/*
 The MIT License (MIT)
 
 Copyright (c) 2013-2017 SRS(ossrs)
 
 Permission is hereby granted, free of charge, to any person obtaining a copy of
 this software and associated documentation files (the "Software"), to deal in
 the Software without restriction, including without limitation the rights to
 use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
 the Software, and to permit persons to whom the Software is furnished to do so,
 subject to the following conditions:
 
 The above copyright notice and this permission notice shall be included in all
 copies or substantial portions of the Software.
 
 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
 FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#include <srs_app_kafka.hpp>

#include <vector>
using namespace std;

#include <srs_kernel_error.hpp>
#include <srs_kernel_log.hpp>
#include <srs_app_config.hpp>
#include <srs_app_async_call.hpp>
#include <srs_app_utility.hpp>
#include <srs_kernel_utility.hpp>
#include <srs_protocol_utility.hpp>
#include <srs_kernel_balance.hpp>
#include <srs_kafka_stack.hpp>
#include <srs_core_autofree.hpp>
#include <srs_protocol_json.hpp>

#ifdef SRS_AUTO_KAFKA

#define SRS_KAKFA_CIMS 3000
#define SRS_KAFKA_PRODUCER_TIMEOUT 30000
#define SRS_KAFKA_PRODUCER_AGGREGATE_SIZE 1

std::string srs_kafka_metadata_summary(SrsKafkaTopicMetadataResponse* metadata)
{
    vector<string> bs;
    for (int i = 0; i < metadata->brokers.size(); i++) {
        SrsKafkaBroker* broker = metadata->brokers.at(i);
        
        string hostport = srs_int2str(broker->node_id) + "/" + broker->host.to_str();
        if (broker->port > 0) {
            hostport += ":" + srs_int2str(broker->port);
        }
        
        bs.push_back(hostport);
    }
    
    vector<string> ps;
    for (int i = 0; i < metadata->metadatas.size(); i++) {
        SrsKafkaTopicMetadata* topic = metadata->metadatas.at(i);
        
        for (int j = 0; j < topic->metadatas.size(); j++) {
            string desc = "topic=" + topic->name.to_str();
            
            SrsKafkaPartitionMetadata* partition = topic->metadatas.at(j);
            
            desc += "?partition=" + srs_int2str(partition->partition_id);
            desc += "&leader=" + srs_int2str(partition->leader);
            
            vector<string> replicas = srs_kafka_array2vector(&partition->replicas);
            desc += "&replicas=" + srs_join_vector_string(replicas, ",");
            
            ps.push_back(desc);
        }
    }
    
    std::stringstream ss;
    ss << "brokers=" << srs_join_vector_string(bs, ",");
    ss << ", " << srs_join_vector_string(ps, ", ");
    
    return ss.str();
}

std::string srs_kafka_summary_partitions(const vector<SrsKafkaPartition*>& partitions)
{
    vector<string> ret;
    
    vector<SrsKafkaPartition*>::const_iterator it;
    for (it = partitions.begin(); it != partitions.end(); ++it) {
        SrsKafkaPartition* partition = *it;
        
        string desc = "tcp://";
        desc += partition->host + ":" + srs_int2str(partition->port);
        desc += "?broker=" + srs_int2str(partition->broker);
        desc += "&partition=" + srs_int2str(partition->id);
        ret.push_back(desc);
    }
    
    return srs_join_vector_string(ret, ", ");
}

void srs_kafka_metadata2connector(string topic_name, SrsKafkaTopicMetadataResponse* metadata, vector<SrsKafkaPartition*>& partitions)
{
    for (int i = 0; i < metadata->metadatas.size(); i++) {
        SrsKafkaTopicMetadata* topic = metadata->metadatas.at(i);
        
        for (int j = 0; j < topic->metadatas.size(); j++) {
            SrsKafkaPartitionMetadata* partition = topic->metadatas.at(j);
            
            SrsKafkaPartition* p = new SrsKafkaPartition();
            
            p->topic = topic_name;
            p->id = partition->partition_id;
            p->broker = partition->leader;
            
            for (int i = 0; i < metadata->brokers.size(); i++) {
                SrsKafkaBroker* broker = metadata->brokers.at(i);
                if (broker->node_id == p->broker) {
                    p->host = broker->host.to_str();
                    p->port = broker->port;
                    break;
                }
            }
            
            partitions.push_back(p);
        }
    }
}

SrsKafkaPartition::SrsKafkaPartition()
{
    id = broker = 0;
    port = SRS_CONSTS_KAFKA_DEFAULT_PORT;
    
    transport = NULL;
    kafka = NULL;
}

SrsKafkaPartition::~SrsKafkaPartition()
{
    disconnect();
}

string SrsKafkaPartition::hostport()
{
    if (ep.empty()) {
        ep = host + ":" + srs_int2str(port);
    }
    
