# Copyright (C) 2012-2023 Zammad Foundation, https://zammad-foundation.org/

class Avatar < ApplicationModel
  belongs_to :object_lookup, optional: true

=begin

add an avatar based on auto detection (email address)

  Avatar.auto_detection(
    object: 'User',
    o_id: user.id,
    url: 'somebody@example.com',
    updated_by_id: 1,
    created_by_id: 1,
  )

=end

  def self.auto_detection(data)

    # return if we run import mode
    return if Setting.get('import_mode')
    return if data[:url].blank?

    Avatar.add(
      object:        data[:object],
      o_id:          data[:o_id],
      url:           data[:url],
      source:        'zammad.com',
      deletable:     false,
      updated_by_id: 1,
      created_by_id: 1,
    )
  end

=begin

add avatar by upload

  Avatar.add(
    object: 'User',
    o_id: user.id,
    default: true,
    full: {
      content: '...',
      mime_type: 'image/png',
    },
    resize: {
      content: '...',
      mime_type: 'image/png',
    },
    source: 'web',
    deletable: true,
    updated_by_id: 1,
    created_by_id: 1,
  )

add avatar by url

  Avatar.add(
    object: 'User',
    o_id: user.id,
    default: true,
    url: ...,
    source: 'web',
    deletable: true,
    updated_by_id: 1,
    created_by_id: 1,
  )

=end

  def self.add(data)
    # lookups
    if data[:object]
      object_id = ObjectLookup.by_name(data[:object])
    end

    # add initial avatar
    _add_init_avatar(object_id, data[:o_id])

    record = {
      o_id:             data[:o_id],
      object_lookup_id: object_id,
      default:          true,
      deletable:        data[:deletable],
      initial:          false,
      source:           data[:source],
      source_url:       data[:url],
      updated_by_id:    data[:updated_by_id],
      created_by_id:    data[:created_by_id],
    }

    # check if avatar with url already exists
    avatar_already_exists = nil
    if data[:source].present?
      avatar_already_exists = Avatar.find_by(
        object_lookup_id: object_id,
        o_id:             data[:o_id],
        source:           data[:source],
      )
    end

    # fetch image based on http url
    if data[:url].present?
      if data[:url].instance_of?(Tempfile)
        logger.info "Reading image from tempfile '#{data[:url].inspect}'"
        content = data[:url].read
        filename = data[:url].path
        mime_type = 'image'
        if filename.match?(%r{\.png}i)
          mime_type = 'image/png'
        end
        if filename.match?(%r{\.(jpg|jpeg)}i)
          mime_type = 'image/jpeg'
        end

        # forbid creation of avatars without a specified mime_type (image is not displayed in the UI)
        if mime_type == 'image'
          logger.info "Could not determine mime_type for image '#{data[:url].inspect}'"
          return
        end

        data[:resize] ||= {}
        data[:resize][:content] = content
        data[:resize][:mime_type] = mime_type
        data[:full] ||= {}
        data[:full][:content] = content
        data[:full][:mime_type] = mime_type

      elsif data[:url].to_s.match?(%r{^https?://})
        url = data[:url].to_s

        # check if source was updated within last 2 minutes
        return if avatar_already_exists&.source_url == url && avatar_already_exists.updated_at > 2.minutes.ago

        # twitter workaround to get bigger avatar images
        # see also https://dev.twitter.com/overview/general/user-profile-images-and-banners
        if url.match?(%r{//pbs.twimg.com/}i)
          url.sub!(%r{normal\.(png|jpg|gif)$}, 'bigger.\1')
        end

        # fetch image
        response = UserAgent.get(
          url,
          {},
          {
            open_timeout:  4,
            read_timeout:  6,
            total_timeout: 6,
          },
        )
        if !response.success?
          logger.info "Can't fetch '#{url}' (maybe no avatar available), http code: #{response.code}"
          return
        end
        logger.info "Fetched image '#{url}', http code: #{response.code}"
        mime_type = 'image'
        if url.match?(%r{\.png}i)
          mime_type = 'image/png'
        end
        if url.match?(%r{\.(jpg|jpeg)}i)
          mime_type = 'image/jpeg'
        end

        # fallback to content-type of the response if url does not end with png, jpg or jpeg
        #   see https://github.com/zammad/zammad/issues/3829
        if mime_type == 'image' &&
           response.header['content-type'].present? &&
           Rails.application.config.active_storage.web_image_content_types.include?(response.header['content-type'])
          mime_type = response.header['content-type']
        end

        # forbid creation of avatars without a specified mime_type (image is not displayed in the UI)
        if mime_type == 'image'
          logger.info "Could not determine mime_type for image '#{url}'"
          return
        end

        data[:resize] ||= {}
        data[:resize][:content] = response.body
        data[:resize][:mime_type] = mime_type
        data[:full] ||= {}
        data[:full][:content] = response.body
        data[:full][:mime_type] = mime_type

      # try zammad backend to find image based on email
      elsif data[:url].to_s.match?(URI::MailTo::EMAIL_REGEXP)
        url = data[:url].to_s

        # check if source ist already updated within last 3 minutes
        return if avatar_already_exists&.source_url == url && avatar_already_exists.updated_at > 2.minutes.ago

