/*

 * Copyright (C) the libgit2 contributors. All rights reserved.

 *

 * This file is part of libgit2, distributed under the GNU GPL v2 with

 * a Linking Exception. For full terms see the included COPYING file.

 */

#include "notes.h"

#include "git2.h"

#include "refs.h"

#include "config.h"

#include "iterator.h"

#include "signature.h"

static int note_error_notfound(void)

{

	giterr_set(GITERR_INVALID, "note could not be found");

	return GIT_ENOTFOUND;

}

static int find_subtree_in_current_level(

	git_tree **out,

	git_repository *repo,

	git_tree *parent,

	const char *annotated_object_sha,

	int fanout)

{

	size_t i;

	const git_tree_entry *entry;

	*out = NULL;

	if (parent == NULL)

		return note_error_notfound();

	for (i = 0; i < git_tree_entrycount(parent); i++) {

		entry = git_tree_entry_byindex(parent, i);

		if (!git__ishex(git_tree_entry_name(entry)))

			continue;

		if (S_ISDIR(git_tree_entry_filemode(entry))

			&& strlen(git_tree_entry_name(entry)) == 2

			&& !strncmp(git_tree_entry_name(entry), annotated_object_sha + fanout, 2))

			return git_tree_lookup(out, repo, git_tree_entry_id(entry));

		/* Not a DIR, so do we have an already existing blob? */

		if (!strcmp(git_tree_entry_name(entry), annotated_object_sha + fanout))

			return GIT_EEXISTS;

	}

	return note_error_notfound();

}

static int find_subtree_r(git_tree **out, git_tree *root,

			git_repository *repo, const char *target, int *fanout)

{

	int error;

	git_tree *subtree = NULL;

	*out = NULL;

	error = find_subtree_in_current_level(&subtree, repo, root, target, *fanout);

	if (error == GIT_EEXISTS)

		return git_tree_lookup(out, repo, git_tree_id(root));

	if (error < 0)

		return error;

	*fanout += 2;

	error = find_subtree_r(out, subtree, repo, target, fanout);

	git_tree_free(subtree);

	return error;

}

static int find_blob(git_oid *blob, git_tree *tree, const char *target)

{

	size_t i;

	const git_tree_entry *entry;

	for (i=0; i

		entry = git_tree_entry_byindex(tree, i);

		if (!strcmp(git_tree_entry_name(entry), target)) {

			/* found matching note object - return */

			git_oid_cpy(blob, git_tree_entry_id(entry));

			return 0;

		}

	}

	return note_error_notfound();

}

static int tree_write(

	git_tree **out,

	git_repository *repo,

	git_tree *source_tree,

	const git_oid *object_oid,

	const char *treeentry_name,

	unsigned int attributes)

{

	int error;

	git_treebuilder *tb = NULL;

	const git_tree_entry *entry;

	git_oid tree_oid;

	if ((error = git_treebuilder_new(&tb, repo, source_tree)) < 0)

		goto cleanup;

	if (object_oid) {

		if ((error = git_treebuilder_insert(

				&entry, tb, treeentry_name, object_oid, attributes)) < 0)

			goto cleanup;

	} else {

		if ((error = git_treebuilder_remove(tb, treeentry_name)) < 0)

			goto cleanup;

	}

	if ((error = git_treebuilder_write(&tree_oid, tb)) < 0)

		goto cleanup;

	error = git_tree_lookup(out, repo, &tree_oid);

cleanup:

	git_treebuilder_free(tb);

	return error;

}

static int manipulate_note_in_tree_r(

	git_tree **out,

	git_repository *repo,

	git_tree *parent,

	git_oid *note_oid,

	const char *annotated_object_sha,

	int fanout,

	int (*note_exists_cb)(

		git_tree **out,

		git_repository *repo,

		git_tree *parent,

		git_oid *note_oid,

		const char *annotated_object_sha,

		int fanout,

		int current_error),

	int (*note_notfound_cb)(

		git_tree **out,

		git_repository *repo,

		git_tree *parent,

		git_oid *note_oid,

		const char *annotated_object_sha,

		int fanout,

		int current_error))

{

	int error;

	git_tree *subtree = NULL, *new = NULL;

	char subtree_name[3];

	error = find_subtree_in_current_level(

		&subtree, repo, parent, annotated_object_sha, fanout);

	if (error == GIT_EEXISTS) {

		error = note_exists_cb(

			out, repo, parent, note_oid, annotated_object_sha, fanout, error);

		goto cleanup;

