/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 2003 Poul-Henning Kamp
 * 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.
 * 3. The names of the authors may not be used to endorse or promote
 *    products derived from this software without specific prior written
 *    permission.
 *
 * 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 <sys/types.h>
#include <sys/mman.h>
#include <sys/queue.h>
#include <sys/sbuf.h>
#include <sys/stat.h>
#include <sys/sysctl.h>

#include <assert.h>
#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <paths.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include <bsdxml.h>
#include <libgeom.h>

struct mystate {
        struct gmesh            *mesh;
        struct gclass           *class;
        struct ggeom            *geom;
        struct gprovider        *provider;
        struct gconsumer        *consumer;
        int                     level;
        struct sbuf             *sbuf[20];
        struct gconf            *config;
        int                     nident;
        XML_Parser              parser;
        int                     error;
};

static void
StartElement(void *userData, const char *name, const char **attr)
{
        struct mystate *mt;
        void *id;
        void *ref;
        uintmax_t umax;
        int i;

        mt = userData;
        mt->level++;
        mt->sbuf[mt->level] = sbuf_new_auto();
        id = NULL;
        ref = NULL;
        for (i = 0; attr[i] != NULL; i += 2) {
                if (strcmp(attr[i], "id") == 0) {
                        umax = strtoumax(attr[i + 1], NULL, 0);
                        id = (void *)(uintptr_t)umax;
                        mt->nident++;
                } else if (strcmp(attr[i], "ref") == 0) {
                        umax = strtoumax(attr[i + 1], NULL, 0);
                        ref = (void *)(uintptr_t)umax;
                }
        }
        if (strcmp(name, "class") == 0 && mt->class == NULL) {
                mt->class = calloc(1, sizeof *mt->class);
                if (mt->class == NULL) {
                        mt->error = errno;
                        XML_StopParser(mt->parser, 0);
                        warn("Cannot allocate memory during processing of '%s' "
                            "element", name);
                        return;
                }
                mt->class->lg_id = id;
                LIST_INSERT_HEAD(&mt->mesh->lg_class, mt->class, lg_class);
                LIST_INIT(&mt->class->lg_geom);
                LIST_INIT(&mt->class->lg_config);
                return;
        }
        if (strcmp(name, "geom") == 0 && mt->geom == NULL) {
                mt->geom = calloc(1, sizeof *mt->geom);
                if (mt->geom == NULL) {
                        mt->error = errno;
                        XML_StopParser(mt->parser, 0);
                        warn("Cannot allocate memory during processing of '%s' "
                            "element", name);
                        return;
                }
                mt->geom->lg_id = id;
                LIST_INSERT_HEAD(&mt->class->lg_geom, mt->geom, lg_geom);
                LIST_INIT(&mt->geom->lg_provider);
                LIST_INIT(&mt->geom->lg_consumer);
                LIST_INIT(&mt->geom->lg_config);
                return;
        }
        if (strcmp(name, "class") == 0 && mt->geom != NULL) {
                mt->geom->lg_class = ref;
                return;
        }
        if (strcmp(name, "consumer") == 0 && mt->consumer == NULL) {
                mt->consumer = calloc(1, sizeof *mt->consumer);
                if (mt->consumer == NULL) {
                        mt->error = errno;
                        XML_StopParser(mt->parser, 0);
                        warn("Cannot allocate memory during processing of '%s' "
                            "element", name);
                        return;
                }
                mt->consumer->lg_id = id;
                LIST_INSERT_HEAD(&mt->geom->lg_consumer, mt->consumer,
                    lg_consumer);
                LIST_INIT(&mt->consumer->lg_config);
                return;
        }
        if (strcmp(name, "geom") == 0 && mt->consumer != NULL) {
                mt->consumer->lg_geom = ref;
                return;
        }
        if (strcmp(name, "provider") == 0 && mt->consumer != NULL) {
                mt->consumer->lg_provider = ref;
                return;
        }
        if (strcmp(name, "provider") == 0 && mt->provider == NULL) {
                mt->provider = calloc(1, sizeof *mt->provider);
                if (mt->provider == NULL) {
                        mt->error = errno;
                        XML_StopParser(mt->parser, 0);
                        warn("Cannot allocate memory during processing of '%s' "
                            "element", name);
                        return;
                }
                mt->provider->lg_id = id;
                LIST_INSERT_HEAD(&mt->geom->lg_provider, mt->provider,
                    lg_provider);
                LIST_INIT(&mt->provider->lg_consumers);
                LIST_INIT(&mt->provider->lg_config);
                return;
        }
        if (strcmp(name, "geom") == 0 && mt->provider != NULL) {
                mt->provider->lg_geom = ref;
                return;
        }
        if (strcmp(name, "config") == 0) {
                if (mt->provider != NULL) {
                        mt->config = &mt->provider->lg_config;
                        return;
                }
                if (mt->consumer != NULL) {
                        mt->config = &mt->consumer->lg_config;
                        return;
                }
                if (mt->geom != NULL) {
                        mt->config = &mt->geom->lg_config;
                        return;
                }
                if (mt->class != NULL) {
                        mt->config = &mt->class->lg_config;
                        return;
                }
        }
}

