////////////////////////////////////////////////////////////////////////////////
// Task Lua API
//
// Copyright 2006 - 2010, Paul Beckingham.
// All rights reserved.
//
// This program is free software; you can redistribute it and/or modify it under
// the terms of the GNU General Public License as published by the Free Software
// Foundation; either version 2 of the License, or (at your option) any later
// version.
//
// This program is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
// FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
// details.
//
// You should have received a copy of the GNU General Public License along with
// this program; if not, write to the
//
//     Free Software Foundation, Inc.,
//     51 Franklin Street, Fifth Floor,
//     Boston, MA
//     02110-1301
//     USA
//
// -------------
//
// Copyright © 1994–2008 Lua.org, PUC-Rio.
//
// 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.
//
////////////////////////////////////////////////////////////////////////////////

#include <iostream> // TODO Remove
#include "Context.h"
#include "API.h"

extern Context context;

#ifdef HAVE_LIBLUA

////////////////////////////////////////////////////////////////////////////////
// Returns a string representing the task version number, such as '1.9.0'.
static int api_task_version (lua_State* L)
{
  lua_pushstring (L, PACKAGE_VERSION);
  return 1;
}

////////////////////////////////////////////////////////////////////////////////
// Returns a string representing the Lua version number, such as '5.1.4'.
// Lua 5.2.0 has a 'lua_version' call, but 5.1.4 is the target.
static int api_task_lua_version (lua_State* L)
{
  // Convert "Lua 5.1.4" -> "5.1.4"
  std::string ver = LUA_RELEASE;
  lua_pushstring (L, ver.substr (4, std::string::npos).c_str ());
  return 1;
}

////////////////////////////////////////////////////////////////////////////////
// Returns the type of OS that task is running on.
static int api_task_os (lua_State* L)
{
#if defined (DARWIN)
  lua_pushstring (L, "darwin");
#elif defined (SOLARIS)
  lua_pushstring (L, "solaris");
#elif defined (CYGWIN)
  lua_pushstring (L, "cygwin");
#elif defined (OPENBSD)
  lua_pushstring (L, "openbsd");
#elif defined (HAIKU)
  lua_pushstring (L, "haiku");
#elif defined (FREEBSD)
  lua_pushstring (L, "freebsd");
#elif defined (LINUX)
  lua_pushstring (L, "linux");
#else
  lua_pushstring (L, "unknown");
#endif

  return 1;
}

////////////////////////////////////////////////////////////////////////////////
static int api_task_feature (lua_State* L)
{
  std::string name = luaL_checkstring (L, 1);
  bool value = false;

  if (name == "readline")
  {
#ifdef HAVE_READLINE
    value = true;
#endif
  }

  else if (name == "ncurses")
  {
#ifdef HAVE_NCURSES
     value = true;
#endif
  }

  lua_pushnumber (L, value ? 1 : 0);
  return 1;
}

/*
////////////////////////////////////////////////////////////////////////////////
static int api_task_aliases ()
{
  return {};
}

////////////////////////////////////////////////////////////////////////////////
-- Returns values from .taskrc, by name.
static int api_task_get_config (name)
{
  return "foo"
}

////////////////////////////////////////////////////////////////////////////////
-- Temporarily sets .taskrc values, by name.
static int api_task_set_config (name, value)
{
}

////////////////////////////////////////////////////////////////////////////////
-- Returns an internationalized string, by string ID, from the appropriate
-- locale-based strings file.
static int api_task_i18n_string (id)
{
  return "le foo"
}

////////////////////////////////////////////////////////////////////////////////
-- Returns a list of tips, from the appropriate locale-based tips file.
static int api_task_i18n_tips ()
{
  return {}
}

////////////////////////////////////////////////////////////////////////////////
-- Returns the name of the current command.
static int api_task_get_command ()
{
  return "list"
}

////////////////////////////////////////////////////////////////////////////////
-- Returns a list of string messages generated so far.
static int api_task_get_header_messages ()
{
  return {}
}

////////////////////////////////////////////////////////////////////////////////
static int api_task_get_footnote_messages ()
{
  return {}
}

////////////////////////////////////////////////////////////////////////////////
static int api_task_get_debug_messages ()
{
  return {}
}

