from __future__ import annotations

from dataclasses import dataclass
from pathlib import Path
from typing import Any

TRANSIENT_PARTS = {"_UNPACK_", "__UNPACK__", "_FAILED_", "_ADMIN_"}
NOT_READY_STATUSES = {
    "Queued", "QuickCheck", "Verifying", "Repairing", "Fetching", "Extracting",
    "Moving", "Running", "Downloading", "Paused", "Propagating",
}


@dataclass(frozen=True)
class Readiness:
    state: str
    reason: str
    storage: Path | None = None

    @property
    def ready(self) -> bool:
        return self.state == "ready"


def has_transient_part(path: Path) -> bool:
    return any(part in TRANSIENT_PARTS or any(token in part for token in TRANSIENT_PARTS) for part in path.parts)


def classify_history_item(item: dict[str, Any], active_nzo_ids: set[str], category: str, download_root: Path, force_status: bool = False, sab_storage_root: Path | None = None) -> Readiness:
    nzo_id = str(item.get("nzo_id") or item.get("nzoid") or "")
    if not force_status and nzo_id and nzo_id in active_nzo_ids:
        return Readiness("processing", "SAB job is still present in queue")
    item_category = str(item.get("category") or item.get("cat") or "")
    status = str(item.get("status") or "")
    storage_value = str(item.get("storage") or "")
    storage = Path(storage_value).resolve() if storage_value else None
    root = download_root.resolve()
    sab_root = (sab_storage_root or download_root).resolve()
    storage_in_local_root = bool(storage and (storage == root or root in storage.parents))
    storage_in_sab_root = bool(storage and (storage == sab_root or sab_root in storage.parents))
    storage_in_root = storage_in_local_root or storage_in_sab_root
    if item_category != category and not storage_in_root:
        return Readiness("ignored", "SAB category/storage is not owned by Importarr", storage)
    if not force_status and status == "Failed":
        return Readiness("failed", "SAB history reports failure")
    if not force_status and (status in NOT_READY_STATUSES or status != "Completed"):
        return Readiness("processing", f"SAB status is {status or 'unknown'}")
    if storage is None:
        return Readiness("unknown", "SAB completed item has no final storage")
    if not storage_in_root:
        return Readiness("ignored", "SAB storage is outside configured download root", storage)
    if storage_in_sab_root and not storage_in_local_root:
        storage = root / storage.relative_to(sab_root)
    if has_transient_part(storage):
        return Readiness("processing", "SAB storage path contains transient unpack/admin marker", storage)
    if force_status and status != "Completed":
        reason = "forced despite SAB status"
    elif item_category != category:
        reason = "SAB completed inside Importarr download root"
    else:
        reason = "SAB completed in owned category with final storage"
    return Readiness("ready", reason, storage)