package fpp.compiler.codegen

import fpp.compiler.analysis._
import fpp.compiler.ast._
import fpp.compiler.codegen._

/** Writes out C++ for component parameters */
case class ComponentParameters (
  s: CppWriterState,
  aNode: Ast.Annotated[AstNode[Ast.DefComponent]]
) extends ComponentCppWriterUtils(s, aNode) {

  def getConstantMembers: List[CppDoc.Class.Member] = {
    if !hasParameters then Nil
    else List(
      linesClassMember(
        List.concat(
          Line.blank :: lines(s"//! Parameter IDs"),
          wrapInEnum(
            sortedParams.flatMap((id, param) =>
              writeEnumConstant(
                paramIdConstantName(param.getName),
                id,
                AnnotationCppWriter.asStringOpt(param.aNode),
                CppWriterUtils.Hex
              )
            )
          )
        )
      )
    )
  }

  def getPublicFunctionMembers: List[CppDoc.Class.Member] = {
    if !hasParameters then Nil
    else getLoadFunction
  }

  def getProtectedFunctionMembers: List[CppDoc.Class.Member] = {
    if !hasParameters then Nil
    else List.concat(
      getHookFunctions,
      getGetterFunctions,
      getExternalParameterFunctions
    )
  }

  def getPrivateFunctionMembers: List[CppDoc.Class.Member] = {
    if !hasParameters then Nil
    else List.concat(
      getSetters,
      getSaveFunctions
    )
  }

  def getVariableMembers: List[CppDoc.Class.Member] = {
    if !hasParameters then Nil
    else List.concat(
      addAccessTagAndComment(
        "private",
        "Parameter validity flags",
        sortedParams.flatMap { case (_, param) =>
          guardedList (!param.isExternal) (
            List(
              linesClassMember(
                lines(
                  s"""|
                      |//! True if ${param.getName} was successfully received
                      |Fw::ParamValid ${paramValidityFlagName(param.getName)};
                      |"""
                )
              )
            )
          )
        },
        CppDoc.Lines.Hpp
      ),
      addAccessTagAndComment(
        "private",
        "Parameter variables",
        sortedParams.flatMap { case (_, param) =>
          guardedList (!param.isExternal) {
            val paramType = writeParamType(param.paramType, "Fw::ParamString")
            val paramVarName = paramVariableName(param.getName)
            List(
              linesClassMember(
                List.concat(
                  addSeparatedPreComment(
                    s"Parameter ${param.getName}",
                    AnnotationCppWriter.asStringOpt(param.aNode)
                  ),
                  lines(s"$paramType $paramVarName;")
                )
              )
            )
          }
        },
        CppDoc.Lines.Hpp
      ),
      guardedList (hasExternalParameters) (
        List.concat(
          addAccessTagAndComment(
            "private",
            "Parameter delegates",
            List(
              linesClassMember(
                lines(
                  s"""|
                      |//! Delegate to serialize/deserialize an externally stored parameter
                      |Fw::ParamExternalDelegate* paramDelegatePtr;
                      |"""
                )
              )
            )
          )
        )
      )
    )
  }