////////////////////////////////////////////////////////////////////////////////
-- Records additional messages, for subsequent display.
static int api_task_header_message (text)
{
}

////////////////////////////////////////////////////////////////////////////////
static int api_task_footnote_message (text)
{
}

////////////////////////////////////////////////////////////////////////////////
static int api_task_debug_message (text)
{
}
*/

////////////////////////////////////////////////////////////////////////////////
// Causes the shell or interactive mode task to exit.  Ordinarily this does not
// occur.
static int api_task_exit (lua_State* L)
{
  // TODO Is this the correct exception?  How does the shell handle this?
  throw std::string ("Exiting.");
  return 0;
}

/*
////////////////////////////////////////////////////////////////////////////////
-- Shuts off the hook system for any subsequent hook calls for this command.
static int api_task_inhibit_further_hooks ()
{
}

////////////////////////////////////////////////////////////////////////////////
-- Returns a table that contains a complete copy of the task.
static int api_task_get (id)
{
  return task
}

////////////////////////////////////////////////////////////////////////////////
-- Creates a new task from the data specified in the table t.
static int api_task_add (t)
{
}

////////////////////////////////////////////////////////////////////////////////
-- Modifies the task described in the table t.
static int api_task_modify (t)
{
}

////////////////////////////////////////////////////////////////////////////////
-- 'id' is the task id passed to the hook function.  Date attributes are
-- returned as a numeric epoch offset.  Tags and annotations are returned
-- as tables.  A nil value indicates a missing value.
static int api_task_get_uuid (id)
{
  return task.uuid
}

////////////////////////////////////////////////////////////////////////////////
static int api_task_get_description (id)
{
  return task.description
}

////////////////////////////////////////////////////////////////////////////////
static int api_task_get_annotations (id)
{
  return task.annotations
}

////////////////////////////////////////////////////////////////////////////////
static int api_task_get_project (id)
{
  return task.project
}

////////////////////////////////////////////////////////////////////////////////
static int api_task_get_priority (id)
{
  return task.priority
}

////////////////////////////////////////////////////////////////////////////////
static int api_task_get_tags (id)
{
  return task.tags
}

////////////////////////////////////////////////////////////////////////////////
static int api_task_get_status (id)
{
  return task.status
}

////////////////////////////////////////////////////////////////////////////////
static int api_task_get_due (id)
{
  return task.due_date
}

////////////////////////////////////////////////////////////////////////////////
static int api_task_get_entry (id)
{
  return task.entry_date
}

////////////////////////////////////////////////////////////////////////////////
static int api_task_get_start (id)
{
  return task.start_date
}

////////////////////////////////////////////////////////////////////////////////
static int api_task_get_end (id)
{
  return task.end_date
}

////////////////////////////////////////////////////////////////////////////////
static int api_task_get_recur (id)
{
  return task.recur
}

////////////////////////////////////////////////////////////////////////////////
static int api_task_get_until (id)
{
  return task.until_date
}

////////////////////////////////////////////////////////////////////////////////
static int api_task_get_wait (id)
{
  return task.wait_date
}

////////////////////////////////////////////////////////////////////////////////
-- 'id' is the task id passed to the hook function.  Date attributes are
-- expected as numeric epoch offsets.  Tags and annotations are expected
-- as tables.  A nil value indicates a missing value.
static int api_task_set_description (id, value)
{
  task.description = value
}

////////////////////////////////////////////////////////////////////////////////
static int api_task_set_annotations (id, value)
{
  task.annotations = value
}

////////////////////////////////////////////////////////////////////////////////
static int api_task_set_project (id, value)
{
  task.project = value
}

////////////////////////////////////////////////////////////////////////////////
static int api_task_set_priority (id, value)
{
  task.priority = value
}

////////////////////////////////////////////////////////////////////////////////
static int api_task_set_tags (id, value)
{
  task.tags = value
}

////////////////////////////////////////////////////////////////////////////////
static int api_task_set_status (id, value)
{
  task.status = value
}

////////////////////////////////////////////////////////////////////////////////
static int api_task_set_due (id, value)
{
  task.due_date = value
}

////////////////////////////////////////////////////////////////////////////////
static int api_task_set_start (id, value)
{
  task.start_date = value
}

////////////////////////////////////////////////////////////////////////////////
static int api_task_set_recur (id, value)
{
  task.recur = value
}

