/*******************************************************************************
 * Copyright (c) 2017 Politecnico di Torino and others.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Apache License, Version 2.0
 * which accompanies this distribution, and is available at
 * http://www.apache.org/licenses/LICENSE-2.0
 *******************************************************************************/
package it.polito.verigraph.grpc.test;

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import org.junit.After;
import org.junit.Before;
import org.junit.FixMethodOrder;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;
import org.junit.runners.MethodSorters;

import static org.junit.Assert.assertEquals;

import java.io.BufferedReader;
import java.io.FilenameFilter;
import java.io.InputStreamReader;

import com.fasterxml.jackson.core.JsonParseException;
import com.fasterxml.jackson.databind.JsonMappingException;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.github.fge.jsonschema.core.exceptions.ProcessingException;
import com.github.fge.jsonschema.main.JsonSchema;

import it.polito.verigraph.grpc.GraphGrpc;
import it.polito.verigraph.grpc.NewGraph;
import it.polito.verigraph.grpc.Policy;
import it.polito.verigraph.grpc.VerificationGrpc;
import it.polito.verigraph.client.VerifyClientException;
import it.polito.verigraph.grpc.client.Client;
import it.polito.verigraph.grpc.server.GrpcUtils;
import it.polito.verigraph.grpc.server.Service;
import it.polito.verigraph.service.ValidationUtils;
import it.polito.verigraph.test.TestCase;
import it.polito.verigraph.test.TestExecutionException;

@RunWith(JUnit4.class)
@FixMethodOrder(MethodSorters.NAME_ASCENDING)
public class ReachabilityTest {
    private File schema;
    private List<File>testFiles= new ArrayList<File>();
    private List<TestCase>testCases= new ArrayList<TestCase>();
    private Client client;
    private Service server;

    @Before
    public void setUpBeforeClass() throws Exception {
        client = new Client("localhost" , 50051);
        server = new Service(50051);
        server.start();

        String folderName = System.getProperty("user.dir") + "/tester/testcases";
        File folder = new File(folderName);
        if (!folder.exists()) {
            BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
            String s;
            do{
                System.out.println("Please enter the testcases folder path: ");
                s = in.readLine();
                if (isValidpath(s)){
                    folder = new File(s);
                    break;
                }
            }while (s != null && s.length() != 0);
            if(s == null)
                System.exit(0);
        }
        String schemaName = System.getProperty("user.dir") + "/tester/testcase_schema.json";
        File schema = new File(schemaName);
        if (!schema.exists()) {
            BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
            String s;
            do{
                System.out.println("Please enter the full path of 'testcase_schema.json': ");
                s = in.readLine();
                if (isValidpath(s)){
                    folder = new File(s);
                    break;
                }
            }while (s != null && s.length() != 0);
            if(s == null)
                System.exit(0);
        }

        this.schema = schema;
        this.testFiles = getTests(folder);
        this.testCases = getTestCases(this.testFiles);
    }

    @After
    public void tearDown() throws Exception {
        server.stop();
        client.shutdown();
    }

    @Test
    public final void wrongReachability() {
        System.out.println("[DEBUG] wrongReachability starts");
        System.out.println("DEBUG: starting testWrongReachability");

        VerificationGrpc nullVer = VerificationGrpc.newBuilder()
                .setErrorMessage("There is no Graph whose Id is '52'").build();
        //verification on uncreated graph
        if(client.getGraph(52) != null){
            client.deleteGraph(52);
        }
        Policy policyToVerify = Client.createPolicy("Node1", "Node4", "reachability", null, 52);
        VerificationGrpc ver = client.verify(policyToVerify);
        assertEquals(ver, nullVer);

        //verification on uncreated nodes
        GraphGrpc graph = GraphGrpc.newBuilder().build();
        graph = client.createGraph(graph).getGraph();
        nullVer = VerificationGrpc.newBuilder()
                .setErrorMessage("The \'source\' parameter \'Node5\' is not valid, please insert the name of an existing node").build();
        policyToVerify = Client.createPolicy("Node5", "Node4", "reachability", null, graph.getId());
        ver = client.verify(policyToVerify);
        assertEquals(ver, nullVer);

        //verification on uncreated nodes
        nullVer = VerificationGrpc.newBuilder()
                .setErrorMessage("The \'source\' parameter \'Node1\' is not valid, please insert the name of an existing node").build();

        policyToVerify = Client.createPolicy("Node1", "Node10", "reachability", null, graph.getId());
        ver = client.verify(policyToVerify);
        assertEquals(ver, nullVer);

