//! @file hfst-fst2fst.cc
//!
//! @brief Format conversion command line tool
//!
//! @author HFST Team

//  This program is free software: you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation, version 3 of the License.
//
//  This program is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU General Public License
//  along with this program.  If not, see <http://www.gnu.org/licenses/>.

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#ifdef WINDOWS
#include <io.h>
#endif

#include <fstream>
#include <iostream>
#include <memory>

#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <getopt.h>

#include "HfstInputStream.h"
#include "HfstOutputStream.h"
#include "HfstTransducer.h"
#include "hfst-commandline.h"
#include "hfst-program-options.h"
#include "hfst-tool-metadata.h"

#include "inc/globals-common.h"
#include "inc/globals-unary.h"

using hfst::HfstInputStream;
using hfst::HfstOutputStream;
using hfst::HfstTransducer;
using hfst::ImplementationType;

// tool-specific variables

ImplementationType output_type = hfst::UNSPECIFIED_TYPE;
bool hfst_format = true;
std::string options = "";

void
set_output_type(ImplementationType type)
{
    if (output_type != hfst::UNSPECIFIED_TYPE)
    {
        hfst_error(EXIT_FAILURE, 0, "Output type defined several times.");
    }
    output_type = type;
}

void
print_usage()
{
    // c.f. http://www.gnu.org/prep/standards/standards.html#g_t_002d_002dhelp
    fprintf(message_out,
            "Usage: %s [OPTIONS...] [INFILE]\n"
            "Convert transducers between binary formats\n"
            "\n",
            program_name);

    print_common_program_options(message_out);
    print_common_unary_program_options(message_out);
    fprintf(message_out,
            "Conversion options:\n"
            "  -f, --format=FMT                  Write result in FMT format\n"
            "  -b, --use-backend-format          Write result in "
            "implementation format, without any HFST wrappers\n"
            "  -S, --sfst                        Write output in (HFST's) "
            "SFST implementation\n"
            "  -F, --foma                        Write output in (HFST's) "
            "foma implementation\n"
            "  -x, --xfsm                        Write output in native xfsm "
            "format\n"
            "  -t, --openfst-tropical            Write output in (HFST's) "
            "tropical weight (OpenFST) implementation\n"
            "  -l, --openfst-log                 Write output in (HFST's) log "
            "weight (OpenFST) implementation\n"
            "  -O, --optimized-lookup-unweighted Write output in the HFST "
            "optimized-lookup implementation\n"
            "  -w, --optimized-lookup-weighted   Write output in "
            "optimized-lookup (weighted) implementation\n"
            "  -Q  --quick                       When converting to "
            "optimized-lookup, don't try hard to compress\n");
    fprintf(message_out, "\n");
    print_common_unary_program_parameter_instructions(message_out);
    fprintf(message_out,
            "FMT must be name of a format usable by libhfst, i.e. one of the "
            "following:\n"
            "{ foma, openfst-tropical, openfst-log, sfst, xfsm\n"
            "  optimized-lookup-weighted, optimized-lookup-unweighted }.\n"
            "Note that xfsm format is always written in native format without "
            "HFST wrappers.\n");
    fprintf(message_out, "\n");
    print_report_bugs();
    fprintf(message_out, "\n");
    print_more_info();
}

int
parse_options(int argc, char **argv)
{
    extend_options_getenv(&argc, &argv);
    // use of this function requires options are settable on global scope
    while (true)
    {
        static const struct option long_options[]
            = { HFST_GETOPT_COMMON_LONG,
                HFST_GETOPT_UNARY_LONG,
                // add tool-specific options here
                { "use-backend-format", no_argument, 0, 'b' },
                { "format", required_argument, 0, 'f' },
                { "sfst", no_argument, 0, 'S' },
                { "foma", no_argument, 0, 'F' },
                { "xfsm", no_argument, 0, 'x' },
                { "openfst-tropical", no_argument, 0, 't' },
                { "openfst-log", no_argument, 0, 'l' },
                { "optimized-lookup-unweighted", no_argument, 0, 'O' },
                { "optimized-lookup-weighted", no_argument, 0, 'w' },
                { "quick", no_argument, 0, 'Q' },
                { 0, 0, 0, 0 } };
        int option_index = 0;
        // add tool-specific options here
        int c = getopt_long(argc, argv,
                            HFST_GETOPT_COMMON_SHORT HFST_GETOPT_UNARY_SHORT
                            "SFtlOwQf:bx",
                            long_options, &option_index);
        if (-1 == c)
        {
            break;
        }

        switch (c)
        {
#include "inc/getopt-cases-common.h"
#include "inc/getopt-cases-unary.h"
            // add tool-specific cases here
        case 'f':
            set_output_type(hfst_parse_format_name(optarg));
#ifndef HAVE_XFSM
            if (output_type == hfst::XFSM_TYPE)
            {
                hfst_error(EXIT_FAILURE, 0, "xfsm back-end is not available");
            }
#endif
            break;
        case 'b':
            hfst_format = false;
            break;
        case 'S':
            set_output_type(hfst::SFST_TYPE);
            break;
        case 'F':
            set_output_type(hfst::FOMA_TYPE);
            break;
        case 'x':
#ifdef HAVE_XFSM
            set_output_type(hfst::XFSM_TYPE);
#else
            hfst_error(EXIT_FAILURE, 0, "xfsm back-end is not available");
#endif
            break;
        case 't':
            set_output_type(hfst::TROPICAL_OPENFST_TYPE);
            break;
        case 'l':
            set_output_type(hfst::LOG_OPENFST_TYPE);
            break;
        case 'O':
            set_output_type(hfst::HFST_OL_TYPE);
            break;
        case 'w':
            set_output_type(hfst::HFST_OLW_TYPE);
            break;
        case 'Q':
            options = "quick";
            break;
#include "inc/getopt-cases-error.h"
        }
    }