////////////////////////////////////////////////////////////////////////////////
static int api_task_set_until (id, value)
{
  task.until_date = value
}

////////////////////////////////////////////////////////////////////////////////
static int api_task_set_wait (id, value)
{
  task.wait_date = value
}
*/

////////////////////////////////////////////////////////////////////////////////
API::API ()
: L (NULL)
{
}

////////////////////////////////////////////////////////////////////////////////
API::~API ()
{
  if (L)
  {
    lua_close (L);
    L = NULL;
  }
}

////////////////////////////////////////////////////////////////////////////////
void API::initialize ()
{
  // Initialize Lua.
  L = lua_open ();
  luaL_openlibs (L);  // TODO Error handling

  // Register all the API functions in Lua global space.
  lua_pushcfunction (L, api_task_version);               lua_setglobal (L, "task_version");
  lua_pushcfunction (L, api_task_lua_version);           lua_setglobal (L, "task_lua_version");
  lua_pushcfunction (L, api_task_os);                    lua_setglobal (L, "task_os");
  lua_pushcfunction (L, api_task_feature);               lua_setglobal (L, "task_feature");
/*
  lua_pushcfunction (L, api_task_aliases);               lua_setglobal (L, "api_task_aliases");
  lua_pushcfunction (L, api_task_get_config);            lua_setglobal (L, "api_task_get_config");
  lua_pushcfunction (L, api_task_set_config);            lua_setglobal (L, "api_task_set_config");
  lua_pushcfunction (L, api_task_i18n_string);           lua_setglobal (L, "api_task_i18n_string");
  lua_pushcfunction (L, api_task_i18n_tips);             lua_setglobal (L, "api_task_i18n_tips");
  lua_pushcfunction (L, api_task_get_command);           lua_setglobal (L, "api_task_get_command");
  lua_pushcfunction (L, api_task_get_header_messages);   lua_setglobal (L, "api_task_get_header_messages");
  lua_pushcfunction (L, api_task_get_footnote_messages); lua_setglobal (L, "api_task_get_footnote_messages");
  lua_pushcfunction (L, api_task_get_debug_messages);    lua_setglobal (L, "api_task_get_debug_messages");
  lua_pushcfunction (L, api_task_header_message);        lua_setglobal (L, "api_task_header_message");
  lua_pushcfunction (L, api_task_footnote_message);      lua_setglobal (L, "api_task_footnote_message");
  lua_pushcfunction (L, api_task_debug_message);         lua_setglobal (L, "api_task_debug_message");
*/
  lua_pushcfunction (L, api_task_exit);                  lua_setglobal (L, "task_exit");
/*
  lua_pushcfunction (L, api_task_inhibit_further_hooks); lua_setglobal (L, "api_task_inhibit_further_hooks");
  lua_pushcfunction (L, api_task_get);                   lua_setglobal (L, "api_task_get");
  lua_pushcfunction (L, api_task_add);                   lua_setglobal (L, "api_task_add");
  lua_pushcfunction (L, api_task_modify);                lua_setglobal (L, "api_task_modify");
  lua_pushcfunction (L, api_task_get_uuid);              lua_setglobal (L, "api_task_get_uuid");
  lua_pushcfunction (L, api_task_get_description);       lua_setglobal (L, "api_task_get_description");
  lua_pushcfunction (L, api_task_get_annotations);       lua_setglobal (L, "api_task_get_annotations");
  lua_pushcfunction (L, api_task_get_project);           lua_setglobal (L, "api_task_get_project");
  lua_pushcfunction (L, api_task_get_priority);          lua_setglobal (L, "api_task_get_priority");
  lua_pushcfunction (L, api_task_get_tags);              lua_setglobal (L, "api_task_get_tags");
  lua_pushcfunction (L, api_task_get_status);            lua_setglobal (L, "api_task_get_status");
  lua_pushcfunction (L, api_task_get_due);               lua_setglobal (L, "api_task_get_due");
  lua_pushcfunction (L, api_task_get_entry);             lua_setglobal (L, "api_task_get_entry");
  lua_pushcfunction (L, api_task_get_start);             lua_setglobal (L, "api_task_get_start");
  lua_pushcfunction (L, api_task_get_end);               lua_setglobal (L, "api_task_get_end");
  lua_pushcfunction (L, api_task_get_recur);             lua_setglobal (L, "api_task_get_recur");
  lua_pushcfunction (L, api_task_get_until);             lua_setglobal (L, "api_task_get_until");
  lua_pushcfunction (L, api_task_get_wait);              lua_setglobal (L, "api_task_get_wait");
  lua_pushcfunction (L, api_task_set_description);       lua_setglobal (L, "api_task_set_description");
  lua_pushcfunction (L, api_task_set_annotations);       lua_setglobal (L, "api_task_set_annotations");
  lua_pushcfunction (L, api_task_set_project);           lua_setglobal (L, "api_task_set_project");
  lua_pushcfunction (L, api_task_set_priority);          lua_setglobal (L, "api_task_set_priority");
  lua_pushcfunction (L, api_task_set_tags);              lua_setglobal (L, "api_task_set_tags");
  lua_pushcfunction (L, api_task_set_status);            lua_setglobal (L, "api_task_set_status");
  lua_pushcfunction (L, api_task_set_due);               lua_setglobal (L, "api_task_set_due");
  lua_pushcfunction (L, api_task_set_start);             lua_setglobal (L, "api_task_set_start");
  lua_pushcfunction (L, api_task_set_recur);             lua_setglobal (L, "api_task_set_recur");
  lua_pushcfunction (L, api_task_set_until);             lua_setglobal (L, "api_task_set_until");
  lua_pushcfunction (L, api_task_set_wait);              lua_setglobal (L, "api_task_set_wait");
*/
}

