/*

 * Copyright (C) 2008  Kristian Høgsberg <krh@redhat.com>

 * Copyright (C) 2008  Red Hat, Inc

 *

 * 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; either version 2 of the License, or

 * (at your option) any later version.

 *

 * 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, write to the Free Software Foundation, Inc.,

 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

 */

#define _GNU_SOURCE

#include <string.h>

#include <stdio.h>

#include <sys/stat.h>

#include <sys/mman.h>

#include <unistd.h>

#include <fcntl.h>

#include <errno.h>

#include <expat.h>

#include <zlib.h>

#include "razor.h"

/* Import a yum filelist as a razor package set. */

enum {

	YUM_STATE_BEGIN,

	YUM_STATE_PACKAGE_NAME,

	YUM_STATE_PACKAGE_ARCH,

	YUM_STATE_CHECKSUM,

	YUM_STATE_REQUIRES,

	YUM_STATE_PROVIDES,

	YUM_STATE_OBSOLETES,

	YUM_STATE_CONFLICTS,

	YUM_STATE_FILE

};

struct yum_context {

	XML_Parser primary_parser;

	XML_Parser filelists_parser;

	XML_Parser current_parser;

	struct razor_importer *importer;

	struct import_property_context *current_property_context;

	char name[256], arch[64], buffer[512], *p;

	char pkgid[128];

	int state;

};

static enum razor_version_relation

yum_to_razor_flags (const char *flags)

{

	/* FIXME? */

	if (!flags)

		return RAZOR_VERSION_EQUAL;

	if (flags[0] == 'L') {

		if (flags[1] == 'T')

			return RAZOR_VERSION_LESS;

		else

			return RAZOR_VERSION_LESS_OR_EQUAL;

	} else if (flags[0] == 'G') {

		if (flags[1] == 'T')

			return RAZOR_VERSION_GREATER;

		else

			return RAZOR_VERSION_GREATER_OR_EQUAL;

	} else

		return RAZOR_VERSION_EQUAL;

}

static void

yum_primary_start_element(void *data, const char *name, const char **atts)

{

	struct yum_context *ctx = data;

	const char *n, *epoch, *version, *release, *flags;

	char buffer[128];

	int i;

	if (strcmp(name, "name") == 0) {

		ctx->state = YUM_STATE_PACKAGE_NAME;

		ctx->p = ctx->name;

	} else if (strcmp(name, "arch") == 0) {

		ctx->state = YUM_STATE_PACKAGE_ARCH;

		ctx->p = ctx->arch;

	} else if (strcmp(name, "version") == 0) {

		epoch = NULL;

		version = NULL;

		release = NULL;

		for (i = 0; atts[i]; i += 2) {

			if (strcmp(atts[i], "epoch") == 0)

				epoch = atts[i + 1];

			else if (strcmp(atts[i], "ver") == 0)

				version = atts[i + 1];

			else if (strcmp(atts[i], "rel") == 0)

				release = atts[i + 1];

		}

		if (version == NULL || release == NULL) {

			fprintf(stderr, "invalid version tag, "

				"missing version or  release attribute\n");

			return;

		}

		razor_build_evr(buffer, sizeof buffer, epoch, version, release);

		razor_importer_begin_package(ctx->importer,

					     ctx->name, buffer, ctx->arch);

	} else if (strcmp(name, "checksum") == 0) {

		ctx->p = ctx->pkgid;

		ctx->state = YUM_STATE_CHECKSUM;

	} else if (strcmp(name, "rpm:requires") == 0) {

		ctx->state = YUM_STATE_REQUIRES;

	} else if (strcmp(name, "rpm:provides") == 0) {

		ctx->state = YUM_STATE_PROVIDES;

	} else if (strcmp(name, "rpm:obsoletes") == 0) {

		ctx->state = YUM_STATE_OBSOLETES;

	} else if (strcmp(name, "rpm:conflicts") == 0) {

		ctx->state = YUM_STATE_CONFLICTS;

	} else if (strcmp(name, "rpm:entry") == 0 &&

		   ctx->state != YUM_STATE_BEGIN) {

		n = NULL;

		epoch = NULL;

		version = NULL;

		release = NULL;

		flags = NULL;

		for (i = 0; atts[i]; i += 2) {

			if (strcmp(atts[i], "name") == 0)

				n = atts[i + 1];

			else if (strcmp(atts[i], "epoch") == 0)

				epoch = atts[i + 1];

			else if (strcmp(atts[i], "ver") == 0)

				version = atts[i + 1];

			else if (strcmp(atts[i], "rel") == 0)

				release = atts[i + 1];

			else if (strcmp(atts[i], "flags") == 0)

				flags = atts[i + 1];

		}

		if (n == NULL) {

			fprintf(stderr, "invalid rpm:entry, "

				"missing name or version attributes\n");

			return;

		}

		razor_build_evr(buffer, sizeof buffer, epoch, version, release);

		switch (ctx->state) {

		case YUM_STATE_REQUIRES:

			razor_importer_add_property(ctx->importer, n,

						    yum_to_razor_flags (flags),

						    buffer,

						    RAZOR_PROPERTY_REQUIRES);

			break;

		case YUM_STATE_PROVIDES:

			razor_importer_add_property(ctx->importer, n,

						    yum_to_razor_flags (flags),

						    buffer,

						    RAZOR_PROPERTY_PROVIDES);

			break;

		case YUM_STATE_OBSOLETES:

			razor_importer_add_property(ctx->importer, n,

						    yum_to_razor_flags (flags),

						    buffer,

						    RAZOR_PROPERTY_OBSOLETES);

			break;

		case YUM_STATE_CONFLICTS:

			razor_importer_add_property(ctx->importer, n,

						    yum_to_razor_flags (flags),

						    buffer,

						    RAZOR_PROPERTY_CONFLICTS);

			break;

