require 'elasticsearch'
require 'date'
require 'pp'

module Ag::Storage
  module_function

  def index_name(list)
    'ml-' + list
  end

  def index_status(indexname)
    $es.cluster.health(level: :indices)['indices'][indexname]['status'] || 'FAIL'
  end

  def index_ready?(indexname)
    # watch out if you rewrite this
    # if you call index_status twice, you might get different results!
    [:green, :yellow].include? index_status(indexname).downcase.to_sym
  end

  # throws Elasticsearch::Transport::Transport::Errors::NotFound
  # if the list does not exist
  def delete_index(list)
    $es.indices.delete(index: index_name(list))
  end

  # Create an index for list
  # sleep in 5ms intervals until it is ready
  def create_index(list, sleeptime: 0.005)
    indexname = index_name(list)
    $es.indices.create(
      index: indexname,
      body: {
        mappings: {
          message: {
            properties: {
              attachments: {
                properties: {
                  filename: {
                    type: 'string',
                    index: 'not_analyzed'
                  },
                  mime: {
                    type: 'string',
                    index: 'not_analyzed'
                  }
                }
              },
              received: {
                properties: {
                  hop: {
                    type: 'string',
                    index: 'not_analyzed'
                  },
                  date: {
                    type: 'date',
                    format: 'dateOptionalTime'
                  }
                }
              },
              cc: {
                type: 'string'
              },
              content: {
                type: 'string'
              },
              date: {
                type: 'date',
                format: 'dateOptionalTime'
              },
              from: {
                type: 'string'
              },
              from_realname: {
                type: 'string'
              },
              month: {
                type: 'integer'
              },
              parent: {
                type: 'string',
                index: 'not_analyzed'
              },
              raw_message_id: {
                type: 'string',
                index: 'not_analyzed'
              },
              raw_filename: {
                type: 'string',
                index: 'not_analyzed'
              },
              raw_parent: {
                type: 'string'
              },
              subject: {
                type: 'string'
              },
              to: {
                type: 'string'
              },
              hidden: {
                type: 'boolean'
              },
              comment: {
                type: 'string',
                index: 'not_analyzed'
              }
            }
          }
        }
      })

    # Give elasticsearch some time to process the new index
    sleep sleeptime until index_ready?(indexname)
  end

  def get_content(message, filename)
    content = 'Cannot parse MIME/contents.'
    begin
      raw_content = Ag::Rendering::HTMLizer.HTMLize(message)
      content = Ag::Utils.fix_encoding(raw_content || '').strip

      if content == ''
        $stderr.puts "#{message.message_id}: Content empty?" if $options.debug
      end
    rescue => e
      $stderr.puts "Cannot render message #{message.message_id} (file: #{filename}): #{e}" if $options.debug
    end

    content
  end

  def resolve_by_field(list, field, value)
    return nil if value.nil?

    result = $es.search(
      index: index_name(list),
      body: {
        query: {
          filtered: {
            filter: {
              term: { field => value }
            }
          }
        },
        fields: ['_id']
      }
    )

    return nil if result['hits']['total'] == 0
    result['hits']['hits'].first['_id']
  end

  def resolve_message_id(list, message_id = nil)
    resolve_by_field(list, :raw_message_id, message_id)
  end

  def resolve_filename(list, filename)
    resolve_by_field(list, :raw_filename, filename)
  end

  def resolve_hash(list, hash = nil)
    resolve_by_field(list, :_id, hash)
  end

  def store(list, message, filename)
    content = get_content(message, filename)

    identifier = nil
    begin
      identifier = message['X-Archives-Hash'].value
    rescue NoMethodError
      raise 'No archives hash found in the message headers'
    end

    raw_parent = Ag::Threading.get_parent_message_id(message)

    from = Ag::Utils.resolve_address_header(message, :from).first
    from_realname = Ag::Utils.get_sender_displayname(message)
    to = Ag::Utils.resolve_address_header(message, :to)
    cc = Ag::Utils.resolve_address_header(message, :cc)
    subject = Ag::Utils.fix_encoding(message.subject)

    date = [message.received].flatten.first.field.date_time

    received = []
    [message.received].flatten.each do |hop|
      begin
        received << {
          hop: hop.field.info,
          date: hop.field.date_time
        }
      rescue => e
        next
      end
    end

    attachments = []
    if message.has_attachments?
      message.attachments.each do |attachment|
        attachments << {
          filename: attachment.filename,
          mime: attachment.mime_type
        }
      end
    end

    $es.index(
      index: index_name(list),
      type: 'message',
      id: identifier,
      body: {
        raw_message_id: message.message_id,
        subject: subject,
        to: to,
        cc: cc,
        from: from,
        from_realname: from_realname,
        date: date,
        month: ('%i%02i' % [date.year, date.month]).to_i, # this is a sortable number!
        content: content,
        attachments: attachments,
        received: received,
        raw_parent: raw_parent,
        raw_filename: filename
      }
    )
  end

  def fix_threading(list, pass)
    result = $es.search(
      index: index_name(list),
      size: 5000,
      body: {
        size: 5000,
        query: {
          filtered: {
            filter: {
              and: [
                {
                  missing: {
                    field: 'parent'
                  }
                },
                {
                  exists: {
                    field: 'raw_parent'
                  }
                }
              ]
            }
          }
        }
      }
    )

    opts = {
      in_processes: Ag::Utils.proc_count
    }
    opts[:progress] = "Calculating Threading (Pass #{pass})" if $options.progress
    Parallel.each(result['hits']['hits'], opts) do |hit|
      msg = resolve_message_id(list, hit['_source']['raw_parent'])
      update(list, hit['_id'], doc: { parent: msg }) unless msg.nil?
    end

    result['hits']['total']
  end

  def delete(list, id)
    $es.delete(index: index_name(list), type: 'message', id: id)
  end

  def _hide_unhide(list, id, hide_status, comment)
    doc = { hidden: hide_status }
    doc[:comment] = comment if comment # Only modify it if it exists
    update(list, id, doc: doc,
                     detect_noop: true)
  end

  def hide(list, id, comment)
    hide_unhide(list, id, true, comment)
  end

  def unhide(list, id, comment)
    _hide_unhide(list, id, false, comment)
  end

  def update(list, id, doc_changes)
    raise "Invalid update for #{list}/#{id} #{doc_changes}" unless doc_changes.is_a?(Hash)
    $es.update(
      index: index_name(list),
      type: 'message',
      id: id,
      body: doc_changes
    )
  end

  def get(list, id)
    result = $es.search(
      index: index_name(list),
      size: 1,
      body: {
        query: {
          filtered: {
            filter: {
              term: { _id: id }
            }
          }
        }
      }
    )

    return nil if result['hits']['total'] == 0
    result['hits']['hits'].first
  end
end
# vim: ts=2 sts=2 et ft=ruby: