/* -*- c-basic-offset:2; tab-width:2; indent-tabs-mode:nil -*- */

//
// im_scim_1.4.cpp - SCIM plugin for mlterm (c++ part)
//
// Copyright (C) 2005 Seiichi SATO <ssato@sh.rim.or.jp>
//

// This file is partially based on gtkimcontextscim.cpp of SCIM
//
// Copyright (C) 2002-2005 James Su <suzhe@tsinghua.org.cn>
//
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2 of the License, or (at your option) any later version.
//
// This library 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 Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this program; if not, write to the
// Free Software Foundation, Inc., 59 Temple Place, Suite 330,
// Boston, MA  02111-1307  USA
//

#include <iostream>
#include <stdio.h>
#include <X11/Xlib.h>  // KeySym, XKeyEvent
#include <string.h>

#include "im_scim.h"

#define Uses_SCIM_CONFIG_PATH
#define Uses_SCIM_IMENGINE_MODULE
#define Uses_SCIM_BACKEND
#define Uses_SCIM_PANEL
#define Uses_SCIM_TRANSACTION
#define Uses_SCIM_HOTKEY
#include <scim.h>

#define SCIM_TRANS_MAGIC 0x4d494353

#define TIMEOUT 5000  // msec

using namespace scim;

typedef struct im_scim_context_private {
  IMEngineFactoryPointer factory;
  IMEngineInstancePointer instance;
  int id;

  int on;
  int focused;

  WideString preedit_str;
  AttributeList preedit_attr;
  int preedit_caret;

  void *self;
  im_scim_callbacks_t *cb;

} im_scim_context_private_t;

#define C_STR(s) (char *)(utf8_wcstombs((s)).c_str())

// --- static variables ---

static std::vector<im_scim_context_private_t *> context_table;

static String lang;

static ConfigModule *config_module = NULL;
static ConfigPointer config = NULL;

static BackEndPointer be = NULL;

static FrontEndHotkeyMatcher keymatcher_frontend;
static IMEngineHotkeyMatcher keymatcher_imengine;

static PanelClient panel_client;

static bool is_vertical_lookup;
static int valid_key_mask = 0;

static int next_new_id = 0; /* XXX */

// --- static functions ---

static im_scim_context_private_t *id_to_context(int id) {
  size_t i;

  for (i = 0; i < context_table.size(); i++) {
    if (context_table[i]->id == id) {
      return context_table[i];
    }
  }

  return NULL;
}

//
// callback for config modules
//

static void cb_config_load(const ConfigPointer &config) {
  KeyEvent key;

  keymatcher_frontend.load_hotkeys(config);
  keymatcher_imengine.load_hotkeys(config);

  scim_string_to_key(key, config->read(String(SCIM_CONFIG_HOTKEYS_FRONTEND_VALID_KEY_MASK),
                                       String("Shift+Control+Alt+Lock")));

  valid_key_mask = key.mask > 0 ? key.mask : 0xffff;
  valid_key_mask |= SCIM_KEY_ReleaseMask;

  scim_global_config_flush();

  // hack
  is_vertical_lookup = config->read(String("/Panel/Gtk/LookupTableVertical"), false);
}

//
// callbacks for backend
//

static void cb_commit(IMEngineInstanceBase *instance, const WideString &wstr) {
  im_scim_context_private_t *context;

  context = static_cast<im_scim_context_private_t *>(instance->get_frontend_data());

  if (context && context->on) {
    context->preedit_attr.clear();

    (*context->cb->commit)(context->self, C_STR(wstr));
    (*context->cb->candidate_hide)(context->self);
  }
}

static void cb_preedit_update(IMEngineInstanceBase *instance, const WideString &wstr,
                              const AttributeList &attr) {
  im_scim_context_private_t *context;

  context = static_cast<im_scim_context_private_t *>(instance->get_frontend_data());

  if (context && context->on) {
    context->preedit_str = wstr;
    context->preedit_attr = attr;
  }
}

static void cb_preedit_hide(IMEngineInstanceBase *instance) {
  im_scim_context_private_t *context;

  context = static_cast<im_scim_context_private_t *>(instance->get_frontend_data());

  if (context && context->on) {
    context->preedit_str = WideString();
    context->preedit_attr.clear();

