/**
 * 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.
 */

#include "expect.h"
#include "hdfs.h"
#include "native_mini_dfs.h"

#include <errno.h>
#include <semaphore.h>
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>

#define TLH_MAX_THREADS 100

static sem_t tlhSem;

static struct NativeMiniDfsCluster* tlhCluster;

struct tlhThreadInfo {
    /** Thread index */
    int threadIdx;
    /** 0 = thread was successful; error code otherwise */
    int success;
    /** pthread identifier */
    pthread_t thread;
};

static int hdfsSingleNameNodeConnect(struct NativeMiniDfsCluster *cl, hdfsFS *fs)
{
    int ret, port;
    hdfsFS hdfs;
    
    port = nmdGetNameNodePort(cl);
    if (port < 0) {
        fprintf(stderr, "hdfsSingleNameNodeConnect: nmdGetNameNodePort "
                "returned error %d\n", port);
        return port;
    }
    hdfs = hdfsConnectNewInstance("localhost", port);
    if (!hdfs) {
        ret = -errno;
        return ret;
    }
    *fs = hdfs;
    return 0;
}

static int doTestHdfsOperations(struct tlhThreadInfo *ti, hdfsFS fs)
{
    char prefix[256], tmp[256];
    hdfsFile file;
    int ret, expected;

    snprintf(prefix, sizeof(prefix), "/tlhData%04d", ti->threadIdx);

    if (hdfsExists(fs, prefix) == 0) {
        EXPECT_ZERO(hdfsDelete(fs, prefix, 1));
    }
    EXPECT_ZERO(hdfsCreateDirectory(fs, prefix));
    snprintf(tmp, sizeof(tmp), "%s/file", prefix);

    /* There should not be any file to open for reading. */
    EXPECT_NULL(hdfsOpenFile(fs, tmp, O_RDONLY, 0, 0, 0));

    file = hdfsOpenFile(fs, tmp, O_WRONLY, 0, 0, 0);
    EXPECT_NONNULL(file);

    /* TODO: implement writeFully and use it here */
    expected = strlen(prefix);
    ret = hdfsWrite(fs, file, prefix, expected);
    if (ret < 0) {
        ret = errno;
        fprintf(stderr, "hdfsWrite failed and set errno %d\n", ret);
        return ret;
    }
    if (ret != expected) {
        fprintf(stderr, "hdfsWrite was supposed to write %d bytes, but "
                "it wrote %d\n", ret, expected);
        return EIO;
    }
    EXPECT_ZERO(hdfsFlush(fs, file));
    EXPECT_ZERO(hdfsCloseFile(fs, file));

    /* Let's re-open the file for reading */
    file = hdfsOpenFile(fs, tmp, O_RDONLY, 0, 0, 0);
    EXPECT_NONNULL(file);

    /* TODO: implement readFully and use it here */
    ret = hdfsRead(fs, file, tmp, sizeof(tmp));
    if (ret < 0) {
        ret = errno;
        fprintf(stderr, "hdfsRead failed and set errno %d\n", ret);
        return ret;
    }
    if (ret != expected) {
        fprintf(stderr, "hdfsRead was supposed to read %d bytes, but "
                "it read %d\n", ret, expected);
        return EIO;
    }
    EXPECT_ZERO(memcmp(prefix, tmp, expected));
    EXPECT_ZERO(hdfsCloseFile(fs, file));

    // TODO: Non-recursive delete should fail?
    //EXPECT_NONZERO(hdfsDelete(fs, prefix, 0));

    EXPECT_ZERO(hdfsDelete(fs, prefix, 1));
    return 0;
}

static void *testHdfsOperations(void *v)
{
    struct tlhThreadInfo *ti = (struct tlhThreadInfo*)v;
    hdfsFS fs = NULL;
    int ret;

    fprintf(stderr, "testHdfsOperations(threadIdx=%d): starting\n",
        ti->threadIdx);
    ret = hdfsSingleNameNodeConnect(tlhCluster, &fs);
    if (ret) {
        fprintf(stderr, "testHdfsOperations(threadIdx=%d): "
            "hdfsSingleNameNodeConnect failed with error %d.\n",
            ti->threadIdx, ret);
        ti->success = EIO;
        return NULL;
    }
    ti->success = doTestHdfsOperations(ti, fs);
    if (hdfsDisconnect(fs)) {
        ret = errno;
        fprintf(stderr, "hdfsDisconnect error %d\n", ret);
        ti->success = ret;
    }
    return NULL;
}

static int checkFailures(struct tlhThreadInfo *ti, int tlhNumThreads)
{
    int i, threadsFailed = 0;
    const char *sep = "";

    for (i = 0; i < tlhNumThreads; i++) {
        if (ti[i].success != 0) {
            threadsFailed = 1;
        }
    }
    if (!threadsFailed) {
        fprintf(stderr, "testLibHdfs: all threads succeeded.  SUCCESS.\n");
        return EXIT_SUCCESS;
    }
    fprintf(stderr, "testLibHdfs: some threads failed: [");
    for (i = 0; i < tlhNumThreads; i++) {
        if (ti[i].success != 0) {
            fprintf(stderr, "%s%d", sep, i);
            sep = ", "; 
        }
    }
    fprintf(stderr, "].  FAILURE.\n");
    return EXIT_FAILURE;
}

/**
 * Test that we can write a file with libhdfs and then read it back
 */
int main(void)
{
    int i, tlhNumThreads;
    const char *tlhNumThreadsStr;
    struct tlhThreadInfo ti[TLH_MAX_THREADS];
    struct NativeMiniDfsConf conf = {
        .doFormat = 1,
    };

    tlhNumThreadsStr = getenv("TLH_NUM_THREADS");
    if (!tlhNumThreadsStr) {
        tlhNumThreadsStr = "3";
    }
    tlhNumThreads = atoi(tlhNumThreadsStr);
    if ((tlhNumThreads <= 0) || (tlhNumThreads > TLH_MAX_THREADS)) {
        fprintf(stderr, "testLibHdfs: must have a number of threads "
                "between 1 and %d inclusive, not %d\n",
                TLH_MAX_THREADS, tlhNumThreads);
        return EXIT_FAILURE;
    }
    memset(&ti[0], 0, sizeof(ti));
    for (i = 0; i < tlhNumThreads; i++) {
        ti[i].threadIdx = i;
    }

    EXPECT_ZERO(sem_init(&tlhSem, 0, tlhNumThreads));
    tlhCluster = nmdCreate(&conf);
    EXPECT_NONNULL(tlhCluster);
    EXPECT_ZERO(nmdWaitClusterUp(tlhCluster));

    for (i = 0; i < tlhNumThreads; i++) {
        EXPECT_ZERO(pthread_create(&ti[i].thread, NULL,
            testHdfsOperations, &ti[i]));
    }
    for (i = 0; i < tlhNumThreads; i++) {
        EXPECT_ZERO(pthread_join(ti[i].thread, NULL));
    }

    EXPECT_ZERO(nmdShutdown(tlhCluster));
    nmdFree(tlhCluster);
    EXPECT_ZERO(sem_destroy(&tlhSem));
    return checkFailures(ti, tlhNumThreads);
}