	}

	if (error == GIT_ENOTFOUND) {

		error = note_notfound_cb(

			out, repo, parent, note_oid, annotated_object_sha, fanout, error);

		goto cleanup;

	}

	if (error < 0)

		goto cleanup;

	/* An existing fanout has been found, let's dig deeper */

	error = manipulate_note_in_tree_r(

		&new, repo, subtree, note_oid, annotated_object_sha,

		fanout + 2, note_exists_cb, note_notfound_cb);

	if (error < 0)

		goto cleanup;

	strncpy(subtree_name, annotated_object_sha + fanout, 2);

	subtree_name[2] = '\0';

	error = tree_write(out, repo, parent, git_tree_id(new),

			   subtree_name, GIT_FILEMODE_TREE);

cleanup:

	git_tree_free(new);

	git_tree_free(subtree);

	return error;

}

static int remove_note_in_tree_eexists_cb(

	git_tree **out,

	git_repository *repo,

	git_tree *parent,

	git_oid *note_oid,

	const char *annotated_object_sha,

	int fanout,

	int current_error)

{

	GIT_UNUSED(note_oid);

	GIT_UNUSED(current_error);

	return tree_write(out, repo, parent, NULL, annotated_object_sha + fanout, 0);

}

static int remove_note_in_tree_enotfound_cb(

	git_tree **out,

	git_repository *repo,

	git_tree *parent,

	git_oid *note_oid,

	const char *annotated_object_sha,

	int fanout,

	int current_error)

{

	GIT_UNUSED(out);

	GIT_UNUSED(repo);

	GIT_UNUSED(parent);

	GIT_UNUSED(note_oid);

	GIT_UNUSED(fanout);

	giterr_set(GITERR_REPOSITORY, "object '%s' has no note", annotated_object_sha);

	return current_error;

}

static int insert_note_in_tree_eexists_cb(git_tree **out,

	git_repository *repo,

	git_tree *parent,

	git_oid *note_oid,

	const char *annotated_object_sha,

	int fanout,

	int current_error)

{

	GIT_UNUSED(out);

	GIT_UNUSED(repo);

	GIT_UNUSED(parent);

	GIT_UNUSED(note_oid);

	GIT_UNUSED(fanout);

	giterr_set(GITERR_REPOSITORY, "note for '%s' exists already", annotated_object_sha);

	return current_error;

}

static int insert_note_in_tree_enotfound_cb(git_tree **out,

	git_repository *repo,

	git_tree *parent,

	git_oid *note_oid,

	const char *annotated_object_sha,

	int fanout,

	int current_error)

{

	GIT_UNUSED(current_error);

	/* No existing fanout at this level, insert in place */

	return tree_write(

		out,

		repo,

		parent,

		note_oid,

		annotated_object_sha + fanout,

		GIT_FILEMODE_BLOB);

}

static int note_write(git_oid *out,

	git_repository *repo,

	const git_signature *author,

	const git_signature *committer,

	const char *notes_ref,

	const char *note,

	git_tree *commit_tree,

	const char *target,

	git_commit **parents,

	int allow_note_overwrite)

{

	int error;

	git_oid oid;

	git_tree *tree = NULL;

	// TODO: should we apply filters?

	/* create note object */

	if ((error = git_blob_create_frombuffer(&oid, repo, note, strlen(note))) < 0)

		goto cleanup;

	if ((error = manipulate_note_in_tree_r(

		&tree, repo, commit_tree, &oid, target, 0,

		allow_note_overwrite ? insert_note_in_tree_enotfound_cb : insert_note_in_tree_eexists_cb,

		insert_note_in_tree_enotfound_cb)) < 0)

		goto cleanup;

	if (out)

		git_oid_cpy(out, &oid;;

	error = git_commit_create(&oid, repo, notes_ref, author, committer,

				  NULL, GIT_NOTES_DEFAULT_MSG_ADD,

				  tree, *parents == NULL ? 0 : 1, (const git_commit **) parents);

cleanup:

	git_tree_free(tree);

	return error;

}

static int note_new(

	git_note **out,

	git_oid *note_oid,

	git_commit *commit,

	git_blob *blob)

{

	git_note *note = NULL;

	note = git__malloc(sizeof(git_note));

	GITERR_CHECK_ALLOC(note);

	git_oid_cpy(&note->id, note_oid);

	if (git_signature_dup(&note->author, git_commit_author(commit)) < 0 ||

		git_signature_dup(&note->committer, git_commit_committer(commit)) < 0)

		return -1;

	note->message = git__strndup(git_blob_rawcontent(blob), git_blob_rawsize(blob));

