"""Local file ingest for the download center (E7 S5) — the non-yt-dlp path into the media library.

A user-uploaded file joins the SAME library as a downloaded one, so it inherits the whole function
set already built (metadata chips, share links, and — for media — in-app play/edit). Unlike a
download it bypasses yt-dlp AND the worker entirely: the file is already on the host, so ingest
probes it, places it on disk, and creates an already-`ready` MediaAsset + `done` DownloadJob in one
step — the same "the file exists, mark it done now" shortcut `service.enqueue` takes on a cache hit.

Kinds (the invariant lives in `mediakind`): a probe with a real video stream -> video, audio-only
-> audio, neither -> a generic 'file' (pdf/zip/docx/…) that is download-only and never rendered
inline (see the force-download serving in the file/watch routes). This module is the ingest seam a
future sub-function (e.g. convert) plugs a new adapter into, mirroring how it sidesteps the worker.

An upload does NOT get an `expires_at`: it's user-provided and may be irreplaceable (there's no
source to re-download), so it doesn't age out on the retention clock the way a re-fetchable download
does — it lives until the user deletes it.
"""

import json
import secrets
import subprocess
from datetime import datetime, timezone
from pathlib import Path

from sqlalchemy.orm import Session

from app.config import settings
from app.downloads import edit as editmod
from app.downloads import mediakind, quota, service, storage
from app.models import DownloadJob, MediaAsset


def _probe(path: Path) -> tuple[str | None, str | None, int | None, int | None, int | None]:
    """(vcodec, acodec, width, height, duration_s) from one ffprobe call; all None if ffprobe fails
    or the file isn't media (a file we can't probe is treated as a generic non-media upload).

    A video stream flagged `attached_pic` (embedded cover art in an mp3/m4a) is skipped — it's a
    thumbnail, not a real video track, so an audio file with album art still classifies as audio."""
    try:
        out = subprocess.run(
            [
                "ffprobe",
                "-v",
                "error",
                "-show_streams",
                "-show_format",
                "-of",
                "json",
                str(path),
            ],
            capture_output=True,
            text=True,
            timeout=30,
            check=True,
        ).stdout
        data = json.loads(out)
    except (subprocess.TimeoutExpired, subprocess.CalledProcessError, OSError, ValueError):
        return None, None, None, None, None

    vcodec = acodec = None
    width = height = None
    for stream in data.get("streams", []):
        kind = stream.get("codec_type")
        if kind == "video" and vcodec is None:
            if (stream.get("disposition") or {}).get("attached_pic"):
                continue  # cover art, not a video track
            vcodec = stream.get("codec_name")
            width = stream.get("width")
            height = stream.get("height")
        elif kind == "audio" and acodec is None:
            acodec = stream.get("codec_name")

    duration = None
    try:
        raw = (data.get("format") or {}).get("duration")
        if raw is not None:
            duration = int(float(raw))
    except (TypeError, ValueError):
        duration = None
    return vcodec, acodec, width, height, duration


def _title_from_filename(filename: str) -> str:
    """A human display title from the original upload name: the stem with separators tidied to
    spaces (kept as-is otherwise — this is display metadata, not the shell-safe on-disk name)."""
    stem = Path(filename).stem.replace("_", " ").replace(".", " ").strip()
    return (stem or "Upload")[:255]


def ingest_upload(
    db: Session,
    user_id: int,
    *,
    filename: str,
    src_path: Path,
    size: int,
    display_name: str | None = None,
) -> DownloadJob:
    """Ingest an already-uploaded file at `src_path` into `user_id`'s library and return the `done`
    job. `src_path` is MOVED into place on success (the caller stages it to a temp file first).

    Raises quota.QuotaExceeded (holdings/footprint cap) — checked BEFORE any disk write, so a
    rejected upload leaves nothing behind and the caller just cleans up its temp file."""
    quota.check_upload(db, user_id, size)  # the file's size is known → charge it up front

    vcodec, acodec, width, height, duration = _probe(src_path)
    kind = mediakind.derive(vcodec, acodec)

    # An upload never dedups (each file is its own asset): a random ref makes the cache key unique,
    # so `format_sig` is a constant marker rather than a format hash.
    ref = f"{user_id}:{secrets.token_hex(8)}"[:512]
    asset = MediaAsset(
        source_kind="upload", source_ref=ref, format_sig="upload", status="pending", ref_count=0
    )
    db.add(asset)
    db.flush()  # need asset.id for the on-disk path

    rel = storage.upload_rel_path(user_id, asset.id, filename)
    storage.place_file(src_path, settings.download_root, rel)
    final = storage.abs_path(settings.download_root, rel)
    actual_size = final.stat().st_size if final.exists() else size

    asset.status = "ready"
    asset.rel_path = rel
    asset.size_bytes = actual_size
    asset.container = storage.upload_ext(filename)
    asset.vcodec = vcodec
    asset.acodec = acodec
    asset.width = width
    asset.height = height
    asset.duration_s = duration
    asset.media_kind = kind
    asset.title = (display_name or "").strip() or _title_from_filename(filename)
    asset.last_access_at = datetime.now(timezone.utc)
    # No expires_at — see the module docstring (an upload is irreplaceable, so it doesn't age out).
    if kind == mediakind.VIDEO:
        # A frame poster gives the library row a thumbnail + the share link an og:image. Audio has no
        # frame and a generic file no player, so neither gets one. Best-effort (ffmpeg decodes server
        # side even for a codec the browser can't play).
        asset.poster_path = editmod.ensure_poster(asset, settings.download_root)

    job = DownloadJob(
        user_id=user_id,
        asset_id=asset.id,
        job_kind="upload",
        source_kind="upload",
        source_ref=ref,
        profile_snapshot={},
        display_name=(display_name or "").strip() or None,
        status="done",
        progress=100,
        queue_pos=service.next_queue_pos(db),
    )
    db.add(job)
    service.incr_ref_count(db, asset.id)
    db.commit()
    db.refresh(job)
    return job