  private def getLoadFunction: List[CppDoc.Class.Member] = {
    addAccessTagAndComment(
      "public",
      "Parameter loading",
      List(
        functionClassMember(
          Some(
            s"""|\\brief Load the parameters from a parameter source
                |
                |Connect the parameter first
                |"""
          ),
          "loadParameters",
          Nil,
          CppDoc.Type("void"),
          intersperseBlankLines(
            List(
              lines(
                s"""|Fw::ParamBuffer _buff;
                    |Fw::SerializeStatus _stat = Fw::FW_SERIALIZE_OK;
                    |const FwPrmIdType _baseId = static_cast<FwPrmIdType>(this->getIdBase());
                    |FW_ASSERT(this->${portVariableName(prmGetPort.get)}[0].isConnected());
                    |
                    |FwPrmIdType _id{};
                    |"""
              ),
              guardedList (hasExternalParameters) (lines("Fw::ParamValid param_valid;")),
              intersperseBlankLines(
                sortedParams.map((_, param) =>
                  if (param.isExternal) {
                    List.concat(
                      lines(
                        s"""|_id = _baseId + ${paramIdConstantName(param.getName)};
                            |
                            |// Get parameter ${param.getName}
                            |param_valid = this->${portVariableName(prmGetPort.get)}[0].invoke(
                            |  _id,
                            |  _buff
                            |);
                            |
                            |// Get the local ID to pass to the delegate
                            |_id = ${paramIdConstantName(param.getName)};
                            |// If there was a deserialization issue, mark it invalid
                            |"""
                      ),
                      wrapInIfElse(
                        s"param_valid == Fw::ParamValid::VALID",
                        lines(
                          s"""|// Pass the local ID to the delegate
                              |_id = ${paramIdConstantName(param.getName)};
                              |
                              |FW_ASSERT(this->paramDelegatePtr != nullptr);
                              |// Call the delegate deserialize function for ${paramVariableName(param.getName)}
                              |_stat = this->paramDelegatePtr->deserializeParam(_baseId, _id, param_valid, _buff);
                              |"""
                        ) ++
                          wrapInIf(
                            "_stat != Fw::FW_SERIALIZE_OK",
                            lines(
                              s"param_valid = Fw::ParamValid::INVALID;"
                            )
                          ),
                        lines(s"param_valid = Fw::ParamValid::INVALID;")
                      )
                    )
                  } else {
                    List.concat(
                      lines(
                        s"""|_id = _baseId + ${paramIdConstantName(param.getName)};
                            |
                            |// Get parameter ${param.getName}
                            |this->${paramValidityFlagName(param.getName)} =
                            |  this->${portVariableName(prmGetPort.get)}[0].invoke(
                            |    _id,
                            |    _buff
                            |  );
                            |
                            |// Deserialize value
                            |this->m_paramLock.lock();
                            |
                            |// If there was a deserialization issue, mark it invalid
                            |"""
                      ),
                      wrapInIfElse(
                        s"this->${paramValidityFlagName(param.getName)} == Fw::ParamValid::VALID",
                        line(s"_stat = _buff.deserializeTo(this->${paramVariableName(param.getName)});") ::
                          wrapInIf(
                            "_stat != Fw::FW_SERIALIZE_OK",
                            param.default match {
                              case Some(value) => lines(
                                s"""|this->${paramValidityFlagName(param.getName)} = Fw::ParamValid::DEFAULT;
                                    |// Set default value
                                    |this->${paramVariableName(param.getName)} = ${ValueCppWriter.write(s, value)};
                                    |"""
                              )
                              case None => lines(
                                s"this->${paramValidityFlagName(param.getName)} = Fw::ParamValid::INVALID;"
                              )
                            }
                          ),
                        param.default match {
                          case Some(value) => lines(
                            s"""|// Set default value
                                |this->${paramValidityFlagName(param.getName)} = Fw::ParamValid::DEFAULT;
                                |this->${paramVariableName(param.getName)} = ${ValueCppWriter.write(s, value)};
                                |"""
                          )
                          case None => lines("// No default")
                        }
                      ),
                      Line.blank :: lines("this->m_paramLock.unLock();")
                    )
                  }
                )
              ),
              lines(
                """|// Call notifier
                   |this->parametersLoaded();
                   |"""
              )
            )
          )
        )
      )
    )
  }

  private def getHookFunctions: List[CppDoc.Class.Member] = {
    addAccessTagAndComment(
      "protected",
      "Parameter update hook",
      List(
        functionClassMember(
          Some(
            s"""|\\brief Called whenever a parameter is updated
                |
                |This function does nothing by default. You may override it.
                |"""
          ),
          "parameterUpdated",
          List(
            CppDoc.Function.Param(
              CppDoc.Type("FwPrmIdType"),
              "id",
              Some("The parameter ID")
            )
          ),
          CppDoc.Type("void"),
          lines("// Do nothing by default"),
          CppDoc.Function.Virtual
        ),
        linesClassMember(
          CppDocWriter.writeBannerComment(
            "Parameter load hook"
          )
        ),
        functionClassMember(
          Some(
            s"""|\\brief Called whenever parameters are loaded
                |
                |This function does nothing by default. You may override it.
                |"""
          ),
          "parametersLoaded",
          Nil,
          CppDoc.Type("void"),
          lines("// Do nothing by default"),
          CppDoc.Function.Virtual
        )
      )
    )
  }