static void
EndElement(void *userData, const char *name)
{
        struct mystate *mt;
        struct gconf *c;
        struct gconfig *gc;
        char *p;

        mt = userData;
        p = NULL;
        if (sbuf_finish(mt->sbuf[mt->level]) == 0)
                p = strdup(sbuf_data(mt->sbuf[mt->level]));
        sbuf_delete(mt->sbuf[mt->level]);
        mt->sbuf[mt->level] = NULL;
        mt->level--;
        if (p == NULL) {
                mt->error = errno;
                XML_StopParser(mt->parser, 0);
                warn("Cannot allocate memory during processing of '%s' "
                    "element", name);
                return;
        }
        if (strlen(p) == 0) {
                free(p);
                p = NULL;
        }

        if (strcmp(name, "name") == 0) {
                if (mt->provider != NULL) {
                        mt->provider->lg_name = p;
                        return;
                } else if (mt->geom != NULL) {
                        mt->geom->lg_name = p;
                        return;
                } else if (mt->class != NULL) {
                        mt->class->lg_name = p;
                        return;
                }
        }
        if (strcmp(name, "rank") == 0 && mt->geom != NULL) {
                mt->geom->lg_rank = strtoul(p, NULL, 0);
                free(p);
                return;
        }
        if (strcmp(name, "mode") == 0 && mt->provider != NULL) {
                mt->provider->lg_mode = p;
                return;
        }
        if (strcmp(name, "mode") == 0 && mt->consumer != NULL) {
                mt->consumer->lg_mode = p;
                return;
        }
        if (strcmp(name, "mediasize") == 0 && mt->provider != NULL) {
                mt->provider->lg_mediasize = strtoumax(p, NULL, 0);
                free(p);
                return;
        }
        if (strcmp(name, "sectorsize") == 0 && mt->provider != NULL) {
                mt->provider->lg_sectorsize = strtoul(p, NULL, 0);
                free(p);
                return;
        }
        if (strcmp(name, "stripesize") == 0 && mt->provider != NULL) {
                mt->provider->lg_stripesize = strtoumax(p, NULL, 0);
                free(p);
                return;
        }
        if (strcmp(name, "stripeoffset") == 0 && mt->provider != NULL) {
                mt->provider->lg_stripeoffset = strtoumax(p, NULL, 0);
                free(p);
                return;
        }

        if (strcmp(name, "config") == 0) {
                mt->config = NULL;
                free(p);
                return;
        }

        if (mt->config != NULL || (strcmp(name, "wither") == 0 &&
            (mt->provider != NULL || mt->geom != NULL))) {
                if (mt->config != NULL)
                        c = mt->config;
                else if (mt->provider != NULL)
                        c = &mt->provider->lg_config;
                else
                        c = &mt->geom->lg_config;
                gc = calloc(1, sizeof *gc);
                if (gc == NULL) {
                        mt->error = errno;
                        XML_StopParser(mt->parser, 0);
                        warn("Cannot allocate memory during processing of '%s' "
                            "element", name);
                        free(p);
                        return;
                }
                gc->lg_name = strdup(name);
                if (gc->lg_name == NULL) {
                        mt->error = errno;
                        XML_StopParser(mt->parser, 0);
                        warn("Cannot allocate memory during processing of '%s' "
                            "element", name);
                        free(gc);
                        free(p);
                        return;
                }
                gc->lg_val = p;
                LIST_INSERT_HEAD(c, gc, lg_config);
                return;
        }

        if (p != NULL) {
#if DEBUG_LIBGEOM > 0
                printf("Unexpected XML: name=%s data=\"%s\"\n", name, p);
#endif
                free(p);
        }

