#pragma once

#include <chrono>
#include <cstdint>
#include <deque>
#include <expected>
#include <functional>
#include <memory>
#include <optional>
#include <string>
#include <vector>

#include <modulus.hpp>

#include <luma/control.hpp>


namespace luma {

enum class dialog_result {
  NONE,
  ACCEPTED,
  CANCELED,
};

struct dialog_options {
  std::string title{};
  std::unique_ptr<luma::control> body{};
  std::string accept_text{"OK"};
  std::string cancel_text{"Cancel"};
  std::function<void(luma::dialog_result)> on_close{};
};

struct toast {
  std::string message{};
  std::chrono::milliseconds duration{2500};
};

class overlay_host final : public luma::control {
public:
  auto show_dialog(luma::dialog_options options) -> std::expected<void, modulus::error>;
  auto close_dialog(luma::dialog_result result) -> std::expected<void, modulus::error>;
  auto show_toast(luma::toast toast) -> std::expected<void, modulus::error>;
  auto tick(std::chrono::steady_clock::duration delta) -> std::bool_t;
  auto measure(luma::draw_context &context, luma::theme const &theme, luma::constraints limits) -> luma::size override;
  auto arrange(luma::rect bounds) -> void override;
  auto draw(luma::draw_context &context, luma::theme const &theme) const -> void override;
  auto handle_touch(luma::touch_event const &event) -> std::bool_t override;
  auto invalidate_layout() -> void override;
  auto bind_layout_invalidator(std::function<void()> invalidator) -> void override;
private:
  friend auto overlays(std::unique_ptr<luma::control> content) -> std::expected<std::unique_ptr<luma::overlay_host>, modulus::error>;
  explicit overlay_host(std::unique_ptr<luma::control> content);
  auto begin_traversal() const -> void;
  auto end_traversal() const -> void;
  auto retire_dialog_body(std::unique_ptr<luma::control> body) -> void;
  auto flush_retired_dialog_bodies() const -> void;
  std::unique_ptr<luma::control> content_{};
  std::optional<luma::dialog_options> dialog_{};
  std::deque<luma::toast> toasts_{};
  std::chrono::steady_clock::duration toast_elapsed_{};
  mutable std::vector<std::unique_ptr<luma::control>> retired_dialog_bodies_{};
  mutable std::uint32_t traversal_depth_{};
};

auto overlays(std::unique_ptr<luma::control> content) -> std::expected<std::unique_ptr<luma::overlay_host>, modulus::error>;

}