Support importing Taskwarrior v2.x data files

This should ease the pain of upgrading from v2.x to v3.x.

doc/man/task.1.in

@@ -414,6 +414,11 @@ few example scripts, such as:
   import-yaml.pl
 .fi
 
+.TP
+.B task import-v2
+Imports tasks from the Taskwarrior v2.x format. This is used when upgrading from
+version 2.x to version 3.x.
+
 .TP
 .B task log <mods>
 Adds a new task that is already completed, to the task list. It is affected by

src/CMakeLists.txt

@@ -14,6 +14,7 @@ add_library (task STATIC CLI2.cpp CLI2.h
                   Hooks.cpp Hooks.h
                   Lexer.cpp Lexer.h
                   Operation.cpp Operation.h
+                  TF2.cpp TF2.h
                   TDB2.cpp TDB2.h
                   Task.cpp Task.h
                   Variant.cpp Variant.h

src/TF2.cpp

@@ -0,0 +1,186 @@
+////////////////////////////////////////////////////////////////////////////////
+//
+// Copyright 2006 - 2021, Tomas Babej, Paul Beckingham, Federico Hernandez.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+//
+// https://www.opensource.org/licenses/mit-license.php
+//
+////////////////////////////////////////////////////////////////////////////////
+
+#include <Color.h>
+#include <Context.h>
+#include <Datetime.h>
+#include <TF2.h>
+#include <Table.h>
+#include <cmake.h>
+#include <format.h>
+#include <main.h>
+#include <shared.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <util.h>
+
+#include <algorithm>
+#include <iostream>
+#include <list>
+#include <set>
+#include <sstream>
+
+#define STRING_TDB2_REVERTED "Modified task reverted."
+
+////////////////////////////////////////////////////////////////////////////////
+TF2::TF2() : _loaded_tasks(false), _loaded_lines(false) {}
+
+////////////////////////////////////////////////////////////////////////////////
+TF2::~TF2() {}
+
+////////////////////////////////////////////////////////////////////////////////
+void TF2::target(const std::string& f) { _file = File(f); }
+
+////////////////////////////////////////////////////////////////////////////////
+const std::vector<std::map<std::string, std::string>>& TF2::get_tasks() {
+  if (!_loaded_tasks) load_tasks();
+
+  return _tasks;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// Attempt an FF4 parse.
+//
+// Note that FF1, FF2, FF3, and JSON are no longer supported.
+//
+// start --> [ --> Att --> ] --> end
+//              ^       |
+//              +-------+
+//
+std::map<std::string, std::string> TF2::load_task(const std::string& input) {
+  std::map<std::string, std::string> data;
+
+  // File format version 4, from 2009-5-16 - now, v1.7.1+
+  // This is the parse format tried first, because it is most used.
+  data.clear();
+
+  if (input[0] == '[') {
+    // Not using Pig to parse here (which would be idiomatic), because we
+    // don't need to differentiate betwen utf-8 and normal characters.
+    // Pig's scanning the string can be expensive.
+    auto ending_bracket = input.find_last_of(']');
+    if (ending_bracket != std::string::npos) {
+      std::string line = input.substr(1, ending_bracket);
+
+      if (line.length() == 0) throw std::string("Empty record in input.");
+
+      Pig attLine(line);
+      std::string name;
+      std::string value;
+      while (!attLine.eos()) {
+        if (attLine.getUntilAscii(':', name) && attLine.skip(':') &&
+            attLine.getQuoted('"', value)) {
+#ifdef PRODUCT_TASKWARRIOR
+          legacyAttributeMap(name);
+#endif
+
+          data[name] = decode(json::decode(value));
+        }
+
+        attLine.skip(' ');
+      }
+
+      std::string remainder;
+      attLine.getRemainder(remainder);
+      if (remainder.length()) throw std::string("Unrecognized characters at end of line.");
+    }
+  } else {
+    throw std::string("Record not recognized as format 4.");
+  }
+
+  // for compatibility, include all tags in `tags` as `tag_..` attributes
+  if (data.find("tags") != data.end()) {
+    for (auto& tag : split(data["tags"], ',')) {
+      data[Task::tag2Attr(tag)] = "x";
+    }
+  }
+
+  // same for `depends` / `dep_..`
+  if (data.find("depends") != data.end()) {
+    for (auto& dep : split(data["depends"], ',')) {
+      data[Task::dep2Attr(dep)] = "x";
+    }
+  }
+
+  return data;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// Decode values after parse.
+//   [  <- &open;
+//   ]  <- &close;
+const std::string TF2::decode (const std::string& value) const
+{
+  if (value.find ('&') == std::string::npos)
+    return value;
+
+  auto modified = str_replace (value,    "&open;",  "[");
+  return          str_replace (modified, "&close;", "]");
+}
+
+////////////////////////////////////////////////////////////////////////////////
+void TF2::load_tasks() {
+  Timer timer;
+
+  if (!_loaded_lines) {
+    load_lines();
+  }
+
+  // Reduce unnecessary allocations/copies.
+  // Calling it on _tasks is the right thing to do even when from_gc is set.
+  _tasks.reserve(_lines.size());
+
+  int line_number = 0;  // Used for error message in catch block.
+  try {
+    for (auto& line : _lines) {
+      ++line_number;
+      auto task = load_task(line);
+      _tasks.push_back(task);
+    }
+
+    _loaded_tasks = true;
+  }
+
+  catch (const std::string& e) {
+    throw e + format(" in {1} at line {2}", _file._data, line_number);
+  }
+
+  Context::getContext().time_load_us += timer.total_us();
+}
+
+////////////////////////////////////////////////////////////////////////////////
+void TF2::load_lines() {
+  if (_file.open()) {
+    if (Context::getContext().config.getBoolean("locking")) _file.lock();
+
+    _file.read(_lines);
+    _file.close();
+    _loaded_lines = true;
+  }
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// vim: ts=2 et sw=2

