"""Build a playlist's materialized folder from a FINISHED organize-by-playlist
download batch.

The batch already carries the real on-disk location of every resolved track:

  - **owned** tracks → ``analysis_results[*]['matched_file_path']`` (the library
    matcher's result, captured during analysis), and
  - **downloaded** tracks → ``download_tasks[tid]['final_file_path']`` (where the
    import landed).

So this is pure stitching + filesystem work: **no re-matching, no source-ID
lookup, no mirrored-playlist resolution**. It works for any organize-by-playlist
download, mirrored or not, and for the all-owned case (where nothing downloads).

Each stored path is run through ``resolve_library_file_path`` — the same resolver
playback uses — so a DB path that's host-formatted (Docker) maps to the real file
the container can see; a freshly-downloaded path already exists and passes
through unchanged.
"""

from __future__ import annotations

from typing import Any, List, Optional

from core.imports.paths import docker_resolve_path
from core.playlists.materialize import (
    RebuildSummary,
    normalize_mode,
    rebuild_playlist_folder,
)


def collect_batch_real_paths(batch: dict, download_tasks: dict, *, config_manager) -> List[str]:
    """Real on-disk paths of every track in a finished batch that resolved —
    owned (from analysis) + downloaded (from completed tasks) — resolved to this
    process's filesystem and de-duplicated, in playlist order then download order."""
    from core.library.path_resolver import resolve_library_file_path

    out: List[str] = []
    seen = set()

    def _add(stored_path: Any) -> None:
        if not stored_path:
            return
        real = resolve_library_file_path(str(stored_path), config_manager=config_manager)
        if real and real not in seen:
            seen.add(real)
            out.append(real)

    for res in (batch.get("analysis_results") or []):
        if res.get("found"):
            _add(res.get("matched_file_path"))

    for tid in (batch.get("queue") or []):
        task = (download_tasks or {}).get(tid) or {}
        if task.get("status") == "completed":
            _add(task.get("final_file_path"))

    return out


def materialize_playlist_from_batch(batch: dict, download_tasks: dict, config_manager) -> Optional[RebuildSummary]:
    """(Re)build the playlist folder for a finished organize-by-playlist batch.

    Returns the :class:`RebuildSummary`, or ``None`` when the batch isn't an
    organize-by-playlist batch. Reads ``playlists.materialize_path`` /
    ``playlists.materialize_mode`` from config."""
    if not batch or not batch.get("playlist_folder_mode"):
        return None
    name = batch.get("playlist_name") or "Unknown Playlist"
    real_paths = collect_batch_real_paths(batch, download_tasks, config_manager=config_manager)
    root = docker_resolve_path(config_manager.get("playlists.materialize_path", "./Playlists"))
    mode = normalize_mode(config_manager.get("playlists.materialize_mode", "symlink"))
    return rebuild_playlist_folder(root, name, real_paths, mode)


def reconcile_batch_playlists(batch: dict, download_tasks: dict, config_manager):
    """One post-batch step: drop the batch's newly-resolved tracks into the right
    ``Playlists/<name>/`` folders. Path-independent — covers an organize-by-playlist
    download AND a late wishlist arrival — using the per-track playlist provenance
    each download already carries, plus the file paths the batch already captured
    (so it needs no DB re-match and no waiting on the server scan/sync).

      - The batch's OWN organize playlist is fully rebuilt from the batch payload
        (owned + downloaded), pruning tracks no longer present.
      - A track that completed for a DIFFERENT playlist (e.g. a wishlist
        fulfillment) is ADDED to that playlist's folder — no prune, since this
        batch isn't that playlist's full membership (removals are handled by a
        full rebuild on the next sync / the manual button).