		}

	}

}

static void

yum_primary_end_element (void *data, const char *name)

{

	struct yum_context *ctx = data;

	switch (ctx->state) {

	case YUM_STATE_PACKAGE_NAME:

	case YUM_STATE_PACKAGE_ARCH:

	case YUM_STATE_CHECKSUM:

	case YUM_STATE_FILE:

		ctx->state = YUM_STATE_BEGIN;

		break;

	}

	if (strcmp(name, "package") == 0) {

		XML_StopParser(ctx->current_parser, XML_TRUE);

		ctx->current_parser = ctx->filelists_parser;

	}

}

static void

yum_character_data (void *data, const XML_Char *s, int len)

{

	struct yum_context *ctx = data;

	switch (ctx->state) {

	case YUM_STATE_PACKAGE_NAME:

	case YUM_STATE_PACKAGE_ARCH:

	case YUM_STATE_CHECKSUM:

	case YUM_STATE_FILE:

		memcpy(ctx->p, s, len);

		ctx->p += len;

		*ctx->p = '\0';

		break;

	}

}

static void

yum_filelists_start_element(void *data, const char *name, const char **atts)

{

	struct yum_context *ctx = data;

	const char *pkg, *pkgid;

	int i;

	if (strcmp(name, "package") == 0) {

		pkg = NULL;

		pkgid = NULL;

		for (i = 0; atts[i]; i += 2) {

			if (strcmp(atts[i], "name") == 0)

				pkg = atts[i + 1];

			else if (strcmp(atts[i], "pkgid") == 0)

				pkgid = atts[i + 1];

		}

		if (strcmp(pkgid, ctx->pkgid) != 0)

			fprintf(stderr, "primary.xml and filelists.xml "

				"mismatch for %s: %s vs %s",

				pkg, pkgid, ctx->pkgid);

	} else if (strcmp(name, "file") == 0) {

		ctx->state = YUM_STATE_FILE;

		ctx->p = ctx->buffer;

	}

}

static void

yum_filelists_end_element (void *data, const char *name)

{

	struct yum_context *ctx = data;

	ctx->state = YUM_STATE_BEGIN;

	if (strcmp(name, "package") == 0) {

		XML_StopParser(ctx->current_parser, XML_TRUE);

		ctx->current_parser = ctx->primary_parser;

		razor_importer_finish_package(ctx->importer);

	} else if (strcmp(name, "file") == 0)

		razor_importer_add_file(ctx->importer, ctx->buffer);

}

#define XML_BUFFER_SIZE 4096

struct razor_set *

razor_set_create_from_yum(void)

{

	struct yum_context ctx;

	void *buf;

	int len, ret;

	gzFile primary, filelists;

	XML_ParsingStatus status;

	ctx.importer = razor_importer_new();	

	ctx.state = YUM_STATE_BEGIN;

	ctx.primary_parser = XML_ParserCreate(NULL);

	XML_SetUserData(ctx.primary_parser, &ctx);

	XML_SetElementHandler(ctx.primary_parser,

			      yum_primary_start_element,

			      yum_primary_end_element);

	XML_SetCharacterDataHandler(ctx.primary_parser,

				    yum_character_data);

	ctx.filelists_parser = XML_ParserCreate(NULL);

	XML_SetUserData(ctx.filelists_parser, &ctx);

	XML_SetElementHandler(ctx.filelists_parser,

			      yum_filelists_start_element,

			      yum_filelists_end_element);

	XML_SetCharacterDataHandler(ctx.filelists_parser,

				    yum_character_data);

	primary = gzopen("primary.xml.gz", "rb");

	if (primary == NULL)

		return NULL;

	filelists = gzopen("filelists.xml.gz", "rb");

	if (filelists == NULL)

		return NULL;

	ctx.current_parser = ctx.primary_parser;

	do {

		XML_GetParsingStatus(ctx.current_parser, &status);

		switch (status.parsing) {

		case XML_SUSPENDED:

			ret = XML_ResumeParser(ctx.current_parser);

			break;

		case XML_PARSING:

		case XML_INITIALIZED:

			buf = XML_GetBuffer(ctx.current_parser,

					    XML_BUFFER_SIZE);

			if (ctx.current_parser == ctx.primary_parser)

				len = gzread(primary, buf, XML_BUFFER_SIZE);

			else

				len = gzread(filelists, buf, XML_BUFFER_SIZE);

			if (len < 0) {

				fprintf(stderr,

					"couldn't read input: %s\n",

					strerror(errno));

				return NULL;

			}

			XML_ParseBuffer(ctx.current_parser, len, len == 0);

			break;

		case XML_FINISHED:

			break;

		}

	} while (status.parsing != XML_FINISHED);

	XML_ParserFree(ctx.primary_parser);

	XML_ParserFree(ctx.filelists_parser);

	gzclose(primary);

	gzclose(filelists);

	return razor_importer_finish(ctx.importer);

}