/*-

 * Copyright (c)2003 Citrus Project,

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND

 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE

 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

 * SUCH DAMAGE.

 */

#include "dcmtk/config/osconfig.h"

#include "citrus_csmapper.h"

#include <sys/types.h>

#ifdef HAVE_SYS_QUEUE_H

#include <sys/queue.h>

#else

#include "dcmtk/oficonv/queue.h"

#endif

#include <errno.h>

#include <limits.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include "citrus_bcs.h"

#include "citrus_types.h"

#include "citrus_region.h"

#include "citrus_lock.h"

#include "citrus_memstream.h"

#include "citrus_mmap.h"

#include "citrus_module.h"

#include "citrus_hash.h"

#include "citrus_mapper.h"

#include "citrus_pivot_file.h"

#include "citrus_db.h"

#include "citrus_db_hash.h"

#include "citrus_lookup.h"

#include "oficonv_strlcpy.h"

static struct _citrus_mapper_area   *maparea = NULL;

#ifdef WITH_THREADS

#ifdef HAVE_WINDOWS_H

static SRWLOCK ma_lock = SRWLOCK_INIT;

#elif defined(HAVE_PTHREAD_H)

static pthread_rwlock_t ma_lock = PTHREAD_RWLOCK_INITIALIZER;

#endif

#endif

#define CS_ALIAS_FILENAME "charset.alias"

#define CS_PIVOT_FILENAME "charset.pivot"

/* ---------------------------------------------------------------------- */

/* write the full path to the CSMAPPER directory and the given filename (which may be NULL)

 * to the path_out buffer, which is expected to be OFICONV_PATH_MAX in size.

 */

static void getCSMapperPath(char *path_out, size_t path_size, const char *filename)

{

    get_data_path(path_out, path_size, OFICONV_CSMAPPER_DIR, filename);

}

static int

get32(struct _citrus_region *r, uint32_t *rval)

{

    if (_citrus_region_size(r) != 4)

        return (EFTYPE);

    memcpy(rval, _citrus_region_head(r), (size_t)4);

    *rval = be32toh(*rval);

    return (0);

}

static int

open_subdb(struct _citrus_db **subdb, struct _citrus_db *db, const char *src)

{

    struct _citrus_region r;

    int ret;

    ret = _citrus_db_lookup_by_string(db, src, &r, NULL);

    if (ret)

        return (ret);

    ret = _citrus_db_open(subdb, &r, _CITRUS_PIVOT_SUB_MAGIC, _citrus_db_hash_std, NULL);

    if (ret)

        return (ret);

    return (0);

}

#define NO_SUCH_FILE    EOPNOTSUPP

static int

find_best_pivot_pvdb(const char *src, const char *dst, char *pivot,

    size_t pvlen, unsigned long *rnorm)

{

    struct _citrus_db *db1, *db2, *db3;

    struct _citrus_region fr, r1, r2;

    char buf[LINE_MAX];

    char mapper_path[OFICONV_PATH_MAX];

    uint32_t val32;

    unsigned long norm;

    int i, num, ret;

    getCSMapperPath(mapper_path, sizeof(mapper_path), CS_PIVOT_FILENAME ".pvdb");

    ret = _citrus_map_file(&fr, mapper_path);

    if (ret) {

        if (ret == ENOENT)

            ret = NO_SUCH_FILE;

        return (ret);

    }

    ret = _citrus_db_open(&db1, &fr, _CITRUS_PIVOT_MAGIC, _citrus_db_hash_std, NULL);

    if (ret)

        goto quit1;

    ret = open_subdb(&db2, db1, src);

    if (ret)

        goto quit2;

    num = _citrus_db_get_number_of_entries(db2);

    *rnorm = ULONG_MAX;

    for (i = 0; i < num; i++) {

        /* iterate each pivot */

        ret = _citrus_db_get_entry(db2, i, &r1, &r2);

        if (ret)

            goto quit3;

        /* r1:pivot name, r2:norm among src and pivot */

        ret = get32(&r2, &val32);

        if (ret)

            goto quit3;

        norm = val32;

        snprintf(buf, sizeof(buf), "%.*s",

             (int)_citrus_region_size(&r1), (char *)_citrus_region_head(&r1));

        /* buf: pivot name */

        ret = open_subdb(&db3, db1, buf);

        if (ret)

            goto quit3;

        if (_citrus_db_lookup_by_string(db3, dst, &r2, NULL) != 0)

            /* don't break the loop, test all src/dst pairs. */

            goto quit4;

        /* r2: norm among pivot and dst */

        ret = get32(&r2, &val32);

        if (ret)

            goto quit4;

        norm += val32;