        if (strcmp(name, "consumer") == 0 && mt->consumer != NULL) {
                mt->consumer = NULL;
                return;
        }
        if (strcmp(name, "provider") == 0 && mt->provider != NULL) {
                mt->provider = NULL;
                return;
        }
        if (strcmp(name, "geom") == 0 && mt->consumer != NULL) {
                return;
        }
        if (strcmp(name, "geom") == 0 && mt->provider != NULL) {
                return;
        }
        if (strcmp(name, "geom") == 0 && mt->geom != NULL) {
                mt->geom = NULL;
                return;
        }
        if (strcmp(name, "class") == 0 && mt->geom != NULL) {
                return;
        }
        if (strcmp(name, "class") == 0 && mt->class != NULL) {
                mt->class = NULL;
                return;
        }
}

static void
CharData(void *userData , const XML_Char *s , int len)
{
        struct mystate *mt;
        const char *b, *e;

        mt = userData;

        b = s;
        e = s + len - 1;
        while (isspace(*b) && b < e)
                b++;
        while (isspace(*e) && e > b)
                e--;
        if (e != b || (*b && !isspace(*b)))
                sbuf_bcat(mt->sbuf[mt->level], b, e - b + 1);
}

struct gident *
geom_lookupid(const struct gmesh *gmp, const void *id)
{
        struct gident *gip;

        for (gip = gmp->lg_ident; gip->lg_id != NULL; gip++)
                if (gip->lg_id == id)
                        return (gip);
        return (NULL);
}

static void *
geom_lookup_class(const struct gmesh *gmp, const void *id)
{
        struct gident *gip;

        if ((gip = geom_lookupid(gmp, id)) == NULL)
                return (NULL);
        assert(gip->lg_what == ISCLASS);
        return (gip->lg_ptr);
}

static void *
geom_lookup_geom(const struct gmesh *gmp, const void *id)
{
        struct gident *gip;

        if ((gip = geom_lookupid(gmp, id)) == NULL)
                return (NULL);
        assert(gip->lg_what == ISGEOM);
        return (gip->lg_ptr);
}

static void *
geom_lookup_provider(const struct gmesh *gmp, const void *id)
{
        struct gident *gip;

        if ((gip = geom_lookupid(gmp, id)) == NULL)
                return (NULL);
        assert(gip->lg_what == ISPROVIDER);
        return (gip->lg_ptr);
}

static void * __unused
geom_lookup_consumer(const struct gmesh *gmp, const void *id)
{
        struct gident *gip;

        if ((gip = geom_lookupid(gmp, id)) == NULL)
                return (NULL);
        assert(gip->lg_what == ISCONSUMER);
        return (gip->lg_ptr);
}

int
geom_xml2tree(struct gmesh *gmp, char *p)
{
        XML_Parser parser;
        struct mystate *mt;
        struct gclass *cl;
        struct ggeom *ge;
        struct gprovider *pr;
        struct gconsumer *co;
        int error, i;

