package rtmp

import (
	"net"
	"encoding/binary"
	"stream_server/rtmp/amf"
)

type ChunkWrapper struct {
	conn net.Conn
	params *ProtocolParams
	open_chnkstrms map[uint32]*ChunkStream
	open_msgs map[uint32]*Message
	chunk_buffs *ChunkBuffers
}

func NewChunkWrapper(conn net.Conn) (chnk_wrp_ptr *ChunkWrapper) {
	chnk_wrp_ptr = new(ChunkWrapper)

	chnk_wrp_ptr.conn = conn
	chnk_wrp_ptr.params = &ProtocolParams{1024, 512, 0, 0, ""}
	chnk_wrp_ptr.open_chnkstrms = make(map[uint32]*ChunkStream)
	chnk_wrp_ptr.open_msgs = make(map[uint32]*Message)
	buffers := ChunkBuffers{
		make([]byte, 4),
		make([]byte, 4),
		make([]byte, 1),
		make([]byte, 4),
		make([]byte, 1),
		make([]byte, 2),
	}
	chnk_wrp_ptr.chunk_buffs = &buffers
	return
}

func (chnk_wrp_ptr *ChunkWrapper) ReadChunk() (*Message, error) {
	full_msg_ptr, err := ReadChunk(
		chnk_wrp_ptr.conn,
		chnk_wrp_ptr.open_chnkstrms,
		chnk_wrp_ptr.open_msgs,
		chnk_wrp_ptr.params.peer_chunk_size,
		chnk_wrp_ptr.chunk_buffs,
		&(chnk_wrp_ptr.params.curr_read),
	)
	if err != nil {
		return nil, err
	}
	return full_msg_ptr, nil
}

func (chnk_wrp_ptr *ChunkWrapper) WriteChunk(csid uint32, msg_strmid uint32, msg_ptr *Message) (error) {
	err := WriteChunk(
		chnk_wrp_ptr.conn,
		csid,
		msg_strmid,
		msg_ptr,
		chnk_wrp_ptr.params.chunk_size,
	)
	if err != nil {
		return err
	}
	return nil
}

func (chnk_wrp_ptr *ChunkWrapper) ReadPeerChunkSize() (error) {
	set_chunk_size_msg, err := chnk_wrp_ptr.ReadChunk()
	if err != nil || set_chunk_size_msg.msg_type != 1 || set_chunk_size_msg.msg_len != 4 {
		return err
	}
	chnk_wrp_ptr.params.peer_chunk_size = binary.BigEndian.Uint32(set_chunk_size_msg.data)
	return nil
}

func (chnk_wrp_ptr *ChunkWrapper) ReadConnectCommand() (error) {
	connect_cmd_msg, err := chnk_wrp_ptr.ReadChunk()
	if err != nil || connect_cmd_msg.msg_type != 20 {
		return err
	}
	amf_obj, err := amf.DecodeAMF(&(connect_cmd_msg.data))
	if err != nil {
		return err
	}
	err = amf_obj.ProcessConnect()
	if err != nil {
		return err
	}
	return err
}

func (chnk_wrp_ptr *ChunkWrapper) WriteWindowAckSize() (error) {
	msg_ptr := new(Message)
	msg_ptr.msg_type = 5
	msg_ptr.data = make([]byte, 4)
	msg_ptr.msg_len = 4
	binary.BigEndian.PutUint32(msg_ptr.data, 5000000)
	if err := chnk_wrp_ptr.WriteChunk(2, 0, msg_ptr); err != nil {
		return err
	}
	return nil
}

func (chnk_wrp_ptr *ChunkWrapper) WritePeerBandwidth() (error) {
	msg_ptr := new(Message)
	msg_ptr.msg_type = 6
	msg_ptr.data = make([]byte, 5)
	msg_ptr.msg_len = 5
	binary.BigEndian.PutUint32(msg_ptr.data, 5000000)
	msg_ptr.data[4] = 2
	if err := chnk_wrp_ptr.WriteChunk(2, 0, msg_ptr); err != nil {
		return err
	}
	return nil
}

func (chnk_wrp_ptr *ChunkWrapper) WriteChunkSize() (error) {
	msg_ptr := new(Message)
	msg_ptr.msg_type = 1
	msg_ptr.data = make([]byte, 4)
	msg_ptr.msg_len = 4
	binary.BigEndian.PutUint32(msg_ptr.data, chnk_wrp_ptr.params.chunk_size)
	if err := chnk_wrp_ptr.WriteChunk(2, 0, msg_ptr); err != nil {
		return err
	}
	return nil
}

func (chnk_wrp_ptr *ChunkWrapper) WriteConnectResponse() (error) {
	msg_ptr := new(Message)
	msg_ptr.msg_type = 20
	if err := amf.EncodeConnectResponse(msg_ptr); err != nil {
		return err
	}
	if err := chnk_wrp_ptr.WriteChunk(3, 0, msg_ptr); err != nil {
		return err
	}
	return nil
}