#include "Replicator.h"
#include "IOCoordinator.h"
#include "SMLogging.h"
#include "Utilities.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <sys/sendfile.h>
#include <boost/filesystem.hpp>
#define BOOST_SPIRIT_THREADSAFE
#include <boost/property_tree/json_parser.hpp>
#include <boost/shared_array.hpp>
#include <boost/format.hpp>
#include <iostream>

using namespace std;

namespace
{
    storagemanager::Replicator *rep = NULL;
    boost::mutex m;
}
namespace storagemanager
{

Replicator::Replicator()
{
    mpConfig = Config::get();
    mpLogger = SMLogging::get();
    try
    {
        msJournalPath = mpConfig->getValue("ObjectStorage", "journal_path");
        if (msJournalPath.empty())
        {
            mpLogger->log(LOG_CRIT, "ObjectStorage/journal_path is not set");
            throw runtime_error("Please set ObjectStorage/journal_path in the storagemanager.cnf file");
        }
    }
    catch (...)
    {
        mpLogger->log(LOG_CRIT, "Could not load metadata_path from storagemanger.cnf file.");
        throw runtime_error("Please set ObjectStorage/metadata_path in the storagemanager.cnf file");
    }
    try
    {
        boost::filesystem::create_directories(msJournalPath);
    }
    catch (exception &e)
    {
        syslog(LOG_CRIT, "Failed to create %s, got: %s", msJournalPath.c_str(), e.what());
        throw e;
    }
    msCachePath = mpConfig->getValue("Cache", "path");
    if (msCachePath.empty())
    {
        mpLogger->log(LOG_CRIT, "Cache/path is not set");
        throw runtime_error("Please set Cache/path in the storagemanager.cnf file");
    }
    try
    {
        boost::filesystem::create_directories(msCachePath);
    }
    catch (exception &e)
    {
        mpLogger->log(LOG_CRIT, "Failed to create %s, got: %s", msCachePath.c_str(), e.what());
        throw e;
    }
}

Replicator::~Replicator()
{
}

Replicator * Replicator::get()
{
    if (rep)
        return rep;
    boost::mutex::scoped_lock s(m);
    if (rep)
        return rep;
    rep = new Replicator();
    return rep;
}

#define OPEN(name, mode) \
    fd = ::open(name, mode, 0600); \
    if (fd < 0) \
        return fd; \
    ScopedCloser sc(fd);

int Replicator::newObject(const char *filename, const uint8_t *data, off_t offset, size_t length )
{
    int fd, err;
    string objectFilename = msCachePath + "/" + string(filename);

    OPEN(objectFilename.c_str(), O_WRONLY | O_CREAT);
    size_t count = 0;
    while (count < length) {
        err = ::pwrite(fd, &data[count], length - count, offset);
        if (err <= 0)
        {
            if (count > 0)   // return what was successfully written
                return count;
            else
                return err;
        }
        count += err;
    }

    return count;
}

int Replicator::addJournalEntry(const char *filename, const uint8_t *data, off_t offset, size_t length)
{
    int fd, err;
    uint64_t offlen[] = {(uint64_t) offset,length};
    size_t count = 0;
    int version = 1;
    string journalFilename = msJournalPath + "/" + string(filename) + ".journal";
    uint64_t thisEntryMaxOffset = (offset + length - 1);

    bool exists = boost::filesystem::exists(journalFilename);
    OPEN(journalFilename.c_str(), (exists ? O_RDWR : O_WRONLY | O_CREAT))
    
    if (!exists)
    {
        // create new journal file with header
        //OPEN(journalFilename.c_str(), O_WRONLY | O_CREAT);
        string header = (boost::format("{ \"version\" : \"%03i\", \"max_offset\" : \"%011u\" }") % version % thisEntryMaxOffset).str();
        err = ::write(fd, header.c_str(), header.length() + 1);
        assert((uint) err == header.length() + 1);
        if (err <= 0)
            return err;
    }
    else
    {
        // read the existing header and check if max_offset needs to be updated
        //OPEN(journalFilename.c_str(), O_RDWR);
        boost::shared_array<char> headertxt = seekToEndOfHeader1(fd);
        stringstream ss;
        ss << headertxt.get();
        boost::property_tree::ptree header;
        boost::property_tree::json_parser::read_json(ss, header);
        assert(header.get<int>("version") == 1);
        uint64_t currentMaxOffset = header.get<uint64_t>("max_offset");
        if (thisEntryMaxOffset > currentMaxOffset)
        {
            string header = (boost::format("{ \"version\" : \"%03i\", \"max_offset\" : \"%011u\" }") % version % thisEntryMaxOffset).str();
            err = ::pwrite(fd, header.c_str(), header.length() + 1,0);
            assert((uint) err == header.length() + 1);
            if (err <= 0)
                return err;
        }
    }

    // XXXPAT: avoid closing and right away opening the file again when it's easy not to.  
    // Just reposition the file pointer.
    //OPEN(journalFilename.c_str(), O_WRONLY | O_APPEND);
    ::lseek(fd, 0, SEEK_END);
    
    err = ::write(fd, offlen, JOURNAL_ENTRY_HEADER_SIZE);
    assert(err == JOURNAL_ENTRY_HEADER_SIZE);
    if (err <= 0)
        return err;

    while (count < length) {
        err = ::write(fd, &data[count], length - count);
        if (err < 0)
        {
            /* XXXPAT: We can't return anything but success here, unless we also update the entry's
               header */
            if (count > 0)   // return what was successfully written
                return count;
            else
                return err;
        }
        count += err;
    }

    return count;
}

int Replicator::remove(const boost::filesystem::path &filename, Flags flags)
{
    int ret = 0;
    
    if (flags & NO_LOCAL)
        return 0;  // not implemented yet
        
    try
    {
        //#ifndef NDEBUG
        //    assert(boost::filesystem::remove_all(filename) > 0);
        //#else
            boost::filesystem::remove_all(filename);
        //#endif
    }
    catch(boost::filesystem::filesystem_error &e)
    {
        #ifndef NDEBUG
            cout << "Replicator::remove(): caught an execption: " << e.what() << endl;
            assert(0);
        #endif
        errno = e.code().value();
        ret = -1;
    }
    return ret;
}


int Replicator::remove(const char *filename, Flags flags)
{
    if (flags & NO_LOCAL)
        return 0;   // not implemented yet
        
    boost::filesystem::path p(filename);
    return remove(p);
}

int Replicator::updateMetadata(const char *filename, MetadataFile &meta)
{
    return meta.writeMetadata(filename);
}

}