import os
import json
import uuid
import shutil
from datetime import datetime
from app.logger_config import logger as logging
import gradio as gr
# TMP_DIR = "/tmp/canary_aed_streaming"

TMP_DIR = os.getenv("TMP_DIR", "/tmp/canary_aed_streaming")
ACTIVE_SESSIONS_FILE = os.path.join(TMP_DIR, "active_sessions.json")


# ---------------------------
# Helper to manage the JSON
# ---------------------------
def _read_sessions():
    if not os.path.exists(ACTIVE_SESSIONS_FILE):
        return {}
    try:
        with open(ACTIVE_SESSIONS_FILE, "r") as f:
            return json.load(f)
    except Exception:
        return {}


def _write_sessions(data):
    os.makedirs(os.path.dirname(ACTIVE_SESSIONS_FILE), exist_ok=True)
    with open(ACTIVE_SESSIONS_FILE, "w") as f:
        json.dump(data, f, indent=2)


# ---------------------------
# LOAD
# ---------------------------
def on_load(request: gr.Request):
    """Called when a new visitor opens the app."""
    session_hash = request.session_hash  # ✅ Directly use session_hash as unique ID
    sessions = _read_sessions()

    sessions[session_hash] = {
        "session_hash": session_hash,
        "file": "",
        "start_time": datetime.utcnow().strftime("%H:%M:%S"),
        "status": "active",
    }

    _write_sessions(sessions)
    logging.info(f"[{session_hash}] Session registered (on_load).")

    return session_hash, session_hash  # can be used as gr.State + display


# ---------------------------
# UNLOAD
# ---------------------------
def on_unload(request: gr.Request):
    """Called when the visitor closes or refreshes the app."""
    sid = request.session_hash
    sessions = _read_sessions()

    if sid in sessions:
        sessions.pop(sid)
        _write_sessions(sessions)
        remove_session_data(sid)
        unregister_session(sid)
        logging.info(f"[{sid}] Session removed (on_unload).")
    else:
        logging.info(f"[{sid}] No active session found to remove.")

def ensure_tmp_dir():
    """Ensures the base temporary directory exists."""
    try:
        os.makedirs(TMP_DIR, exist_ok=True)
    except Exception as e:
        logging.error(f"Failed to create tmp directory {TMP_DIR}: {e}")


def reset_all_active_sessions():
    """Removes all temporary session files and folders at startup."""
    ensure_tmp_dir()

    try:
        # --- Remove active sessions file ---
        if os.path.exists(ACTIVE_SESSIONS_FILE):
            os.remove(ACTIVE_SESSIONS_FILE)
            logging.info("Active sessions file reset at startup.")
        else:
            logging.debug("No active sessions file found to reset.")
       
    except Exception as e:
        logging.error(f"Error resetting active sessions: {e}")

def remove_session_data(session_id: str):
    """Removes all temporary files and data related to a specific session."""
    if not session_id:
        logging.warning("reset_session() called without a valid session_id.")
        return

    try:
        # --- Remove session from active_sessions.json ---
        if os.path.exists(ACTIVE_SESSIONS_FILE):
            try:
                with open(ACTIVE_SESSIONS_FILE, "r") as f:
                    data = json.load(f)
                if session_id in data:
                    data.pop(session_id)
                    with open(ACTIVE_SESSIONS_FILE, "w") as f:
                        json.dump(data, f, indent=2)
                    logging.debug(f"[{session_id}] Removed from active_sessions.json.")
            except Exception as e:
                logging.warning(f"[{session_id}] Failed to update active_sessions.json: {e}")

        # --- Define all possible session file patterns ---
        files_to_remove = [
            f"progress_{session_id}.json",
            # f"stream_stop_flag_{session_id}.txt",
            f"transcribe_stop_flag_{session_id}.txt",
            f"transcribe_active_{session_id}.txt",
        ]

        # --- Remove all temporary files ---
        for fname in files_to_remove:
            path = os.path.join(TMP_DIR, fname)
            if os.path.exists(path):
                try:
                    os.remove(path)
                    logging.debug(f"[{session_id}] Removed file: {fname}")
                except Exception as e:
                    logging.warning(f"[{session_id}] Failed to remove file {fname}: {e}")

        # --- Remove chunk folder if exists ---
        chunk_dir = os.path.join(TMP_DIR, f"chunks_{session_id}")
        if os.path.isdir(chunk_dir):
            try:
                shutil.rmtree(chunk_dir)
                logging.debug(f"[{session_id}] Removed chunk folder: chunks_{session_id}")
            except Exception as e:
                logging.warning(f"[{session_id}] Failed to remove chunk folder: {e}")

        logging.info(f"[{session_id}] Session fully reset.")

    except Exception as e:
        logging.error(f"[{session_id}] Error during reset_session: {e}")
def generate_session_id() -> str:
    """Generates a unique session ID."""
    sid = str(uuid.uuid4())
    logging.debug(f"[{sid}] New session created.")
    return sid


def register_session(session_id: str, filepath: str):
    """Registers a new session."""
    ensure_tmp_dir()
    data = {}
    if os.path.exists(ACTIVE_SESSIONS_FILE):
        with open(ACTIVE_SESSIONS_FILE, "r") as f:
            try:
                data = json.load(f)
            except Exception:
                data = {}

    data[session_id] = {
        "session_hash": session_id,
        "file": filepath,
        "start_time": datetime.utcnow().strftime("%H:%M:%S"),
        "status": "active",
    }

    with open(ACTIVE_SESSIONS_FILE, "w") as f:
        json.dump(data, f)

    logging.debug(f"[{session_id}] Session registered in active_sessions.json.")


def unregister_session(session_id: str):
    """Removes a session from the registry."""
    if not os.path.exists(ACTIVE_SESSIONS_FILE):
        return

    try:
        with open(ACTIVE_SESSIONS_FILE, "r") as f:
            data = json.load(f)
        if session_id in data:
            data.pop(session_id)
            with open(ACTIVE_SESSIONS_FILE, "w") as f:
                json.dump(data, f)
            logging.debug(f"[{session_id}] Session unregistered.")
    except Exception as e:
        logging.error(f"[{session_id}] Error unregistering session: {e}")


def get_active_sessions():
    """Returns active sessions as a list of rows for the DataFrame."""
    if not os.path.exists(ACTIVE_SESSIONS_FILE):
        return []

    try:
        with open(ACTIVE_SESSIONS_FILE, "r") as f:
            data = json.load(f)

        rows = [
            [
                s.get("session_hash", ""),
                s.get("file", ""),
                s.get("start_time", ""),
                s.get("status", ""),
            ]
            for s in data.values()
        ]
        return rows
    except Exception as e:
        logging.error(f"Error reading active sessions: {e}")
        return []