////////////////////////////////////////////////////////////////////////////////
bool API::callProgramHook (
  const std::string& file,
  const std::string& function)
{
  loadFile (file);

  // Get function.
  lua_getglobal (L, function.c_str ());
  if (!lua_isfunction (L, -1))
  {
    lua_pop (L, 1);
    throw std::string ("The Lua function '") + function + "' was not found.";
  }

  // Make call.
  if (lua_pcall (L, 0, 2, 0) != 0)
    throw std::string ("Error calling '") + function + "' - " + lua_tostring (L, -1);

  // Call successful - get return values.
  // 0, nil    -> success
  // 0, string -> warning
  // 1, string -> error
  if (!lua_isnumber (L, -2)) throw std::string ("Error: '") + function + "' did not return a success indicator";
//  if (!lua_isstring (L, -1)) throw std::string ("Error: '") + function + "' did not return a message";

  int rc              = lua_tointeger (L, -2);
  const char* message = lua_tostring  (L, -1);

  if (rc == 0)
  {
    if (message)
      context.footnote (std::string ("Warning: ") + message);
  }
  else
  {
    if (message)
      throw std::string ("Error: ") + message;
  }

  lua_pop (L, 1);
  return rc == 0 ? true : false;
}

////////////////////////////////////////////////////////////////////////////////
bool API::callListHook (
  const std::string& file,
  const std::string& function/*,
  iterator i*/)
{
  loadFile (file);

  // TODO Get function.
  // TODO Prepare args.
  // TODO Make call.
  // TODO Get exit status.

  return true;
}

////////////////////////////////////////////////////////////////////////////////
bool API::callTaskHook (
  const std::string& file,
  const std::string& function,
  int id)
{
  loadFile (file);

  // TODO Get function.
  // TODO Prepare args.
  // TODO Make call.
  // TODO Get exit status.

  return true;
}

////////////////////////////////////////////////////////////////////////////////
bool API::callFieldHook (
  const std::string& file,
  const std::string& function,
  const std::string& field,
  const std::string& value)
{
  loadFile (file);

  // TODO Get function.
  // TODO Prepare args.
  // TODO Make call.
  // TODO Get exit status.

  return true;
}

////////////////////////////////////////////////////////////////////////////////
void API::loadFile (const std::string& file)
{
  if (std::find (loaded.begin (), loaded.end (), file) == loaded.end ())
  {
    // Load the file, if possible.
    if (luaL_loadfile (L, file.c_str ()) || lua_pcall (L, 0, 0, 0))
      throw std::string ("Error: ") + std::string (lua_tostring (L, -1));

    // Mark this as loaded, so as to not bother again.
    loaded.push_back (file);
  }
}

////////////////////////////////////////////////////////////////////////////////

#endif