#include "cache.h"
#include "tag.h"
#include "commit.h"
#include "tree.h"
#include "blob.h"
#include "diff.h"
#include "tree-walk.h"
#include "revision.h"
#include "list-objects.h"

static void process_blob(struct rev_info *revs,
			 struct blob *blob,
			 show_object_fn show,
			 struct name_path *path,
			 const char *name,
			 void *cb_data)
{
	struct object *obj = &blob->object;

	if (!revs->blob_objects)
		return;
	if (!obj)
		die("bad blob object");
	if (obj->flags & (UNINTERESTING | SEEN))
		return;
	obj->flags |= SEEN;
	show(obj, path, name, cb_data);
}

/*
 * Processing a gitlink entry currently does nothing, since
 * we do not recurse into the subproject.
 *
 * We *could* eventually add a flag that actually does that,
 * which would involve:
 *  - is the subproject actually checked out?
 *  - if so, see if the subproject has already been added
 *    to the alternates list, and add it if not.
 *  - process the commit (or tag) the gitlink points to
 *    recursively.
 *
 * However, it's unclear whether there is really ever any
 * reason to see superprojects and subprojects as such a
 * "unified" object pool (potentially resulting in a totally
 * humongous pack - avoiding which was the whole point of
 * having gitlinks in the first place!).
 *
 * So for now, there is just a note that we *could* follow
 * the link, and how to do it. Whether it necessarily makes
 * any sense what-so-ever to ever do that is another issue.
 */
static void process_gitlink(struct rev_info *revs,
			    const unsigned char *sha1,
			    show_object_fn show,
			    struct name_path *path,
			    const char *name,
			    void *cb_data)
{
	/* Nothing to do */
}

static void process_tree(struct rev_info *revs,
			 struct tree *tree,
			 show_object_fn show,
			 struct name_path *path,
			 struct strbuf *base,
			 const char *name,
			 void *cb_data)
{
	struct object *obj = &tree->object;
	struct tree_desc desc;
	struct name_entry entry;
	struct name_path me;
	int match = revs->diffopt.pathspec.nr == 0 ? 2 : 0;
	int baselen = base->len;

	if (!revs->tree_objects)
		return;
	if (!obj)
		die("bad tree object");
	if (obj->flags & (UNINTERESTING | SEEN))
		return;
	if (parse_tree(tree) < 0)
		die("bad tree object %s", sha1_to_hex(obj->sha1));
	obj->flags |= SEEN;
	show(obj, path, name, cb_data);
	me.up = path;
	me.elem = name;
	me.elem_len = strlen(name);

	if (!match) {
		strbuf_addstr(base, name);
		if (base->len)
			strbuf_addch(base, '/');
	}

	init_tree_desc(&desc, tree->buffer, tree->size);

	while (tree_entry(&desc, &entry)) {
		if (match != 2) {
			match = tree_entry_interesting(&entry, base, 0,
						       &revs->diffopt.pathspec);
			if (match < 0)
				break;
			if (match == 0)
				continue;
		}

		if (S_ISDIR(entry.mode))
			process_tree(revs,
				     lookup_tree(entry.sha1),
				     show, &me, base, entry.path,
				     cb_data);
		else if (S_ISGITLINK(entry.mode))
			process_gitlink(revs, entry.sha1,
					show, &me, entry.path,
					cb_data);
		else
			process_blob(revs,
				     lookup_blob(entry.sha1),
				     show, &me, entry.path,
				     cb_data);
	}
	strbuf_setlen(base, baselen);
	free(tree->buffer);
	tree->buffer = NULL;
}

static void mark_edge_parents_uninteresting(struct commit *commit,
					    struct rev_info *revs,
					    show_edge_fn show_edge)
{
	struct commit_list *parents;

	for (parents = commit->parents; parents; parents = parents->next) {
		struct commit *parent = parents->item;
		if (!(parent->object.flags & UNINTERESTING))
			continue;
		mark_tree_uninteresting(parent->tree);
		if (revs->edge_hint && !(parent->object.flags & SHOWN)) {
			parent->object.flags |= SHOWN;
			show_edge(parent);
		}
	}
}

void mark_edges_uninteresting(struct commit_list *list,
			      struct rev_info *revs,
			      show_edge_fn show_edge)
{
	for ( ; list; list = list->next) {
		struct commit *commit = list->item;

		if (commit->object.flags & UNINTERESTING) {
			mark_tree_uninteresting(commit->tree);
			continue;
		}
		mark_edge_parents_uninteresting(commit, revs, show_edge);
	}
}

static void add_pending_tree(struct rev_info *revs, struct tree *tree)
{
	add_pending_object(revs, &tree->object, "");
}

void traverse_commit_list(struct rev_info *revs,
			  show_commit_fn show_commit,
			  show_object_fn show_object,
			  void *data)
{
	int i;
	struct commit *commit;
	struct strbuf base;

	strbuf_init(&base, PATH_MAX);
	while ((commit = get_revision(revs)) != NULL) {
		/*
		 * an uninteresting boundary commit may not have its tree
		 * parsed yet, but we are not going to show them anyway
		 */
		if (commit->tree)
			add_pending_tree(revs, commit->tree);
		show_commit(commit, data);
	}
	for (i = 0; i < revs->pending.nr; i++) {
		struct object_array_entry *pending = revs->pending.objects + i;
		struct object *obj = pending->item;
		const char *name = pending->name;
		if (obj->flags & (UNINTERESTING | SEEN))
			continue;
		if (obj->type == OBJ_TAG) {
			obj->flags |= SEEN;
			show_object(obj, NULL, name, data);
			continue;
		}
		if (obj->type == OBJ_TREE) {
			process_tree(revs, (struct tree *)obj, show_object,
				     NULL, &base, name, data);
			continue;
		}
		if (obj->type == OBJ_BLOB) {
			process_blob(revs, (struct blob *)obj, show_object,
				     NULL, name, data);
			continue;
		}
		die("unknown pending object %s (%s)",
		    sha1_to_hex(obj->sha1), name);
	}
	if (revs->pending.nr) {
		free(revs->pending.objects);
		revs->pending.nr = 0;
		revs->pending.alloc = 0;
		revs->pending.objects = NULL;
	}
	strbuf_release(&base);
}