    (*context->cb->preedit_update)(context->self, NULL, 0);
  }
}

static void cb_preedit_caret(IMEngineInstanceBase *instance, int caret) {
  im_scim_context_private_t *context;

  context = static_cast<im_scim_context_private_t *>(instance->get_frontend_data());

  if (context && context->on) {
    context->preedit_caret = caret;

    (*context->cb->preedit_update)(context->self, C_STR(context->preedit_str), caret);
  }
}

static void cb_lookup_update(IMEngineInstanceBase *instance, const LookupTable &table) {
  im_scim_context_private_t *context;
  int num_candiate;
  int index;
  char **str;
  int i;

  context = static_cast<im_scim_context_private_t *>(instance->get_frontend_data());

  if (!context) {
    return;
  }

  if (!context->on) {
    return;
  }

  num_candiate = table.get_current_page_size();
  index = table.get_cursor_pos_in_current_page();

  str = new char *[num_candiate];

  for (i = 0; i < num_candiate; i++) {
    str[i] = strdup(C_STR(table.get_candidate_in_current_page(i)));
  }

  (*context->cb->candidate_update)(context->self, is_vertical_lookup ? 1 : 0, num_candiate, str,
                                   index);

  for (i = 0; i < num_candiate; i++) {
    free(str[i]);
  }

  delete[] str;
}

static void cb_lookup_show(IMEngineInstanceBase *instance) {
  im_scim_context_private_t *context;

  context = static_cast<im_scim_context_private_t *>(instance->get_frontend_data());

  if (context && context->on) {
    (*context->cb->candidate_show)(context->self);
  }
}

static void cb_lookup_hide(IMEngineInstanceBase *instance) {
  im_scim_context_private_t *context;

  context = static_cast<im_scim_context_private_t *>(instance->get_frontend_data());

  if (context && context->on) {
    (*context->cb->candidate_hide)(context->self);
  }
}

static void cb_prop_register(IMEngineInstanceBase *instance, const PropertyList &props) {
  im_scim_context_private_t *context;

  context = static_cast<im_scim_context_private_t *>(instance->get_frontend_data());

  if (context && panel_client.is_connected()) {
    panel_client.prepare(context->id);
    panel_client.register_properties(context->id, props);
    panel_client.send();
  }
}

static void cb_prop_update(IMEngineInstanceBase *instance, const Property &prop) {
  im_scim_context_private_t *context;

  context = static_cast<im_scim_context_private_t *>(instance->get_frontend_data());

  if (context && panel_client.is_connected()) {
    panel_client.prepare(context->id);
    panel_client.update_property(context->id, prop);
    panel_client.send();
  }
}

static void set_callbacks(im_scim_context_private_t *context) {
  context->instance->signal_connect_commit_string(slot(cb_commit));

  context->instance->signal_connect_update_preedit_string(slot(cb_preedit_update));
  context->instance->signal_connect_hide_preedit_string(slot(cb_preedit_hide));

  context->instance->signal_connect_update_preedit_caret(slot(cb_preedit_caret));

  context->instance->signal_connect_update_lookup_table(slot(cb_lookup_update));
  context->instance->signal_connect_show_lookup_table(slot(cb_lookup_show));
  context->instance->signal_connect_hide_lookup_table(slot(cb_lookup_hide));

  context->instance->signal_connect_register_properties(slot(cb_prop_register));
  context->instance->signal_connect_update_property(slot(cb_prop_update));

  context->instance->set_frontend_data(static_cast<void *>(context));
}

//
// callbacks for panel clients
//

static void cb_panel_request_factory_menu(int id) {
  std::vector<IMEngineFactoryPointer> factories;
  std::vector<PanelFactoryInfo> menu;
  size_t i;

  be->get_factories_for_encoding(factories, "UTF-8");
  for (i = 0; i < factories.size(); i++) {
    menu.push_back(PanelFactoryInfo(factories[i]->get_uuid(),
                                    utf8_wcstombs(factories[i]->get_name()),
                                    factories[i]->get_language(), factories[i]->get_icon_file()));
  }

  panel_client.prepare(id);
  panel_client.show_factory_menu(id, menu);
  panel_client.send();
}

