/*
 * Copyright (C) 2017 Mentor Graphics Development (Deutschland) GmbH
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "app.hpp"
#include "json_helper.hpp"
#include "layers.hpp"
#include "layout.hpp"
#include "util.hpp"
#include "wayland.hpp"

#include <cstdio>
#include <memory>

#include <cassert>

#include <json-c/json.h>

#include <algorithm>
#include <bits/signum.h>
#include <csignal>
#include <fstream>
#include <thread>
#include <json.hpp>

namespace wm {

namespace {
App *g_app;

using json = nlohmann::json;

struct wm::area area_from_json(json const &j) {
   return wm::area{
      j["name"],
      {
         j["width"], j["height"], j["x"], j["y"],
      },
      j["zorder"],
   };
}

result<struct layout> layout_from_json(json const &j) {
   auto &ja = j["areas"];

   auto l = layout{j["name"], uint32_t(ja.size()), {}};

   if (ja.size() > layout::MAX_N_AREAS) {
      return Err<struct layout>("Invalid number of areas in layout");
   }

   logdebug("Loading layout '%s' with %u areas", l.name.c_str(),
            unsigned(ja.size()));

   std::transform(std::cbegin(ja), std::cend(ja), std::begin(l.areas),
                  area_from_json);

   return Ok(l);
}

result<json> file_to_json(char const *filename) {
   std::ifstream i(filename);
   if (i.fail()) {
      return Err<json>("Could not open config file");
   }
   json j;
   i >> j;
   return Ok(j);
}

// Will throw if parsing fails
struct result<layouts_type> load_layout(char const *filename) {
   logdebug("loading layout from %s", filename);

   auto j = file_to_json(filename);
   if (j.is_err()) {
      return Err<layouts_type>(j.unwrap_err());
   }
   json jlayouts = j.unwrap();

   auto layouts = layouts_type();
   layouts.reserve(jlayouts.size());
   std::transform(std::cbegin(jlayouts), std::cend(jlayouts),
                  std::back_inserter(layouts), layout_from_json);

   return Ok(layouts);
}

struct result<layer_map>
   load_layer_map(char const *filename) {
   logdebug("loading IDs from %s", filename);

   auto j = file_to_json(filename);
   if (j.is_err()) {
      return Err<layer_map>(j.unwrap_err());
   }
   json jids = j.unwrap();

   return to_layer_map(jids);
}

}  // namespace

//       _                    _                  _                 _
//   ___| | __ _ ___ ___     / \   _ __  _ __   (_)_ __ ___  _ __ | |
//  / __| |/ _` / __/ __|   / _ \ | '_ \| '_ \  | | '_ ` _ \| '_ \| |
// | (__| | (_| \__ \__ \  / ___ \| |_) | |_) | | | | | | | | |_) | |
//  \___|_|\__,_|___/___/ /_/   \_\ .__/| .__/  |_|_| |_| |_| .__/|_|
//                                |_|   |_|                 |_|
App::App(wl::display *d)
   : api{this},
     chooks{this},
     display{d},
     controller{},
     outputs(),
     config(),
     layouts(),
     layers(),
     name_mapping(),
     id_alloc{},
     last_active() {
   assert(g_app == nullptr);
   g_app = this;

   try {
      {
         auto l = load_layer_map(
            this->config.get_string("layers.json").value().c_str());
         if (l.is_ok()) {
            this->layers = l.unwrap();
         } else {
            logerror("%s", l.err().value());
         }
      }

      {
         auto l =
            load_layout(this->config.get_string("layout.json").value().c_str());
         if (l.is_ok()) {
            this->layouts = l.unwrap();
         } else {
            logerror("%s", l.err().value());
         }
      }
   } catch (std::exception &e) {
      logerror("Loading of configuration failed: %s", e.what());
   }
}

