modules/dropbox.py

import asyncio
import json
from fastapi import HTTPException
from pydantic import BaseModel
import os
import dropbox
from dropbox.files import FolderMetadata, FileMetadata
from dotenv import load_dotenv
from datetime import datetime, timedelta, timezone

load_dotenv()

REFRESH_TOKEN = os.getenv("DROPBOX_REFRESH_TOKEN")
APP_KEY = os.getenv("DROPBOX_APP_KEY")
APP_SECRET = os.getenv("DROPBOX_APP_SECRET")

if not REFRESH_TOKEN:
    raise Exception("DROPBOX_REFRESH_TOKEN missing")

if not APP_KEY:
    raise Exception("APP_KEY missing")

if not APP_SECRET:
    raise Exception("APP_SECRET missing")

dbx = dropbox.Dropbox(
    app_key=APP_KEY, app_secret=APP_SECRET, oauth2_refresh_token=REFRESH_TOKEN
)


def list_dropbox_folder_hierarchy(dbx: dropbox.Dropbox, base_path: str = ""):
    """
    Recursively fetches the folder/file hierarchy from Dropbox starting at base_path.
    Includes direct temporary download links for files.

    Args:
        dbx (dropbox.Dropbox): Authenticated Dropbox client.
        base_path (str): Path inside Dropbox ("" means root).

    Returns:
        dict: Nested dict with folders -> {subfolders/files with links}.
    """
    hierarchy = {}

    try:
        print("listing files in", base_path)
        result = dbx.files_list_folder(base_path)

        while True:
            for entry in result.entries:
                if isinstance(entry, FolderMetadata):
                    # Recurse into subfolder
                    hierarchy[entry.name] = list_dropbox_folder_hierarchy(
                        dbx, entry.path_lower
                    )
                elif isinstance(entry, FileMetadata):
                    try:
                        link = dbx.files_get_temporary_link(entry.path_lower).link
                        hierarchy.setdefault("__files__", []).append(
                            {
                                "name": entry.name,
                                "path": entry.path_lower,
                                "download_url": link,
                            }
                        )
                    except Exception as link_err:
                        print(
                            f"Could not generate link for {entry.path_lower}: {link_err}"
                        )

            if result.has_more:
                result = dbx.files_list_folder_continue(result.cursor)
            else:
                break

    except Exception as e:
        print(f"Error listing folder {base_path}: {e}")

    return hierarchy


class AudioRequest(BaseModel):
    scripture_name: str
    global_index: int


# cache = {(scripture_name, global_index, type): {"url": ..., "expiry": ...}}
audio_cache: dict[tuple[str, int, str], dict] = {}
CACHE_TTL = timedelta(hours=3, minutes=30)  # refresh before 4h expiry


async def get_audio_urls(req: AudioRequest):
    base_path = f"/{req.scripture_name}/audio"
    files_to_check = {
        "recitation": f"{req.global_index}-recitation.mp3",
        "santhai": f"{req.global_index}-santhai.mp3",
    }

    urls = {}
    now = datetime.now(timezone.utc)  # timezone-aware UTC datetime

    for key, filename in files_to_check.items():
        cache_key = (req.scripture_name, req.global_index, key)

        # Check cache first
        cached = audio_cache.get(cache_key)
        if cached and cached["expiry"] > now:
            urls[key] = cached["url"]
            continue

        # Generate new temporary link
        file_path = f"{base_path}/{filename}"
        try:
            metadata = dbx.files_get_metadata(file_path)
            if isinstance(metadata, FileMetadata):
                temp_link = dbx.files_get_temporary_link(file_path).link
                urls[key] = temp_link
                # store in cache with expiry
                audio_cache[cache_key] = {"url": temp_link, "expiry": now + CACHE_TTL}
        except dropbox.exceptions.ApiError:
            urls[key] = None

    if not any(urls.values()):
        raise HTTPException(status_code=404, detail="No audio files found")

    return urls


async def cleanup_audio_url_cache(interval_seconds: int = 600):
    """Periodically remove expired entries from audio_cache."""
    while True:
        now = datetime.now(timezone.utc)
        expired_keys = [key for key, val in audio_cache.items() if val["expiry"] <= now]
        for key in expired_keys:
            del audio_cache[key]
        # Debug log
        if expired_keys:
            print(f"Cleaned up {len(expired_keys)} expired cache entries")
        await asyncio.sleep(interval_seconds)


if __name__ == "__main__":
    # Create Dropbox client with your access token
    # data = list_dropbox_folder_hierarchy(dbx, "")
    data = asyncio.run(
        get_audio_urls(AudioRequest(scripture_name="divya_prabandham", global_index=0))
    )
    print(json.dumps(data, indent=2))