    }

    public List<File> getTests(File folder) {
        List<File> filesList = new ArrayList<File>();

        System.out.println("Test folder set to '" + folder.getAbsolutePath() + "'");

        File[] files = folder.listFiles(new FilenameFilter() {

            @Override
            public boolean accept(File dir, String name) {
                return name.endsWith(".json");
            }
        });

        for (File f : files) {
            filesList.add(f);
            System.out.println("File '" + f.getName() + "' added to test files");
        }

        return filesList;
    }

    public List<TestCase> getTestCases(List<File> files)throws JsonParseException, JsonMappingException, IOException,
    Exception {
        List<TestCase> testCases = new ArrayList<TestCase>();

        for (File file : files) {
            validateTestFile(file);
            try {
                TestCase tc = new ObjectMapper().readValue(file, TestCase.class);
                testCases.add(tc);
            }
            catch (Exception e) {
                throw e;
            }
        }

        return testCases;
    }

    @Test
    public void runTestCases() throws VerifyClientException, TestExecutionException {
        System.out.println("[DEBUG] runTestCases starts");
        int counter = 0;
        for (TestCase tc : this.testCases) {
            List<String> results = runTestCase(tc);
            Iterator<String> iter = tc.getResults().iterator();

            if(results.isEmpty()){
                throw new TestExecutionException("Error running test given in file '"+ this.testFiles.get(counter).getName()+ "'.");
            }

            for(String result : results){
                if (iter.hasNext()){
                    if( !result.equals(iter.next()))
                        throw new TestExecutionException("Error running test given in file '"+ this.testFiles.get(counter).getName()
                                + "'. Test returned '" + result + "' instead of '" + tc.getResults() + "'.");
                    else
                        System.out.println("Test given in file '"+ this.testFiles.get(counter).getName() + "' returned '"
                                + result + "' as expected");
                } else throw new TestExecutionException("Error running test given in file '"+ this.testFiles.get(counter).getName()
                        + "'. Test returned '" + result + "' instead of '" + tc.getResults() + "'.");
            }
            counter++;

        }
        System.out.println("All tests PASSED");
    }

    private List<String> runTestCase(TestCase tc) throws VerifyClientException, TestExecutionException{
        GraphGrpc graph = GrpcUtils.obtainGraph(tc.getGraph());
        ArrayList<String> results = new ArrayList<String>();

        NewGraph newGraph = this.client.createGraph(graph);
        if(newGraph.getSuccess() == false)
            throw new VerifyClientException("gRPC request failed");
        GraphGrpc createdGraph = newGraph.getGraph();

        GraphGrpc addedgraph = client.getGraph(createdGraph.getId());
        System.out.println(addedgraph);

        for(String url : tc.getPolicyUrlParameters()){
            final Map<String, String> map = GrpcUtils.getParamGivenString(url);
            Policy policy = Client.createPolicy(map.get("source"),
                    map.get("destination"),
                    map.get("type"),
                    map.get("middlebox"),
                    createdGraph.getId());
            VerificationGrpc verification = this.client.verify(policy);
            results.add(verification.getResult());
        }
        return results;
    }

    public void validateTestFile(File testFile) throws Exception {
        JsonSchema schemaNode = null;
        try {
            schemaNode = ValidationUtils.getSchemaNode(schema);
        }
        catch (IOException e) {
            throw new Exception("Unable to load '" + schema.getAbsolutePath() + "' schema file");
        }
        catch (ProcessingException e) {
            throw new Exception("Unable to resolve '" + schema.getAbsolutePath() + "' schema file as a schema node");
        }

        JsonNode jsonNode;
        try {
            jsonNode = ValidationUtils.getJsonNode(testFile);
        }
        catch (IOException e) {
            throw new Exception("Unable to load '" + testFile.getAbsolutePath() + "' as a json node");
        }

        try {
            ValidationUtils.validateJson(schemaNode, jsonNode);
        }
        catch (ProcessingException e) {
            throw new Exception("There were errors in the validation of file '"+ testFile.getAbsolutePath()
            + "' against the json schema '" + schema.getAbsolutePath() + "': " + e.getMessage());

        }
    }

    private static boolean isValidpath(String s) {
        if (s==null)
            return false;
        File file = new File(s);
        return file.exists();
    }

}