App::~App() { g_app = nullptr; }

int App::init() {
   if (!this->display->ok()) {
      return -1;
   }

   if (this->layers.mapping.empty()) {
      logerror("No surface -> layer mapping loaded");
      return -1;
   }

   this->display->add_global_handler(
      "wl_output", [this](wl_registry *r, uint32_t name, uint32_t v) {
         this->outputs.emplace_back(std::make_unique<wl::output>(r, name, v));
      });

   this->display->add_global_handler(
      "ivi_controller", [this](wl_registry *r, uint32_t name, uint32_t v) {
         this->controller = std::make_unique<struct genivi::controller>(r, name, v);

         // Init controller hooks
         this->controller->chooks = &this->chooks;

         // XXX: This protocol needs the output, so lets just add our mapping
         // here...
         this->controller->add_proxy_to_id_mapping(
            this->outputs.back()->proxy.get(),
            wl_proxy_get_id(reinterpret_cast<struct wl_proxy *>(
               this->outputs.back()->proxy.get())));
      });

   // First level objects
   this->display->roundtrip();
   // Second level objects
   this->display->roundtrip();
   // Third level objects
   this->display->roundtrip();

   return init_layout();
}

int App::dispatch_events() {
   int ret = this->display->dispatch();
   if (ret == -1) {
      logerror("wl_display_dipatch() returned error %d",
               this->display->get_error());
      return -1;
   }
   this->display->flush();

   // execute pending tasks, that is layout changes etc.
   //this->execute_pending();

   return 0;
}

//  _       _ _       _                         _    ____
// (_)_ __ (_) |_    | | __ _ _   _  ___  _   _| |_ / /\ \
// | | '_ \| | __|   | |/ _` | | | |/ _ \| | | | __| |  | |
// | | | | | | |_    | | (_| | |_| | (_) | |_| | |_| |  | |
// |_|_| |_|_|\__|___|_|\__,_|\__, |\___/ \__,_|\__| |  | |
//              |_____|       |___/                 \_\/_/
int App::init_layout() {
   if (!this->controller) {
      logerror("ivi_controller global not available");
      return -1;
   }

   if (this->outputs.empty()) {
      logerror("no output was set up!");
      return -1;
   }

   auto &c = this->controller;

   auto &o = this->outputs.front();
   auto &s = c->screens.begin()->second;
   auto &layers = c->layers;

   // XXX: Write output dimensions to ivi controller...
   c->output_size = genivi::size{uint32_t(o->width), uint32_t(o->height)};

   // Clear scene
   layers.clear();

   // Clear screen
   s->clear();

   // Quick and dirty setup of layers
   // XXX: This likely needs to be sorted by order (note, we don't (yet?)
   // do any zorder arrangement).
   for (auto const &i : this->layers.mapping) {
      c->layer_create(i.layer_id, o->width, o->height);
      auto &l = layers[i.layer_id];
      l->set_destination_rectangle(0, 0, o->width, o->height);
      l->set_visibility(1);
      logdebug("Setting up layer %s (%d) for surfaces %d-%d", i.name.c_str(),
               i.layer_id, i.id_min, i.id_max);
   }

   // Add layers to screen (XXX: are they sorted correctly?)
   s->set_render_order(this->layers.layers);

   c->commit_changes();

   this->display->flush();

   return 0;
}

namespace {

// This can fix the HomeScreen...
void redraw_fix(App *app, std::unique_ptr<genivi::surface> &s, int x, int y, int w, int h) {
   { // XXX: Work around weston redraw issues
      // trigger an update by changing the source dimensions!
      s->set_configuration(w, h);
      s->set_source_rectangle(0, 0, w, h);
      s->set_destination_rectangle(x, y, w, h);
      app->controller->commit_changes();
      app->display->roundtrip();

      // wait some time, for the process to do its thing...
      using namespace std::chrono_literals;
      std::this_thread::sleep_for(100ms);

