/*
   Copyright 2020 the original author or authors.

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

        http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
*/
package openflow

import (
	"bytes"
	"context"
	"encoding/binary"
	"encoding/json"
	"fmt"
	"github.com/opencord/goloxi"
	ofp "github.com/opencord/goloxi/of13"
	"github.com/opencord/voltha-lib-go/v5/pkg/log"
	"github.com/opencord/voltha-protos/v4/go/openflow_13"
	"github.com/opencord/voltha-protos/v4/go/voltha"
)

func parseOxm(ctx context.Context, ofbField *openflow_13.OfpOxmOfbField) (goloxi.IOxm, error) {
	if logger.V(log.DebugLevel) {
		js, _ := json.Marshal(ofbField)
		logger.Debugw(ctx, "parseOxm called",
			log.Fields{"ofbField": js})
	}

	switch ofbField.Type {
	case voltha.OxmOfbFieldTypes_OFPXMT_OFB_IN_PORT:
		ofpInPort := ofp.NewOxmInPort()
		val := ofbField.GetValue().(*openflow_13.OfpOxmOfbField_Port)
		ofpInPort.Value = ofp.Port(val.Port)
		return ofpInPort, nil
	case voltha.OxmOfbFieldTypes_OFPXMT_OFB_ETH_TYPE:
		ofpEthType := ofp.NewOxmEthType()
		val := ofbField.GetValue().(*openflow_13.OfpOxmOfbField_EthType)
		ofpEthType.Value = ofp.EthernetType(val.EthType)
		return ofpEthType, nil
	case voltha.OxmOfbFieldTypes_OFPXMT_OFB_IN_PHY_PORT:
		ofpInPhyPort := ofp.NewOxmInPhyPort()
		val := ofbField.GetValue().(*openflow_13.OfpOxmOfbField_PhysicalPort)
		ofpInPhyPort.Value = ofp.Port(val.PhysicalPort)
		return ofpInPhyPort, nil
	case voltha.OxmOfbFieldTypes_OFPXMT_OFB_IP_PROTO:
		ofpIpProto := ofp.NewOxmIpProto()
		val := ofbField.GetValue().(*openflow_13.OfpOxmOfbField_IpProto)
		ofpIpProto.Value = ofp.IpPrototype(val.IpProto)
		return ofpIpProto, nil
	case voltha.OxmOfbFieldTypes_OFPXMT_OFB_IPV4_DST:
		ofpIpv4Dst := ofp.NewOxmIpv4Dst()
		val := ofbField.GetValue().(*openflow_13.OfpOxmOfbField_Ipv4Dst)
		buf := new(bytes.Buffer)
		err := binary.Write(buf, binary.BigEndian, val.Ipv4Dst)
		if err != nil {
			logger.Errorw(ctx, "error writing ipv4 address %v",
				log.Fields{"error": err})
		}
		ofpIpv4Dst.Value = buf.Bytes()
		return ofpIpv4Dst, nil
	case voltha.OxmOfbFieldTypes_OFPXMT_OFB_UDP_SRC:
		ofpUdpSrc := ofp.NewOxmUdpSrc()
		val := ofbField.GetValue().(*openflow_13.OfpOxmOfbField_UdpSrc)
		ofpUdpSrc.Value = uint16(val.UdpSrc)
		return ofpUdpSrc, nil
	case voltha.OxmOfbFieldTypes_OFPXMT_OFB_UDP_DST:
		ofpUdpDst := ofp.NewOxmUdpDst()
		val := ofbField.GetValue().(*openflow_13.OfpOxmOfbField_UdpDst)
		ofpUdpDst.Value = uint16(val.UdpDst)
		return ofpUdpDst, nil
	case voltha.OxmOfbFieldTypes_OFPXMT_OFB_VLAN_VID:
		ofpVlanVid := ofp.NewOxmVlanVid()
		val := ofbField.GetValue()
		if val == nil {
			ofpVlanVid.Value = uint16(0)
			return ofpVlanVid, nil
		}
		vlanId := val.(*openflow_13.OfpOxmOfbField_VlanVid)
		if ofbField.HasMask {
			ofpVlanVidMasked := ofp.NewOxmVlanVidMasked()
			valMask := ofbField.GetMask()
			vlanMask := valMask.(*openflow_13.OfpOxmOfbField_VlanVidMask)
			if vlanId.VlanVid == 4096 && vlanMask.VlanVidMask == 4096 {
				ofpVlanVidMasked.Value = uint16(vlanId.VlanVid)
				ofpVlanVidMasked.ValueMask = uint16(vlanMask.VlanVidMask)
			} else {
				ofpVlanVidMasked.Value = uint16(vlanId.VlanVid) | 0x1000
				ofpVlanVidMasked.ValueMask = uint16(vlanMask.VlanVidMask)