    Returns a list of ``(playlist_name, RebuildSummary)``. Callers wrap non-fatally."""
    from core.library.path_resolver import resolve_library_file_path

    results = []
    root = docker_resolve_path(config_manager.get("playlists.materialize_path", "./Playlists"))
    mode = normalize_mode(config_manager.get("playlists.materialize_mode", "symlink"))
    batch_name = batch.get("playlist_name") if batch.get("playlist_folder_mode") else None

    # 1. The batch's own organize playlist → full materialize (prunes removed).
    if batch_name:
        summary = materialize_playlist_from_batch(batch, download_tasks, config_manager)
        if summary:
            results.append((batch_name, summary))

    # 2. Tracks that completed for OTHER playlists (e.g. wishlist fulfilling a
    #    track that belongs to an organize playlist) → add-only into that folder.
    extra: dict = {}
    for tid in (batch.get("queue") or []):
        task = (download_tasks or {}).get(tid) or {}
        if task.get("status") != "completed" or not task.get("final_file_path"):
            continue
        pname = (task.get("track_info") or {}).get("_playlist_name")
        if pname and pname != batch_name:
            extra.setdefault(pname, []).append(task["final_file_path"])

    for name, stored in extra.items():
        real, seen = [], set()
        for p in stored:
            r = resolve_library_file_path(str(p), config_manager=config_manager)
            if r and r not in seen:
                seen.add(r)
                real.append(r)
        if real:
            results.append((name, rebuild_playlist_folder(root, name, real, mode, prune_stale=False)))

    return results


def _rebuild_one_from_db(db, config_manager, playlist: dict):
    """Rebuild ONE playlist's folder from its CURRENT membership × ownership —
    re-matching each member via the app's own ``check_track_exists`` (by name, not
    source IDs), resolving to disk, and rebuilding WITH prune. Because it's driven
    by current membership, a track that has LEFT the playlist drops out of the set
    and its symlink is pruned. Returns ``(playlist_name, RebuildSummary)``."""
    from core.library.path_resolver import resolve_library_file_path

    root = docker_resolve_path(config_manager.get("playlists.materialize_path", "./Playlists"))
    mode = normalize_mode(config_manager.get("playlists.materialize_mode", "symlink"))
    real_paths: List[str] = []
    seen = set()
    for t in (db.get_mirrored_playlist_tracks(playlist["id"]) or []):
        title = (t.get("track_name") or "").strip()
        artist = (t.get("artist_name") or "").strip()
        if not title:
            continue
        try:
            db_track, conf = db.check_track_exists(title, artist, confidence_threshold=0.7)
        except Exception:
            continue
        if db_track is None or conf < 0.7:
            continue
        real = resolve_library_file_path(getattr(db_track, "file_path", None), config_manager=config_manager)
        if real and real not in seen:
            seen.add(real)
            real_paths.append(real)
    name = playlist.get("name") or "Unnamed Playlist"
    return name, rebuild_playlist_folder(root, name, real_paths, mode)   # prune_stale=True


def rebuild_organized_playlists_from_db(db, config_manager, *, profile_id: int = 1):
    """Rebuild EVERY "organize by playlist" folder from current library ownership —
    for the manual "Rebuild" button. Self-heals after a library reorganize moves
    files or membership changes. Returns a list of ``(playlist_name, summary)``."""
    return [
        _rebuild_one_from_db(db, config_manager, pl)
        for pl in (db.get_mirrored_playlists(profile_id) or [])
        if pl.get("organize_by_playlist")
    ]


def rebuild_mirrored_playlist_if_organized(db, config_manager, playlist_id, *, profile_id: int = 1):
    """Mirror-update hook: after a playlist's membership is re-synced, rebuild its
    folder (with prune) IF it's organize-by-playlist — so a track that just LEFT
    the playlist has its symlink cleaned up the instant membership changes (the
    mirror image of the post-download reconcile that handles additions). Returns
    the summary, or ``None`` when the playlist isn't organized / can't be found."""
    if playlist_id is None:
        return None
    pl = db.get_mirrored_playlist(playlist_id)
    if not pl or not pl.get("organize_by_playlist"):
        return None
    _name, summary = _rebuild_one_from_db(db, config_manager, pl)
    return summary


__all__ = [
    "collect_batch_real_paths",
    "materialize_playlist_from_batch",
    "reconcile_batch_playlists",
    "rebuild_organized_playlists_from_db",
    "rebuild_mirrored_playlist_if_organized",
]