        /* judge minimum norm */

        if (norm < *rnorm) {

            *rnorm = norm;

            strlcpy(pivot, buf, pvlen);

        }

quit4:

        _citrus_db_close(db3);

        if (ret)

            goto quit3;

    }

quit3:

    _citrus_db_close(db2);

quit2:

    _citrus_db_close(db1);

quit1:

    _citrus_unmap_file(&fr);

    if (ret)

        return (ret);

    if (*rnorm == ULONG_MAX)

        return (ENOENT);

    return (0);

}

/* ---------------------------------------------------------------------- */

struct zone {

    const char *begin, *end;

};

struct parse_arg {

    char dst[OFICONV_PATH_MAX];

    unsigned long norm;

};

static int

parse_line(struct parse_arg *pa, struct _citrus_region *r)

{

    struct zone z1, z2;

    char buf[20];

    size_t len;

    len = _citrus_region_size(r);

    z1.begin = _citrus_bcs_skip_ws_len(_citrus_region_head(r), &len);

    if (len == 0)

        return (EFTYPE);

    z1.end = _citrus_bcs_skip_nonws_len(z1.begin, &len);

    if (len == 0)

        return (EFTYPE);

    z2.begin = _citrus_bcs_skip_ws_len(z1.end, &len);

    if (len == 0)

        return (EFTYPE);

    z2.end = _citrus_bcs_skip_nonws_len(z2.begin, &len);

    /* z1 : dst name, z2 : norm */

    snprintf(pa->dst, sizeof(pa->dst),

        "%.*s", (int)(z1.end-z1.begin), z1.begin);

    snprintf(buf, sizeof(buf),

        "%.*s", (int)(z2.end-z2.begin), z2.begin);

    pa->norm = _citrus_bcs_strtoul(buf, NULL, 0);

    return (0);

}

static int

find_dst(struct parse_arg *pasrc, const char *dst)

{

    struct _citrus_lookup *cl;

    struct parse_arg padst;

    struct _citrus_region data;

    int ret;

    char mapper_path[OFICONV_PATH_MAX];

    getCSMapperPath(mapper_path, sizeof(mapper_path), CS_PIVOT_FILENAME);

    ret = _citrus_lookup_seq_open(&cl, mapper_path, _CITRUS_LOOKUP_CASE_IGNORE);

    if (ret)

        return (ret);

    ret = _citrus_lookup_seq_lookup(cl, pasrc->dst, &data);

    while (ret == 0) {

        ret = parse_line(&padst, &data);

        if (ret)

            break;

        if (strcmp(dst, padst.dst) == 0) {

            pasrc->norm += padst.norm;

            break;

        }

        ret = _citrus_lookup_seq_next(cl, NULL, &data);

    }

    _citrus_lookup_seq_close(cl);

    return (ret);

}

static int

find_best_pivot_lookup(const char *src, const char *dst, char *pivot,

    size_t pvlen, unsigned long *rnorm)

{

    struct _citrus_lookup *cl;

    struct _citrus_region data;

    struct parse_arg pa;

    char pivot_min[OFICONV_PATH_MAX];

    unsigned long norm_min;

    int ret;

    char mapper_path[OFICONV_PATH_MAX];

    getCSMapperPath(mapper_path, sizeof(mapper_path), CS_PIVOT_FILENAME);

    ret = _citrus_lookup_seq_open(&cl, mapper_path, _CITRUS_LOOKUP_CASE_IGNORE);

    if (ret)

        return (ret);

    norm_min = ULONG_MAX;

    /* find pivot code */

    ret = _citrus_lookup_seq_lookup(cl, src, &data);

    while (ret == 0) {

        ret = parse_line(&pa, &data);

        if (ret)

            break;

        ret = find_dst(&pa, dst);

        if (ret)

            break;

        if (pa.norm < norm_min) {

            norm_min = pa.norm;

            strlcpy(pivot_min, pa.dst, sizeof(pivot_min));

        }

        ret = _citrus_lookup_seq_next(cl, NULL, &data);

    }

    _citrus_lookup_seq_close(cl);

    if (ret != ENOENT)

        return (ret);

    if (norm_min == ULONG_MAX)

        return (ENOENT);

    strlcpy(pivot, pivot_min, pvlen);

    if (rnorm)

        *rnorm = norm_min;

    return (0);

}

static int

find_best_pivot(const char *src, const char *dst, char *pivot, size_t pvlen,

    unsigned long *rnorm)

{

    int ret;

    ret = find_best_pivot_pvdb(src, dst, pivot, pvlen, rnorm);

    if (ret == NO_SUCH_FILE)

        ret = find_best_pivot_lookup(src, dst, pivot, pvlen, rnorm);

    return (ret);

