v.info: Add JSON output for history

vector/v.info/local_proto.h

@@ -5,6 +5,7 @@
 #define SHELL_BASIC  0x02
 #define SHELL_REGION 0x04
 #define SHELL_TOPO   0x08
+#define MAX_STR_LEN  1001
 
 enum OutputFormat { PLAIN, SHELL, JSON };
 
@@ -24,3 +25,4 @@ void print_columns(struct Map_info *, const char *, const char *,
 void print_info(struct Map_info *);
 void print_shell(struct Map_info *, const char *, enum OutputFormat,
                  JSON_Object *);
+void print_history(struct Map_info, enum OutputFormat);

vector/v.info/main.c

@@ -72,12 +72,7 @@ int main(int argc, char *argv[])
 
     if (hist_flag || col_flag) {
         if (hist_flag) {
-            char buf[1001];
-
-            Vect_hist_rewind(&Map);
-            while (Vect_hist_read(buf, 1000, &Map) != NULL) {
-                fprintf(stdout, "%s\n", buf);
-            }
+            print_history(Map, format);
         }
         else if (col_flag) {
             print_columns(&Map, input_opt, field_opt, format);

vector/v.info/print.c

@@ -771,3 +771,84 @@ void print_info(struct Map_info *Map)
     divider('+');
     fprintf(stdout, "\n");
 }
+
+void print_history(struct Map_info Map, enum OutputFormat format)
+{
+    char buf[MAX_STR_LEN];
+    char command[MAX_STR_LEN] = {0}, gisdbase[MAX_STR_LEN] = {0};
+    char location[MAX_STR_LEN] = {0}, mapset[MAX_STR_LEN] = {0};
+    char user[MAX_STR_LEN] = {0}, date[MAX_STR_LEN] = {0};
+    char mapset_path[3 * MAX_STR_LEN] = {0};
+
+    JSON_Value *root_value = NULL, *record_value = NULL;
+    JSON_Object *root_object = NULL;
+    JSON_Array *record_array = NULL;
+
+    if (format == JSON) {
+        root_value = json_value_init_object();
+        if (root_value == NULL) {
+            G_fatal_error(
+                _("Failed to initialize JSON object. Out of memory?"));
+        }
+        root_object = json_object(root_value);
+
+        record_value = json_value_init_array();
+        if (record_value == NULL) {
+            G_fatal_error(_("Failed to initialize JSON array. Out of memory?"));
+        }
+        record_array = json_array(record_value);
+    }
+
+    Vect_hist_rewind(&Map);
+    while (Vect_hist_read(buf, 1000, &Map) != NULL) {
+        switch (format) {
+        case PLAIN:
+        case SHELL:
+            fprintf(stdout, "%s\n", buf);
+            break;
+        case JSON:
+            // Parse each line based on its prefix
+            if (strncmp(buf, "COMMAND:", 8) == 0) {
+                sscanf(buf, "COMMAND: %[^\n]", command);
+            }
+            else if (strncmp(buf, "GISDBASE:", 9) == 0) {
+                sscanf(buf, "GISDBASE: %[^\n]", gisdbase);
+            }
+            else if (strncmp(buf, "LOCATION:", 9) == 0) {
+                sscanf(buf, "LOCATION: %s MAPSET: %s USER: %s DATE: %[^\n]",
+                       location, mapset, user, date);
+
+                JSON_Value *info_value = json_value_init_object();
+                if (info_value == NULL) {
+                    G_fatal_error(
+                        _("Failed to initialize JSON object. Out of memory?"));
+                }
+                JSON_Object *info_object = json_object(info_value);
+
+                json_object_set_string(info_object, "command", command);
+                snprintf(mapset_path, sizeof(mapset_path), "%s/%s/%s", gisdbase,
+                         location, mapset);
+                json_object_set_string(info_object, "mapset_path", mapset_path);
+                json_object_set_string(info_object, "user", user);
+                json_object_set_string(info_object, "date", date);
+
+                json_array_append_value(record_array, info_value);
+            }
+            break;
+        }
+    }
+
+    if (format == JSON) {
+        json_object_set_value(root_object, "records", record_value);
+
+        char *serialized_string = json_serialize_to_string_pretty(root_value);
+        if (!serialized_string) {
+            json_value_free(root_value);
+            G_fatal_error(_("Failed to initialize pretty JSON string."));
+        }
+        puts(serialized_string);
+
+        json_free_serialized_string(serialized_string);
+        json_value_free(root_value);
+    }
+}

vector/v.info/testsuite/test_vinfo.py

@@ -271,6 +271,33 @@ def test_json_column(self):
 
         self.assertDictEqual(expected_json, result)
 
+    def test_json_histroy(self):
+        """Test the v.info JSON output format with the history flag."""
+        module = SimpleModule(
+            "v.info", map=self.test_vinfo_with_db_3d, format="json", flags="h"
+        )
+        self.runModule(module)
+        result = json.loads(module.outputs.stdout)
+
+        expected_json = {
+            "records": [
+                {
+                    "command": 'v.random -z output="test_vinfo_with_db_3d" npoints=5 layer="-1" zmin=0 zmax=100 column="elevation" column_type="double precision"'
+                }
+            ]
+        }
+
+        # The following fields vary depending on the Grass sample data's path,
+        # date, and user. Therefore, only check for their presence in the JSON output
+        # and not for their exact values.
+        remove_fields = ["mapset_path", "date", "user"]
+        for record in result["records"]:
+            for field in remove_fields:
+                self.assertIn(field, record)
+                record.pop(field)
+
+        self.assertDictEqual(expected_json, result)
+
     def test_database_table(self):
         """Test the database table column and type of the two vector maps with attribute data"""
         self.assertModuleKeyValue(