    return ep;
}

int SrsKafkaPartition::connect()
{
    int ret = ERROR_SUCCESS;
    
    if (transport) {
        return ret;
    }
    transport = new SrsTcpClient(host, port, SRS_KAFKA_PRODUCER_TIMEOUT);
    kafka = new SrsKafkaClient(transport);
    
    if ((ret = transport->connect()) != ERROR_SUCCESS) {
        disconnect();
        srs_error("connect to %s partition=%d failed. ret=%d", hostport().c_str(), id, ret);
        return ret;
    }
    
    srs_trace("connect at %s, partition=%d, broker=%d", hostport().c_str(), id, broker);
    
    return ret;
}

int SrsKafkaPartition::flush(SrsKafkaPartitionCache* pc)
{
    return kafka->write_messages(topic, id, *pc);
}

void SrsKafkaPartition::disconnect()
{
    srs_freep(kafka);
    srs_freep(transport);
}

SrsKafkaMessage::SrsKafkaMessage(SrsKafkaProducer* p, int k, SrsJsonObject* j)
{
    producer = p;
    key = k;
    obj = j;
}

SrsKafkaMessage::~SrsKafkaMessage()
{
    srs_freep(obj);
}

int SrsKafkaMessage::call()
{
    int ret = producer->send(key, obj);
    
    // the obj is manged by producer now.
    obj = NULL;
    
    return ret;
}

string SrsKafkaMessage::to_string()
{
    return "kafka";
}

SrsKafkaCache::SrsKafkaCache()
{
    count = 0;
    nb_partitions = 0;
}

SrsKafkaCache::~SrsKafkaCache()
{
    map<int32_t, SrsKafkaPartitionCache*>::iterator it;
    for (it = cache.begin(); it != cache.end(); ++it) {
        SrsKafkaPartitionCache* pc = it->second;
        
        for (vector<SrsJsonObject*>::iterator it2 = pc->begin(); it2 != pc->end(); ++it2) {
            SrsJsonObject* obj = *it2;
            srs_freep(obj);
        }
        pc->clear();
        
        srs_freep(pc);
    }
    cache.clear();
}

void SrsKafkaCache::append(int key, SrsJsonObject* obj)
{
    count++;
    
    int partition = 0;
    if (nb_partitions > 0) {
        partition = key % nb_partitions;
    }
    
    SrsKafkaPartitionCache* pc = NULL;
    map<int32_t, SrsKafkaPartitionCache*>::iterator it = cache.find(partition);
    if (it == cache.end()) {
        pc = new SrsKafkaPartitionCache();
        cache[partition] = pc;
    } else {
        pc = it->second;
    }
    
    pc->push_back(obj);
}

int SrsKafkaCache::size()
{
    return count;
}

bool SrsKafkaCache::fetch(int* pkey, SrsKafkaPartitionCache** ppc)
{
    map<int32_t, SrsKafkaPartitionCache*>::iterator it;
    for (it = cache.begin(); it != cache.end(); ++it) {
        int32_t key = it->first;
        SrsKafkaPartitionCache* pc = it->second;
        
        if (!pc->empty()) {
            *pkey = (int)key;
            *ppc = pc;
            return true;
        }
    }
    
    return false;
}

int SrsKafkaCache::flush(SrsKafkaPartition* partition, int key, SrsKafkaPartitionCache* pc)
{
    int ret = ERROR_SUCCESS;
    
    // ensure the key exists.
    srs_assert (cache.find(key) != cache.end());
    
    // the cache is vector, which is continous store.
    // we remember the messages we have written and clear it when completed.
    int nb_msgs = (int)pc->size();
    if (pc->empty()) {
        return ret;
    }
    
    // connect transport.
    if ((ret = partition->connect()) != ERROR_SUCCESS) {
        srs_error("kafka connect to partition failed. ret=%d", ret);
        return ret;
    }
    
    // write the json objects.
    if ((ret = partition->flush(pc)) != ERROR_SUCCESS) {
        srs_error("kafka write messages failed. ret=%d", ret);
        return ret;
    }
    
    // free all wrote messages.
    for (vector<SrsJsonObject*>::iterator it = pc->begin(); it != pc->end(); ++it) {
        SrsJsonObject* obj = *it;
        srs_freep(obj);
    }
    
    // remove the messages from cache.
    if ((int)pc->size() == nb_msgs) {
        pc->clear();
    } else {
        pc->erase(pc->begin(), pc->begin() + nb_msgs);
    }
    
    return ret;
}

ISrsKafkaCluster::ISrsKafkaCluster()
{
}

ISrsKafkaCluster::~ISrsKafkaCluster()
{
}

// @global kafka event producer, user must use srs_initialize_kafka to initialize it.
ISrsKafkaCluster* _srs_kafka = NULL;

int srs_initialize_kafka()
{
    int ret = ERROR_SUCCESS;
    
