package notify

import (
	"context"
	"errors"
	"fmt"
	"io"
	"net"
	"time"
)

const bulkDispatchRejectTimeout = 300 * time.Millisecond

func (c *ClientCommon) dispatchFastBulkFrame(frame bulkFastFrame) {
	c.dispatchFastBulkFrameWithOwner(frame, nil)
}

func (c *ClientCommon) dispatchFastBulkFrameWithOwner(frame bulkFastFrame, owner *bulkReadPayloadOwner) {
	if frame.DataID == 0 {
		return
	}
	runtime := c.getBulkRuntime()
	if runtime == nil {
		return
	}
	bulk, ok := runtime.lookupByDataID(clientFileScope(), frame.DataID)
	if !ok {
		if c.showError || c.debugMode {
			fmt.Println("client bulk data for unknown data id", frame.DataID)
		}
		c.bestEffortRejectInboundBulkData("", frame.DataID, errBulkNotFound.Error())
		return
	}
	if !bulk.acceptsClientSessionEpoch(c.currentClientSessionEpoch()) {
		if c.showError || c.debugMode {
			fmt.Println("client bulk data rejected by stale session epoch", frame.DataID)
		}
		detachErr := transportDetachedSessionEpochError()
		bulk.markReset(detachErr)
		c.bestEffortRejectInboundBulkData(bulk.ID(), frame.DataID, detachErr.Error())
		return
	}
	switch frame.Type {
	case bulkFastPayloadTypeData:
		var err error
		if owner != nil {
			err = bulk.pushChunkWithOwnershipOptionsAndRelease(frame.Payload, true, true, owner.retainChunk())
		} else {
			err = bulk.pushOwnedChunk(frame.Payload)
		}
		if err != nil {
			if c.showError || c.debugMode {
				fmt.Println("client bulk push chunk error", err)
			}
			if !errors.Is(err, io.EOF) {
				c.bestEffortRejectInboundBulkData(bulk.ID(), frame.DataID, err.Error())
			}
		}
	case bulkFastPayloadTypeClose:
		if frame.Flags&bulkFastPayloadFlagFullClose != 0 {
			bulk.markPeerClosed()
			return
		}
		bulk.markRemoteClosed()
	case bulkFastPayloadTypeReset:
		resetErr := errBulkReset
		if len(frame.Payload) > 0 {
			resetErr = bulkRemoteResetError(string(frame.Payload))
		}
		bulk.markReset(bulkResetError(resetErr))
	case bulkFastPayloadTypeRelease:
		bytes, chunks, err := decodeBulkDedicatedReleasePayload(frame.Payload)
		if err != nil {
			if c.showError || c.debugMode {
				fmt.Println("client bulk release decode error", err)
			}
			c.bestEffortRejectInboundBulkData(bulk.ID(), frame.DataID, err.Error())
			return
		}
		bulk.releaseOutboundWindow(bytes, chunks)
	}
}

func (c *ClientCommon) dispatchFastBulkData(frame bulkFastDataFrame) {
	c.dispatchFastBulkFrameWithOwner(frame, nil)
}

func (s *ServerCommon) dispatchFastBulkFrame(logical *LogicalConn, transport *TransportConn, conn net.Conn, frame bulkFastFrame) {
	s.dispatchFastBulkFrameWithOwner(logical, transport, conn, frame, nil)
}

func (s *ServerCommon) dispatchFastBulkFrameWithOwner(logical *LogicalConn, transport *TransportConn, conn net.Conn, frame bulkFastFrame, owner *bulkReadPayloadOwner) {
	if logical == nil || frame.DataID == 0 {
		return
	}
	runtime := s.getBulkRuntime()
	if runtime == nil {
		return
	}
	bulk, ok := runtime.lookupByDataID(serverFileScope(logical), frame.DataID)
	if !ok {
		if s.showError || s.debugMode {
			fmt.Println("server bulk data for unknown data id", frame.DataID)
		}
		s.bestEffortRejectInboundBulkData(logical, transport, conn, "", frame.DataID, errBulkNotFound.Error())
		return
	}
	if !bulk.acceptsTransportGeneration(transport) {
		if s.showError || s.debugMode {
			fmt.Println("server bulk data rejected by transport generation mismatch", frame.DataID)
		}
		detachErr := transportDetachedGenerationMismatchError(bulk.TransportGeneration(), transport)
		s.bestEffortRejectInboundBulkData(logical, transport, conn, bulk.ID(), frame.DataID, detachErr.Error())
		return
	}
	switch frame.Type {
	case bulkFastPayloadTypeData:
		var err error
		if owner != nil {
			err = bulk.pushChunkWithOwnershipOptionsAndRelease(frame.Payload, true, true, owner.retainChunk())
		} else {
			err = bulk.pushOwnedChunk(frame.Payload)
		}
		if err != nil {
			if s.showError || s.debugMode {
				fmt.Println("server bulk push chunk error", err)
			}
			if !errors.Is(err, io.EOF) {
				s.bestEffortRejectInboundBulkData(logical, transport, conn, bulk.ID(), frame.DataID, err.Error())
			}
		}
	case bulkFastPayloadTypeClose:
		if frame.Flags&bulkFastPayloadFlagFullClose != 0 {
			bulk.markPeerClosed()
			return
		}
		bulk.markRemoteClosed()
	case bulkFastPayloadTypeReset:
		resetErr := errBulkReset
		if len(frame.Payload) > 0 {
			resetErr = bulkRemoteResetError(string(frame.Payload))
		}
		bulk.markReset(bulkResetError(resetErr))
	case bulkFastPayloadTypeRelease:
		bytes, chunks, err := decodeBulkDedicatedReleasePayload(frame.Payload)
		if err != nil {
			if s.showError || s.debugMode {
				fmt.Println("server bulk release decode error", err)
			}
			s.bestEffortRejectInboundBulkData(logical, transport, conn, bulk.ID(), frame.DataID, err.Error())
			return
		}
		bulk.releaseOutboundWindow(bytes, chunks)
	}
}

