package mem

import (
	"encoding/binary"
	"unsafe"

	"golang.org/x/sys/unix"
)

func getStdRIP(r *unix.PtraceRegs) (rip uint64) {

	return
}

func getRIP(r *unix.PtraceRegs) uint64 {
	// amd64
	if binary.Size(unix.PtraceRegs{}) == 216 {
		return r.Rip
	}
	// arm64
	type regsArm64 struct{ Regs [18]uint64 }
	return (*regsArm64)(unsafe.Pointer(r)).Regs[16] // PC
}

func setRIP(r *unix.PtraceRegs, v uint64) *unix.PtraceRegs {
	if binary.Size(unix.PtraceRegs{}) == 216 {
		r.Rip = v
	} else {
		type regsArm64 struct{ Regs [18]uint64 }
		(*regsArm64)(unsafe.Pointer(r)).Regs[16] = v
	}
	return r
}

func getRSP(r *unix.PtraceRegs) uint64 {
	if binary.Size(unix.PtraceRegs{}) == 216 {
		return r.Rsp
	}
	type regsArm64 struct{ Regs [18]uint64 }
	return (*regsArm64)(unsafe.Pointer(r)).Regs[17] // SP
}

func setRSP(r *unix.PtraceRegs, v uint64) *unix.PtraceRegs {
	if binary.Size(unix.PtraceRegs{}) == 216 {
		r.Rsp = v
	} else {
		type regsArm64 struct{ Regs [18]uint64 }
		(*regsArm64)(unsafe.Pointer(r)).Regs[17] = v
	}
	return r
}

func setArg0(r *unix.PtraceRegs, v uint64) *unix.PtraceRegs {
	if binary.Size(unix.PtraceRegs{}) == 216 {
		r.Rdi = v
	} else {
		type regsArm64 struct{ Regs [18]uint64 }
		(*regsArm64)(unsafe.Pointer(r)).Regs[0] = v // X0
	}
	return r
}

func setArg1(r *unix.PtraceRegs, v uint64) *unix.PtraceRegs {
	if binary.Size(unix.PtraceRegs{}) == 216 {
		r.Rsi = v
	} else {
		type regsArm64 struct{ Regs [18]uint64 }
		(*regsArm64)(unsafe.Pointer(r)).Regs[1] = v // X1
	}
	return r
}

func setArg2(r *unix.PtraceRegs, v uint64) *unix.PtraceRegs {
	if binary.Size(unix.PtraceRegs{}) == 216 {
		r.Rdx = v
	} else {
		type regsArm64 struct{ Regs [18]uint64 }
		(*regsArm64)(unsafe.Pointer(r)).Regs[2] = v // X2
	}
	return r
}