[gnome-todo] todo-txt: implement task description/notes

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 295bf8c09955af1b23e6297dafcd7532aa915576
Author: Rohit Kaushik <kaushikrohit325 gmail com>
Date:   Thu May 17 23:30:01 2018 +0530

    todo-txt: implement task description/notes
    
    The patch implement notes functionality for todo.txt.
    It implements:
            1) Caching and loading task notes.
            2) handle special cases like notes overlowing
            in multiple lines or special characters in
            between notes by escaping special characters
            while caching and teaching parser to ignore
            extra "\" while loading/
    
    Issue Link: https://gitlab.gnome.org/GNOME/gnome-todo/issues/124

 plugins/todo-txt/gtd-provider-todo-txt.c |   8 +++
 plugins/todo-txt/gtd-todo-txt-parser.c   | 110 +++++++++++++++++++++++++------
 2 files changed, 97 insertions(+), 21 deletions(-)
---
diff --git a/plugins/todo-txt/gtd-provider-todo-txt.c b/plugins/todo-txt/gtd-provider-todo-txt.c
index 136dc7e..12a753e 100644
--- a/plugins/todo-txt/gtd-provider-todo-txt.c
+++ b/plugins/todo-txt/gtd-provider-todo-txt.c
@@ -84,6 +84,7 @@ print_task (GString *output,
 {
   GtdTaskList *list;
   GDateTime *dt;
+  const gchar *description;
   gint priority;
   gboolean is_complete;
 
@@ -91,6 +92,7 @@ print_task (GString *output,
   priority = gtd_task_get_priority (task);
   dt = gtd_task_get_due_date (task);
   list = gtd_task_get_list (task);
+  description = gtd_task_get_description (task);
 
   if (is_complete)
     g_string_append (output, "x ");
@@ -116,6 +118,12 @@ print_task (GString *output,
       g_string_append_printf (output, " due:%s", formatted_time);
     }
 
+  if (description)
+    {
+      g_autofree gchar *new_description = g_strescape (description, NULL);
+      g_string_append_printf (output, " note:\"%s\"", new_description);
+    }
+
   g_string_append (output, "\n");
 }
 
diff --git a/plugins/todo-txt/gtd-todo-txt-parser.c b/plugins/todo-txt/gtd-todo-txt-parser.c
index 7ee197f..1f02f54 100644
--- a/plugins/todo-txt/gtd-todo-txt-parser.c
+++ b/plugins/todo-txt/gtd-todo-txt-parser.c
@@ -38,9 +38,16 @@ typedef enum
   TOKEN_TITLE,
   TOKEN_LIST_NAME,
   TOKEN_LIST_COLOR,
-  TOKEN_DUE_DATE
+  TOKEN_DUE_DATE,
+  TOKEN_NOTE
 } Token;
 
+typedef struct
+{
+  Token               last_token;
+  gboolean            in_description;
+} GtdTodoTxtParserState;
+
 static gint
 parse_priority (const gchar *token)
 {
@@ -98,9 +105,51 @@ is_date (const gchar *dt)
   return g_date_valid (&date);
 }
 
+static void
+append_note (const gchar           *token,
+             GString               *note,
+             GtdTodoTxtParserState *state)
+{
+  g_autofree gchar *esc_token = NULL;
+
+  if (!state->in_description && g_str_has_prefix (token , "note:"))
+    {
+      /* Remove the extra "\" added for escaping special character */
+      esc_token = g_strcompress (token + strlen ("note:\""));
+      g_string_append (note, esc_token);
+      g_string_append (note, " ");
+      state->in_description = TRUE;
+    }
+  else if (state->in_description)
+    {
+      if (g_str_has_suffix (token, "\""))
+        {
+          g_autofree gchar *new_token = NULL;
+
+          new_token = g_strdup (token);
+          /* Remove the last "\"" */
+          new_token [strlen (new_token) - 1] = '\0';
+
+          /* Remove the extra "\" added for escaping special character */
+          esc_token = g_strcompress (new_token);
+          g_string_append (note, esc_token);
+
+          /* Revert back parser state in_description to FALSE */
+          state->in_description = FALSE;
+        }
+      else
+        {
+          /* Remove the extra "\" added for escaping special character */
+          esc_token = g_strcompress (token);
+          g_string_append (note, esc_token);
+          g_string_append (note, " ");
+        }
+    }
+}
+
 static Token
-parse_token_id (const gchar *token,
-                gint         last_read)
+parse_token_id (const gchar           *token,
+                GtdTodoTxtParserState *state)
 {
   gint token_length;
 
@@ -127,15 +176,21 @@ parse_token_id (const gchar *token,
   if (g_str_has_prefix (token , "due:"))
     return TOKEN_DUE_DATE;
 