  private def getGetterFunctions: List[CppDoc.Class.Member] = {
    addAccessTagAndComment(
      "protected",
      "Parameter get functions",
      sortedParams.map((_, param) =>
        functionClassMember(
          Some(
            addSeparatedString(
              s"Get parameter ${param.getName}\n\n\\return The parameter value",
              AnnotationCppWriter.asStringOpt(param.aNode)
            )
          ),
          paramGetterName(param.getName),
          List(
            CppDoc.Function.Param(
              CppDoc.Type("Fw::ParamValid&"),
              "valid",
              Some("Whether the parameter is valid")
            )
          ),
          CppDoc.Type(writeParamType(param.paramType, "Fw::ParamString")),
          if(param.isExternal) {
            lines(
              s"""|${writeParamType(param.paramType, "Fw::ParamString")} _local{};
                  |Fw::ParamBuffer _getBuff;
                  |// Get the base ID
                  |const FwPrmIdType _baseId = static_cast<FwPrmIdType>(this->getIdBase());
                  |// Get the local ID to pass to the delegate
                  |const FwPrmIdType _localId = ${paramIdConstantName(param.getName)};
                  |
                  |FW_ASSERT(this->paramDelegatePtr != nullptr);
                  |// Get the external parameter from the delegate
                  |Fw::SerializeStatus _stat = this->paramDelegatePtr->serializeParam(_baseId, _localId, _getBuff);
                  |if(_stat == Fw::FW_SERIALIZE_OK) {
                  |  _stat = _getBuff.deserializeTo(_local);
                  |  FW_ASSERT(_stat == Fw::FW_SERIALIZE_OK, static_cast<FwAssertArgType>(_stat));
                  |  valid = Fw::ParamValid::VALID;
                  |} else {
                  |  valid = Fw::ParamValid::INVALID;
                  |}
                  |return _local;
                  |"""
            )
          }
          else
          {
            lines(
              s"""|${writeParamType(param.paramType, "Fw::ParamString")} _local{};
                  |this->m_paramLock.lock();
                  |valid = this->${paramValidityFlagName(param.getName)};
                  |_local = this->${paramVariableName(param.getName)};
                  |this->m_paramLock.unLock();
                  |return _local;
                  |"""
            )
          }
        )
      )
    )
  }

  private def getSetters: List[CppDoc.Class.Member] = {
    addAccessTagAndComment(
      "private",
      "Parameter set functions",
      sortedParams.map((_, param) =>
        functionClassMember(
          Some(
            s"""|Set parameter ${param.getName}
                |
                |\\return The command response
                |"""
          ),
          paramHandlerName(param.getName, Command.Param.Set),
          List(
            CppDoc.Function.Param(
              CppDoc.Type("Fw::SerializeBufferBase&"),
              "val",
              Some("The serialization buffer")
            ),
          ),
          CppDoc.Type("Fw::CmdResponse"),
          if (param.isExternal) {
            lines(
              s"""|const FwPrmIdType _localId = ${paramIdConstantName(param.getName)};
                  |const FwPrmIdType _baseId = static_cast<FwPrmIdType>(this->getIdBase());
                  |
                  |FW_ASSERT(this->paramDelegatePtr != nullptr);
                  |// Call the delegate serialize function for ${paramVariableName(param.getName)}
                  |const Fw::SerializeStatus _stat = this->paramDelegatePtr->deserializeParam(
                  |  _baseId,
                  |  _localId,
                  |  Fw::ParamValid::VALID,
                  |  val
                  |);
                  |if (_stat != Fw::FW_SERIALIZE_OK) {
                  |  return Fw::CmdResponse::VALIDATION_ERROR;
                  |}
                  |
                  |// Call notifier
                  |this->parameterUpdated(${paramIdConstantName(param.getName)});
                  |return Fw::CmdResponse::OK;
                  |"""
            )
          } else {
            lines(
              s"""|${writeParamType(param.paramType, "Fw::ParamString")} _localVal{};
                  |const Fw::SerializeStatus _stat = val.deserializeTo(_localVal);
                  |if (_stat != Fw::FW_SERIALIZE_OK) {
                  |  return Fw::CmdResponse::VALIDATION_ERROR;
                  |}
                  |
                  |// Assign value only if successfully deserialized
                  |this->m_paramLock.lock();
                  |this->${paramVariableName(param.getName)} = _localVal;
                  |this->${paramValidityFlagName(param.getName)} = Fw::ParamValid::VALID;
                  |this->m_paramLock.unLock();
                  |
                  |// Call notifier
                  |this->parameterUpdated(${paramIdConstantName(param.getName)});
                  |return Fw::CmdResponse::OK;
                  |"""
            )
          }
        )
      )
    )
  }