func (s *ServerCommon) dispatchFastBulkData(logical *LogicalConn, transport *TransportConn, conn net.Conn, frame bulkFastDataFrame) {
	s.dispatchFastBulkFrameWithOwner(logical, transport, conn, frame, nil)
}

func (c *ClientCommon) tryDispatchBorrowedBulkTransportPayload(payload []byte) bool {
	if c == nil || len(payload) == 0 {
		return false
	}
	profile := c.clientTransportProtectionSnapshot()
	plain, plainRelease, err := decryptTransportPayloadCodecOwnedPooled(profile.mode, profile.runtime, profile.msgDe, profile.secretKey, payload)
	if err != nil {
		if c.showError || c.debugMode {
			fmt.Println("client decode transport payload error", err)
		}
		return true
	}
	owner := newBulkReadPayloadOwner(plainRelease)
	matched, walkErr := walkBulkFastFrames(plain, func(frame bulkFastFrame) error {
		c.dispatchFastBulkFrameWithOwner(frame, owner)
		return nil
	})
	if owner != nil {
		owner.done()
	}
	if !matched {
		return false
	}
	if walkErr != nil && (c.showError || c.debugMode) {
		fmt.Println("client decode bulk fast payload error", walkErr)
	}
	return true
}

func (s *ServerCommon) tryDispatchBorrowedBulkTransportPayload(source interface{}, payload []byte) bool {
	if s == nil || len(payload) == 0 {
		return false
	}
	logical, transport := s.resolveInboundSource(source)
	if logical == nil {
		return false
	}
	plain, plainRelease, err := decryptTransportPayloadCodecOwnedPooled(logical.protectionModeSnapshot(), logical.modernPSKRuntimeSnapshot(), logical.msgDeSnapshot(), logical.secretKeySnapshot(), payload)
	if err != nil {
		if s.showError || s.debugMode {
			fmt.Println("server decode transport payload error", err)
		}
		return true
	}
	conn := serverInboundConn(source)
	owner := newBulkReadPayloadOwner(plainRelease)
	matched, walkErr := walkBulkFastFrames(plain, func(frame bulkFastFrame) error {
		s.dispatchFastBulkFrameWithOwner(logical, transport, conn, frame, owner)
		return nil
	})
	if owner != nil {
		owner.done()
	}
	if !matched {
		return false
	}
	if walkErr != nil && (s.showError || s.debugMode) {
		fmt.Println("server decode bulk fast payload error", walkErr)
	}
	return true
}

func (c *ClientCommon) bestEffortRejectInboundBulkData(bulkID string, dataID uint64, message string) {
	if c == nil || (bulkID == "" && dataID == 0) {
		return
	}
	ctx, cancel := context.WithTimeout(context.Background(), bulkDispatchRejectTimeout)
	defer cancel()
	_, _ = sendBulkResetClient(ctx, c, BulkResetRequest{
		BulkID: bulkID,
		DataID: dataID,
		Error:  message,
	})
}

func (s *ServerCommon) bestEffortRejectInboundBulkData(logical *LogicalConn, transport *TransportConn, conn net.Conn, bulkID string, dataID uint64, message string) {
	if s == nil || logical == nil || (bulkID == "" && dataID == 0) {
		return
	}
	payload, err := encode(BulkResetRequest{
		BulkID: bulkID,
		DataID: dataID,
		Error:  message,
	})
	if err != nil {
		return
	}
	env, err := wrapTransferMsgEnvelope(TransferMsg{
		Key:   BulkResetSignalKey,
		Value: payload,
		Type:  MSG_ASYNC,
	}, s.sequenceEn)
	if err != nil {
		return
	}
	_ = s.sendEnvelopeInboundTransport(logical, transport, conn, env)
}