-  if (last_read == TOKEN_START ||
-      last_read == TOKEN_DATE ||
-      last_read == TOKEN_PRIORITY ||
-      last_read == TOKEN_COMPLETE||
-      last_read == TOKEN_TITLE)
+  if ((!state->in_description && g_str_has_prefix (token , "note:")) ||
+      (state->last_token == TOKEN_NOTE && state->in_description))
+    {
+      return TOKEN_NOTE;
+    }
+
+  if (state->last_token == TOKEN_START ||
+      state->last_token == TOKEN_DATE ||
+      state->last_token == TOKEN_PRIORITY ||
+      state->last_token == TOKEN_COMPLETE||
+      state->last_token == TOKEN_TITLE)
     {
       return TOKEN_TITLE;
     }
-  else if (last_read == TOKEN_LIST_NAME)
+  else if (state->last_token == TOKEN_LIST_NAME)
     {
       return TOKEN_LIST_NAME;
     }
@@ -165,18 +220,21 @@ gtd_todo_txt_parser_parse_task (GtdProvider  *provider,
   g_autoptr (GString) parent_task_name = NULL;
   g_autoptr (GString) list_name = NULL;
   g_autoptr (GString) title = NULL;
+  g_autoptr (GString) note = NULL;
   g_autoptr (GtdTask) task = NULL;
+  GtdTodoTxtParserState state;
   g_auto (GStrv) tokens = NULL;
   GDateTime *dt;
-  Token last_token;
   Token token_id;
   guint i;
 
   dt = NULL;
   title = g_string_new (NULL);
   list_name = g_string_new (NULL);
+  note = g_string_new (NULL);
   parent_task_name = g_string_new (NULL);
-  last_token = TOKEN_START;
+  state.last_token = TOKEN_START;
+  state.in_description = FALSE;
 
   task = gtd_provider_todo_txt_generate_task (GTD_PROVIDER_TODO_TXT (provider));
   tokens = tokenize_line (line);
@@ -186,7 +244,7 @@ gtd_todo_txt_parser_parse_task (GtdProvider  *provider,
       const gchar *token;
 
       token = tokens[i];
-      token_id = parse_token_id (token, last_token);
+      token_id = parse_token_id (token, &state);
 
       switch (token_id)
         {
@@ -198,7 +256,7 @@ gtd_todo_txt_parser_parse_task (GtdProvider  *provider,
           return NULL;
 
         case TOKEN_PRIORITY:
-          last_token = TOKEN_PRIORITY;
+          state.last_token = TOKEN_PRIORITY;
           gtd_task_set_priority (task, parse_priority (token));
           break;
 
@@ -221,13 +279,17 @@ gtd_todo_txt_parser_parse_task (GtdProvider  *provider,
           gtd_task_set_due_date (task, dt);
           break;
 
+        case TOKEN_NOTE:
+          append_note (token, note, &state);
+          break;
+
         case TOKEN_LIST_COLOR:
         case TOKEN_START:
         default:
           break;
         }
 
-      last_token = token_id;
+      state.last_token = token_id;
     }
 
   g_strstrip (parent_task_name->str);
@@ -235,6 +297,7 @@ gtd_todo_txt_parser_parse_task (GtdProvider  *provider,
   g_strstrip (title->str);
 
   gtd_task_set_title (task, title->str);
+  gtd_task_set_description (task, note->str);
 
   if (out_list_name)
     *out_list_name = g_strdup (list_name->str + 1);
@@ -327,15 +390,15 @@ gtd_todo_txt_parser_get_line_type (const gchar  *line,
 {
   GtdTodoTxtLineType line_type;
   g_auto (GStrv) tokens;
+  GtdTodoTxtParserState state;
   gboolean task_list_name_tk;
-  Token last_read;
   Token token_id;
   gint i;
 
   GTD_ENTRY;
 
   tokens = tokenize_line (line);
-  last_read = TOKEN_START;
+  state.last_token = TOKEN_START;
   line_type = GTD_TODO_TXT_LINE_TYPE_TASKLIST;
   task_list_name_tk = FALSE;
 
@@ -343,12 +406,12 @@ gtd_todo_txt_parser_get_line_type (const gchar  *line,
     {
       const gchar *token = tokens[i];
 
-      token_id = parse_token_id (token, last_read);
+      token_id = parse_token_id (token, &state);
 
       switch (token_id)
         {
         case TOKEN_COMPLETE:
-          if (last_read == TOKEN_START)
+          if (state.last_token == TOKEN_START)
             line_type = GTD_TODO_TXT_LINE_TYPE_TASK;
           break;
 
@@ -356,12 +419,12 @@ gtd_todo_txt_parser_get_line_type (const gchar  *line,
           return GTD_TODO_TXT_LINE_TYPE_TASKLIST;
 
         case TOKEN_PRIORITY:
-          if (last_read <= TOKEN_COMPLETE)
+          if (state.last_token <= TOKEN_COMPLETE)
             line_type = GTD_TODO_TXT_LINE_TYPE_TASK;
           break;
 
         case TOKEN_DATE:
-          if (last_read <= TOKEN_PRIORITY)
+          if (state.last_token <= TOKEN_PRIORITY)
             {
               line_type = GTD_TODO_TXT_LINE_TYPE_TASK;
 
@@ -403,12 +466,17 @@ gtd_todo_txt_parser_get_line_type (const gchar  *line,
 
           break;
 
+        case TOKEN_NOTE:
+          state.in_description = TRUE;
+          line_type = GTD_TODO_TXT_LINE_TYPE_TASK;
+          break;
+
         case TOKEN_START:
           /* Nothing */
           break;
         }
 
-      last_read = token_id;
+      state.last_token = token_id;
     }
 
   if (!task_list_name_tk)