/*

  * 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.

  */

 #include <string.h>

 #include "razor-internal.h"

 #include "razor.h"

 #define UPSTREAM_SOURCE 0x80

 struct source {

 	struct razor_set *set;

 	uint32_t *property_map;

 	uint32_t *file_map;

 };

 struct razor_merger {

 	struct razor_set *set;

 	struct hashtable table;

 	struct hashtable file_table;

 	struct source source1;

 	struct source source2;

 };

 struct razor_merger *

 razor_merger_create(struct razor_set *set1, struct razor_set *set2)

 {

 	struct razor_merger *merger;

 	int count;

 	size_t size;

 	merger = zalloc(sizeof *merger);

 	merger->set = razor_set_create();

 	hashtable_init(&merger->table, &merger->set->string_pool);

 	hashtable_init(&merger->file_table, &merger->set->file_string_pool);

 	merger->source1.set = set1;

 	count = set1->properties.size / sizeof (struct razor_property);

 	size = count * sizeof merger->source1.property_map[0];

 	merger->source1.property_map = zalloc(size);

 	count = set1->files.size / sizeof (struct razor_entry);

 	size = count * sizeof merger->source1.file_map[0];

 	merger->source1.file_map = zalloc(size);

 	merger->source2.set = set2;

 	count = set2->properties.size / sizeof (struct razor_property);

 	size = count * sizeof merger->source2.property_map[0];

 	merger->source2.property_map = zalloc(size);

 	count = set2->files.size / sizeof (struct razor_entry);

 	size = count * sizeof merger->source2.file_map[0];

 	merger->source2.file_map = zalloc(size);

 	return merger;

 }

 void

 razor_merger_add_package(struct razor_merger *merger,

 			 struct razor_package *package)

 {

 	char *pool;

 	struct list *r;

 	struct razor_package *p;

 	struct razor_set *set1;

 	struct source *source;

 	uint32_t flags;

 	set1 = merger->source1.set;

 	if (set1->packages.data <= (void *) package &&

 	    (void *) package < set1->packages.data + set1->packages.size) {

 		source = &merger->source1;

 		flags = 0;

 	} else {

 		source = &merger->source2;

 		flags = UPSTREAM_SOURCE;

 	}

 	pool = source->set->string_pool.data;

 	p = array_add(&merger->set->packages, sizeof *p);

 	p->name = hashtable_tokenize(&merger->table, &pool[package->name]);

 	p->flags = flags;

 	p->version = hashtable_tokenize(&merger->table,

 					&pool[package->version]);

 	p->arch = hashtable_tokenize(&merger->table,

 				     &pool[package->arch]);

 	p->properties = package->properties;

 	r = list_first(&package->properties, &source->set->property_pool);

 	while (r) {

 		source->property_map[r->data] = 1;

 		r = list_next(r);

 	}

 	p->files = package->files;

 	r = list_first(&package->files, &source->set->file_pool);

 	while (r) {

 		source->file_map[r->data] = 1;

 		r = list_next(r);

 	}

 }

 static uint32_t

 add_property(struct razor_merger *merger,

 	     const char *name, uint32_t flags, const char *version)

 {

 	struct razor_property *p;

 	p = array_add(&merger->set->properties, sizeof *p);

 	p->name = hashtable_tokenize(&merger->table, name);

 	p->flags = flags;

 	p->version = hashtable_tokenize(&merger->table, version);

 	return p - (struct razor_property *) merger->set->properties.data;

 }

 static void

 merge_properties(struct razor_merger *merger)

 {

 	struct razor_property *p1, *p2;

 	struct razor_set *set1, *set2;

 	uint32_t *map1, *map2;

 	int i, j, cmp, count1, count2;

 	char *pool1, *pool2;

 	set1 = merger->source1.set;

 	set2 = merger->source2.set;

 	map1 = merger->source1.property_map;

 	map2 = merger->source2.property_map;

 	i = 0;

 	j = 0;

 	pool1 = set1->string_pool.data;

 	pool2 = set2->string_pool.data;

 	count1 = set1->properties.size / sizeof *p1;

 	count2 = set2->properties.size / sizeof *p2;

 	while (i < count1 || j < count2) {

 		if (i < count1 && map1[i] == 0) {

 			i++;

 			continue;

