filter: implement saving of filter presets to git repositories

On the mailing list it was decided that users might want to
move their filter presets across computers via the cloud.
Notably, in the future one might access statistics on mobile and
these might by controlled by filter presets.

The git save routines use the same string formatting as the
XML save routines. The string formatting is found in
core/filterconstraint.cpp. Thus, duplication of code and
inconsistencies should be minimized.

Each filter preset is saved into a file in the "02-Filterpresets"
folder in the root of the git repository.

Each file consists of one "name" line, zero or one "fulltext" line
and zero or more "constraint" lines.

The modes, types and the actual payload is controlled via attributes.
Thus, a preset file might look like this:

name "test"
fulltext mode="substring" query="clown"
constraint type="location" stringmode="starstwith" data="mafia"
constraint type="sac" rangemode="range" negate data="5000,10000"

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

1 files changed, 84 insertions, 0 deletions

diff --git a/core/save-git.c b/core/save-git.c
index ec594f131..4c8969047 100644
--- a/core/save-git.c
+++ b/core/save-git.c
@@ -18,6 +18,8 @@
 
 #include "dive.h"
 #include "divesite.h"
+#include "filterconstraint.h"
+#include "filterpreset.h"
 #include "subsurface-string.h"
 #include "trip.h"
 #include "device.h"
@@ -916,6 +918,87 @@ static void save_divesites(git_repository *repo, struct dir *tree)
 	}
 }
 
+/*
+ * Format a filter constraint line to the membuffer b.
+ * The format is
+ *	constraint type "type of the constraint" [stringmode "string mode"] [rangemode "rangemode"] [negate] data "data of the constraint".
+ * where brackets indicate optional blocks.
+ * For possible types and how data is interpreted see core/filterconstraint.[c|h]
+ * Whether stringmode or rangemode exist depends on the type of the constraint.
+ * Any constraint can be negated.
+ */
+static void format_one_filter_constraint(int preset_id, int constraint_id, struct membuffer *b)
+{
+	const struct filter_constraint *constraint = filter_preset_constraint(preset_id, constraint_id);
+	const char *type = filter_constraint_type_to_string(constraint->type);
+	char *data;
+
+	show_utf8(b, "constraint type=", type, "");
+	if (filter_constraint_has_string_mode(constraint->type)) {
+		const char *mode = filter_constraint_string_mode_to_string(constraint->string_mode);
+		show_utf8(b, " stringmode=", mode, "");
+	}
+	if (filter_constraint_has_range_mode(constraint->type)) {
+		const char *mode = filter_constraint_range_mode_to_string(constraint->range_mode);
+		show_utf8(b, " rangemode=", mode, "");
+	}
+	if (constraint->negate)
+		put_format(b, " negate");
+	data = filter_constraint_data_to_string(constraint);
+	show_utf8(b, " data=", data, "\n");
+	free(data);
+}
+
+/*
+ * Write a filter constraint to the membuffer b.
+ * Each line starts with a type, which is either "name", "fulltext" or "constraint".
+ * There must be one "name" entry, zero or ont "fulltext" entries and an arbitrary number of "contraint" entries.
+ * The "name" entry gives the name of the filter constraint.
+ * The "fulltext" entry has the format
+ *	fulltext mode "fulltext mode" query "the query as entered by the user"
+ * The format of the "constraint" entry is described in the format_one_filter_constraint() function.
+ */
+static void format_one_filter_preset(int preset_id, struct membuffer *b)
+{
+	char *name, *fulltext;
+
+	name = filter_preset_name(preset_id);
+	show_utf8(b, "name ", name, "\n");
+	free(name);
+
+	fulltext = filter_preset_fulltext_query(preset_id);
+	if (!empty_string(fulltext)) {
+		show_utf8(b, "fulltext mode=", filter_preset_fulltext_mode(preset_id), "");
+		show_utf8(b, " query=", fulltext, "\n");
+	}
+
+	for (int i = 0; i < filter_preset_constraint_count(preset_id); i++)
+		format_one_filter_constraint(preset_id, i, b);
+}
+
+static void save_filter_presets(git_repository *repo, struct dir *tree)
+{
+	struct membuffer dirname = { 0 };
+	struct dir *filter_dir;
+	put_format(&dirname, "02-Filterpresets");
+	filter_dir = new_directory(repo, tree, &dirname);
+	free_buffer(&dirname);
+
+	for (int i = 0; i < filter_presets_count(); i++)
+	{
+		struct membuffer preset_name = { 0 };
+		struct membuffer preset_buffer = { 0 };
+
+		put_format(&preset_name, "Preset-%03d", i);
+		format_one_filter_preset(i, &preset_buffer);
+
+		blob_insert(repo, filter_dir, &preset_buffer, mb_cstring(&preset_name));
+
+		free_buffer(&preset_name);
+		free_buffer(&preset_buffer);
+	}
+}
+
 static int create_git_tree(git_repository *repo, struct dir *root, bool select_only, bool cached_ok)
 {
 	int i;
@@ -926,6 +1009,7 @@ static int create_git_tree(git_repository *repo, struct dir *root, bool select_o
 	save_settings(repo, root);
 
 	save_divesites(repo, root);
+	save_filter_presets(repo, root);
 
 	for (i = 0; i < trip_table.nr; ++i)
 		trip_table.trips[i]->saved = 0;