/*

 * 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;

}