require_relative 'providers/generic_odbc'
require_relative 'providers/mysql'
require_relative 'providers/postgresql'
require_relative 'providers/sqlserver'
require_relative 'providers/hive'
require_relative 'providers/pg_fdw'

module Carto
  class Connector

    # Here we map provider identifiers (as used in APIs, etc.) to the Provider class and basic attributes.
    # `name` is the human-readable name
    # `public` means that the provider is publicly announced (so it is accessible through UI, visible in lists of
    # providers, etc.) A provider may be available or not (see Connector.limits) independently of its public status,
    # so that a public provider may not be available for all users, and non-public providers may be available to
    # some users (e.g. 'odbc' provider for tests)
    PROVIDERS = {
      'odbc' => {
        name: 'ODBC',
        class: GenericOdbcProvider,
        public: false # Intended for internal development/tests
      },
      'postgres' => {
        name: 'PostgreSQL',
        class: PostgreSQLProvider,
        public: true
      },
      'mysql' => {
        name: 'MySQL',
        class: MySqlProvider,
        public: true
      },
      'sqlserver' => {
        name: 'Microsoft SQL Server',
        class: SqlServerProvider,
        public: true
      },
      'hive' => {
        name: 'Hive',
        class: HiveProvider,
        public: true
      }
    }

    DEFAULT_PROVIDER = nil # No default provider

    class << self
      def provider_class(provider_id)
        provider_item provider_id, :class
      end

      def provider_public?(provider_id)
        provider_item provider_id, :public
      end

      def provider_name(provider_id)
        provider_item provider_id, :name
      end

      def provider_ids
        PROVIDERS.keys
      end

      private

      def provider_data(provider_id)
        provider_id ||= DEFAULT_PROVIDER
        PROVIDERS[provider_id.to_s]
      end

      def provider_item(provider_id, item)
        data = provider_data(provider_id)
        data && data[item.to_sym]
      end
    end

  end
end