#include "cmdline.h"
#include "images.h"
#include "printdata.h"

#include <fstream>

using namespace std;
using namespace mysqlpp;


// This is just an implementation detail for the example.  Skip down to
// main() for the concept this example is trying to demonstrate.  You
// can simply assume that, given a BLOB containing a valid JPEG, it
// returns true.
static bool
is_jpeg(const mysqlpp::sql_blob& img, const char** whynot)
{
    // See http://stackoverflow.com/questions/2253404/ for
    // justification for the various tests.
    const unsigned char* idp =
            reinterpret_cast<const unsigned char*>(img.data());
    if (img.size() < 125) {
        *whynot = "a valid JPEG must be at least 125 bytes";
    }
    else if ((idp[0] != 0xFF) || (idp[1] != 0xD8)) {
        *whynot = "file does not begin with JPEG sigil bytes";
    }
    else if ((memcmp(idp + 6, "JFIF", 4) != 0) &&
             (memcmp(idp + 6, "Exif", 4) != 0)) {
        *whynot = "file does not contain JPEG type word";
    }
    else {
        *whynot = 0;
        return true;
    }

    return false;
}


// Skip to main() before studying this.  This is a little too
// low-level to bother with on your first pass thru the code.
static bool
load_jpeg_file(const mysqlpp::examples::CommandLine& cmdline,
        images& img, string& img_name)
{
    if (cmdline.extra_args().size() == 0) {
        // Nothing for us to do here.  Caller will insert NULL BLOB.
        return true;
    }

    // Got a file's name on the command line, so open it.
    img_name = cmdline.extra_args()[0];
    ifstream img_file(img_name.c_str(), ios::binary);
    if (img_file) {
        // Slurp file contents into RAM with minimum copying.  (Idiom
        // explained here: http://stackoverflow.com/questions/116038/)
        //
        // By loading the file into a C++ string (stringstream::str())
        // and assigning that directly to a mysqlpp::sql_blob, we avoid
        // truncating the binary data at the first null character.
        img.data.data = static_cast<const stringstream*>(
                &(stringstream() << img_file.rdbuf()))->str();

        // Check JPEG data for sanity.
        const char* error;
        if (is_jpeg(img.data.data, &error)) {
            return true;
        }
        else {
            cerr << '"' << img_name << "\" isn't a JPEG: " <<
                    error << '!' << endl;
        }
    }

    cmdline.print_usage("[jpeg_file]");
    return false;
}


int
main(int argc, char *argv[])
{
    // Get database access parameters from command line
    mysqlpp::examples::CommandLine cmdline(argc, argv);
    if (!cmdline) {
        return 1;
    }

    try {
        // Establish the connection to the database server.
        mysqlpp::Connection con(mysqlpp::examples::db_name,
                cmdline.server(), cmdline.user(), cmdline.pass());

        // Load the file named on the command line
        images img(mysqlpp::null, mysqlpp::null);
        string img_name("NULL");
        if (load_jpeg_file(cmdline, img, img_name)) {
            // Insert image data or SQL NULL into the images.data BLOB
            // column.  The key here is that we're holding the raw
            // binary data in a mysqlpp::sql_blob, which avoids data
            // conversion problems that can lead to treating BLOB data
            // as C strings, thus causing null-truncation.  The fact
            // that we're using SSQLS here is a side issue, simply
            // demonstrating that mysqlpp::Null<mysqlpp::sql_blob> is
            // now legal in SSQLS, as of MySQL++ 3.0.7.
            Query query = con.query();
            query.insert(img);
            SimpleResult res = query.execute();

            // Report successful insertion
            cout << "Inserted \"" << img_name <<
                    "\" into images table, " << img.data.data.size() <<
                    " bytes, ID " << res.insert_id() << endl;
        }
    }
    catch (const BadQuery& er) {
        // Handle any query errors
        cerr << "Query error: " << er.what() << endl;
        return -1;
    }
    catch (const BadConversion& er) {
        // Handle bad conversions
        cerr << "Conversion error: " << er.what() << endl <<
                "\tretrieved data size: " << er.retrieved <<
                ", actual size: " << er.actual_size << endl;
        return -1;
    }
    catch (const Exception& er) {
        // Catch-all for any other MySQL++ exceptions
        cerr << "Error: " << er.what() << endl;
        return -1;
    }

    return 0;
}