static void cb_panel_request_help(int id) {
  im_scim_context_private_t *context;
  String desc;
  String str;

  context = id_to_context(id);

  desc += utf8_wcstombs(context->factory->get_name()) + String(":\n\n");
  desc += utf8_wcstombs(context->factory->get_authors()) + String("\n\n");
  desc += String("  Help:\n    ") + utf8_wcstombs(context->factory->get_help()) + String("\n\n");
  desc += utf8_wcstombs(context->factory->get_credits()) + String("\n\n");

  panel_client.prepare(id);
  panel_client.show_help(id, desc);
  panel_client.send();
}

static void cb_panel_change_factory(int id, const String &uuid) {
  im_scim_context_private_t *context;
  IMEngineFactoryPointer factory;
  PanelFactoryInfo info;

  context = id_to_context(id);

  factory = be->get_factory(uuid);
  if (factory.null()) {
    return;
  }

  panel_client.prepare(id);

  if (uuid.length() == 0) {
    panel_client.turn_off(id);
    panel_client.focus_out(id);
    panel_client.send();
    context->on = 0;
    return;
  }

  context->factory = factory;
  context->instance->focus_out();
  be->set_default_factory(lang, context->factory->get_uuid());
  context->instance = context->factory->create_instance(String("UTF-8"), context->id);
  set_callbacks(context);
  info = PanelFactoryInfo(context->factory->get_uuid(), utf8_wcstombs(context->factory->get_name()),
                          context->factory->get_language(), context->factory->get_icon_file());
  panel_client.update_factory_info(id, info);
  panel_client.send();
  context->instance->focus_in();
}

static void cb_panel_trigger_property(int id, const String &prop) {
  im_scim_context_private_t *context;

  context = id_to_context(id);

  panel_client.prepare(id);
  context->instance->trigger_property(prop);
  panel_client.send();
}

static int hotkey(im_scim_context_t _context, const KeyEvent &scim_key) {
  im_scim_context_private_t *context;
  FrontEndHotkeyAction hotkey_action;
  PanelFactoryInfo info;

  context = (im_scim_context_private_t *)_context;

  keymatcher_frontend.push_key_event(scim_key);
  keymatcher_imengine.push_key_event(scim_key);

  hotkey_action = keymatcher_frontend.get_match_result();

  if (hotkey_action == SCIM_FRONTEND_HOTKEY_OFF && !context->on) {
    return 0;
  }

  if (hotkey_action == SCIM_FRONTEND_HOTKEY_ON && context->on) {
    return 0;
  }

  if (hotkey_action == SCIM_FRONTEND_HOTKEY_TRIGGER) {
    if (context->on) {
      hotkey_action = SCIM_FRONTEND_HOTKEY_OFF;
    } else {
      hotkey_action = SCIM_FRONTEND_HOTKEY_ON;
    }
  }

  info = PanelFactoryInfo(context->factory->get_uuid(), utf8_wcstombs(context->factory->get_name()),
                          context->factory->get_language(), context->factory->get_icon_file());

  switch (hotkey_action) {
    case SCIM_FRONTEND_HOTKEY_ON:
      if (panel_client.is_connected()) {
        panel_client.prepare(context->id);
        panel_client.update_factory_info(context->id, info);
        panel_client.turn_on(context->id);
        panel_client.focus_in(context->id, context->instance->get_factory_uuid());
        panel_client.send();
      }

      (*context->cb->preedit_update)(context->self, C_STR(context->preedit_str),
                                     context->preedit_caret);
      (*context->cb->candidate_show)(context->self);

      context->instance->focus_in();

      context->on = 1;

      return 0;
    case SCIM_FRONTEND_HOTKEY_OFF:
      if (panel_client.is_connected()) {
        panel_client.prepare(context->id);
        panel_client.turn_off(context->id);
        panel_client.focus_out(context->id);
        panel_client.send();
      }

      (*context->cb->preedit_update)(context->self, NULL, 0);
      (*context->cb->candidate_hide)(context->self);

      context->instance->focus_out();

      context->on = 0;

      return 0;
    case SCIM_FRONTEND_HOTKEY_NEXT_FACTORY:
    case SCIM_FRONTEND_HOTKEY_PREVIOUS_FACTORY:
    case SCIM_FRONTEND_HOTKEY_SHOW_FACTORY_MENU:
      // not implemented yet
      return 0;
    default:
      return 1;
  }
}

