#include "common.hh"

#include "xcb_colors.hh"
#include "xcb_connection.hh"
#include "xcb_event.hh"

#include <map>
#include <vector>
#include <xcb/xproto.h>

namespace xcb {

namespace {

class ColorsImpl : public Colors {
public:
  ColorsImpl(shared_conn conn, xcb_colormap_t colormap)
    : conn_(conn), colormap_(colormap),
      storage_(std::make_shared<StorageImpl>()) {}

  Color get_with_fallback(uint8_t r, uint8_t g, uint8_t b,
                          uint32_t fallback) override {
    auto key = make_key(r, g, b);
    auto it = index_.find(key);
    size_t index;
    if (it == index_.end()) {
      index = cookie_.size();
      cookie_.push_back(xcb_alloc_color(conn_.get(), colormap_,
                                        static_cast<uint16_t>(r) << 8,
                                        static_cast<uint16_t>(g) << 8,
                                        static_cast<uint16_t>(b) << 8));
      fallback_.push_back(fallback);
      index_.emplace(key, index);
    } else {
      index = it->second;
    }
    return Color(storage_, index);
  }

  bool sync() override {
    std::vector<uint32_t> colors;
    colors.reserve(cookie_.size());
    for (size_t i = 0; i < cookie_.size(); ++i) {
      xcb::reply<xcb_alloc_color_reply_t> reply(
          xcb_alloc_color_reply(conn_.get(), cookie_[i], nullptr));
      if (reply) {
        colors.push_back(reply->pixel);
      } else {
        colors.push_back(fallback_[i]);
      }
    }
    storage_->set(std::move(colors));
    return true;
  }

private:
  class StorageImpl : public Storage {
  public:
    uint32_t get(size_t id) const override {
      assert(id < resolved_.size());
      return resolved_[id];
    }

    void set(std::vector<uint32_t> resolved) {
      resolved_ = std::move(resolved);
    }

  private:
    std::vector<uint32_t> resolved_;
  };

  static uint32_t make_key(uint8_t r, uint8_t g, uint8_t b) {
    return static_cast<uint32_t>(r) << 16 |
      static_cast<uint32_t>(g) << 8 | b;
  }

  shared_conn conn_;
  xcb_colormap_t colormap_;
  std::map<uint32_t, size_t> index_;
  std::vector<xcb_alloc_color_cookie_t> cookie_;
  std::vector<uint32_t> fallback_;
  std::shared_ptr<StorageImpl> storage_;
};

}  // namespace

std::unique_ptr<Colors> Colors::create(shared_conn conn,
                                       xcb_colormap_t colormap) {
  return std::make_unique<ColorsImpl>(conn, colormap);
}

}  // namespace xcb