package nl

import (
	"unsafe"
)

// Message types
const (
	TCA_UNSPEC = iota
	TCA_KIND
	TCA_OPTIONS
	TCA_STATS
	TCA_XSTATS
	TCA_RATE
	TCA_FCNT
	TCA_STATS2
	TCA_STAB
	TCA_MAX = TCA_STAB
)

const (
	TCA_ACT_TAB = 1
	TCAA_MAX    = 1
)

const (
	TCA_PRIO_UNSPEC = iota
	TCA_PRIO_MQ
	TCA_PRIO_MAX = TCA_PRIO_MQ
)

const (
	SizeofTcMsg       = 0x14
	SizeofTcActionMsg = 0x04
	SizeofTcPrioMap   = 0x14
	SizeofTcRateSpec  = 0x0c
	SizeofTcTbfQopt   = 2*SizeofTcRateSpec + 0x0c
	SizeofTcU32Key    = 0x10
	SizeofTcU32Sel    = 0x10 // without keys
	SizeofTcMirred    = 0x1c
)

// struct tcmsg {
//   unsigned char tcm_family;
//   unsigned char tcm__pad1;
//   unsigned short  tcm__pad2;
//   int   tcm_ifindex;
//   __u32   tcm_handle;
//   __u32   tcm_parent;
//   __u32   tcm_info;
// };

type TcMsg struct {
	Family  uint8
	Pad     [3]byte
	Ifindex int32
	Handle  uint32
	Parent  uint32
	Info    uint32
}

func (msg *TcMsg) Len() int {
	return SizeofTcMsg
}

func DeserializeTcMsg(b []byte) *TcMsg {
	return (*TcMsg)(unsafe.Pointer(&b[0:SizeofTcMsg][0]))
}

func (x *TcMsg) Serialize() []byte {
	return (*(*[SizeofTcMsg]byte)(unsafe.Pointer(x)))[:]
}

// struct tcamsg {
//   unsigned char tca_family;
//   unsigned char tca__pad1;
//   unsigned short  tca__pad2;
// };

type TcActionMsg struct {
	Family uint8
	Pad    [3]byte
}

func (msg *TcActionMsg) Len() int {
	return SizeofTcActionMsg
}

func DeserializeTcActionMsg(b []byte) *TcActionMsg {
	return (*TcActionMsg)(unsafe.Pointer(&b[0:SizeofTcActionMsg][0]))
}

func (x *TcActionMsg) Serialize() []byte {
	return (*(*[SizeofTcActionMsg]byte)(unsafe.Pointer(x)))[:]
}

const (
	TC_PRIO_MAX = 15
)

// struct tc_prio_qopt {
// 	int bands;      /* Number of bands */
// 	__u8  priomap[TC_PRIO_MAX+1]; /* Map: logical priority -> PRIO band */
// };

type TcPrioMap struct {
	Bands   int32
	Priomap [TC_PRIO_MAX + 1]uint8
}

func (msg *TcPrioMap) Len() int {
	return SizeofTcPrioMap
}

func DeserializeTcPrioMap(b []byte) *TcPrioMap {
	return (*TcPrioMap)(unsafe.Pointer(&b[0:SizeofTcPrioMap][0]))
}

func (x *TcPrioMap) Serialize() []byte {
	return (*(*[SizeofTcPrioMap]byte)(unsafe.Pointer(x)))[:]
}

const (
	TCA_TBF_UNSPEC = iota
	TCA_TBF_PARMS
	TCA_TBF_RTAB
	TCA_TBF_PTAB
	TCA_TBF_RATE64
	TCA_TBF_PRATE64
	TCA_TBF_BURST
	TCA_TBF_PBURST
	TCA_TBF_MAX = TCA_TBF_PBURST
)

// struct tc_ratespec {
//   unsigned char cell_log;
//   __u8    linklayer; /* lower 4 bits */
//   unsigned short  overhead;
//   short   cell_align;
//   unsigned short  mpu;
//   __u32   rate;
// };

type TcRateSpec struct {
	CellLog   uint8
	Linklayer uint8
	Overhead  uint16
	CellAlign int16
	Mpu       uint16
	Rate      uint32
}

func (msg *TcRateSpec) Len() int {
	return SizeofTcRateSpec
}

func DeserializeTcRateSpec(b []byte) *TcRateSpec {
	return (*TcRateSpec)(unsafe.Pointer(&b[0:SizeofTcRateSpec][0]))
}

func (x *TcRateSpec) Serialize() []byte {
	return (*(*[SizeofTcRateSpec]byte)(unsafe.Pointer(x)))[:]
}

// struct tc_tbf_qopt {
//   struct tc_ratespec rate;
//   struct tc_ratespec peakrate;
//   __u32   limit;
//   __u32   buffer;
//   __u32   mtu;
// };

type TcTbfQopt struct {
	Rate     TcRateSpec
	Peakrate TcRateSpec
	Limit    uint32
	Buffer   uint32
	Mtu      uint32
}

func (msg *TcTbfQopt) Len() int {
	return SizeofTcTbfQopt
}

func DeserializeTcTbfQopt(b []byte) *TcTbfQopt {
	return (*TcTbfQopt)(unsafe.Pointer(&b[0:SizeofTcTbfQopt][0]))
}

func (x *TcTbfQopt) Serialize() []byte {
	return (*(*[SizeofTcTbfQopt]byte)(unsafe.Pointer(x)))[:]
}

const (
	TCA_U32_UNSPEC = iota
	TCA_U32_CLASSID
	TCA_U32_HASH
	TCA_U32_LINK
	TCA_U32_DIVISOR
	TCA_U32_SEL
	TCA_U32_POLICE
	TCA_U32_ACT
	TCA_U32_INDEV
	TCA_U32_PCNT
	TCA_U32_MARK
	TCA_U32_MAX = TCA_U32_MARK
)