 		}

 		if (j < count2 && map2[j] == 0) {

 			j++;

 			continue;

 		}

 		p1 = (struct razor_property *) set1->properties.data + i;

 		p2 = (struct razor_property *) set2->properties.data + j;

 		if (i < count1 && j < count2)

 			cmp = strcmp(&pool1[p1->name], &pool2[p2->name]);

 		else if (i < count1)

 			cmp = -1;

 		else

 			cmp = 1;

 		if (cmp == 0)

 			cmp = p1->flags - p2->flags;

 		if (cmp == 0)

 			cmp = razor_versioncmp(&pool1[p1->version],

 					       &pool2[p2->version]);

 		if (cmp < 0) {

 			map1[i++] = add_property(merger,

 						 &pool1[p1->name],

 						 p1->flags,

 						 &pool1[p1->version]);

 		} else if (cmp > 0) {

 			map2[j++] = add_property(merger,

 						 &pool2[p2->name],

 						 p2->flags,

 						 &pool2[p2->version]);

 		} else  {

 			map1[i++] = map2[j++] =

 				add_property(merger,

 					     &pool1[p1->name],

 					     p1->flags,

 					     &pool1[p1->version]);

 		}

 	}

 }

 static void

 emit_properties(struct list_head *properties, struct array *source_pool,

 		uint32_t *map, struct array *pool)

 {

 	uint32_t r;

 	struct list *p, *q;

 	r = pool->size / sizeof *q;

 	p = list_first(properties, source_pool);

 	while (p) {

 		q = array_add(pool, sizeof *q);

 		q->data = map[p->data];

 		q->flags = p->flags;

 		p = list_next(p);

 	}

 	list_set_ptr(properties, r);

 }

 static uint32_t

 add_file(struct razor_merger *merger, const char *name)

 {

 	struct razor_entry *e;

 	e = array_add(&merger->set->files, sizeof *e);

 	e->name = hashtable_tokenize(&merger->file_table, name);

 	e->flags = 0;

 	e->start = 0;

 	return e - (struct razor_entry *)merger->set->files.data;

 }

 /* FIXME. Blah */

 static int

 fix_file_map(uint32_t *map,

 	     struct razor_entry *files,

 	     struct razor_entry *top)

 {

 	uint32_t e;

 	int found_file = 0;

 	e = top - files;

 	do {

 		if (files[e].start &&

 		    fix_file_map(map, files, &files[files[e].start]))

 			map[e] = 1;

 		if (map[e])

 			found_file = 1;

 	} while (!(files[e++].flags & RAZOR_ENTRY_LAST));

 	return found_file;

 }

 struct merge_directory {

 	uint32_t merged, dir1, dir2;

 };

 static void

 merge_one_directory(struct razor_merger *merger, struct merge_directory *md)

 {

 	struct razor_entry *root1, *root2, *mroot, *e1, *e2;

 	struct razor_set *set1, *set2;

 	struct array merge_stack;

 	struct merge_directory *child_md, *end_md;

 	uint32_t *map1, *map2, start, last;

 	int cmp;

 	char *pool1, *pool2;

 	set1 = merger->source1.set;

 	set2 = merger->source2.set;

 	map1 = merger->source1.file_map;

 	map2 = merger->source2.file_map;

 	pool1 = set1->file_string_pool.data;

 	pool2 = set2->file_string_pool.data;

 	root1 = (struct razor_entry *) set1->files.data;

 	root2 = (struct razor_entry *) set2->files.data;

 	array_init(&merge_stack);

 	start = merger->set->files.size / sizeof (struct razor_entry);

 	last = 0xFFFFFFFF;

 	e1 = md->dir1 != 0xFFFFFFFF ? root1 + md->dir1 : NULL;

 	e2 = md->dir2 != 0xFFFFFFFF ? root2 + md->dir2 : NULL;

 	while (e1 || e2) {

 		if (!e2 && !map1[e1 - root1]) {

 			if ((e1++)->flags & RAZOR_ENTRY_LAST)

 				e1 = NULL;

 			continue;

