#include "json_helper.hpp"
#include "util.hpp"
#include "wayland.hpp"

#include <algorithm>
#include <json.h>

#define AFB_BINDING_VERSION 2

extern "C" {
#include <afb/afb-binding.h>
#include <systemd/sd-event.h>
}

namespace {
struct wayland {
   std::unique_ptr<wl::display> display;
   std::unique_ptr<genivi::controller> controller;
   std::vector<std::unique_ptr<wl::output>> outputs;

   wayland() : display(new wl::display), controller(nullptr), outputs() {}

   int init();
};

struct wayland *g_wayland;

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

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

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

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

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

   return 0;
}

//  _       _ _       _                         _    ____
// (_)_ __ (_) |_    | | __ _ _   _  ___  _   _| |_ / /\ \
// | | '_ \| | __|   | |/ _` | | | |/ _ \| | | | __| |  | |
// | | | | | | |_    | | (_| | |_| | (_) | |_| | |_| |  | |
// |_|_| |_|_|\__|___|_|\__,_|\__, |\___/ \__,_|\__| |  | |
//              |_____|       |___/                 \_\/_/
char const *init_layout() {
   if (!g_wayland->controller) {
      return "ivi_controller global not available";
   }

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

   auto &c = g_wayland->controller;

   auto &o = g_wayland->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();

   g_wayland->display->flush();

   return nullptr;
}

int display_event_callback(sd_event_source *evs, int fd, uint32_t events,
                           void *data) {
   if ((events & EPOLLHUP) != 0) {
      AFB_ERROR("The compositor hung up, dying now.");
      delete g_wayland;
      g_wayland = nullptr;
      goto error;
   }

   if (events & EPOLLIN) {
      int ret = g_wayland->display->dispatch();
      if (ret == -1) {
         AFB_ERROR("wl_display_dipatch() returned error %d",
                   g_wayland->display->get_error());
         goto error;
      }
      g_wayland->display->flush();

      // execute pending tasks, that is layout changes etc.
      g_wayland->controller->execute_pending();
      g_wayland->display->roundtrip();
   }

   return 0;

error:
   sd_event_source_unref(evs);
   return -1;
}

//  _     _           _ _                 _       _ _    ____
// | |__ (_)_ __   __| (_)_ __   __ _    (_)_ __ (_) |_ / /\ \
// | '_ \| | '_ \ / _` | | '_ \ / _` |   | | '_ \| | __| |  | |
// | |_) | | | | | (_| | | | | | (_| |   | | | | | | |_| |  | |
// |_.__/|_|_| |_|\__,_|_|_| |_|\__, |___|_|_| |_|_|\__| |  | |
//                              |___/_____|             \_\/_/
int binding_init_() {
   lognotice("WinMan ver. %s", WINMAN_VERSION_STRING);

   if (g_wayland != nullptr) {
      AFB_ERROR("Wayland context already initialized?");
      return 0;
   }

   if (getenv("XDG_RUNTIME_DIR") == nullptr) {
      AFB_ERROR("Environment variable XDG_RUNTIME_DIR not set");
      goto error;
   }

   g_wayland = new wayland;
   if (g_wayland->init() == -1) {
      AFB_ERROR("Could not connect to compositor");
      goto error;
   }

   if (char const *e = init_layout()) {
      AFB_ERROR("Could not init layout: %s", e);
      goto error;
   }

   {
      int ret = sd_event_add_io(afb_daemon_get_event_loop(), nullptr,
                                g_wayland->display->get_fd(), EPOLLIN,
                                display_event_callback, g_wayland);
      if (ret < 0) {
         AFB_ERROR("Could not initialize wayland event handler: %d", -ret);
         goto error;
      }
   }

   atexit([] { delete g_wayland; });

   return 0;

error:
   delete g_wayland;
   g_wayland = nullptr;
   return -1;
}

int binding_init() noexcept {
   try {
      return binding_init_();
   } catch (std::exception &e) {
      AFB_ERROR("Uncaught exception in binding_init(): %s", e.what());
   }
   return -1;
}

#define CHECK_WAYLAND()                                                    \
   do {                                                                    \
      if (g_wayland == nullptr) {                                          \
         afb_req_fail(req, "failed",                                       \
                      "Binding not initialized, did the compositor die?"); \
         return;                                                           \
      }                                                                    \
   } while (0)

//      _      _                         _        _              ____
//   __| | ___| |__  _   _  __ _     ___| |_ __ _| |_ _   _ ___ / /\ \
//  / _` |/ _ \ '_ \| | | |/ _` |   / __| __/ _` | __| | | / __| |  | |
// | (_| |  __/ |_) | |_| | (_| |   \__ \ || (_| | |_| |_| \__ \ |  | |
//  \__,_|\___|_.__/ \__,_|\__, |___|___/\__\__,_|\__|\__,_|___/ |  | |
//                         |___/_____|                          \_\/_/
void debug_status(struct afb_req req) noexcept {
   // Quick and dirty, dump current surfaces and layers
   AFB_REQ_DEBUG(req, "status");

   CHECK_WAYLAND();

   auto o = json_object_new_object();
   json_object_object_add(o, "surfaces",
                          to_json(g_wayland->controller->surfaces));
   json_object_object_add(o, "layers", to_json(g_wayland->controller->layers));
   json_object_object_add(o, "screens",
                          to_json(g_wayland->controller->screens));

   afb_req_success(req, o, "status");
}

void debug_surfaces(afb_req req) noexcept {
   CHECK_WAYLAND();

   afb_req_success(req, to_json(g_wayland->controller->surfaces), "surfaces");
}

void debug_layers(afb_req req) noexcept {
   CHECK_WAYLAND();

   afb_req_success(req, to_json(g_wayland->controller->layers), "layers");
}

const struct afb_verb_v2 verbs[] = {
   {"status", debug_status, NULL, NULL, AFB_SESSION_NONE_V2},
   {"layers", debug_layers, NULL, NULL, AFB_SESSION_NONE_V2},
   {"surfaces", debug_surfaces, NULL, NULL, AFB_SESSION_NONE_V2},
   {},
};
}  // namespace

extern "C" const struct afb_binding_v2 afbBindingV2 = {
   "winman", NULL, NULL, verbs, NULL, binding_init, NULL, 1};