#ifndef LIBAV_CODEC_CONTEXT_HPP
#define LIBAV_CODEC_CONTEXT_HPP

#include "libav/fmt/context.hpp"

#include <utility> //exchange

extern "C"{
#  include <libavcodec/avcodec.h>
}

namespace libav::codec{

	class context
	{
	private:
		AVCodecContext* m_context = nullptr;
		const AVCodec* m_codec = nullptr;
		bool m_open = false;
	public:
		context(const libav::fmt::input_context& ctx, int index){
			AVCodecParameters* cparms = ctx->streams[index]->codecpar;
			m_codec = avcodec_find_decoder(cparms->codec_id);
			m_context = avcodec_alloc_context3(m_codec);
			if(!m_context)
				return;
			avcodec_parameters_to_context(m_context, cparms);
		}
		context(const libav::fmt::output_context& ctx, int index){
			AVCodecParameters* cparms = ctx->streams[index]->codecpar;
			m_codec = avcodec_find_encoder(cparms->codec_id);
			m_context = avcodec_alloc_context3(m_codec);
			if(!m_context)
				return;
			avcodec_parameters_to_context(m_context, cparms);
		}
		context(const AVCodec* codec){
			m_codec = codec;
			m_context = avcodec_alloc_context3(m_codec);
		}
		context(const context&) = delete;
		context(context&& c)noexcept:
			m_context(std::exchange(c.m_context, nullptr)),
			m_codec(c.m_codec),
			m_open(c.m_open){}
		~context(void){
			reset();
		}

		context& operator=(const context&) = delete;
		context& operator=(context&& c)noexcept{
			std::swap(m_context, c.m_context);
			m_codec = c.m_codec;
			std::swap(m_open, c.m_open);
			return *this;
		}
		bool open(void){
			if(!m_open){
				int ret = avcodec_open2(m_context, m_codec, NULL);
				return (m_open = (ret >= 0));
			}
			return false;
		}
		bool is_open(void)const{
			return m_open;
		}
		void reset(void){
			if(m_open)
				avcodec_close(m_context);
			if(m_context)
				avcodec_free_context(&m_context);
			m_open = false;
			m_context = nullptr;
			m_codec = nullptr;
		}
		AVCodecContext* release(void){
			return std::exchange(m_context, nullptr);
		}

		AVCodecContext* operator->(void){
			return m_context;
		}
		const AVCodecContext* operator->(void)const{
			return m_context;
		}

		AVCodecContext* get(void){
			return m_context;
		}
		const AVCodecContext* get(void)const{
			return m_context;
		}
		operator AVCodecContext*(void){
			return m_context;
		}
		operator const AVCodecContext*(void)const{
			return m_context;
		}
		operator bool(void)const{
			return m_context;
		}
	};

}

#endif