    SrsKafkaProducer* kafka = new SrsKafkaProducer();
    _srs_kafka = kafka;
    
    if ((ret = kafka->initialize()) != ERROR_SUCCESS) {
        srs_error("initialize the kafka producer failed. ret=%d", ret);
        return ret;
    }
    
    if ((ret = kafka->start()) != ERROR_SUCCESS) {
        srs_error("start kafka failed. ret=%d", ret);
        return ret;
    }
    
    return ret;
}

void srs_dispose_kafka()
{
    SrsKafkaProducer* kafka = dynamic_cast<SrsKafkaProducer*>(_srs_kafka);
    kafka->stop();
    
    srs_freep(kafka);
    _srs_kafka = NULL;
}

SrsKafkaProducer::SrsKafkaProducer()
{
    metadata_ok = false;
    metadata_expired = st_cond_new();
    
    lock = st_mutex_new();
    pthread = new SrsReusableThread("kafka", this, SRS_KAKFA_CIMS);
    worker = new SrsAsyncCallWorker();
    cache = new SrsKafkaCache();
    
    lb = new SrsLbRoundRobin();
}

SrsKafkaProducer::~SrsKafkaProducer()
{
    clear_metadata();
    
    srs_freep(lb);
    
    srs_freep(worker);
    srs_freep(pthread);
    srs_freep(cache);
    
    st_mutex_destroy(lock);
    st_cond_destroy(metadata_expired);
}

int SrsKafkaProducer::initialize()
{
    int ret = ERROR_SUCCESS;
    
    enabled = _srs_config->get_kafka_enabled();
    srs_info("initialize kafka ok, enabled=%d.", enabled);
    
    return ret;
}

int SrsKafkaProducer::start()
{
    int ret = ERROR_SUCCESS;
    
    if (!enabled) {
        return ret;
    }
    
    if ((ret = worker->start()) != ERROR_SUCCESS) {
        srs_error("start kafka worker failed. ret=%d", ret);
        return ret;
    }
    
    if ((ret = pthread->start()) != ERROR_SUCCESS) {
        srs_error("start kafka thread failed. ret=%d", ret);
    }
    
    refresh_metadata();
    
    return ret;
}

void SrsKafkaProducer::stop()
{
    if (!enabled) {
        return;
    }
    
    pthread->stop();
    worker->stop();
}

int SrsKafkaProducer::send(int key, SrsJsonObject* obj)
{
    int ret = ERROR_SUCCESS;
    
    // cache the json object.
    cache->append(key, obj);
    
    // too few messages, ignore.
    if (cache->size() < SRS_KAFKA_PRODUCER_AGGREGATE_SIZE) {
        return ret;
    }
    
    // too many messages, warn user.
    if (cache->size() > SRS_KAFKA_PRODUCER_AGGREGATE_SIZE * 10) {
        srs_warn("kafka cache too many messages: %d", cache->size());
    }
    
    // sync with backgound metadata worker.
    st_mutex_lock(lock);
    
    // flush message when metadata is ok.
    if (metadata_ok) {
        ret = flush();
    }
    
    st_mutex_unlock(lock);
    
    return ret;
}

int SrsKafkaProducer::on_client(int key, SrsListenerType type, string ip)
{
    int ret = ERROR_SUCCESS;
    
    if (!enabled) {
        return ret;
    }
    
    SrsJsonObject* obj = SrsJsonAny::object();
    
    obj->set("msg", SrsJsonAny::str("accept"));
    obj->set("type", SrsJsonAny::integer(type));
    obj->set("ip", SrsJsonAny::str(ip.c_str()));
    
    return worker->execute(new SrsKafkaMessage(this, key, obj));
}

int SrsKafkaProducer::on_close(int key)
{
    int ret = ERROR_SUCCESS;
    
    if (!enabled) {
        return ret;
    }
    
    SrsJsonObject* obj = SrsJsonAny::object();
    
    obj->set("msg", SrsJsonAny::str("close"));
    
    return worker->execute(new SrsKafkaMessage(this, key, obj));
}

int SrsKafkaProducer::cycle()
{
    int ret = ERROR_SUCCESS;
    
    if ((ret = do_cycle()) != ERROR_SUCCESS) {
        srs_warn("ignore kafka error. ret=%d", ret);
    }
    
    return ret;
}

int SrsKafkaProducer::on_before_cycle()
{
    // wait for the metadata expired.
    // when metadata is ok, wait for it expired.
    if (metadata_ok) {
        st_cond_wait(metadata_expired);
    }
    