}

static __inline int

open_serial_mapper(struct _citrus_mapper_area * ma,

    struct _citrus_csmapper * * rcm,

    const char *src, const char *pivot, const char *dst)

{

    char buf[OFICONV_PATH_MAX];

#if ( defined(__GNUC__) && (__GNUC__ > 7 || (__GNUC__ == 7 && __GNUC_MINOR__ >= 1 ) ) )

#pragma GCC diagnostic push

#pragma GCC diagnostic ignored "-Wformat-truncation"

#endif

    snprintf(buf, sizeof(buf), "%s/%s,%s/%s", src, pivot, pivot, dst);

#if ( defined(__GNUC__) && (__GNUC__ > 7 || (__GNUC__ == 7 && __GNUC_MINOR__ >= 1 ) ) )

#pragma GCC diagnostic pop

#endif

    return (_citrus_mapper_open_direct(ma, rcm, "mapper_serial", buf));

}

static struct _citrus_csmapper *csm_none = NULL;

static int

get_none(struct _citrus_mapper_area * ma,

    struct _citrus_csmapper * * rcsm)

{

    int ret;

    WLOCK(&ma_lock);

    if (csm_none) {

        *rcsm = csm_none;

        ret = 0;

        goto quit;

    }

    ret = _citrus_mapper_open_direct(ma, &csm_none, "mapper_none", "");

    if (ret)

        goto quit;

    _citrus_mapper_set_persistent(csm_none);

    *rcsm = csm_none;

    ret = 0;

quit:

    UNLOCK(&ma_lock);

    return (ret);

}

void _citrus_cleanup_csmapper_none()

{

    WLOCK(&ma_lock);

    if (csm_none) {

        _citrus_mapper_close_nohash(csm_none);

        csm_none = NULL;

    }

    UNLOCK(&ma_lock);

    return;

}

int

_citrus_csmapper_open(struct _citrus_csmapper * * rcsm,

    const char * src, const char * dst, uint32_t flags,

    unsigned long *rnorm)

{

    const char *realsrc, *realdst;

#ifdef DCMTK_USE_OFICONV_CHARSET_ALIAS_FILE

    char buf1[OFICONV_PATH_MAX], buf2[OFICONV_PATH_MAX];

    char alias_path[OFICONV_PATH_MAX];

#endif

    char key[OFICONV_PATH_MAX], pivot[OFICONV_PATH_MAX];

    char mapper_path[OFICONV_PATH_MAX];

    unsigned long norm;

    int ret;

    norm = 0;

    getCSMapperPath(mapper_path, sizeof(mapper_path), NULL);

    ret = _citrus_mapper_create_area(&maparea, mapper_path);

    if (ret)

        return (ret);

#ifdef DCMTK_USE_OFICONV_CHARSET_ALIAS_FILE

    // Look up alias names in csmapper/charset.alias.db or csmapper/charset.alias

    getCSMapperPath(alias_path, sizeof(alias_path), CS_ALIAS_FILENAME);

    realsrc = _citrus_lookup_alias(alias_path, src, buf1, sizeof(buf1), _CITRUS_LOOKUP_CASE_IGNORE);

    realdst = _citrus_lookup_alias(alias_path, dst, buf2, sizeof(buf2), _CITRUS_LOOKUP_CASE_IGNORE);

#else

    // Don't use the alias files csmapper/charset.alias.db or csmapper/charset.alias

    realsrc = src;

    realdst = dst;

#endif

    if (!strcmp(realsrc, realdst)) {

        ret = get_none(maparea, rcsm);

        if (ret == 0 && rnorm != NULL)

            *rnorm = 0;

        return (ret);

    }

    snprintf(key, sizeof(key), "%s/%s", realsrc, realdst);

    ret = _citrus_mapper_open(maparea, rcsm, key);

    if (ret == 0) {

        if (rnorm != NULL)

            *rnorm = 0;

        return (0);

    }

    if (ret != ENOENT || (flags & _CITRUS_CSMAPPER_F_PREVENT_PIVOT)!=0)

        return (ret);

    ret = find_best_pivot(realsrc, realdst, pivot, sizeof(pivot), &norm);

    if (ret)

        return (ret);

    ret = open_serial_mapper(maparea, rcsm, realsrc, pivot, realdst);

    if (ret == 0 && rnorm != NULL)

        *rnorm = norm;

    return (ret);

}

void

_citrus_csmapper_free()

{

    if (maparea)

    {

        _citrus_mapper_delete_area(&maparea);

    }

}