require 'active_record'

require_relative './carto_json_serializer'
require_dependency 'common/map_common'
require_dependency 'carto/bounding_box_utils'

class Carto::Map < ActiveRecord::Base
  include Carto::MapBoundaries

  has_many :layers_maps, dependent: :destroy
  has_many :layers, -> { order(:order) }, class_name: 'Carto::Layer',
                                          through: :layers_maps,
                                          after_add: Proc.new { |map, layer| layer.after_added_to_map(map) }

  has_many :base_layers, -> { order(:order) }, class_name: 'Carto::Layer',
                                               through: :layers_maps,
                                               source: :layer

  # autosave must be explicitly disabled due to https://github.com/rails/rails/issues/9336
  has_one :user_table, class_name: Carto::UserTable, inverse_of: :map, dependent: :destroy, autosave: false

  belongs_to :user

  # Autosave disabled because this caused the `inverse_of` to break (visualization.map != self) until `reload`
  # Fixed in Rails 5 https://github.com/rails/rails/pull/23197
  has_one :visualization, class_name: Carto::Visualization, inverse_of: :map, autosave: false

  # bounding_box_sw, bounding_box_new and center should probably be JSON serialized fields
  # However, many callers expect to get an string (and do the JSON deserialization themselves), mainly in presenters
  # So for now, we are just treating them as strings (see the .to_s in the constant below), but this could be improved
  DEFAULT_OPTIONS = {
    zoom:            3,
    bounding_box_sw: [Carto::BoundingBoxUtils::DEFAULT_BOUNDS[:miny],
                      Carto::BoundingBoxUtils::DEFAULT_BOUNDS[:minx]].to_s,
    bounding_box_ne: [Carto::BoundingBoxUtils::DEFAULT_BOUNDS[:maxy],
                      Carto::BoundingBoxUtils::DEFAULT_BOUNDS[:maxx]].to_s,
    provider:        'leaflet',
    center:          [30, 0].to_s
  }.freeze

  serialize :options, ::Carto::CartoJsonSerializer
  validates :options, carto_json_symbolizer: true

  validate :validate_options

  after_initialize :ensure_options
  after_save :notify_map_change
  after_save :save_table # Manual save, since autosave is disabled

  def data_layers
    layers.select(&:data_layer?)
  end

  def carto_layers
    layers.select(&:carto?)
  end

  def user_layers
    layers.select(&:user_layer?)
  end

  def torque_layers
    layers.select(&:torque?)
  end

  def other_layers
    layers.reject(&:carto?)
          .reject(&:tiled?)
          .reject(&:background?)
          .reject(&:gmapsbase?)
          .reject(&:wms?)
  end

  def named_map_layers
    layers.select(&:named_map_layer?)
  end

  def viz_updated_at
    latest_mapcap = visualization.latest_mapcap

    latest_mapcap ? latest_mapcap.created_at : get_the_last_time_tiles_have_changed_to_render_it_in_vizjsons
  end

  def self.provider_for_baselayer_kind(kind)
    kind == 'tiled' ? 'leaflet' : 'googlemaps'
  end

  # (lat,lon) points on all map data
  def center_data
    (center.nil? || center == '') ? DEFAULT_OPTIONS[:center] : center.gsub(/\[|\]|\s*/, '').split(',')
  end

  def view_bounds_data
    if view_bounds_sw.nil? || view_bounds_sw == ''
      bbox_sw = DEFAULT_OPTIONS[:bounding_box_sw]
    else
      bbox_sw = view_bounds_sw.gsub(/\[|\]|\s*/, '').split(',').map(&:to_f)
    end
    if view_bounds_ne.nil? || view_bounds_ne == ''
      bbox_ne = DEFAULT_OPTIONS[:bounding_box_ne]
    else
      bbox_ne = view_bounds_ne.gsub(/\[|\]|\s*/, '').split(',').map(&:to_f)
    end

    {
      # LowerCorner longitude, in decimal degrees
      west:  bbox_sw[1],
      # LowerCorner latitude, in decimal degrees
      south: bbox_sw[0],
      # UpperCorner longitude, in decimal degrees
      east:  bbox_ne[1],
      # UpperCorner latitude, in decimal degrees
      north: bbox_ne[0]
    }
  end

  def writable_by_user?(user)
    visualization.writable_by?(user)
  end

  def contains_layer?(layer)
    return false unless layer

    layers_maps.map(&:layer_id).include?(layer.id)
  end

  def notify_map_change
    visualization.try(:invalidate_after_commit)
  end
  alias :force_notify_map_change :notify_map_change

  def update_dataset_dependencies
    data_layers.each(&:register_table_dependencies)
  end

  def dashboard_menu=(value)
    options[:dashboard_menu] = value
  end

  def dashboard_menu
    options[:dashboard_menu]
  end

  def layer_selector=(value)
    options[:layer_selector] = value
  end

  def layer_selector
    options[:layer_selector]
  end

  def admits_layer?(layer)
    return admits_more_torque_layers? if layer.torque?
    return admits_more_data_layers? if layer.data_layer?
    return admits_more_base_layers?(layer) if layer.base_layer?
  end

  def can_add_layer?(user, layer)
    return true if layer.base_layer?
    return false if user.max_layers && user.max_layers <= data_layers.count

    visualization.writable_by?(user)
  end

  def process_privacy_in(layer)
    if layer.uses_private_tables? && visualization.can_be_private?
      visualization.privacy = Carto::Visualization::PRIVACY_PRIVATE
      visualization.save
    end
  end

  private

  def save_table
    if user_table && !user_table.persisted?
      user_table.map = self
      user_table.save!
    end
  end

  def admits_more_data_layers?
    !visualization.canonical? || data_layers.empty?
  end

  def admits_more_torque_layers?
    !visualization.canonical? || torque_layers.empty?
  end

  def admits_more_base_layers?(layer)
    # no basemap layer, always allow
    return true if user_layers.empty?
    # have basemap? then allow only if comes on top (for labels)
    layer.order >= layers.last.order
  end

  def ensure_options
    self.zoom ||= DEFAULT_OPTIONS[:zoom]
    self.bounding_box_sw ||= DEFAULT_OPTIONS[:bounding_box_sw]
    self.bounding_box_ne ||= DEFAULT_OPTIONS[:bounding_box_ne]
    self.center ||= DEFAULT_OPTIONS[:center]
    self.provider ||= DEFAULT_OPTIONS[:provider]

    self.options ||= {}
    options[:dashboard_menu] = true if options[:dashboard_menu].nil?
    options[:layer_selector] = false if options[:layer_selector].nil?
    options[:legends] = legends if options[:legends].nil?
    options[:scrollwheel] = scrollwheel if options[:scrollwheel].nil?

    options
  end

  def validate_options
    location = "#{Rails.root}/lib/formats/map/options.json"
    schema = Carto::Definition.instance.load_from_file(location)

    options_wia = options.with_indifferent_access
    json_errors = JSON::Validator.fully_validate(schema, options_wia)
    errors.add(:options, json_errors.join(', ')) if json_errors.any?
  end

  def get_the_last_time_tiles_have_changed_to_render_it_in_vizjsons
    from_table = user_table.service.data_last_modified if user_table

    [from_table, data_layers.map(&:updated_at)].flatten.compact.max
  end

  def table_name
    user_table.try(:name)
  end
end