#pragma once

#include <fsdk/IObject.h>
#include <fsdk/FSDKError.h>
#include <fsdk/Optional.h>
#include <fsdk/Types.h>

namespace fsdk {

#ifndef DOXYGEN_SHOULD_SKIP_THIS
	DECLARE_SMARTPTR(IGlassesEstimator);
#endif

	/** @brief Glasses estimation enum.
	 * \li \c noglasses:  checks whether person is wearing glasses or not. 
	 * true - no glasses, false - with glasses;
	 * \li \c eyeglasses: checks whether person is wearing eyeglasses or not. 
	 * true - eyeglasses, false - not eyeglasses;
	 * \li \c sunglasses: checks whether person is wearing sunglasses or not. 
	 * true - sunglasses, false - not sunglasses.
	 * */
	enum class GlassesEstimation: uint8_t{
		NoGlasses,//!< Person is not wearing glasses
		EyeGlasses,//!< Person is wearing eyeglasses
		SunGlasses,//!< Person is wearing sunglasses
		EstimationError//!< failed to estimate
	};

	/**
	 * @brief Glasses estimator interface.
	 * @note This estimator is designed to work with a person face image;
	**/
	struct IGlassesEstimator : IRefCounted {
		/**
		* brief checks whether person wearing any glasses or not.
		* @param [in] warp image with warped face; @see IWarper for details.
		* @return ResultValue with error code and output enum value inside.
		* @see GlassesEstimation, Image, ResultValue and FSDKError for details.
		* @note warp format must be R8G8B8, @see Format.
		* */
		virtual ResultValue<FSDKError, GlassesEstimation>
		estimate(const Image& warp) const noexcept  = 0;

		/**
		 * @brief Checks if people are wearing glasses or not for multiple warped images in a single estimate function call
		 * @param [in] warps span of images with warped faces.
		 * @param [out] glassesEstimations output GlassesEstimation span.
		 * @return Result with error code.
		 * @see Span, GlassesEstimation, Image, Result and FSDKError for details.
		 * @note warps format must be R8G8B8, @see Format.
		 * @note all spans should be based on user owned continuous collections.
		 * @note all spans should be equal size.
		 * */
		virtual Result<FSDKError>
		estimate(
			Span<const Image> warps,
			Span<GlassesEstimation> glassesEstimations) const noexcept = 0;

		/**
		 * @brief Validate input of multiple frames in a single function call.
		 * @param [in] warps span of images with warped faces.
		 * @param [out] errors output span of errors for each image.
		 * @return Result with error code.
		 * @see Span, Image, Result and FSDKError for details.
		 * @note warps format must be R8G8B8, @see Format.
		 * @note all spans should be based on user owned continuous collections.
		 * @note all spans should be equal size.
		 * */
		virtual Result<FSDKError>
		validate(
			Span<const Image> warps,
			Span<Result<FSDKError>> errors) const noexcept = 0;
	};

} // namespace fsdk