Dependencies

- Supports new "depends" attribute.
- Supports "task <id> depends:1,2".
- Supports "task <id> depends:-1,-2".
- Supports id <--> uuid mapping in TDB.

src/Att.cpp

@@ -63,6 +63,7 @@ static const char* modifiableNames[] =
   "recur",
   "until",
   "wait",
+  "depends",
 };
 
 // Synonyms on the same line.

src/TDB.cpp

@@ -304,6 +304,10 @@ int TDB::loadPending (std::vector <Task>& tasks, Filter& filter)
             task.id = mId++;
 
             mPending.push_back (task);
+
+            // Maintain mapping for ease of link/dependency resolution.
+            mI2U[task.id] = task.get ("uuid");
+            mU2I[task.get ("uuid")] = task.id;
           }
 
           ++line_number;
@@ -425,6 +429,8 @@ int TDB::loadCompleted (std::vector <Task>& tasks, Filter& filter)
 void TDB::add (const Task& task)
 {
   mNew.push_back (task);
+  mI2U[task.id] = task.get ("uuid");
+  mU2I[task.get ("uuid")] = task.id;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -1425,6 +1431,26 @@ void TDB::merge (const std::string& mergeFile)
   mods.clear();
 }
 
+////////////////////////////////////////////////////////////////////////////////
+std::string TDB::uuid (int id) const
+{
+  std::map <int, std::string>::const_iterator i;
+  if ((i = mI2U.find (id)) != mI2U.end ())
+    return i->second;
+
+  return "";
+}
+
+////////////////////////////////////////////////////////////////////////////////
+int TDB::id (const std::string& uuid) const
+{
+  std::map <std::string, int>::const_iterator i;
+  if ((i = mU2I.find (uuid)) != mU2I.end ())
+    return i->second;
+
+  return 0;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 FILE* TDB::openAndLock (const std::string& file)
 {

src/TDB.h

@@ -64,6 +64,9 @@ public:
   void  undo ();
   void  merge (const std::string&);
 
+  std::string uuid (int) const;
+  int id (const std::string&) const;
+
 private:
   FILE* openAndLock (const std::string&);
   void writeUndo (const Task&, FILE*);
@@ -79,6 +82,9 @@ private:
   std::vector <Task> mCompleted; // Contents of pending.data
   std::vector <Task> mNew;       // Uncommitted new tasks
   std::vector <Task> mModified;  // Uncommitted modified tasks
+
+  std::map <int, std::string> mI2U; // ID -> UUID map
+  std::map <std::string, int> mU2I; // UUID -> ID map
 };
 
 #endif

src/Task.cpp

@@ -467,6 +467,72 @@ void Task::removeAnnotations ()
   }
 }
 
+////////////////////////////////////////////////////////////////////////////////
+void Task::addDependency (int id)
+{
+  std::string uuid = context.tdb.uuid (id);
+  if (uuid == "")
+  {
+    std::stringstream s;
+    s << "Could not create a dependency on task " << id << " - not found.";
+    throw s.str ();
+  }
+
+  std::string depends = get ("depends");
+  if (depends.length ())
+  {
+    if (depends.find (uuid) == std::string::npos)
+      set ("depends", depends + "," + uuid);
+  }
+  else
+    set ("depends", uuid);
+}
+
+////////////////////////////////////////////////////////////////////////////////
+void Task::removeDependency (int id)
+{
+  std::string uuid = context.tdb.uuid (id);
+  if (uuid == "")
+  {
+    std::stringstream s;
+    s << "Could not find a UUID for id " << id << ".";
+    throw s.str ();
+  }
+
+  std::vector <std::string> deps;
+  split (deps, get ("depends"), ',');
+
+  std::vector <std::string>::iterator i;
+  i = std::find (deps.begin (), deps.end (), uuid);
+  if (i != deps.end ())
+  {
+    deps.erase (i);
+    std::string combined;
+    join (combined, ",", deps);
+    set ("depends", combined);
+  }
+}
+
+////////////////////////////////////////////////////////////////////////////////
+void Task::getDependencies (std::vector <int>& all) const
+{
+  std::vector <std::string> deps;
+  split (deps, get ("depends"), ',');
+
+  all.clear ();
+
+  std::vector <std::string>::iterator i;
+  for (i = deps.begin (); i != deps.end (); ++i)
+    all.push_back (context.tdb.id (*i));
+}
+
+////////////////////////////////////////////////////////////////////////////////
+void Task::getDependencies (std::vector <std::string>& all) const
+{
+  all.clear ();
+  split (all, get ("depends"), ',');
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 int Task::getTagCount ()
 {

src/Task.h

@@ -73,6 +73,11 @@ public:
   void addAnnotation (const std::string&);
   void removeAnnotations ();
 
+  void addDependency (int);
+  void removeDependency (int);
+  void getDependencies (std::vector <int>&) const;
+  void getDependencies (std::vector <std::string>&) const;
+
   void validate () const;
 
 private:

src/command.cpp

@@ -99,6 +99,8 @@ int handleAdd (std::string &outs)
         !context.task.has ("recur"))
       throw std::string ("You cannot specify an until date for a non-recurring task.");
 
+    // TODO Resolve dependencies.
+
     // Only valid tasks can be added.
     context.task.validate ();
 
@@ -164,6 +166,8 @@ int handleLog (std::string &outs)
     foreach (tag, context.tagAdditions)
       context.task.addTag (*tag);
 
+    // TODO Resolve dependencies.
+
     // Only valid tasks can be added.
     context.task.validate ();
 
@@ -2231,7 +2235,25 @@ int deltaAttributes (Task& task)
           task.setStatus (Task::waiting);
       }
 
-      if (att->second.value () == "")
+      // Modifying dependencies requires adding/removing uuids.
+      else if (att->second.name () == "depends")
+      {
+        std::vector <std::string> deps;
+        split (deps, att->second.value (), ',');
+
+        std::vector <std::string>::iterator i;
+        for (i = deps.begin (); i != deps.end (); i++)
+        {
+          int id = atoi (i->c_str ());
+          if (id < 0)
+            task.removeDependency (-id);
+          else
+            task.addDependency (id);
+        }
+      }
+
+      // Now the generalized handling.
+      else if (att->second.value () == "")
         task.remove (att->second.name ());
       else
         // One of the few places where the compound attribute name is used.