from __future__ import annotations
from typing import TYPE_CHECKING
import llvmlite.ir as ir
if TYPE_CHECKING:
    from lib.core.Translator.LlvmGenerator import LlvmGeneratorMixin


def EmitRawCopyLlvm(DstPtr: ir.Value, SrcPtr: ir.Value, Gen: LlvmGeneratorMixin,
                    NamePrefix: str = "rawcopy") -> bool:
    """Emit `*dst = *src` as a raw byte copy (Load semantics); False if unusable.

    The width comes from the destination pointee and the source pointer is
    bitcast to it, so this reinterprets memory instead of converting values
    (e.g. `*&bits = *&dbl` must keep the IEEE bits, not fptosi).
    """
    if not isinstance(DstPtr.type, ir.PointerType) or not isinstance(SrcPtr.type, ir.PointerType):
        return False
    Pointee: ir.Type = DstPtr.type.pointee
    if isinstance(Pointee, ir.VoidType):
        return False
    TargetPtrTy: ir.PointerType = ir.PointerType(Pointee)
    SrcCast: ir.Value = SrcPtr if SrcPtr.type == TargetPtrTy else Gen.builder.bitcast(SrcPtr, TargetPtrTy, name=f"{NamePrefix}_src_cast")
    Loaded: ir.Value | None = Gen._load(SrcCast, name=f"{NamePrefix}_loaded")
    if Loaded is None:
        return False
    DstCast: ir.Value = DstPtr if DstPtr.type == TargetPtrTy else Gen.builder.bitcast(DstPtr, TargetPtrTy, name=f"{NamePrefix}_dst_cast")
    Gen._store(Loaded, DstCast)
    return True