//
// Created by m on 7/27/17.
//

#include <algorithm>

#include "json_helper.hpp"
#include "layers.hpp"
#include "util.hpp"

namespace wm {

surface_id_to_layer::surface_id_to_layer(nlohmann::json const &j) {
   DB(j);
   if (j["type"] == "range") {
      this->id_min = get<int>(j["first_surface_id"]);
      this->id_max = get<int>(j["last_surface_id"]);
   } else {
      this->id_min = this->id_max = get<int>(j["surface_id"]);
   }
   this->name = j["name"].get<std::string>();
   this->layer_id = get<int>(j["layer_id"]);
}

struct result<struct surface_id_to_layer_map> to_surface_id_to_layer_map(
   nlohmann::json const &j) {
   DB(j);
   try {
      surface_id_to_layer_map stl{};
      std::transform(
         std::cbegin(j), std::cend(j),
         std::inserter(stl.mapping, stl.mapping.end()),
         [](nlohmann::json const &j) { return surface_id_to_layer(j); });
      for (auto i : stl.mapping) {
         if (i.name.empty()) {
            return Err<struct surface_id_to_layer_map>(
               "Found mapping w/o name");
         }
         if (i.layer_id == -1 || i.id_min == -1 || i.id_max == -1) {
            return Err<struct surface_id_to_layer_map>(
               "Found invalid/unset IDs in mapping");
         }
      }
      return Ok(stl);
   } catch (std::exception &e) {
      return Err<struct surface_id_to_layer_map>(e.what());
   }
}

// Helper to allow std::lower_bound with a int key only
inline bool
   operator<(struct surface_id_to_layer const &a, int b) {
   return a.id_max < b;
}

optional<int> surface_id_to_layer_map::get_layer_for_surface(int surface_id) {
   auto i = std::lower_bound(std::cbegin(this->mapping),
                             std::cend(this->mapping), surface_id);

   if (i != this->mapping.end()) {
      // std::less only checks for surface_id_to_layer::id_max, so check
      // that we are actually inside of an interval here.
      if (i->id_min <= surface_id) {
         return optional<int>(i->layer_id);
      }
   }

   return nullopt;
}

}  // namespace wm