	GITERR_CHECK_ALLOC(note->message);

	*out = note;

	return 0;

}

static int note_lookup(

	git_note **out,

	git_repository *repo,

	git_commit *commit,

	git_tree *tree,

	const char *target)

{

	int error, fanout = 0;

	git_oid oid;

	git_blob *blob = NULL;

	git_note *note = NULL;

	git_tree *subtree = NULL;

	if ((error = find_subtree_r(&subtree, tree, repo, target, &fanout)) < 0)

		goto cleanup;

	if ((error = find_blob(&oid, subtree, target + fanout)) < 0)

		goto cleanup;

	if ((error = git_blob_lookup(&blob, repo, &oid)) < 0)

		goto cleanup;

	if ((error = note_new(&note, &oid, commit, blob)) < 0)

		goto cleanup;

	*out = note;

cleanup:

	git_tree_free(subtree);

	git_blob_free(blob);

	return error;

}

static int note_remove(git_repository *repo,

		const git_signature *author, const git_signature *committer,

		const char *notes_ref, git_tree *tree,

		const char *target, git_commit **parents)

{

	int error;

	git_tree *tree_after_removal = NULL;

	git_oid oid;

	if ((error = manipulate_note_in_tree_r(

		&tree_after_removal, repo, tree, NULL, target, 0,

		remove_note_in_tree_eexists_cb, remove_note_in_tree_enotfound_cb)) < 0)

		goto cleanup;

	error = git_commit_create(&oid, repo, notes_ref, author, committer,

	  NULL, GIT_NOTES_DEFAULT_MSG_RM,

	  tree_after_removal,

	  *parents == NULL ? 0 : 1,

	  (const git_commit **) parents);

cleanup:

	git_tree_free(tree_after_removal);

	return error;

}

static int note_get_default_ref(char **out, git_repository *repo)

{

	git_config *cfg;

	int ret = git_repository_config__weakptr(&cfg, repo);

	*out = (ret != 0) ? NULL : git_config__get_string_force(

		cfg, "core.notesref", GIT_NOTES_DEFAULT_REF);

	return ret;

}

static int normalize_namespace(char **out, git_repository *repo, const char *notes_ref)

{

	if (notes_ref) {

		*out = git__strdup(notes_ref);

		GITERR_CHECK_ALLOC(*out);

		return 0;

	}

	return note_get_default_ref(out, repo);

}

static int retrieve_note_tree_and_commit(

	git_tree **tree_out,

	git_commit **commit_out,

	char **notes_ref_out,

	git_repository *repo,

	const char *notes_ref)

{

	int error;

	git_oid oid;

	if ((error = normalize_namespace(notes_ref_out, repo, notes_ref)) < 0)

		return error;

	if ((error = git_reference_name_to_id(&oid, repo, *notes_ref_out)) < 0)

		return error;

	if (git_commit_lookup(commit_out, repo, &oid) < 0)

		return error;

	if ((error = git_commit_tree(tree_out, *commit_out)) < 0)

		return error;

	return 0;

}

int git_note_read(git_note **out, git_repository *repo,

		  const char *notes_ref_in, const git_oid *oid)

{

	int error;

	char *target = NULL, *notes_ref = NULL;

	git_tree *tree = NULL;

	git_commit *commit = NULL;

	target = git_oid_allocfmt(oid);

	GITERR_CHECK_ALLOC(target);

	if (!(error = retrieve_note_tree_and_commit(

		      &tree, &commit, &notes_ref, repo, notes_ref_in)))

		error = note_lookup(out, repo, commit, tree, target);

	git__free(notes_ref);

	git__free(target);

	git_tree_free(tree);

	git_commit_free(commit);

	return error;

}

int git_note_create(

	git_oid *out,

	git_repository *repo,

	const char *notes_ref_in,

	const git_signature *author,

	const git_signature *committer,

	const git_oid *oid,

	const char *note,

	int allow_note_overwrite)

{

	int error;

	char *target = NULL, *notes_ref = NULL;

	git_commit *commit = NULL;

	git_tree *tree = NULL;

	target = git_oid_allocfmt(oid);

	GITERR_CHECK_ALLOC(target);

	error = retrieve_note_tree_and_commit(&tree, &commit, &notes_ref, repo, notes_ref_in);

	if (error < 0 && error != GIT_ENOTFOUND)

		goto cleanup;

	error = note_write(out, repo, author, committer, notes_ref,

			note, tree, target, &commit, allow_note_overwrite);

cleanup:

	git__free(notes_ref);

	git__free(target);

	git_commit_free(commit);

	git_tree_free(tree);

	return error;