			}
			return ofpVlanVidMasked, nil
		}
		ofpVlanVid.Value = uint16(vlanId.VlanVid) | 0x1000
		return ofpVlanVid, nil
	case voltha.OxmOfbFieldTypes_OFPXMT_OFB_METADATA:
		ofpMetadata := ofp.NewOxmMetadata()
		val := ofbField.GetValue().(*openflow_13.OfpOxmOfbField_TableMetadata)
		ofpMetadata.Value = val.TableMetadata
		return ofpMetadata, nil
	case voltha.OxmOfbFieldTypes_OFPXMT_OFB_VLAN_PCP:
		ofpVlanPcp := ofp.NewOxmVlanPcp()
		val := ofbField.GetValue()
		vlanPcp := val.(*openflow_13.OfpOxmOfbField_VlanPcp)
		ofpVlanPcp.Value = uint8(vlanPcp.VlanPcp)
		return ofpVlanPcp, nil
	case voltha.OxmOfbFieldTypes_OFPXMT_OFB_ETH_DST:
		ofpEthDst := ofp.NewOxmEthDst()
		val := ofbField.GetValue().(*openflow_13.OfpOxmOfbField_EthDst)
		ofpEthDst.Value = val.EthDst
		return ofpEthDst, nil
	default:
		if logger.V(log.WarnLevel) {
			js, _ := json.Marshal(ofbField)
			logger.Warnw(ctx, "ParseOXM Unhandled OxmField",
				log.Fields{"OfbField": js})
		}
	}
	return nil, fmt.Errorf("can't-parse-oxm %+v", ofbField)
}

func parseInstructions(ctx context.Context, ofpInstruction *openflow_13.OfpInstruction) (ofp.IInstruction, error) {
	if logger.V(log.DebugLevel) {
		js, _ := json.Marshal(ofpInstruction)
		logger.Debugw(ctx, "parseInstructions called",
			log.Fields{"Instruction": js,
				"ofp-Instruction": ofpInstruction})
	}
	instType := ofpInstruction.Type
	data := ofpInstruction.GetData()
	switch instType {
	case ofp.OFPITWriteMetadata:
		instruction := ofp.NewInstructionWriteMetadata()
		metadata := data.(*openflow_13.OfpInstruction_WriteMetadata).WriteMetadata
		instruction.Metadata = uint64(metadata.Metadata)
		return instruction, nil
	case ofp.OFPITMeter:
		instruction := ofp.NewInstructionMeter()
		meter := data.(*openflow_13.OfpInstruction_Meter).Meter
		instruction.MeterId = meter.MeterId
		return instruction, nil
	case ofp.OFPITGotoTable:
		instruction := ofp.NewInstructionGotoTable()
		gotoTable := data.(*openflow_13.OfpInstruction_GotoTable).GotoTable
		instruction.TableId = uint8(gotoTable.TableId)
		return instruction, nil
	case ofp.OFPITApplyActions:
		instruction := ofp.NewInstructionApplyActions()

