/*
 * Copyright © 2017-2018 AT&T Intellectual Property.
 * Modifications Copyright © 2019 IBM.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.onap.ccsdk.cds.blueprintsprocessor.selfservice.api

import io.grpc.stub.StreamObserver
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.GlobalScope
import kotlinx.coroutines.launch
import org.onap.ccsdk.cds.blueprintsprocessor.core.api.data.*
import org.onap.ccsdk.cds.blueprintsprocessor.selfservice.api.utils.toProto
import org.onap.ccsdk.cds.controllerblueprints.common.api.EventType
import org.onap.ccsdk.cds.controllerblueprints.core.BluePrintConstants
import org.onap.ccsdk.cds.controllerblueprints.core.config.BluePrintLoadConfiguration
import org.onap.ccsdk.cds.controllerblueprints.core.interfaces.BluePrintCatalogService
import org.onap.ccsdk.cds.controllerblueprints.core.interfaces.BluePrintWorkflowExecutionService
import org.onap.ccsdk.cds.controllerblueprints.core.utils.BluePrintMetadataUtils
import org.slf4j.LoggerFactory
import org.springframework.stereotype.Service
import java.util.stream.Collectors

@Service
class ExecutionServiceHandler(private val bluePrintLoadConfiguration: BluePrintLoadConfiguration,
                              private val blueprintsProcessorCatalogService: BluePrintCatalogService,
                              private val bluePrintWorkflowExecutionService
                              : BluePrintWorkflowExecutionService<ExecutionServiceInput, ExecutionServiceOutput>) {

    private val log = LoggerFactory.getLogger(ExecutionServiceHandler::class.toString())

    suspend fun process(executionServiceInput: ExecutionServiceInput,
                        responseObserver: StreamObserver<org.onap.ccsdk.cds.controllerblueprints.processing.api.ExecutionServiceOutput>) {
        when {
            executionServiceInput.actionIdentifiers.mode == ACTION_MODE_ASYNC -> {
                GlobalScope.launch(Dispatchers.Default) {
                    val executionServiceOutput = doProcess(executionServiceInput)
                    responseObserver.onNext(executionServiceOutput.toProto())
                    responseObserver.onCompleted()
                }
                responseObserver.onNext(response(executionServiceInput).toProto())
            }
            executionServiceInput.actionIdentifiers.mode == ACTION_MODE_SYNC -> {
                val executionServiceOutput = doProcess(executionServiceInput)
                responseObserver.onNext(executionServiceOutput.toProto())
                responseObserver.onCompleted()
            }
            else -> responseObserver.onNext(response(executionServiceInput,
                    "Failed to process request, 'actionIdentifiers.mode' not specified. Valid value are: 'sync' or 'async'.",
                    true).toProto());
        }
    }

    suspend fun doProcess(executionServiceInput: ExecutionServiceInput): ExecutionServiceOutput {
        val requestId = executionServiceInput.commonHeader.requestId
        log.info("processing request id $requestId")
        val actionIdentifiers = executionServiceInput.actionIdentifiers
        val blueprintName = actionIdentifiers.blueprintName
        val blueprintVersion = actionIdentifiers.blueprintVersion
        try {
            val basePath = blueprintsProcessorCatalogService.getFromDatabase(blueprintName, blueprintVersion)
            log.info("blueprint base path $basePath")

            val blueprintRuntimeService = BluePrintMetadataUtils.getBluePrintRuntime(requestId, basePath.toString())

            val output = bluePrintWorkflowExecutionService.executeBluePrintWorkflow(blueprintRuntimeService,
                    executionServiceInput, hashMapOf())

            val errors = blueprintRuntimeService.getBluePrintError().errors
            if (errors.isNotEmpty()) {
                val errorMessage = errors.stream().map { it.toString() }.collect(Collectors.joining(", "))
                setErrorStatus(errorMessage, output.status)
            }
            return output
        } catch (e: Exception) {
            log.error("fail processing request id $requestId", e)
            return response(executionServiceInput, e.localizedMessage ?: e.message ?: e.toString(), true)
        }
    }

    private fun setErrorStatus(errorMessage: String, status: Status) {
        status.errorMessage = errorMessage
        status.eventType = EventType.EVENT_COMPONENT_FAILURE.name
        status.code = 500
        status.message = BluePrintConstants.STATUS_FAILURE
    }

    private fun response(executionServiceInput: ExecutionServiceInput, errorMessage: String = "",
                         failure: Boolean = false): ExecutionServiceOutput {
        val executionServiceOutput = ExecutionServiceOutput()
        executionServiceOutput.commonHeader = executionServiceInput.commonHeader
        executionServiceOutput.actionIdentifiers = executionServiceInput.actionIdentifiers
        executionServiceOutput.payload = executionServiceInput.payload

        val status = Status()
        if (failure) {
            setErrorStatus(errorMessage, status)
        } else {
            status.eventType = EventType.EVENT_COMPONENT_PROCESSING.name
            status.code = 200
            status.message = BluePrintConstants.STATUS_PROCESSING
        }

        executionServiceOutput.status = status

        return executionServiceOutput
    }

}