        # fetch image
        image = Service::Image.user(url)
        return if !image

        data[:resize] = image
        data[:full] = image
      end
    end

    # check if avatar needs to be updated
    if data[:resize].present? && data[:resize][:content].present?
      record[:store_hash] = Digest::MD5.hexdigest(data[:resize][:content])
      if avatar_already_exists&.store_hash == record[:store_hash]
        avatar_already_exists.touch # rubocop:disable Rails/SkipsModelValidations
        return avatar_already_exists
      end
    end

    # store images
    object_name = "Avatar::#{data[:object]}"
    if data[:full].present?
      store_full = Store.create!(
        object:        "#{object_name}::Full",
        o_id:          data[:o_id],
        data:          data[:full][:content],
        filename:      'avatar_full',
        preferences:   {
          'Mime-Type' => data[:full][:mime_type]
        },
        created_by_id: data[:created_by_id],
      )
      record[:store_full_id] = store_full.id
      record[:store_hash]    = Digest::MD5.hexdigest(data[:full][:content])
    end
    if data[:resize].present?
      store_resize = Store.create!(
        object:        "#{object_name}::Resize",
        o_id:          data[:o_id],
        data:          data[:resize][:content],
        filename:      'avatar',
        preferences:   {
          'Mime-Type' => data[:resize][:mime_type]
        },
        created_by_id: data[:created_by_id],
      )
      record[:store_resize_id] = store_resize.id
      record[:store_hash]      = Digest::MD5.hexdigest(data[:resize][:content])
    end

    return if record[:store_resize_id].blank? || record[:store_hash].blank?

    # update existing
    if avatar_already_exists
      avatar_already_exists.update!(record)
      avatar = avatar_already_exists

    # add new one and set it as default
    else
      avatar = Avatar.create(record)
      set_default_items(object_id, data[:o_id], avatar.id)
    end

    avatar
  end

=begin

set avatars as default

  Avatar.set_default('User', 123, avatar_id)

=end

  def self.set_default(object_name, o_id, avatar_id)
    object_id = ObjectLookup.by_name(object_name)
    avatar = Avatar.find_by(
      object_lookup_id: object_id,
      o_id:             o_id,
      id:               avatar_id,
    )
    avatar.default = true
    avatar.save!

    # set all other to default false
    set_default_items(object_id, o_id, avatar_id)

    avatar
  end

=begin

remove all avatars of an object

  Avatar.remove('User', 123)

=end

  def self.remove(object_name, o_id)
    object_id = ObjectLookup.by_name(object_name)
    Avatar.where(
      object_lookup_id: object_id,
      o_id:             o_id,
    ).destroy_all

    object_name_store = "Avatar::#{object_name}"
    Store.remove(
      object: "#{object_name_store}::Full",
      o_id:   o_id,
    )
    Store.remove(
      object: "#{object_name_store}::Resize",
      o_id:   o_id,
    )
  end

=begin

remove one avatars of an object

  Avatar.remove_one('User', 123, avatar_id)

=end

  def self.remove_one(object_name, o_id, avatar_id)
    object_id = ObjectLookup.by_name(object_name)
    Avatar.where(
      object_lookup_id: object_id,
      o_id:             o_id,
      id:               avatar_id,
    ).destroy_all
  end

=begin

return all avatars of an user

  avatars = Avatar.list('User', 123)

  avatars = Avatar.list('User', 123, no_init_add_as_boolean) # per default true

=end

  def self.list(object_name, o_id, no_init_add_as_boolean = true)
    object_id = ObjectLookup.by_name(object_name)
    avatars = Avatar.where(
      object_lookup_id: object_id,
      o_id:             o_id,
    ).order(initial: :desc, deletable: :asc, created_at: :asc)

    # add initial avatar
    if no_init_add_as_boolean
      _add_init_avatar(object_id, o_id)
    end

    avatar_list = []
    avatars.each do |avatar|
      data = avatar.attributes
      if avatar.store_resize_id
        file            = Store.find(avatar.store_resize_id)
        data['content'] = "data:#{file.preferences['Mime-Type']};base64,#{Base64.strict_encode64(file.content)}"
      end
      avatar_list.push data
    end
    avatar_list
  end

=begin

get default avatar image of user by hash

  store = Avatar.get_by_hash(hash)

returns:

  store object

=end

  def self.get_by_hash(hash)
    avatar = Avatar.find_by(
      store_hash: hash,
    )
    return if !avatar

    Store.find(avatar.store_resize_id)
  end

=begin

get default avatar of user by user id

  avatar = Avatar.get_default('User', user_id)

returns:

  avatar object

=end

  def self.get_default(object_name, o_id)
    object_id = ObjectLookup.by_name(object_name)
    Avatar.find_by(
      object_lookup_id: object_id,
      o_id:             o_id,
      default:          true,
    )
  end

  def self.set_default_items(object_id, o_id, avatar_id)
    avatars = Avatar.where(
      object_lookup_id: object_id,
      o_id:             o_id,
    ).order(created_at: :asc)
    avatars.each do |avatar|
      next if avatar.id == avatar_id

      avatar.default = false
      avatar.save!
    end
  end

  def self._add_init_avatar(object_id, o_id)

    count = Avatar.where(
      object_lookup_id: object_id,
      o_id:             o_id,
    ).count
    return if count.positive?

    object_name = ObjectLookup.by_id(object_id)
    return if !object_name.constantize.exists?(id: o_id)

    Avatar.create!(
      o_id:             o_id,
      object_lookup_id: object_id,
      default:          true,
      source:           'init',
      initial:          true,
      deletable:        false,
      updated_by_id:    1,
      created_by_id:    1,
    )
  end
end