// struct tc_u32_key {
//   __be32    mask;
//   __be32    val;
//   int   off;
//   int   offmask;
// };

type TcU32Key struct {
	Mask    uint32 // big endian
	Val     uint32 // big endian
	Off     int32
	OffMask int32
}

func (msg *TcU32Key) Len() int {
	return SizeofTcU32Key
}

func DeserializeTcU32Key(b []byte) *TcU32Key {
	return (*TcU32Key)(unsafe.Pointer(&b[0:SizeofTcU32Key][0]))
}

func (x *TcU32Key) Serialize() []byte {
	return (*(*[SizeofTcU32Key]byte)(unsafe.Pointer(x)))[:]
}

// struct tc_u32_sel {
//   unsigned char   flags;
//   unsigned char   offshift;
//   unsigned char   nkeys;
//
//   __be16      offmask;
//   __u16     off;
//   short     offoff;
//
//   short     hoff;
//   __be32      hmask;
//   struct tc_u32_key keys[0];
// };

const (
	TC_U32_TERMINAL  = 1 << iota
	TC_U32_OFFSET    = 1 << iota
	TC_U32_VAROFFSET = 1 << iota
	TC_U32_EAT       = 1 << iota
)

type TcU32Sel struct {
	Flags    uint8
	Offshift uint8
	Nkeys    uint8
	Pad      uint8
	Offmask  uint16 // big endian
	Off      uint16
	Offoff   int16
	Hoff     int16
	Hmask    uint32 // big endian
	Keys     []TcU32Key
}

func (msg *TcU32Sel) Len() int {
	return SizeofTcU32Sel + int(msg.Nkeys)*SizeofTcU32Key
}

func DeserializeTcU32Sel(b []byte) *TcU32Sel {
	x := &TcU32Sel{}
	copy((*(*[SizeofTcU32Sel]byte)(unsafe.Pointer(x)))[:], b)
	next := SizeofTcU32Sel
	var i uint8
	for i = 0; i < x.Nkeys; i++ {
		x.Keys = append(x.Keys, *DeserializeTcU32Key(b[next:]))
		next += SizeofTcU32Key
	}
	return x
}

func (x *TcU32Sel) Serialize() []byte {
	// This can't just unsafe.cast because it must iterate through keys.
	buf := make([]byte, x.Len())
	copy(buf, (*(*[SizeofTcU32Sel]byte)(unsafe.Pointer(x)))[:])
	next := SizeofTcU32Sel
	for _, key := range x.Keys {
		keyBuf := key.Serialize()
		copy(buf[next:], keyBuf)
		next += SizeofTcU32Key
	}
	return buf
}

const (
	TCA_ACT_MIRRED = 8
)

const (
	TCA_MIRRED_UNSPEC = iota
	TCA_MIRRED_TM
	TCA_MIRRED_PARMS
	TCA_MIRRED_MAX = TCA_MIRRED_PARMS
)

const (
	TCA_EGRESS_REDIR   = 1 /* packet redirect to EGRESS*/
	TCA_EGRESS_MIRROR  = 2 /* mirror packet to EGRESS */
	TCA_INGRESS_REDIR  = 3 /* packet redirect to INGRESS*/
	TCA_INGRESS_MIRROR = 4 /* mirror packet to INGRESS */
)

const (
	TC_ACT_UNSPEC     = int32(-1)
	TC_ACT_OK         = 0
	TC_ACT_RECLASSIFY = 1
	TC_ACT_SHOT       = 2
	TC_ACT_PIPE       = 3
	TC_ACT_STOLEN     = 4
	TC_ACT_QUEUED     = 5
	TC_ACT_REPEAT     = 6
	TC_ACT_JUMP       = 0x10000000
)

// #define tc_gen \
//   __u32                 index; \
//   __u32                 capab; \
//   int                   action; \
//   int                   refcnt; \
//   int                   bindcnt
// struct tc_mirred {
// 	tc_gen;
// 	int                     eaction;   /* one of IN/EGRESS_MIRROR/REDIR */
// 	__u32                   ifindex;  /* ifindex of egress port */
// };

type TcMirred struct {
	Index   uint32
	Capab   uint32
	Action  int32
	Refcnt  int32
	Bindcnt int32
	Eaction int32
	Ifindex uint32
}

func (msg *TcMirred) Len() int {
	return SizeofTcMirred
}

func DeserializeTcMirred(b []byte) *TcMirred {
	return (*TcMirred)(unsafe.Pointer(&b[0:SizeofTcMirred][0]))
}

func (x *TcMirred) Serialize() []byte {
	return (*(*[SizeofTcMirred]byte)(unsafe.Pointer(x)))[:]
}