=begin
#Fastly API

#Via the Fastly API you can perform any of the operations that are possible within the management console,  including creating services, domains, and backends, configuring rules or uploading your own application code, as well as account operations such as user administration and billing reports. The API is organized into collections of endpoints that allow manipulation of objects related to Fastly services and accounts. For the most accurate and up-to-date API reference content, visit our [Developer Hub](https://www.fastly.com/documentation/reference/api/) 

The version of the OpenAPI document: 1.0.0
Contact: oss@fastly.com

=end

require 'date'
require 'time'

module Fastly
  module ValueField
    class << self
      # List of class defined in oneOf (OpenAPI v3)
      def fastly_one_of
        [
          :'Array<Float>',
          :'Array<Integer>',
          :'Array<String>',
          :'Boolean',
          :'Float',
          :'Integer',
          :'String'
        ]
      end

      # Builds the object
      # @param [Mixed] Data to be matched against the list of oneOf items
      # @return [Object] Returns the model or the data itself
      def build(data)
        # Go through the list of oneOf items and attempt to identify the appropriate one.
        # Note:
        # - We do not attempt to check whether exactly one item matches.
        # - No advanced validation of types in some cases (e.g. "x: { type: string }" will happily match { x: 123 })
        #   due to the way the deserialization is made in the base_object template (it just casts without verifying).
        # - TODO: scalar values are de facto behaving as if they were nullable.
        # - TODO: logging when debugging is set.
        fastly_one_of.each do |klass|
          begin
            next if klass == :AnyType # "nullable: true"
            typed_data = find_and_cast_into_type(klass, data)
            return typed_data if typed_data
          rescue # rescue all errors so we keep iterating even if the current item lookup raises
          end
        end

        fastly_one_of.include?(:AnyType) ? data : nil
      end

      private

      SchemaMismatchError = Class.new(StandardError)

      # Note: 'File' is missing here because in the regular case we get the data _after_ a call to JSON.parse.
      def find_and_cast_into_type(klass, data)
        return if data.nil?

        case klass.to_s
        when 'Boolean'
          return data if data.instance_of?(TrueClass) || data.instance_of?(FalseClass)
        when 'Float'
          return data if data.instance_of?(Float)
        when 'Integer'
          return data if data.instance_of?(Integer)
        when 'Time'
          return Time.parse(data)
        when 'Date'
          return Date.parse(data)
        when 'String'
          return data if data.instance_of?(String)
        when 'Object' # "type: object"
          return data if data.instance_of?(Hash)
        when /\AArray<(?<sub_type>.+)>\z/ # "type: array"
          if data.instance_of?(Array)
            sub_type = Regexp.last_match[:sub_type]
            return data.map { |item| find_and_cast_into_type(sub_type, item) }
          end
        when /\AHash<String, (?<sub_type>.+)>\z/ # "type: object" with "additionalProperties: { ... }"
          if data.instance_of?(Hash) && data.keys.all? { |k| k.instance_of?(Symbol) || k.instance_of?(String) }
            sub_type = Regexp.last_match[:sub_type]
            return data.each_with_object({}) { |(k, v), hsh| hsh[k] = find_and_cast_into_type(sub_type, v) }
          end
        else # model
          const = Fastly.const_get(klass)
          if const
            if const.respond_to?(:fastly_one_of) # nested oneOf model
              model = const.build(data)
              return model if model
            else
              # raise if data contains keys that are not known to the model
              raise unless (data.keys - const.acceptable_attributes).empty?
              model = const.build_from_hash(data)
              return model if model && model.valid?
            end
          end
        end

        raise # if no match by now, raise
      rescue
        raise SchemaMismatchError, "#{data} doesn't match the #{klass} type"
      end
    end
  end

end