// --- global functions ---

int im_scim_initialize(char *locale) {
  SocketAddress address;
  SocketClient client;
  uint32 magic;
  std::vector<String> imengines;
  std::vector<String> config_modules;
  String config_mod_name;

  lang = scim_get_locale_language(String(locale));

  address.set_address(scim_get_default_socket_frontend_address());
  if (!client.connect(address) &&
      !scim_socket_open_connection(magic, String("ConnectionTester"), String("SocketFrontEnd"),
                                   client, TIMEOUT)) {
    bl_error_printf("Unable to connect to the socket frontend.\n");
    goto error;
  }

  if (scim_get_imengine_module_list(imengines) == 0) {
    bl_error_printf("Could not find any IMEngines.\n");
    goto error;
  }

  if (std::find(imengines.begin(), imengines.end(), "socket") == imengines.end()) {
    bl_error_printf("Could not find socket module.\n");
    goto error;
  }

  imengines.clear();
  imengines.push_back("socket");

  if (scim_get_config_module_list(config_modules) == 0) {
    bl_error_printf("Could not find any config modules.\n");
    goto error;
  }

  config_mod_name = scim_global_config_read(SCIM_GLOBAL_CONFIG_DEFAULT_CONFIG_MODULE,
                                            String("simple"));  // String( "socket"));

  if (std::find(config_modules.begin(), config_modules.end(), config_mod_name) ==
      config_modules.end()) {
    // fallback
    config_mod_name = config_modules[0];
  }

  if (!(config_module = new ConfigModule(config_mod_name))) {
    bl_error_printf("ConfigModule failed. (%s)\n", config_mod_name.c_str());
    goto error;
  }

  config = config_module->create_config();

  if (config.null()) {
    // TODO fallback DummyConfig
    bl_error_printf("create_config failed.\n");
    goto error;
  }

  be = new CommonBackEnd(config, imengines);
  if (be.null()) {
    bl_error_printf("CommonBackEnd failed.\n");
    goto error;
  }

  cb_config_load(config);
  config->signal_connect_reload(slot(cb_config_load));

  panel_client.signal_connect_request_factory_menu(slot(cb_panel_request_factory_menu));
  panel_client.signal_connect_request_help(slot(cb_panel_request_help));
  panel_client.signal_connect_change_factory(slot(cb_panel_change_factory));

  panel_client.signal_connect_trigger_property(slot(cb_panel_trigger_property));

  if (panel_client.open_connection(config->get_name(), getenv("DISPLAY")) == false) {
    goto error;
  }

  context_table.clear();

  return 1;

error:

  if (!config.null()) {
    config.reset();
  }

  if (!be.null()) {
    be.reset();
  }

  if (panel_client.is_connected()) {
    panel_client.close_connection();
  }

  return 0;
}

int im_scim_finalize(void) {
  if (panel_client.is_connected()) {
    panel_client.close_connection();
  }

  if (!be.null()) {
    be.reset();
  }

  if (!config.null()) {
    config.reset();
  }

  if (config_module) {
    delete config_module;
    config_module = NULL;
  }

  return 1;
}

im_scim_context_t im_scim_create_context(void *self, im_scim_callbacks_t *callbacks) {
  im_scim_context_private_t *context = NULL;

  context = new im_scim_context_private_t;

  context->factory = be->get_default_factory(lang, String("UTF-8"));

  if (!(context->instance = context->factory->create_instance(String("UTF-8"), next_new_id))) {
    bl_error_printf("Could not create new instance.\n");
    return NULL;
  }

  context_table.push_back(context);

  context->id = next_new_id;
  context->on = 0;
  context->focused = 0;
  context->self = self;
  context->cb = callbacks;

  set_callbacks(context);

  next_new_id++;

  return (im_scim_context_t)context;
}

int im_scim_destroy_context(im_scim_context_t _context) {
  im_scim_context_private_t *context;

  context = (im_scim_context_private_t *)_context;

  context->instance.reset();

