/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.dolphinscheduler.plugin.task.python;

import org.apache.dolphinscheduler.common.utils.JSONUtils;
import org.apache.dolphinscheduler.plugin.task.api.AbstractTask;
import org.apache.dolphinscheduler.plugin.task.api.ShellCommandExecutor;
import org.apache.dolphinscheduler.plugin.task.api.TaskCallBack;
import org.apache.dolphinscheduler.plugin.task.api.TaskConstants;
import org.apache.dolphinscheduler.plugin.task.api.TaskException;
import org.apache.dolphinscheduler.plugin.task.api.TaskExecutionContext;
import org.apache.dolphinscheduler.plugin.task.api.model.Property;
import org.apache.dolphinscheduler.plugin.task.api.model.TaskResponse;
import org.apache.dolphinscheduler.plugin.task.api.parameters.AbstractParameters;
import org.apache.dolphinscheduler.plugin.task.api.shell.IShellInterceptorBuilder;
import org.apache.dolphinscheduler.plugin.task.api.shell.ShellInterceptorBuilderFactory;
import org.apache.dolphinscheduler.plugin.task.api.utils.ParameterUtils;

import org.apache.commons.io.FileUtils;

import java.io.File;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.Map;

import lombok.extern.slf4j.Slf4j;

import com.google.common.base.Preconditions;

@Slf4j
public class PythonTask extends AbstractTask {

    protected PythonParameters pythonParameters;

    private final ShellCommandExecutor shellCommandExecutor;

    protected static final String PYTHON_LAUNCHER = "PYTHON_LAUNCHER";

    public PythonTask(TaskExecutionContext taskRequest) {
        super(taskRequest);

        this.shellCommandExecutor = new ShellCommandExecutor(taskRequest);
    }

    @Override
    public void init() {

        pythonParameters = JSONUtils.parseObject(taskRequest.getTaskParams(), PythonParameters.class);

        log.info("Initialize python task params {}", JSONUtils.toPrettyJsonString(pythonParameters));
        if (pythonParameters == null || !pythonParameters.checkParameters()) {
            throw new TaskException("python task params is not valid");
        }
    }

    @SuppressWarnings("unchecked")
    @Override
    public void handle(TaskCallBack taskCallBack) throws TaskException {
        try {
            // generate the content of this python script
            String pythonScriptContent = buildPythonScriptContent();
            // generate the file path of this python script
            String pythonScriptFile = buildPythonCommandFilePath();

            // create this file
            createPythonCommandFileIfNotExists(pythonScriptContent, pythonScriptFile);

            IShellInterceptorBuilder<?, ?> shellActuatorBuilder = ShellInterceptorBuilderFactory.newBuilder()
                    .appendScript(buildPythonExecuteCommand(pythonScriptFile));

            TaskResponse taskResponse = shellCommandExecutor.run(shellActuatorBuilder, taskCallBack);
            setExitStatusCode(taskResponse.getExitStatusCode());
            setProcessId(taskResponse.getProcessId());
            setTaskOutputParams(shellCommandExecutor.getTaskOutputParams());
            pythonParameters.dealOutParam(shellCommandExecutor.getTaskOutputParams());
            taskRequest.setVarPool(pythonParameters.getVarPool());
        } catch (Exception e) {
            log.error("python task failure", e);
            setExitStatusCode(TaskConstants.EXIT_CODE_FAILURE);
            throw new TaskException("run python task error", e);
        }
    }

    @Override
    public void cancel() throws TaskException {
        // cancel process
        try {
            shellCommandExecutor.cancelApplication();
        } catch (Exception e) {
            throw new TaskException("cancel application error", e);
        }
    }

    @Override
    public AbstractParameters getParameters() {
        return pythonParameters;
    }

    /**
     * create python command file if not exists
     *
     * @param pythonScript     exec python script
     * @param pythonScriptFile python script file
     * @throws IOException io exception
     */
    protected void createPythonCommandFileIfNotExists(String pythonScript, String pythonScriptFile) throws IOException {
        log.info("tenantCode :{}, task dir:{}", taskRequest.getTenantCode(), taskRequest.getExecutePath());

        if (!Files.exists(Paths.get(pythonScriptFile))) {
            log.info("generate python script file:{}", pythonScriptFile);

            StringBuilder sb = new StringBuilder();
            sb.append("#-*- encoding=utf8 -*-").append(System.lineSeparator());

            sb.append(System.lineSeparator());
            sb.append(pythonScript);
            log.info(sb.toString());

            // write data to file
            FileUtils.writeStringToFile(new File(pythonScriptFile),
                    sb.toString(),
                    StandardCharsets.UTF_8);
        }
    }

    /**
     * build python command file path
     *
     * @return python command file path
     */
    protected String buildPythonCommandFilePath() {
        return String.format("%s/py_%s.py", taskRequest.getExecutePath(), taskRequest.getTaskAppId());
    }

    /**
     * build python script content
     *
     * @return raw python script
     */
    protected String buildPythonScriptContent() {
        log.info("raw python script : {}", pythonParameters.getRawScript());
        String rawPythonScript = pythonParameters.getRawScript().replaceAll("\\r\\n", System.lineSeparator());
        Map<String, Property> paramsMap = mergeParamsWithContext(pythonParameters);
        return ParameterUtils.convertParameterPlaceholders(rawPythonScript, ParameterUtils.convert(paramsMap));
    }

    protected Map<String, Property> mergeParamsWithContext(AbstractParameters parameters) {
        // replace placeholder
        return taskRequest.getPrepareParamsMap();
    }

    /**
     * Build the python task command.
     * If user have set the 'PYTHON_LAUNCHER' environment, we will use the 'PYTHON_LAUNCHER',
     * if not, we will default use python.
     *
     * @param pythonFile Python file, cannot be empty.
     * @return Python execute command, e.g. 'python test.py'.
     */
    protected String buildPythonExecuteCommand(String pythonFile) {
        Preconditions.checkNotNull(pythonFile, "Python file cannot be null");

        String pythonHome = String.format("${%s}", PYTHON_LAUNCHER);

        return pythonHome + " " + pythonFile;
    }

}