 		}

 		if (!e1 && !map2[e2 - root2]) {

 			if ((e2++)->flags & RAZOR_ENTRY_LAST)

 				e2 = NULL;

 			continue;

 		}

 		if (e1 && !map1[e1 - root1] &&

 		    e2 && !map2[e2 - root2]) {

 			if ((e1++)->flags & RAZOR_ENTRY_LAST)

 				e1 = NULL;

 			if ((e2++)->flags & RAZOR_ENTRY_LAST)

 				e2 = NULL;

 			continue;

 		}

 		if (!e1)

 			cmp = 1;

 		else if (!e2)

 			cmp = -1;

 		else {

 			cmp = strcmp (&pool1[e1->name],

 				      &pool2[e2->name]);

 		}

 		if (cmp < 0) {

 			if (map1[e1 - root1]) {

 				map1[e1 - root1] = last =

 					add_file(merger, &pool1[e1->name]);

 				if (e1->start) {

 					child_md = array_add(&merge_stack, sizeof (struct merge_directory));

 					child_md->merged = last;

 					child_md->dir1 = e1->start;

 					child_md->dir2 = 0xFFFFFFFF;

 				}

 			}

 			if ((e1++)->flags & RAZOR_ENTRY_LAST)

 				e1 = NULL;

 		} else if (cmp > 0) {

 			if (map2[e2 - root2]) {

 				map2[e2 - root2] = last =

 					add_file(merger, &pool2[e2->name]);

 				if (e2->start) {

 					child_md = array_add(&merge_stack, sizeof (struct merge_directory));

 					child_md->merged = last;

 					child_md->dir1 = 0xFFFFFFFF;

 					child_md->dir2 = e2->start;

 				}

 			}

 			if ((e2++)->flags & RAZOR_ENTRY_LAST)

 				e2 = NULL;

 		} else {

 			map1[e1 - root1] = map2[e2- root2] = last =

 				add_file(merger, &pool1[e1->name]);

 			if (e1->start || e2->start) {

 				child_md = array_add(&merge_stack, sizeof (struct merge_directory));

 				child_md->merged = last;

 				child_md->dir1 = e1->start ? e1->start : 0xFFFFFFFF;

 				child_md->dir2 = e2->start ? e2->start : 0xFFFFFFFF;

 			}

 			if ((e1++)->flags & RAZOR_ENTRY_LAST)

 				e1 = NULL;

 			if ((e2++)->flags & RAZOR_ENTRY_LAST)

 				e2 = NULL;

 		}

 	}

 	mroot = (struct razor_entry *)merger->set->files.data;

 	if (last != 0xFFFFFFFF) {

 		mroot[last].flags = RAZOR_ENTRY_LAST;

 		mroot[md->merged].start = start;

 	}

 	end_md = merge_stack.data + merge_stack.size;

 	for (child_md = merge_stack.data; child_md < end_md; child_md++)

 		merge_one_directory(merger, child_md);

 	array_release(&merge_stack);

 }

 static void

 merge_files(struct razor_merger *merger)

 {

 	struct razor_entry *root;

 	struct merge_directory md;

 	uint32_t *map1, *map2;

 	map1 = merger->source1.file_map;

 	map2 = merger->source2.file_map;

 	md.merged = 0;

 	if (merger->source1.set->files.size) {

 		root = (struct razor_entry *) merger->source1.set->files.data;

 		if (root->start)

 			fix_file_map(map1, root, root);

 		md.dir1 = 0;

 	} else {

 		md.dir1 = 0xFFFFFFFF;

 	}

 	if (merger->source2.set->files.size) {

 		root = (struct razor_entry *) merger->source2.set->files.data;

 		if (root->start)

 			fix_file_map(map2, root, root);

 		md.dir2 = 0;

 	} else {

 		md.dir2 = 0xFFFFFFFF;

 	}

 	/* Remove the unnamed root which razor_set_create() added */

 	array_release(&merger->set->files);

 	array_init(&merger->set->files);

 	merge_one_directory(merger, &md);

 }

 static void

 emit_files(struct list_head *files, struct array *source_pool,

 	   uint32_t *map, struct array *pool)