		var actions []goloxi.IAction
		for _, ofpAction := range ofpInstruction.GetActions().Actions {
			action, err := parseAction(ctx, ofpAction)
			if err == nil {
				actions = append(actions, action)
			} else {
				return nil, fmt.Errorf("can't-parse-action %v", err)
			}
		}
		instruction.Actions = actions
		if logger.V(log.DebugLevel) {
			js, _ := json.Marshal(instruction)
			logger.Debugw(ctx, "parseInstructions returning",
				log.Fields{
					"parsed-instruction": js})
		}
		return instruction, nil
	}
	//shouldn't have reached here :<
	return nil, fmt.Errorf("can't-parse-instruction %+v", ofpInstruction)
}

func parseAction(ctx context.Context, ofpAction *openflow_13.OfpAction) (goloxi.IAction, error) {
	if logger.V(log.DebugLevel) {
		js, _ := json.Marshal(ofpAction)
		logger.Debugw(ctx, "parseAction called",
			log.Fields{"action": js})
	}
	switch ofpAction.Type {
	case openflow_13.OfpActionType_OFPAT_OUTPUT:
		ofpOutputAction := ofpAction.GetOutput()
		outputAction := ofp.NewActionOutput()
		outputAction.Port = ofp.Port(ofpOutputAction.Port)
		outputAction.MaxLen = uint16(ofpOutputAction.MaxLen)
		return outputAction, nil
	case openflow_13.OfpActionType_OFPAT_PUSH_VLAN:
		ofpPushVlanAction := ofp.NewActionPushVlan()
		ofpPushVlanAction.Ethertype = uint16(ofpAction.GetPush().Ethertype)
		return ofpPushVlanAction, nil
	case openflow_13.OfpActionType_OFPAT_POP_VLAN:
		ofpPopVlanAction := ofp.NewActionPopVlan()
		return ofpPopVlanAction, nil
	case openflow_13.OfpActionType_OFPAT_SET_FIELD:
		ofpActionSetField := ofpAction.GetSetField()
		setFieldAction := ofp.NewActionSetField()

		iOxm, err := parseOxm(ctx, ofpActionSetField.GetField().GetOfbField())
		if err == nil {
			setFieldAction.Field = iOxm
		} else {
			return nil, fmt.Errorf("can't-parse-oxm %v", err)
		}
		return setFieldAction, nil
	case openflow_13.OfpActionType_OFPAT_GROUP:
		ofpGroupAction := ofpAction.GetGroup()
		groupAction := ofp.NewActionGroup()
		groupAction.GroupId = ofpGroupAction.GroupId
		return groupAction, nil
	default:
		if logger.V(log.WarnLevel) {
			js, _ := json.Marshal(ofpAction)
			logger.Warnw(ctx, "parseAction unknow action",
				log.Fields{"action": js})
		}
	}
	return nil, fmt.Errorf("can't-parse-action %+v", ofpAction)
}

func parsePortStats(port *voltha.LogicalPort) *ofp.PortStatsEntry {
	stats := port.OfpPortStats
	port.OfpPort.GetPortNo()
	var entry ofp.PortStatsEntry
	entry.SetPortNo(ofp.Port(port.OfpPort.GetPortNo()))
	entry.SetRxPackets(stats.GetRxPackets())
	entry.SetTxPackets(stats.GetTxPackets())
	entry.SetRxBytes(stats.GetRxBytes())
	entry.SetTxBytes(stats.GetTxBytes())
	entry.SetRxDropped(stats.GetRxDropped())
	entry.SetTxDropped(stats.GetTxDropped())
	entry.SetRxErrors(stats.GetRxErrors())
	entry.SetTxErrors(stats.GetTxErrors())
	entry.SetRxFrameErr(stats.GetRxFrameErr())
	entry.SetRxOverErr(stats.GetRxOverErr())
	entry.SetRxCrcErr(stats.GetRxCrcErr())
	entry.SetCollisions(stats.GetCollisions())
	entry.SetDurationSec(stats.GetDurationSec())
	entry.SetDurationNsec(stats.GetDurationNsec())
	return &entry
}