// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
// SPDX-License-Identifier: BSD-3-Clause

//go:build linux && amd64

package debug

import "fmt"

// SetReg modifies a register value in the debuggee.
func (s *Session) SetReg(name string, value uint64) error {
	regs, err := s.GetRegs()
	if err != nil {
		return err
	}
	switch name {
	case "rax", "eax", "ax", "al":
		regs.RAX = value
	case "rbx", "ebx", "bx", "bl":
		regs.RBX = value
	case "rcx", "ecx", "cx", "cl":
		regs.RCX = value
	case "rdx", "edx", "dx", "dl":
		regs.RDX = value
	case "rsi", "esi", "si":
		regs.RSI = value
	case "rdi", "edi", "di":
		regs.RDI = value
	case "rbp", "ebp", "bp":
		regs.RBP = value
	case "rsp", "esp", "sp":
		regs.RSP = value
	case "r8":
		regs.R8 = value
	case "r9":
		regs.R9 = value
	case "r10":
		regs.R10 = value
	case "r11":
		regs.R11 = value
	case "r12":
		regs.R12 = value
	case "r13":
		regs.R13 = value
	case "r14":
		regs.R14 = value
	case "r15":
		regs.R15 = value
	case "rip", "eip":
		regs.RIP = value
	default:
		return fmt.Errorf("debug: unknown register %q", name)
	}
	return s.SetRegs(&regs)
}