}

int git_note_remove(git_repository *repo, const char *notes_ref_in,

		const git_signature *author, const git_signature *committer,

		const git_oid *oid)

{

	int error;

	char *target = NULL, *notes_ref;

	git_commit *commit = NULL;

	git_tree *tree = NULL;

	target = git_oid_allocfmt(oid);

	GITERR_CHECK_ALLOC(target);

	if (!(error = retrieve_note_tree_and_commit(

		      &tree, &commit, &notes_ref, repo, notes_ref_in)))

		error = note_remove(

			repo, author, committer, notes_ref, tree, target, &commit);

	git__free(notes_ref);

	git__free(target);

	git_commit_free(commit);

	git_tree_free(tree);

	return error;

}

int git_note_default_ref(git_buf *out, git_repository *repo)

{

	char *default_ref;

	int error;

	assert(out && repo);

	git_buf_sanitize(out);

	if ((error = note_get_default_ref(&default_ref, repo)) < 0)

		return error;

	git_buf_attach(out, default_ref, strlen(default_ref));

	return 0;

}

const git_signature *git_note_committer(const git_note *note)

{

	assert(note);

	return note->committer;

}

const git_signature *git_note_author(const git_note *note)

{

	assert(note);

	return note->author;

}

const char * git_note_message(const git_note *note)

{

	assert(note);

	return note->message;

}

const git_oid * git_note_id(const git_note *note)

{

	assert(note);

	return &note->id;

}

void git_note_free(git_note *note)

{

	if (note == NULL)

		return;

	git_signature_free(note->committer);

	git_signature_free(note->author);

	git__free(note->message);

	git__free(note);

}

static int process_entry_path(

	const char* entry_path,

	git_oid *annotated_object_id)

{

	int error = 0;

	size_t i = 0, j = 0, len;

	git_buf buf = GIT_BUF_INIT;

	if ((error = git_buf_puts(&buf, entry_path)) < 0)

		goto cleanup;

	len = git_buf_len(&buf;;

	while (i < len) {

		if (buf.ptr[i] == '/') {

			i++;

			continue;

		}

		if (git__fromhex(buf.ptr[i]) < 0) {

			/* This is not a note entry */

			goto cleanup;

		}

		if (i != j)

			buf.ptr[j] = buf.ptr[i];

		i++;

		j++;

	}

	buf.ptr[j] = '\0';

	buf.size = j;

	if (j != GIT_OID_HEXSZ) {

		/* This is not a note entry */

		goto cleanup;

	}

	error = git_oid_fromstr(annotated_object_id, buf.ptr);

cleanup:

	git_buf_free(&buf;;

	return error;

}

int git_note_foreach(

	git_repository *repo,

	const char *notes_ref,

	git_note_foreach_cb note_cb,

	void *payload)

{

	int error;

	git_note_iterator *iter = NULL;

	git_oid note_id, annotated_id;

	if ((error = git_note_iterator_new(&iter, repo, notes_ref)) < 0)

		return error;

	while (!(error = git_note_next(&note_id, &annotated_id, iter))) {

		if ((error = note_cb(&note_id, &annotated_id, payload)) != 0) {

			giterr_set_after_callback(error);

			break;

		}

	}

	if (error == GIT_ITEROVER)

		error = 0;

	git_note_iterator_free(iter);

	return error;

}

void git_note_iterator_free(git_note_iterator *it)

{

	if (it == NULL)

		return;

	git_iterator_free(it);

}

int git_note_iterator_new(

	git_note_iterator **it,

	git_repository *repo,

	const char *notes_ref_in)

{

	int error;

	git_commit *commit = NULL;

	git_tree *tree = NULL;

	char *notes_ref;

	error = retrieve_note_tree_and_commit(&tree, &commit, &notes_ref, repo, notes_ref_in);

	if (error < 0)

		goto cleanup;

	if ((error = git_iterator_for_tree(it, tree, NULL)) < 0)

		git_iterator_free(*it);

cleanup:

	git__free(notes_ref);

	git_tree_free(tree);

	git_commit_free(commit);

	return error;

}

int git_note_next(

	git_oid* note_id,

	git_oid* annotated_id,

	git_note_iterator *it)

{

	int error;

	const git_index_entry *item;

	if ((error = git_iterator_current(&item, it)) < 0)

		return error;

	git_oid_cpy(note_id, &item->id);

	if (!(error = process_entry_path(item->path, annotated_id)))

		git_iterator_advance(NULL, it);

	return error;

}