    // request to lock to acquire the socket.
    st_mutex_lock(lock);
    
    return ERROR_SUCCESS;
}

int SrsKafkaProducer::on_end_cycle()
{
    st_mutex_unlock(lock);
 
    return ERROR_SUCCESS;
}

void SrsKafkaProducer::clear_metadata()
{
    vector<SrsKafkaPartition*>::iterator it;
    
    for (it = partitions.begin(); it != partitions.end(); ++it) {
        SrsKafkaPartition* partition = *it;
        srs_freep(partition);
    }
    
    partitions.clear();
}

int SrsKafkaProducer::do_cycle()
{
    int ret = ERROR_SUCCESS;
    
    // ignore when disabled.
    if (!enabled) {
        return ret;
    }
    
    // when kafka enabled, request metadata when startup.
    if ((ret = request_metadata()) != ERROR_SUCCESS) {
        srs_error("request kafka metadata failed. ret=%d", ret);
        return ret;
    }
    
    return ret;
}

int SrsKafkaProducer::request_metadata()
{
    int ret = ERROR_SUCCESS;
    
    // ignore when disabled.
    if (!enabled) {
        return ret;
    }
    
    // select one broker to connect to.
    SrsConfDirective* brokers = _srs_config->get_kafka_brokers();
    if (!brokers) {
        srs_warn("ignore for empty brokers.");
        return ret;
    }
    
    std::string server;
    int port = SRS_CONSTS_KAFKA_DEFAULT_PORT;
    if (true) {
        srs_assert(!brokers->args.empty());
        std::string broker = lb->select(brokers->args);
        srs_parse_endpoint(broker, server, port);
    }
    
    std::string topic = _srs_config->get_kafka_topic();
    if (true) {
        std::string senabled = srs_bool2switch(enabled);
        std::string sbrokers = srs_join_vector_string(brokers->args, ",");
        srs_trace("kafka request enabled:%s, brokers:%s, current:[%d]%s:%d, topic:%s",
                  senabled.c_str(), sbrokers.c_str(), lb->current(), server.c_str(), port, topic.c_str());
    }
    
    SrsTcpClient* transport = new SrsTcpClient(server, port, SRS_CONSTS_KAFKA_TMMS);
    SrsAutoFree(SrsTcpClient, transport);
    
    SrsKafkaClient* kafka = new SrsKafkaClient(transport);
    SrsAutoFree(SrsKafkaClient, kafka);
    
    // reconnect to kafka server.
    if ((ret = transport->connect()) != ERROR_SUCCESS) {
        srs_error("kafka connect %s:%d failed. ret=%d", server.c_str(), port, ret);
        return ret;
    }
    
    // do fetch medata from broker.
    SrsKafkaTopicMetadataResponse* metadata = NULL;
    if ((ret = kafka->fetch_metadata(topic, &metadata)) != ERROR_SUCCESS) {
        srs_error("kafka fetch metadata failed. ret=%d", ret);
        return ret;
    }
    SrsAutoFree(SrsKafkaTopicMetadataResponse, metadata);
    
    // we may need to request multiple times.
    // for example, the first time to create a none-exists topic, then query metadata.
    if (!metadata->metadatas.empty()) {
        SrsKafkaTopicMetadata* topic = metadata->metadatas.at(0);
        if (topic->metadatas.empty()) {
            srs_warn("topic %s metadata empty, retry.", topic->name.to_str().c_str());
            return ret;
        }
    }
    
    // show kafka metadata.
    string summary = srs_kafka_metadata_summary(metadata);
    srs_trace("kafka metadata: %s", summary.c_str());
    
    // generate the partition info.
    srs_kafka_metadata2connector(topic, metadata, partitions);
    srs_trace("kafka connector: %s", srs_kafka_summary_partitions(partitions).c_str());
    
    // update the total partition for cache.
    cache->nb_partitions = (int)partitions.size();
    
    metadata_ok = true;
    
    return ret;
}

void SrsKafkaProducer::refresh_metadata()
{
    clear_metadata();
    
    metadata_ok = false;
    st_cond_signal(metadata_expired);
    srs_trace("kafka async refresh metadata in background");
}

int SrsKafkaProducer::flush()
{
    int ret = ERROR_SUCCESS;
    
    // flush all available partition caches.
    while (true) {
        int key = -1;
        SrsKafkaPartitionCache* pc = NULL;
        
        // all flushed, or no kafka partition to write to.
        if (!cache->fetch(&key, &pc) || partitions.empty()) {
            break;
        }
        
        // flush specified partition.
        srs_assert(key >= 0 && pc);
        SrsKafkaPartition* partition = partitions.at(key % partitions.size());
        if ((ret = cache->flush(partition, key, pc)) != ERROR_SUCCESS) {
            srs_error("flush partition failed. ret=%d", ret);
            return ret;
        }
    }
    
    return ret;
}

#endif