/*
 * This file is part of the GROMACS molecular simulation package.
 *
 * Copyright 1991- The GROMACS Authors
 * and the project initiators Erik Lindahl, Berk Hess and David van der Spoel.
 * Consult the AUTHORS/COPYING files and https://www.gromacs.org for details.
 *
 * GROMACS is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License
 * as published by the Free Software Foundation; either version 2.1
 * of the License, or (at your option) any later version.
 *
 * GROMACS is distributed in the hope that it will be useful,
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with GROMACS; if not, see
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 */
#include "gmxpre.h"

#include "xlate.h"

#include <cctype>
#include <cstring>

#include <string>
#include <vector>

#include "gromacs/gmxpreprocess/fflibutil.h"
#include "gromacs/gmxpreprocess/grompp_impl.h"
#include "gromacs/topology/residuetypes.h"
#include "gromacs/topology/symtab.h"
#include "gromacs/utility/cstringutil.h"
#include "gromacs/utility/fatalerror.h"
#include "gromacs/utility/futil.h"
#include "gromacs/utility/smalloc.h"
#include "gromacs/utility/strdb.h"

#include "hackblock.h"

typedef struct
{
    char* filebase;
    char* res;
    char* atom;
    char* replace;
} t_xlate_atom;

static void get_xlatoms(const std::filesystem::path& filename, FILE* fp, int* nptr, t_xlate_atom** xlptr)
{
    char          line[STRLEN];
    char          abuf[1024], rbuf[1024], repbuf[1024], dumbuf[1024];
    char*         _ptr;
    int           n, na, idum;
    t_xlate_atom* xl;

    auto filebase = fflib_filename_base(filename);

    n  = *nptr;
    xl = *xlptr;

    while (get_a_line(fp, line, STRLEN))
    {
        na = sscanf(line, "%s%s%s%s", rbuf, abuf, repbuf, dumbuf);
        /* Check if we are reading an old format file with the number of items
         * on the first line.
         */
        if (na == 1 && n == *nptr && sscanf(rbuf, "%d", &idum) == 1)
        {
            continue;
        }
        if (na != 3)
        {
            gmx_fatal(FARGS,
                      "Expected a residue name and two atom names in file '%s', not '%s'",
                      filename.u8string().c_str(),
                      line);
        }

        srenew(xl, n + 1);
        xl[n].filebase = gmx_strdup(filebase.u8string().c_str());

        /* Use wildcards... */
        if (strcmp(rbuf, "*") != 0)
        {
            xl[n].res = gmx_strdup(rbuf);
        }
        else
        {
            xl[n].res = nullptr;
        }

        /* Replace underscores in the string by spaces */
        while ((_ptr = strchr(abuf, '_')) != nullptr)
        {
            *_ptr = ' ';
        }

        xl[n].atom    = gmx_strdup(abuf);
        xl[n].replace = gmx_strdup(repbuf);
        n++;
    }

    *nptr  = n;
    *xlptr = xl;
}

static void done_xlatom(int nxlate, t_xlate_atom* xlatom)
{
    int i;

    for (i = 0; (i < nxlate); i++)
    {
        sfree(xlatom[i].filebase);
        if (xlatom[i].res != nullptr)
        {
            sfree(xlatom[i].res);
        }
        sfree(xlatom[i].atom);
        sfree(xlatom[i].replace);
    }
    sfree(xlatom);
}

void rename_atoms(const std::filesystem::path&           xlfile,
                  const std::filesystem::path&           ffdir,
                  t_atoms*                               atoms,
                  t_symtab*                              symtab,
                  gmx::ArrayRef<const PreprocessResidue> localPpResidue,
                  bool                                   bResname,
                  const ResidueTypeMap&                  rt,
                  bool                                   bReorderNum,
                  bool                                   bVerbose)
{
    int           nxlate, a, i, resind;
    t_xlate_atom* xlatom;
    char          c, *rnm, atombuf[32];
    bool          bReorderedNum, bRenamed, bMatch;
    bool          bStartTerm, bEndTerm;