      // Set a different size then what we actually want.
      s->set_configuration(w + 1, h);
      s->set_source_rectangle(0, 0, w + 1, h);
      s->set_destination_rectangle(x, y, w + 1, h);
      app->controller->commit_changes();
      app->display->roundtrip();

      std::this_thread::sleep_for(100ms);
   }
}

}  // namespace

void App::surface_set_layout(uint32_t surface_id) {
   if (!this->controller->surface_exists(surface_id)) {
      logerror("Surface %d does not exist", int(surface_id));
      return;
   }

   auto o_layer_id = this->layers.get_layer_id(surface_id);

   if (!o_layer_id) {
      logerror("Surface %d is not associated with any layer!", int(surface_id));
      return;
   }

   uint32_t layer_id = o_layer_id.value();
   logdebug("surface_set_layout for surface %u on layer %u", surface_id,
            layer_id);

   auto const &layer = this->layers.get_layer(layer_id);
   auto rect = layer.value().rect;
   auto &s = this->controller->surfaces[surface_id];

   int x = rect.x;
   int y = rect.y;
   int w = rect.w;
   int h = rect.h;

   // less-than-0 values refer to MAX + 1 - $VALUE
   // e.g. MAX is either screen width or height
   if (w < 0) {
      w = this->controller->output_size.w + 1 + w;
   }
   if (h < 0) {
      h = this->controller->output_size.h + 1 + h;
   }

   redraw_fix(this, s, x, y, w, h);

   // configure surface to wxh dimensions
   s->set_configuration(w, h);

   // set source reactangle, even if we should not need to set it.
   s->set_source_rectangle(0, 0, w, h);

   // set destination to the display rectangle
   s->set_destination_rectangle(x, y, w, h);

   s->set_visibility(0);
   s->set_opacity(256);

   this->controller->commit_changes();
   this->display->roundtrip();

   this->controller->layers[layer_id]->add_surface(s.get());

   // activate the main_surface right away
   if (surface_id == static_cast<unsigned>(this->layers.main_surface)) {
      logdebug("Activating main_surface (%d)", surface_id);

      this->activate_surface(surface_id);
   }

   logdebug("Surface %u now on layer %u with rect { %d, %d, %d, %d }",
            surface_id, layer_id, x, y, w, h);
}

char const *App::activate_surface(uint32_t surface_id) {
   if (!this->controller->surface_exists(surface_id)) {
      return "Surface does not exist";
   }

   // This should involve a policy check, but as we do not (yet) have
   // such a thing, we will just switch to this surface.
   // XXX: input focus missing!!1

   // Make it visible, no (or little effect) if already visible
   auto &s = this->controller->surfaces[surface_id];

   // Set all others invisible
   for (auto &i : this->controller->surfaces) {
      auto &si = this->controller->sprops[i.second->id];
      if (int(si.id) != this->layers.main_surface) {
         i.second->set_visibility(0);
         this->controller->commit_changes();
         this->display->flush();
      }
   }
   s->set_visibility(1);

   // commit changes
   this->controller->commit_changes();
   this->display->flush();

   // Current active surface is the first in last_active
   this->last_active.push_front(s->id);
   /// // XXX: I am not sure I even need 5 elements...
   /// this->last_active.resize(std::min(int(this->last_active.size()), 5));

   // no error
   return nullptr;
}

char const *App::deactivate_surface(uint32_t surface_id) {
   if (surface_id == this->layers.main_surface) {
      return "Cannot deactivate main_surface";
   }

   if (this->last_active.empty()) {
      return "Cannot deactivate surface (not active)";
   }

   // XXX: should an active surface not alsways be front() or
   // front+1() of last_active?!