  private def getSaveFunctions: List[CppDoc.Class.Member] = {
    addAccessTagAndComment(
      "private",
      "Parameter save functions",
      sortedParams.map((_, param) =>
        functionClassMember(
          Some(
            s"""|Save parameter ${param.getName}
                |
                |\\return The command response
                |"""
          ),
          paramHandlerName(param.getName, Command.Param.Save),
          Nil,
          CppDoc.Type("Fw::CmdResponse"),
          List.concat(
            lines(
              s"""|Fw::ParamBuffer _saveBuff;
                  |FwPrmIdType _id;
                  |Fw::SerializeStatus _stat;
                  |
                  |"""
            ),
            wrapInIf(
              s"this->${portVariableName(prmSetPort.get)}[0].isConnected()",
              List.concat(
                if (param.isExternal) {
                  lines(
                    s"""|// Get the local and base ID to pass to the delegate
                        |_id = ${paramIdConstantName(param.getName)};
                        |const FwPrmIdType _baseId = static_cast<FwPrmIdType>(this->getIdBase());
                        |
                        |FW_ASSERT(this->paramDelegatePtr != nullptr);
                        |_stat = this->paramDelegatePtr->serializeParam(_baseId, _id, _saveBuff);
                        |"""
                  )
                } else {
                  lines(
                    s"""|this->m_paramLock.lock();
                        |
                        |_stat = _saveBuff.serializeFrom(${paramVariableName(param.getName)});
                        |
                        |this->m_paramLock.unLock();
                        |"""
                  )
                }
              ) ++ lines(
                s"""|if (_stat != Fw::FW_SERIALIZE_OK) {
                    |  return Fw::CmdResponse::VALIDATION_ERROR;
                    |}
                    |
                    |_id = static_cast<FwPrmIdType>(this->getIdBase() + ${paramIdConstantName(param.getName)});
                    |
                    |// Save the parameter
                    |this->${portVariableName(prmSetPort.get)}[0].invoke(
                    |  _id,
                    |  _saveBuff
                    |);
                    |
                    |return Fw::CmdResponse::OK;
                    |"""
              )
            ),
            Line.blank :: lines("return Fw::CmdResponse::EXECUTION_ERROR;")
          )
        )
      )
    )
  }

  private def getExternalParameterFunctions: List[CppDoc.Class.Member] = {
    guardedList (hasExternalParameters) (
      addAccessTagAndComment(
        "protected",
        "External parameter delegate initialization",
        List(
          functionClassMember(
            Some("Initialize the external parameter delegate"),
            "registerExternalParameters",
            List(
              CppDoc.Function.Param(
                CppDoc.Type("Fw::ParamExternalDelegate*"),
                "paramExternalDelegatePtr",
                Some("The delegate for externally managed parameters")
              )
            ),
            CppDoc.Type("void"),
            lines(
              """|FW_ASSERT(paramExternalDelegatePtr != nullptr);
                 |this->paramDelegatePtr = paramExternalDelegatePtr;
                 |"""
            )
          )
        )
      )
    )
  }

  private def paramGetterName(name: String) =
    s"paramGet_$name"

  private def paramVariableName(name: String) =
    s"m_$name"

}