require_relative './internal/abstract_runtime_context'
require_relative './invocation_context'
require_relative './../utils/connection_type'
require_relative './../utils/tcp_connection_data'
require_relative './../core/interpreter/interpreter'

# Represents a single context which allows interaction with a selected technology.
# Refers to a single instance of the called runtime within a particular target OS process.
# This can be either the local currently running process (inMemory) or a particular remote process identified by the IP Address and PORT of the target Javonet instance.
# Multiple Runtime Contexts can be initialized within one process.
# Calling the same technology on inMemory communication channel will return the existing instance of runtime context.
# Calling the same technology on TCP channel but on different nodes will result in unique Runtime Contexts.
# Within the runtime context, any number of libraries can be loaded and any objects from the target technology can be interacted with, as they are aware of each other due to sharing the same memory space and same runtime instance.
# @see Refer to this {https://www.javonet.com/guides/v2/ruby/foundations/runtime-context article on Javonet Guides}
class RuntimeContext < AbstractRuntimeContext
  @@memory_runtime_contexts = Hash.new
  @@network_runtime_contexts = Hash.new

  # accessor get method
  attr_reader :current_command

  # accessor set method
  attr_writer :current_command

  def initialize(runtime_name, connection_type, tcp_connection_data)
    @runtime_name = runtime_name
    @connection_type = connection_type
    @tcp_ip_address = tcp_connection_data
    @current_command = nil
    @interpreter = Interpreter.new
  end

  def self.get_instance(runtime_name, connection_type, tcp_connection_data)
    case connection_type
    when ConnectionType::IN_MEMORY
      if @@memory_runtime_contexts.has_key?(runtime_name)
        runtime_ctx = @@memory_runtime_contexts[runtime_name]
        runtime_ctx.current_command = nil
        return runtime_ctx
      else
        runtime_ctx = RuntimeContext.new(runtime_name, connection_type, tcp_connection_data)
        @@memory_runtime_contexts[runtime_name] = runtime_ctx
        return runtime_ctx
      end
    when ConnectionType::TCP
      key = runtime_name.to_s + ":" + tcp_connection_data.to_s
      if @@network_runtime_contexts.has_key?(key)
        runtime_ctx = @@network_runtime_contexts[key]
        runtime_ctx.current_command = nil
        return runtime_ctx
      else
        runtime_ctx = RuntimeContext.new(runtime_name, connection_type, tcp_connection_data)
        @@network_runtime_contexts[key] = runtime_ctx
        return runtime_ctx
      end
    end
  end

  # Executes the current command. The initial state of RuntimeContext is non-materialized,
  # wrapping either a single command or a chain of recursively nested commands.
  # Commands become nested through each invocation of methods on RuntimeContext.
  # Each invocation triggers the creation of a new RuntimeContext instance wrapping the current command with a new parent command.
  # The developer can decide at any moment of the materialization for the context, taking full control of the chunks of the expression being transferred and processed on the target runtime.
  # @see Refer to this {https://www.javonet.com/guides/v2/ruby/foundations/execute-method article on Javonet Guides}
  def execute
    @response_command = @interpreter.execute(@current_command, @connection_type, @tcp_ip_address)
    @current_command = nil
    if @response_command.command_type == CommandType::EXCEPTION
      raise ExceptionThrower.throw_exception(@response_command)
    end
  end

  # Adds a reference to a library. Javonet allows you to reference and use modules or packages written in various languages.
  # This method allows you to use any library from all supported technologies. The necessary libraries need to be referenced.
  # The argument is a relative or full path to the library. If the library has dependencies on other libraries, the latter needs to be added first.
  # After referencing the library, any objects stored in this package can be used. Use static classes, create instances, call methods, use fields and properties, and much more.
  # @param args [Array] The relative or full path to the library.
  # @return [RuntimeContext] RuntimeContext instance.
  # @see Refer to this {https://www.javonet.com/guides/v2/ruby/getting-started/adding-references-to-libraries article on Javonet Guides}
  def load_library(*args)
    local_command = Command.new(@runtime_name, CommandType::LOAD_LIBRARY, [*args])
    @current_command = build_command(local_command)
    self.execute()
    return self
  end