   // XXX: Should I really be able to deactivate a surface that is not
   // front() of last_active?
   auto is = std::find(this->last_active.begin(),
                       this->last_active.end(),
                       surface_id);

   if (is == this->last_active.end()) {
      return "Cannot deactivate surface (not active)";
   }

   this->last_active.erase(is);

   if (! this->last_active.empty()) {
      // Should be active already, shouldn't it?
      this->activate_surface(this->last_active.front());
   } else {
      this->activate_surface(this->layers.main_surface);
   }

   return nullptr;
}

//                      _          _   _____                 _
//  _ __  _ __ _____  _(_) ___  __| | | ____|_   _____ _ __ | |_ ___
// | '_ \| '__/ _ \ \/ / |/ _ \/ _` | |  _| \ \ / / _ \ '_ \| __/ __|
// | |_) | | | (_) >  <| |  __/ (_| | | |___ \ V /  __/ | | | |_\__ \
// | .__/|_|  \___/_/\_\_|\___|\__,_| |_____| \_/ \___|_| |_|\__|___/
// |_|
void App::surface_created(uint32_t surface_id) {
   //surface_id >>= id_allocator::id_shift;

   logdebug("surface_id is %u", surface_id);

   this->surface_set_layout(surface_id);
}

void App::surface_removed(uint32_t surface_id) {
   //surface_id >>= id_allocator::id_shift;

   logdebug("surface_id is %u", surface_id);

   this->id_alloc.remove_id(surface_id);

   // Also remove from last_active, if found
   auto i = std::find(this->last_active.begin(),
                      this->last_active.end(), surface_id);
   if (i != this->last_active.end()) {
      this->last_active.erase(i);
   }
}

void App::emit_activated(char const *label) {
   this->api.send_event("activated", label);
}

void App::emit_deactivated(char const *label) {
   this->api.send_event("deactivated", label);
}

void App::emit_syncdraw(char const *label) {
   this->api.send_event("syncdraw", label);
}

void App::emit_flushdraw(char const *label) {
   this->api.send_event("syncdraw", label);
}

void App::emit_visible(char const *label, bool is_visible) {
   this->api.send_event(is_visible ? "visible" : "invisible", label);
}

result<int> App::request_surface(char const *drawing_name) {
   auto lid = this->layers.get_layer_id(std::string(drawing_name));
   if (!lid) {
      // XXX: to we need to put these applications on the App layer?
      return Err<int>("Drawing name does not match any role");
   }

   auto rname = this->id_alloc.lookup(drawing_name);
   if (!rname) {
      // name does not exist yet, allocate surface id...
      auto id = int(this->id_alloc.generate_id(drawing_name));
      this->layers.add_surface(id, lid.value());

      // XXX: you should fix this!
      if (!this->layers.main_surface_name.empty() &&
          this->layers.main_surface_name == drawing_name) {
         this->layers.main_surface = id;
         this->activate_surface(id);
         logdebug("Set main_surface id to %u", id);
      }

      return Ok<int>(id);
   }

   // Check currently registered drawing names if it is already there.
   return Err<int>("Surface already present");
}

char const *App::activate_surface(char const *drawing_name) {
   auto osid = this->id_alloc.lookup(drawing_name);

   if (osid) {
      logdebug("ativate surface with name %s and id %u", drawing_name,
               osid.value());
      auto ret = this->activate_surface(osid.value());
      if (!ret) {
         this->emit_activated(drawing_name);
      }
      return ret;
   }

   logerror("surface %s unknown", drawing_name);
   return "Surface unknown";
}

char const *App::deactivate_surface(char const *drawing_name) {
   auto osid = this->id_alloc.lookup(drawing_name);

   if (osid) {
      logdebug("deativate surface with name %s and id %u", drawing_name,
               osid.value());
      return this->deactivate_surface(osid.value());
   }