        memset(gmp, 0, sizeof *gmp);
        LIST_INIT(&gmp->lg_class);
        parser = XML_ParserCreate(NULL);
        if (parser == NULL)
                return (ENOMEM);
        mt = calloc(1, sizeof *mt);
        if (mt == NULL) {
                XML_ParserFree(parser);
                return (ENOMEM);
        }
        mt->mesh = gmp;
        mt->parser = parser;
        error = 0;
        XML_SetUserData(parser, mt);
        XML_SetElementHandler(parser, StartElement, EndElement);
        XML_SetCharacterDataHandler(parser, CharData);
        i = XML_Parse(parser, p, strlen(p), 1);
        if (mt->error != 0)
                error = mt->error;
        else if (i != 1) {
                error = XML_GetErrorCode(parser) == XML_ERROR_NO_MEMORY ?
                    ENOMEM : EILSEQ;
        }
        XML_ParserFree(parser);
        if (error != 0) {
                free(mt);
                return (error);
        }
        gmp->lg_ident = calloc(mt->nident + 1, sizeof(*gmp->lg_ident));
        free(mt);
        if (gmp->lg_ident == NULL)
                return (ENOMEM);
        i = 0;
        /* Collect all identifiers */
        /* XXX we should check for duplicate identifiers */
        LIST_FOREACH(cl, &gmp->lg_class, lg_class) {
                gmp->lg_ident[i].lg_id = cl->lg_id;
                gmp->lg_ident[i].lg_ptr = cl;
                gmp->lg_ident[i].lg_what = ISCLASS;
                i++;
                LIST_FOREACH(ge, &cl->lg_geom, lg_geom) {
                        gmp->lg_ident[i].lg_id = ge->lg_id;
                        gmp->lg_ident[i].lg_ptr = ge;
                        gmp->lg_ident[i].lg_what = ISGEOM;
                        i++;
                        LIST_FOREACH(pr, &ge->lg_provider, lg_provider) {
                                gmp->lg_ident[i].lg_id = pr->lg_id;
                                gmp->lg_ident[i].lg_ptr = pr;
                                gmp->lg_ident[i].lg_what = ISPROVIDER;
                                i++;
                        }
                        LIST_FOREACH(co, &ge->lg_consumer, lg_consumer) {
                                gmp->lg_ident[i].lg_id = co->lg_id;
                                gmp->lg_ident[i].lg_ptr = co;
                                gmp->lg_ident[i].lg_what = ISCONSUMER;
                                i++;
                        }
                }
        }
        /* Substitute all identifiers */
        LIST_FOREACH(cl, &gmp->lg_class, lg_class) {
                LIST_FOREACH(ge, &cl->lg_geom, lg_geom) {
                        ge->lg_class = geom_lookup_class(gmp, ge->lg_class);
                        LIST_FOREACH(pr, &ge->lg_provider, lg_provider) {
                                pr->lg_geom = geom_lookup_geom(gmp, pr->lg_geom);
                        }
                        LIST_FOREACH(co, &ge->lg_consumer, lg_consumer) {
                                co->lg_geom = geom_lookup_geom(gmp, co->lg_geom);
                                if (co->lg_provider != NULL) {
                                        co->lg_provider = geom_lookup_provider(gmp,
                                            co->lg_provider);
                                        if (co->lg_provider != NULL) {
                                                LIST_INSERT_HEAD(
                                                    &co->lg_provider->lg_consumers,
                                                    co, lg_consumers);
                                        }
                                }
                        }
                }
        }
        return (0);
}

int
geom_gettree(struct gmesh *gmp)
{
        char *p;
        int error;

        p = geom_getxml();
        if (p == NULL)
                return (errno);
        error = geom_xml2tree(gmp, p);
        free(p);
        return (error);
}

int
geom_gettree_geom(struct gmesh *gmp, const char *c, const char *g, int parents)
{
        char *p;
        int error;

        if (g != NULL && strncmp(g, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0)
                g += sizeof(_PATH_DEV) - 1;
        p = geom_getxml_geom(c, g, parents);
        if (p == NULL)
                return (errno);
        error = geom_xml2tree(gmp, p);
        free(p);
        return (error);
}

static void 
delete_config(struct gconf *gp)
{
        struct gconfig *cf;

        for (;;) {
                cf = LIST_FIRST(gp);
                if (cf == NULL)
                        return;
                LIST_REMOVE(cf, lg_config);
                free(cf->lg_name);
                free(cf->lg_val);
                free(cf);
        }
}

void
geom_deletetree(struct gmesh *gmp)
{
        struct gclass *cl;
        struct ggeom *ge;
        struct gprovider *pr;
        struct gconsumer *co;

        free(gmp->lg_ident);
        gmp->lg_ident = NULL;
        for (;;) {
                cl = LIST_FIRST(&gmp->lg_class);
                if (cl == NULL) 
                        break;
                LIST_REMOVE(cl, lg_class);
                delete_config(&cl->lg_config);
                free(cl->lg_name);
                for (;;) {
                        ge = LIST_FIRST(&cl->lg_geom);
                        if (ge == NULL) 
                                break;
                        LIST_REMOVE(ge, lg_geom);
                        delete_config(&ge->lg_config);
                        free(ge->lg_name);
                        for (;;) {
                                pr = LIST_FIRST(&ge->lg_provider);
                                if (pr == NULL) 
                                        break;
                                LIST_REMOVE(pr, lg_provider);
                                delete_config(&pr->lg_config);
                                free(pr->lg_name);
                                free(pr->lg_mode);
                                free(pr);
                        }
                        for (;;) {
                                co = LIST_FIRST(&ge->lg_consumer);
                                if (co == NULL) 
                                        break;
                                LIST_REMOVE(co, lg_consumer);
                                delete_config(&co->lg_config);
                                free(co->lg_mode);
                                free(co);
                        }
                        free(ge);
                }
                free(cl);
        }
}