from library.models import Collection, Work, WorkMeta, Document

import logging

logger = logging.getLogger(__name__)


def sync_work(work: Work):
    logger.info("Syncing '%s'", work.name)
    folder_id = work.meta_info.get(name="folderid").value

    storage = work.collection.storage.instance()
    prefix = work.collection.storage.name
    _, files = storage.listdir(folder_id)

    existing = set(
        [
            storage.parse_id(x.partition(":")[2])
            for x in work.docs.values_list("upload", flat=True)
        ]
    )
    logger.debug("%d existing documents", len(existing))

    for file in files:
        if file.id in existing:
            logger.debug("%30s: Skipping existing (%s)", file.name, file.id)
            existing.discard(file.id)
            continue

        if not file.name.lower().endswith(".pdf"):
            logger.debug("%40s: Not a PDF", file.name)
            continue

        logger.info("%40s: Adding", file.name)
        doc = work.docs.create(upload=f"{prefix}:{file}", doctype=Document.DOCTYPE_PDF)
        doc.auto_tag()

    for uri in existing:
        logger.warning("Local entry not in folder: %s", uri)


def sync_collection(collection: Collection, sync_existing: bool = False):
    logger.info("Syncing '%s'", collection)

    if not collection.storage.storage.endswith("GDriveLinkStorage"):
        raise RuntimeError("Not a gdrive storage")

    if not collection.prefix:
        raise KeyError("Prefix must store folder id")

    existing = dict(
        WorkMeta.objects.filter(
            work__collection=collection, name="folderid"
        ).values_list("value", "work_id")
    )

    storage = collection.storage.instance()
    folders, _ = storage.listdir(collection.prefix)

    for folder in folders:
        if folder.id in existing:
            if sync_existing:
                logger.info("%40s: Syncing (%s)", folder.name, folder.id[:12])
                sync_work(Work.objects.get(pk=existing[folder.id]))
            del existing[folder.id]
            continue

        logger.info("%40s: Adding", folder.name)
        work = Work(name=folder.name, collection=collection)
        work.save()
        work.meta_info.create(name="folderid", value=folder.id)
        sync_work(work)

    for folderid, work in existing:
        logger.warning("Folder for work %d no longer in drive (%s)", work, folderid)