    nxlate = 0;
    xlatom = nullptr;
    if (!xlfile.empty())
    {
        gmx::FilePtr fp = gmx::openLibraryFile(xlfile);
        get_xlatoms(xlfile, fp.get(), &nxlate, &xlatom);
    }
    else
    {
        auto fns = fflib_search_file_end(ffdir, ".arn", FALSE);
        for (const auto& filename : fns)
        {
            FILE* fp = fflib_open(filename);
            get_xlatoms(filename, fp, &nxlate, &xlatom);
            gmx_ffclose(fp);
        }
    }

    for (a = 0; (a < atoms->nr); a++)
    {
        resind = atoms->atom[a].resind;

        bStartTerm = (resind == 0) || atoms->resinfo[resind].chainnum != atoms->resinfo[resind - 1].chainnum;
        bEndTerm = (resind >= atoms->nres - 1)
                   || atoms->resinfo[resind].chainnum != atoms->resinfo[resind + 1].chainnum;

        if (bResname)
        {
            rnm = *(atoms->resinfo[resind].name);
        }
        else
        {
            rnm = *(atoms->resinfo[resind].rtp);
        }

        strcpy(atombuf, *(atoms->atomname[a]));
        bReorderedNum = FALSE;
        if (bReorderNum)
        {
            if (isdigit(atombuf[0]))
            {
                c = atombuf[0];
                for (i = 0; (static_cast<size_t>(i) < strlen(atombuf) - 1); i++)
                {
                    atombuf[i] = atombuf[i + 1];
                }
                atombuf[i]    = c;
                bReorderedNum = TRUE;
            }
        }
        bRenamed = FALSE;
        for (i = 0; (i < nxlate) && !bRenamed; i++)
        {
            /* Check if the base file name of the rtp and arn entry match */
            if (localPpResidue.empty()
                || gmx::equalCaseInsensitive(localPpResidue[resind].filebase, xlatom[i].filebase))
            {
                /* Match the residue name */
                bMatch = (xlatom[i].res == nullptr
                          || (gmx_strcasecmp("protein-nterm", xlatom[i].res) == 0
                              && namedResidueHasType(rt, rnm, "Protein") && bStartTerm)
                          || (gmx_strcasecmp("protein-cterm", xlatom[i].res) == 0
                              && namedResidueHasType(rt, rnm, "Protein") && bEndTerm)
                          || (gmx_strcasecmp("protein", xlatom[i].res) == 0
                              && namedResidueHasType(rt, rnm, "Protein"))
                          || (gmx_strcasecmp("DNA", xlatom[i].res) == 0
                              && namedResidueHasType(rt, rnm, "DNA"))
                          || (gmx_strcasecmp("RNA", xlatom[i].res) == 0
                              && namedResidueHasType(rt, rnm, "RNA")));
                if (!bMatch)
                {
                    const char* ptr0 = rnm;
                    const char* ptr1 = xlatom[i].res;
                    while (ptr0[0] != '\0' && ptr1[0] != '\0' && (ptr0[0] == ptr1[0] || ptr1[0] == '?'))
                    {
                        ptr0++;
                        ptr1++;
                    }
                    bMatch = (ptr0[0] == '\0' && ptr1[0] == '\0');
                }
                if (bMatch && strcmp(atombuf, xlatom[i].atom) == 0)
                {
                    /* We have a match. */
                    /* Don't free the old atomname,
                     * since it might be in the symtab.
                     */
                    const char* ptr0 = xlatom[i].replace;
                    if (bVerbose)
                    {
                        printf("Renaming atom '%s' in residue %d %s to '%s'\n",
                               *atoms->atomname[a],
                               atoms->resinfo[resind].nr,
                               *atoms->resinfo[resind].name,
                               ptr0);
                    }
                    atoms->atomname[a] = put_symtab(symtab, ptr0);
                    bRenamed           = TRUE;
                }
            }
        }
        if (bReorderedNum && !bRenamed)
        {
            atoms->atomname[a] = put_symtab(symtab, atombuf);
        }
    }

    done_xlatom(nxlate, xlatom);
}