src/TF2.h

@@ -0,0 +1,66 @@
+////////////////////////////////////////////////////////////////////////////////
+//
+// Copyright 2006 - 2024, Tomas Babej, Paul Beckingham, Federico Hernandez.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+//
+// https://www.opensource.org/licenses/mit-license.php
+//
+////////////////////////////////////////////////////////////////////////////////
+
+#ifndef INCLUDED_TF2
+#define INCLUDED_TF2
+
+#include <FS.h>
+#include <Task.h>
+#include <stdio.h>
+
+#include <map>
+#include <string>
+#include <unordered_map>
+#include <unordered_set>
+#include <vector>
+
+// TF2 Class represents a single 2.x-style file in the task database.
+//
+// This is only used for importing tasks from 2.x. It only reads format 4, based
+// on a stripped-down version of the TF2 class from v2.6.2.
+class TF2 {
+ public:
+  TF2();
+  ~TF2();
+
+  void target(const std::string&);
+
+  const std::vector<std::map<std::string, std::string>>& get_tasks();
+
+  std::map<std::string, std::string> load_task(const std::string&);
+  void load_tasks();
+  void load_lines();
+  const std::string decode(const std::string& value) const;
+
+  bool _loaded_tasks;
+  bool _loaded_lines;
+  std::vector<std::map<std::string,std::string>> _tasks;
+  std::vector<std::string> _lines;
+  File _file;
+};
+
+#endif
+////////////////////////////////////////////////////////////////////////////////

src/commands/CMakeLists.txt

@@ -35,6 +35,7 @@ set (commands_SRCS Command.cpp        Command.h
                    CmdHistory.cpp     CmdHistory.h
                    CmdIDs.cpp         CmdIDs.h
                    CmdImport.cpp      CmdImport.h
+                   CmdImportV2.cpp    CmdImportV2.h
                    CmdInfo.cpp        CmdInfo.h
                    CmdLog.cpp         CmdLog.h
                    CmdLogo.cpp        CmdLogo.h

src/commands/CmdCustom.cpp

@@ -241,7 +241,8 @@ int CmdCustom::execute(std::string& output) {
     Color warning = Color(Context::getContext().config.get("color.warning"));
     std::cerr << warning.colorize(format("Found existing '*.data' files in {1}", location)) << "\n";
     std::cerr << "  Taskwarrior's storage format changed in 3.0, requiring a manual migration.\n";
-    std::cerr << "  See https://taskwarrior.org/docs/upgrade-3/\n";
+    std::cerr << "  See https://taskwarrior.org/docs/upgrade-3/. Run `task import-v2` to import\n";
+    std::cerr << "  the tasks into the Taskwarrior-3.x format\n";
   }
 
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