  context_table.erase(std::find(context_table.begin(), context_table.end(), context));

  delete context;

  return 1;
}

int im_scim_focused(im_scim_context_t _context) {
  im_scim_context_private_t *context;

  context = (im_scim_context_private_t *)_context;

  if (panel_client.is_connected()) {
    panel_client.prepare(context->id);
    panel_client.focus_in(context->id, context->instance->get_factory_uuid());
    if (context->on) {
      PanelFactoryInfo info;
      info = PanelFactoryInfo(context->factory->get_uuid(),
                              utf8_wcstombs(context->factory->get_name()),
                              context->factory->get_language(), context->factory->get_icon_file());
      panel_client.update_factory_info(context->id, info);
      panel_client.turn_on(context->id);
    } else {
      panel_client.turn_off(context->id);
    }
    panel_client.send();
  }

  context->instance->focus_in();

  (*context->cb->candidate_show)(context->self);

  context->focused = 1;

  return 1;
}

int im_scim_unfocused(im_scim_context_t _context) {
  im_scim_context_private_t *context;

  context = (im_scim_context_private_t *)_context;

  if (panel_client.is_connected()) {
    panel_client.prepare(context->id);
    panel_client.turn_off(context->id);
    panel_client.focus_in(context->id, context->instance->get_factory_uuid());
    panel_client.send();
  }

  context->instance->focus_out();

  (*context->cb->candidate_hide)(context->self);

  context->focused = 0;

  return 1;
}

int im_scim_is_on(im_scim_context_t context) {
  if (((im_scim_context_private_t *)context)->on) {
    return 1;
  } else {
    return 0;
  }
}

int im_scim_switch_mode(im_scim_context_t context) {
  KeyEventList keys;
  size_t size;

  if ((size = keymatcher_frontend.find_hotkeys(SCIM_FRONTEND_HOTKEY_TRIGGER, keys)) > 0) {
    return (hotkey(context, keys[0]) == 0);
  } else {
    return 0;
  }
}

int im_scim_key_event(im_scim_context_t context, KeySym ksym, XKeyEvent *event) {
  KeyEvent scim_key;

  scim_key.mask = event->state & valid_key_mask;
  scim_key.code = ksym;
  scim_key.layout = SCIM_KEYBOARD_Default;

  if (hotkey(context, scim_key) == 0) {
    return 0;
  }

  if (!((im_scim_context_private_t *)context)->on) {
    return 1;
  }

  if (((im_scim_context_private_t *)context)->instance->process_key_event(scim_key)) {
    return 0;
  }

  return 1;
}

unsigned int im_scim_preedit_char_attr(im_scim_context_t _context, unsigned int index) {
  im_scim_context_private_t *context;
  AttributeList::const_iterator attr;
  unsigned int result = CHAR_ATTR_UNDERLINE;

  context = (im_scim_context_private_t *)_context;

  for (attr = context->preedit_attr.begin(); attr != context->preedit_attr.end(); attr++) {
    unsigned int start;
    unsigned int end;

    start = attr->get_start();
    end = attr->get_end();

#if 0  // XXX
    if (index < start || end < index)
#else
    if (index < start || end <= index)
#endif
    {
      continue;
    }

    if (attr->get_type() != SCIM_ATTR_DECORATE) {
      // SCIM_ATTR_FOREGROUND and SCIM_ATTR_BACKGROUND
      continue;
    }

    switch (attr->get_value()) {
#if 0
      case SCIM_ATTR_DECORATE_UNDERLINE:
        result |= CHAR_ATTR_UNDERLINE;
        break;
#endif
      case SCIM_ATTR_DECORATE_REVERSE:
        result &= ~CHAR_ATTR_UNDERLINE;
        result |= CHAR_ATTR_REVERSE;
        break;
      case SCIM_ATTR_DECORATE_HIGHLIGHT:
        result |= CHAR_ATTR_BOLD;
        break;
      default:
        break;
    }
  }

  return result;
}

int im_scim_get_panel_fd(void) {
  if (panel_client.is_connected()) {
    return panel_client.get_connection_number();
  }

  return -1;
}

int im_scim_receive_panel_event(void) {
  panel_client.filter_event();

  return 1;
}