   logerror("surface %s unknown", drawing_name);
   return "Surface unknown";
}

//  _     _           _ _                            _   _                 _
// | |__ (_)_ __   __| (_)_ __   __ _     __ _ _ __ (_) (_)_ __ ___  _ __ | |
// | '_ \| | '_ \ / _` | | '_ \ / _` |   / _` | '_ \| | | | '_ ` _ \| '_ \| |
// | |_) | | | | | (_| | | | | | (_| |  | (_| | |_) | | | | | | | | | |_) | |
// |_.__/|_|_| |_|\__,_|_|_| |_|\__, |___\__,_| .__/|_| |_|_| |_| |_| .__/|_|
//                              |___/_____|   |_|                   |_|
binding_api::result_type binding_api::request_surface(
   char const *drawing_name) {
   auto r = this->app->request_surface(drawing_name);
   if (r.is_err()) {
      return Err<json_object *>(r.unwrap_err());
   }
   return Ok(json_object_new_int(r.unwrap()));
}

binding_api::result_type binding_api::activate_surface(
   char const *drawing_name) {
   logdebug("%s drawing_name %s", __func__, drawing_name);
   auto r = this->app->activate_surface(drawing_name);
   if (r != nullptr) {
      return Err<json_object *>(r);
   }
   return Ok(json_object_new_object());
}

binding_api::result_type binding_api::deactivate_surface(char const* drawing_name) {
   logdebug("%s drawing_name %s", __func__, drawing_name);
   auto r = this->app->deactivate_surface(drawing_name);
   if (r != nullptr) {
      return Err<json_object *>(r);
   }
   return Ok(json_object_new_object());
}

binding_api::result_type binding_api::enddraw(char const* drawing_name) {
   logdebug("%s drawing_name %s", __func__, drawing_name);
   return Err<json_object*>("not implemented");
}

binding_api::result_type binding_api::list_drawing_names() {
   logdebug("%s", __func__);
   json j = this->app->id_alloc.names;
   return Ok(json_tokener_parse(j.dump().c_str()));
}

binding_api::result_type binding_api::debug_layers() {
   logdebug("%s", __func__);
   return Ok(json_tokener_parse(this->app->layers.to_json().dump().c_str()));
}

binding_api::result_type binding_api::debug_surfaces() {
   logdebug("%s", __func__);
   return Ok(to_json(this->app->controller->sprops));
}

binding_api::result_type binding_api::debug_status() {
   logdebug("%s", __func__);
   json_object *jr = json_object_new_object();
   json_object_object_add(jr, "surfaces",
                          to_json(this->app->controller->sprops));
   json_object_object_add(jr, "layers", to_json(this->app->controller->lprops));
   return Ok(jr);
}

binding_api::result_type binding_api::debug_terminate() {
   logdebug("%s", __func__);
   raise(SIGKILL);  // XXX afb-daemon kills it's pgroup using TERM, which
                    // doesn't play well with perf
   return Ok(json_object_new_object());
}

binding_api::result_type binding_api::demo_activate_surface(
   uint32_t surfaceid) {
   char const *e = this->app->activate_surface(surfaceid);
   if (e != nullptr) {
      return Err<json_object *>(e);
   }
   return Ok(json_object_new_object());
}

binding_api::result_type binding_api::demo_activate_all() {
   for (auto &s : this->app->controller->surfaces) {
      s.second->set_visibility(1);
   }
   this->app->controller->commit_changes();
   this->app->display->flush();
   return Ok(json_object_new_object());
}

//                  _             _ _            _                 _
//   ___ ___  _ __ | |_ _ __ ___ | | | ___ _ __ | |__   ___   ___ | | _____
//  / __/ _ \| '_ \| __| '__/ _ \| | |/ _ \ '__|| '_ \ / _ \ / _ \| |/ / __|
// | (_| (_) | | | | |_| | | (_) | | |  __/ |   | | | | (_) | (_) |   <\__ \
//  \___\___/|_| |_|\__|_|  \___/|_|_|\___|_|___|_| |_|\___/ \___/|_|\_\___/
//                                         |_____|
void controller_hooks::surface_created(uint32_t surface_id) {
   this->app->surface_created(surface_id);
}

void controller_hooks::surface_removed(uint32_t surface_id) {
   this->app->surface_removed(surface_id);
}

}  // namespace wm