    if (output_type == hfst::UNSPECIFIED_TYPE)
    {
        hfst_error(EXIT_FAILURE, 0,
                   "You must specify an output type "
                   "(one of -S, -F, -t, -x, -l, -O, or -w)");
    }

#include "inc/check-params-common.h"
#include "inc/check-params-unary.h"
    return EXIT_CONTINUE;
}
int
process_stream(HfstInputStream &instream, HfstOutputStream &outstream)
{
    if (instream.get_type() == hfst::FOMA_TYPE
        && !instream.is_hfst_header_included())
    {
        if (!silent)
        {
            hfst_warning(
                0, 0,
                "converting native foma transducer: "
                "inversion may be needed for hfst-lookup to work as expected "
                "(hfst-flookup works as foma's flookup)\n");
        }
    }

    size_t transducer_n = 0;
    while (instream.is_good())
    {
        transducer_n++;
        HfstTransducer orig(instream);

        char *inputname = hfst_get_name(orig, inputfilename);
        if (transducer_n == 1)
        {
            verbose_printf("Converting %s...\n", inputname);
        }
        else
        {
            verbose_printf("Converting %s..." SIZE_T_SPECIFIER "\n", inputname,
                           transducer_n);
        }
        try
        {
            orig.convert(output_type, options);
        }
        HFST_CATCH(HfstException)
        hfst_set_name(orig, orig, "convert");
        hfst_set_formula(orig, orig, "Id");
        outstream << orig;
        free(inputname);
    }
    outstream.flush(); // needed for xfsm transducers whose writing is delayed
    instream.close();
    outstream.close();
    return EXIT_SUCCESS;
}

int
main(int argc, char **argv)
{
#ifdef WINDOWS
    _setmode(0, _O_BINARY);
    _setmode(1, _O_BINARY);
#endif
    hfst_set_program_name(argv[0], "0.1", "HfstFst2Fst");
    int retval = parse_options(argc, argv);
    if (retval != EXIT_CONTINUE)
    {
        return retval;
    }
    // close buffers, we use streams
    if (inputfile != stdin)
    {
        fclose(inputfile);
    }
    if (outfile != stdout)
    {
        fclose(outfile);
    }
    verbose_printf("Reading from %s, writing to %s\n", inputfilename,
                   outfilename);
    if (hfst_format && (output_type != hfst::XFSM_TYPE))
    {
        verbose_printf("Writing %s format transducers with HFST3 headers\n",
                       hfst_strformat(output_type));
    }
    else
    {
        verbose_printf("Writing %s format transducers without HFST specific"
                       " headers\n",
                       hfst_strformat(output_type));
    }

    if (output_type == hfst::XFSM_TYPE)
    {
        if (strcmp(outfilename, "<stdout>") == 0)
        {
            hfst_error(EXIT_FAILURE, 0,
                       "Writing to standard output not supported for xfsm "
                       "transducers,\n"
                       "use 'hfst-fst2fst [--output|-o] OUTFILE' instead");
            return EXIT_FAILURE;
        }
    }

    // here starts the buffer handling part
    std::unique_ptr<HfstInputStream> instream;
    try
    {
        instream.reset((inputfile != stdin)
                           ? new HfstInputStream(inputfilename)
                           : new HfstInputStream());
    }
    catch (const FileIsInGZFormatException e)
    {
        hfst_error(EXIT_FAILURE, 0,
                   "%s seems to be a gzipped native foma file, you must first "
                   "unzip it",
                   inputfilename);
        return EXIT_FAILURE;
    }
    catch (const ImplementationTypeNotAvailableException e)
    {
        hfst_error(EXIT_FAILURE, 0,
                   "%s is in %s format which is not available", inputfilename,
                   hfst::implementation_type_to_format(e.get_type()));
        return EXIT_FAILURE;
    }
    catch (const HfstException e)
    {
        hfst_error(EXIT_FAILURE, 0, "%s is not a valid transducer file",
                   inputfilename);
#if HAVE_XFSM
        if (inputfile == stdin)
        {
            hfst_error(
                EXIT_FAILURE, 0,
                "note that you cannot read xfsm transducers from standard "
                "input,\n"
                "use hfst-fst2fst [--input|-i] INFILE instead");
        }
#endif
        return EXIT_FAILURE;
    }

    auto outstream
        = (outfile != stdout)
              ? std::make_unique<HfstOutputStream>(outfilename, output_type,
                                                   hfst_format)
              : std::make_unique<HfstOutputStream>(output_type, hfst_format);

    retval = process_stream(*instream, *outstream);
    free(inputfilename);
    free(outfilename);
    return retval;
}
