import os, json, uuid
from pathlib import Path

WORKSPACE = "/workspace"
HF_LOCAL_DIR = Path(WORKSPACE) / "hf"
SESSIONS_DIR = HF_LOCAL_DIR / "sessions"

SESSIONS_DIR.mkdir(parents=True, exist_ok=True)

class SessionManager:
    def __init__(self):
        self.current_session = None

    # ------------------ CREATE / LOAD ------------------
    def create_session(self, session_id=None):
        session_id = session_id or f"sess_{uuid.uuid4().hex[:8]}"
        session_path = SESSIONS_DIR / session_id
        session_path.mkdir(parents=True, exist_ok=True)

        self.current_session = session_id

        # initialize files only if not exist
        workspace_file = session_path / "workspace.json"
        history_file = session_path / "history.json"

        if not workspace_file.exists():
            self._write_json("workspace.json", {})
        if not history_file.exists():
            self._write_json("history.json", [])

        print(f"[SESSION] Created {session_id}")
        return session_id

    def load_session(self, session_id):
        session_path = SESSIONS_DIR / session_id
        if not session_path.exists():
            raise Exception(f"❌ Session '{session_id}' not found. Try create_session().")

        self.current_session = session_id
        print(f"[SESSION] Loaded {session_id}")
        return session_id
    # ------------------ PATH ------------------

    def _get_path(self, filename):
        if not self.current_session:
            raise Exception("❌ No active session")

        return SESSIONS_DIR / self.current_session / filename

    # ------------------ READ / WRITE ------------------

    def _write_json(self, filename, data):
        path = self._get_path(filename)
        with open(path, "w") as f:
            json.dump(data, f, indent=2)

    def _read_json(self, filename):
        path = self._get_path(filename)
        if not path.exists():
            return {} if filename == "workspace.json" else []
        return json.load(open(path))

    # ------------------ WORKSPACE ------------------

    def get_workspace(self):
        return self._read_json("workspace.json")

    def update_workspace(self, key, value):
        data = self.get_workspace()
        data[key] = value
        self._write_json("workspace.json", data)

    # ------------------ HISTORY ------------------

    def append_history(self, item):
        hist = self._read_json("history.json")
        hist.append(item)
        self._write_json("history.json", hist)

    def get_history(self):
        return self._read_json("history.json")