import datetime
import logging
import os

from photoflow.core.models import Asset
from photoflow.immich import pipeline

log = logging.getLogger(__name__)


def _now() -> str:
    return datetime.datetime.now(datetime.timezone.utc).isoformat()


def run_ingest(client, store, thumbs_dir, *, date_from=None, date_to=None,
               tag=None, subset=None, full=False) -> dict:
    os.makedirs(thumbs_dir, exist_ok=True)

    tag_ids = None
    if tag:
        tid = client.resolve_tag_id(tag)
        if not tid:
            raise ValueError(f"Tag {tag!r} not found in Immich")
        tag_ids = [tid]

    updated_after = None if full else store.get_meta("last_ingest_at")

    assets = client.search_assets(taken_after=date_from, taken_before=date_to,
                                  tag_ids=tag_ids, updated_after=updated_after)
    if subset is not None:
        assets = assets[:subset]

    processed_marked = 0
    max_updated = updated_after or ""
    tag_counts: dict = {}

    for a in assets:
        # Revision (2): sanitize the Immich-provided id before using it as a
        # path component, guarding against path traversal (mirror /thumb proxy).
        safe_id = os.path.basename(a["id"])
        thumb_path = os.path.join(thumbs_dir, f"{safe_id}.jpg")
        # Revision (1): treat an existing 0-byte file as missing.
        need_thumb = (not os.path.exists(thumb_path)
                      or os.path.getsize(thumb_path) == 0)
        if need_thumb:
            try:
                data = client.download_thumbnail(a["id"])
            except Exception:
                log.exception("Thumbnail download failed for asset %s", a["id"])
                continue
            # Write to a temp path and os.replace into place so a failure
            # never leaves a 0-byte <id>.jpg behind; clean up the temp file
            # if the write itself fails (e.g. disk full).
            tmp_path = f"{thumb_path}.tmp"
            try:
                with open(tmp_path, "wb") as f:
                    f.write(data)
                os.replace(tmp_path, thumb_path)
            except Exception:
                log.exception("Thumbnail write failed for asset %s", a["id"])
                try:
                    os.unlink(tmp_path)
                except OSError:
                    pass
                continue

        store.upsert_asset(Asset(
            immich_id=a["id"], taken_at=a["taken_at"], gps_lat=a["gps_lat"],
            gps_lon=a["gps_lon"], place_city=a["place_city"],
            place_country=a["place_country"], type=a["type"],
            thumb_path=thumb_path, ingested_at=_now(), updated_at=a["updated_at"]))
        store.set_asset_tags(a["id"], a["tags"])
        for t in a["tags"]:
            tag_counts[t] = tag_counts.get(t, 0) + 1

        if pipeline.PROCESSED in a["tags"]:
            store.mark_processed(a["id"])
            processed_marked += 1

        if a["updated_at"] and a["updated_at"] > max_updated:
            max_updated = a["updated_at"]

    for name, count in tag_counts.items():
        store.upsert_tag(name, count=count)

    if max_updated:
        store.set_meta("last_ingest_at", max_updated)

    return {"fetched": len(assets), "processed_marked": processed_marked}