  # Retrieves a reference to a specific type. The type can be a class, interface or enum. The type can be retrieved from any referenced library.
  # @param args [Array] The full name of the type.
  # @return [InvocationContext] InvocationContext instance.
  def get_type(*args)
    local_command = Command.new(@runtime_name, CommandType::GET_TYPE, [*args])
    @current_command = nil
    return InvocationContext.new(@runtime_name, @connection_type, @tcp_ip_address, build_command(local_command), false)
  end

  # Casts the provided value to a specific type. This method is used when invoking methods that require specific types of arguments.
  # The arguments include the target type and the value to be cast. The target type must be retrieved from the called runtime using the getType method.
  # After casting the value, it can be used as an argument when invoking methods.
  # @param args [Array] The target type and the value to be cast.
  # @return [InvocationContext] InvocationContext instance.
  # #see Refer to this {https://www.javonet.com/guides/v2/ruby/casting/casting article on Javonet Guides}
  def cast(*args)
    local_command = Command.new(@runtime_name, CommandType::CAST, [*args])
    @current_command = nil
    return InvocationContext.new(@runtime_name, @connection_type, @tcp_ip_address, build_command(local_command), false)
  end

  # Retrieves a specific item from an enum type. This method is used when working with enums from the called runtime.
  # The arguments include the enum type and the name of the item. The enum type must be retrieved from the called runtime using the getType method.
  # After retrieving the item, it can be used
  # as an argument when invoking methods.
  # @param args [Array] The enum type and the name of the item.
  # @return [InvocationContext] InvocationContext instance.
  # @see Refer to this {https://www.javonet.com/guides/v2/ruby/enums/using-enum-type article on Javonet Guides}
  def get_enum_item(*args)
    local_command = Command.new(@runtime_name, CommandType::GET_ENUM_ITEM, [*args])
    @current_command = nil
    return InvocationContext.new(@runtime_name, @connection_type, @tcp_ip_address, build_command(local_command), false)
  end

  # Creates a reference type argument that can be passed to a method with a ref parameter modifier.
  # This method is used when working with methods from the called runtime that require arguments to be passed by reference.
  # The arguments include the value and optionally the type of the reference.
  # The type must be retrieved from the called runtime using the getType method.
  # After creating the reference, it can be used as an argument when invoking methods.
  # @param args [Array] The value and optionally the type of the reference.
  # @return [InvocationContext] InvocationContext instance.
  # @see Refer to this {https://www.javonet.com/guides/v2/ruby/methods-arguments/passing-arguments-by-reference-with-ref-keyword article on Javonet Guides}
  def as_ref(*args)
    local_command = Command.new(@runtime_name, CommandType::AS_REF, [*args])
    @current_command = nil
    return InvocationContext.new(@runtime_name, @connection_type, @tcp_ip_address, build_command(local_command), false)
  end

  # Creates a reference type argument that can be passed to a method with an out parameter modifier.
  # This method is used when working with methods from the called runtime that require arguments to be passed by reference.
  # The arguments include the value and optionally the type of the reference.
  # The type must be retrieved from the called runtime using the getType method.
  # After creating the reference, it can be used as an argument when invoking methods.
  # @param args [Array] The value and optionally the type of the reference.
  # @return [InvocationContext] InvocationContext instance.
  # @see Refer to this {https://www.javonet.com/guides/v2/ruby/methods-arguments/passing-arguments-by-reference-with-out-keyword article on Javonet Guides}
  def as_out(*args)
    local_command = Command.new(@runtime_name, CommandType::AS_OUT, [*args])
    @current_command = nil
    return InvocationContext.new(@runtime_name, @connection_type, @tcp_ip_address, build_command(local_command), false)
  end

  def build_command(command)
    command.payload.each_index { |i|
      command.payload[i] = encapsulate_payload_item(command.payload[i])
    }
    return command.prepend_arg_to_payload(@current_command)
  end

  def encapsulate_payload_item(payload_item)
    if payload_item.is_a? Command
      payload_item.payload.each_index { |i|
        payload_item.payload[i] = encapsulate_payload_item(payload_item.payload[i])
      }
      return payload_item

    elsif payload_item.is_a? InvocationContext
      return payload_item.current_command

    elsif payload_item.is_a? Array
      payload_item.each_index { |i|
        payload_item[i] = encapsulate_payload_item(payload_item[i])
      }
      return Command.new(@runtime_name, CommandType::ARRAY, [*payload_item])

    else
      return Command.new(@runtime_name, CommandType::VALUE, [*payload_item])
    end
  end
end