound unless file&.last_revision
        disk_file = file.last_revision.disk_file
        raise NotFound unless disk_file && File.exist?(disk_file)
        raise Forbidden unless (!parent.exist? || !parent.folder || DmsfFolder.permissions?(parent.folder))
        # If there is no range (start of ranged download, or direct download) then we log the
        # file access, so we can properly keep logged information
        if @request.env['HTTP_RANGE'].nil?
          access = DmsfFileRevisionAccess.new
          access.user = User.current
          access.dmsf_file_revision = file.last_revision
          access.action = DmsfFileRevisionAccess::DownloadAction
          access.save!
        end
        File.new disk_file
      end

      def reuse_version_for_locked_file(file)
        locks = file.lock
        locks.each do |lock|
          next if lock.expired?
          # lock should be exclusive but just in case make sure we find this users lock
          next if lock.user != User.current
          if lock.dmsf_file_last_revision_id.nil? || (lock.dmsf_file_last_revision_id < file.last_revision.id)
            # At least one new revision has been created since the lock was created, reuse that revision.
            return true
          end
        end
        false
      end

      def set_custom_property(element, value)
        if value.present?
          Redmine::Search.cache_store.write "#{get_property_key}-#{element[:name]}",  value
        else
          Redmine::Search.cache_store.delete "#{get_property_key}-#{element[:name]}"
        end
        OK
      end

      def get_custom_property(element)
        val = Redmine::Search.cache_store.fetch "#{get_property_key}-#{element[:name]}"
        val.present? ? val : NotFound
      end

      def get_property_key
        if file
          return "DmsfFile-#{file.id}"
        elsif folder
          return "DmsfFolder-#{folder.id}"
        elsif subproject
          return "Project-#{subproject.id}"
        else
          return "Project-#{project.id}"
        end
      end
      
    end
  end
end
