//
// Created by mfritzsc on 7/11/17.
//

#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 <fstream>
#include <json.hpp>

namespace wm {

namespace {
App *g_app;

using json = nlohmann::json;

struct wm::area area_from_json(json const &j) {
   DB(j);
   return wm::area{
      j["name"].get<std::string>(),
      {
         get<uint32_t>(j["width"]), get<uint32_t>(j["height"]),
         get<int32_t>(j["x"]), get<int32_t>(j["y"]),
      },
      get<uint32_t>(j["zorder"]),
   };
}

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

   auto l = wm::layout{j["name"].get<std::string>(), 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);
}

struct result<layouts_type> load_layout(char const *filename) {
   DB("loading layout from " << filename);

   json jlayouts;
   std::ifstream i(filename);
   i >> jlayouts;

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

   return Ok(layouts);
}

struct result<surface_id_to_layer_map>
   load_layer_ids(char const *filename) {
   DB("loading IDs from " << filename);

   json jids;
   std::ifstream i(filename);
   i >> jids;

   auto m = to_surface_id_to_layer_map(jids["mappings"]);

   if (m.is_ok()) {
      auto i = m.unwrap();

      auto jtests = jids.value("tests", json());

      std::vector<std::pair<int, int>> tests;
      std::transform(std::cbegin(jtests), std::cend(jtests),
                     std::back_inserter(tests), [](json const &j) {
                        return std::make_pair(get<int>(j["surface_id"]),
                                              get<int>(j["expect_layer_id"]));
                     });

      for (auto sid : tests) {
         if (i.get_layer_for_surface(sid.first).value_or(-1) != sid.second) {
            return Err<surface_id_to_layer_map>("ID Map embedded test failed!");
         }
      }
   }

   return m;
}

}  // namespace

App::App(wl::display *d)
   : api{this}, display{d}, controller{} {
   // layouts(load_layout("../layout.json").unwrap()) {
   assert(g_app == nullptr);
   g_app = this;

   auto a = load_layout("../layout.json");
   auto b = a.map_err([](char const *e) -> char const * {
      DB("Could not load layout: " << e);
      return e;
   });

   auto c = load_layer_ids("../ids.json");
   auto e = c.map_err([](char const *e) -> char const * {
      DB("Could not load ids: " << e);
      return e;
   });
}

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

int App::init() {
   if (!this->display->ok()) {
      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<genivi::controller>(r, name, v);

         // 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->controller->execute_pending();
   this->display->roundtrip();

   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();

   // Setup our dummy scene...
   c->layer_create(100, 0, 0);   // bottom layer, anything else
   c->layer_create(1000, 0, 0);  // top layer, mandelbrot

   auto &l100 = c->layers[100];
   auto &l1k = c->layers[1000];

   // Set layers fullscreen
   l100->set_destination_rectangle(0, 0, o->width, o->height);
   l1k->set_destination_rectangle(0, 0, o->width, o->height);
   l100->set_visibility(1);
   l1k->set_visibility(1);

   // Add layers to screen
   s->set_render_order({100, 1000});

   c->commit_changes();

   this->display->flush();

   return 0;
}

binding_api::result_type binding_api::register_surface(uint32_t appid,
                                                       uint32_t surfid) {
   logdebug("%s appid %u surfid %u", __func__, appid, surfid);
   if (appid > 0xff) {
      return Err<json_object *>("invalid appid");
   }

   if (surfid > 0xffff) {
      return Err<json_object *>("invalid surfaceid");
   }

   return Ok(json_object_new_int((appid << 16) + surfid));
}

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

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);
}

}  // namespace wm