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

//go:build linux && arm64

package debug

import (
	"fmt"

	"golang.org/x/arch/arm64/arm64asm"
)

// Disassemble decodes the instruction at the given address in the debuggee's
// memory and returns its text representation and length in bytes.
func (s *Session) Disassemble(addr uint64) (string, int, error) {
	mem, err := s.ReadMemory(addr, 4)
	if err != nil {
		return "", 0, err
	}
	inst, err := arm64asm.Decode(mem)
	if err != nil {
		return "???", 4, nil
	}
	text := arm64asm.GoSyntax(inst, addr, nil, nil)
	return text, 4, nil
}

// DisassembleN decodes up to n instructions starting at addr.
func (s *Session) DisassembleN(addr uint64, n int) string {
	var result string
	pc := addr
	for i := 0; i < n; i++ {
		text, length, err := s.Disassemble(pc)
		if err != nil {
			result += fmt.Sprintf("  %#08x: <error: %v>\n", pc, err)
			break
		}
		result += fmt.Sprintf("  %#08x: %s\n", pc, text)
		if length == 0 {
			length = 4
		}
		pc += uint64(length)
	}
	return result
}