from __future__ import annotations

import json

import os

from dataclasses import dataclass

from typing import Optional

@dataclass

class ProgramArtifact:

kind: str # e.g., "prefix_text", "prefix_tuning", "lora", "prefix_kv"

base_model: Optional[str]

path: str # directory for manifest-based artifacts; file path for text prefix

metadata: dict

def load_artifact(path: str) -> ProgramArtifact:

"""

Load a program artifact which can be either:

- A directory containing a manifest 'program.json' (preferred)

- A single text file treated as a prompt/prefix (MVP fallback)

"""

if os.path.isdir(path):

manifest_path = os.path.join(path, "program.json")

if not os.path.isfile(manifest_path):

raise FileNotFoundError(f"Missing program.json in {path}")

with open(manifest_path, "r", encoding="utf-8") as f:

m = json.load(f)

kind = m.get("kind", "prefix_text")

base_model = m.get("base_model")

return ProgramArtifact(kind=kind, base_model=base_model, path=path, metadata=m)

if os.path.isfile(path):

# If there is a sibling manifest, prefer it

manifest_path = os.path.join(os.path.dirname(path), "program.json")

base_model = None

metadata = {}

if os.path.isfile(manifest_path):

try:

with open(manifest_path, "r", encoding="utf-8") as f:

m = json.load(f)

base_model = m.get("base_model")

metadata = m

kind = m.get("kind", "prefix_text")

return ProgramArtifact(kind=kind, base_model=base_model, path=os.path.dirname(path), metadata=metadata)

except Exception:

pass

# Fallback: treat the file itself as a text prefix

return ProgramArtifact(kind="prefix_text", base_model=base_model, path=path, metadata=metadata)

raise FileNotFoundError(path)