 {

 	uint32_t r;

 	struct list *p, *q;

 	r = pool->size / sizeof *q;

 	p = list_first(files, source_pool);

 	while (p) {

 		q = array_add(pool, sizeof *q);

 		q->data = map[p->data];

 		q->flags = p->flags;

 		p = list_next(p);

 	}

 	list_set_ptr(files, r);

 }

 /* Rebuild property->packages maps.  We can't just remap these, as a

  * property may have lost or gained a number of packages.  Allocate an

  * array per property and loop through the packages and add them to

  * the arrays for their properties. */

 static void

 rebuild_property_package_lists(struct razor_set *set)

 {

 	struct array *pkgs, *a;

 	struct razor_package *pkg, *pkg_end;

 	struct razor_property *prop, *prop_end;

 	struct list *r;

 	uint32_t *q;

 	int count;

 	count = set->properties.size / sizeof (struct razor_property);

 	pkgs = zalloc(count * sizeof *pkgs);

 	pkg_end = set->packages.data + set->packages.size;

 	for (pkg = set->packages.data; pkg < pkg_end; pkg++) {

 		r = list_first(&pkg->properties, &set->property_pool);

 		while (r) {

 			q = array_add(&pkgs[r->data], sizeof *q);

 			*q = pkg - (struct razor_package *) set->packages.data;

 			r = list_next(r);

 		}

 	}

 	prop_end = set->properties.data + set->properties.size;

 	a = pkgs;

 	for (prop = set->properties.data; prop < prop_end; prop++, a++) {

 		list_set_array(&prop->packages, &set->package_pool, a, 0);

 		array_release(a);

 	}

 	free(pkgs);

 }

 static void

 rebuild_file_package_lists(struct razor_set *set)

 {

 	struct array *pkgs, *a;

 	struct razor_package *pkg, *pkg_end;

 	struct razor_entry *entry, *entry_end;

 	struct list *r;

 	uint32_t *q;

 	int count;

 	count = set->files.size / sizeof (struct razor_entry);

 	pkgs = zalloc(count * sizeof *pkgs);

 	pkg_end = set->packages.data + set->packages.size;

 	for (pkg = set->packages.data; pkg < pkg_end; pkg++) {

 		r = list_first(&pkg->files, &set->file_pool);

 		while (r) {

 			q = array_add(&pkgs[r->data], sizeof *q);

 			*q = pkg - (struct razor_package *) set->packages.data;

 			r = list_next(r);

 		}

 	}

 	entry_end = set->files.data + set->files.size;

 	a = pkgs;

 	for (entry = set->files.data; entry < entry_end; entry++, a++) {

 		list_set_array(&entry->packages, &set->package_pool, a, 0);

 		array_release(a);

 	}

 	free(pkgs);

 }

 struct razor_set *

 razor_merger_finish(struct razor_merger *merger)

 {

 	struct razor_set *result;

 	struct razor_package *p, *pend;

 	/* As we built the package list, we filled out a bitvector of

 	 * the properties that are referenced by the packages in the

 	 * new set.  Now we do a parallel loop through the properties

 	 * and emit those marked in the bit vector to the new set.  In

 	 * the process, we update the bit vector to actually map from

 	 * indices in the old property list to indices in the new

 	 * property list for both sets. */

 	merge_properties(merger);

 	merge_files(merger);

 	/* Now we loop through the packages again and emit the

 	 * property lists, remapped to point to the new properties. */

 	pend = merger->set->packages.data + merger->set->packages.size;

 	for (p = merger->set->packages.data; p < pend; p++) {

 		struct source *src;

 		if (p->flags & UPSTREAM_SOURCE)

 			src = &merger->source2;

 		else

 			src = &merger->source1;

 		emit_properties(&p->properties,

 				&src->set->property_pool,

 				src->property_map,

 				&merger->set->property_pool);

 		emit_files(&p->files,

 			   &src->set->file_pool,

 			   src->file_map,

 			   &merger->set->file_pool);

 		p->flags &= ~UPSTREAM_SOURCE;

 	}

 	rebuild_property_package_lists(merger->set);

 	rebuild_file_package_lists(merger->set);

 	result = merger->set;

 	hashtable_release(&merger->table);

 	hashtable_release(&merger->file_table);

 	free(merger);

 	return result;

 }