import logging
import os
from typing import Sequence

from sqlalchemy import select
from sqlalchemy.orm import Session

from app.assets.database.models import Asset, AssetInfo, Tag
from app.assets.database.queries import (
    add_tags_to_asset_info,
    get_asset_by_hash,
    get_asset_tags,
    get_or_create_asset_info,
    list_cache_states_by_asset_id,
    remove_missing_tag_for_asset_id,
    set_asset_info_metadata,
    set_asset_info_tags,
    update_asset_info_timestamps,
    upsert_asset,
    upsert_cache_state,
)
from app.assets.helpers import normalize_tags, select_best_live_path
from app.assets.services.path_utils import compute_relative_filename
from app.assets.services.schemas import (
    IngestResult,
    RegisterAssetResult,
    UserMetadata,
    extract_asset_data,
    extract_info_data,
)
from app.database.db import create_session


def ingest_file_from_path(
    abs_path: str,
    asset_hash: str,
    size_bytes: int,
    mtime_ns: int,
    mime_type: str | None = None,
    info_name: str | None = None,
    owner_id: str = "",
    preview_id: str | None = None,
    user_metadata: UserMetadata = None,
    tags: Sequence[str] = (),
    tag_origin: str = "manual",
    require_existing_tags: bool = False,
) -> IngestResult:
    locator = os.path.abspath(abs_path)

    asset_created = False
    asset_updated = False
    state_created = False
    state_updated = False
    asset_info_id: str | None = None

    with create_session() as session:
        if preview_id:
            if not session.get(Asset, preview_id):
                preview_id = None

        asset, asset_created, asset_updated = upsert_asset(
            session,
            asset_hash=asset_hash,
            size_bytes=size_bytes,
            mime_type=mime_type,
        )

        state_created, state_updated = upsert_cache_state(
            session,
            asset_id=asset.id,
            file_path=locator,
            mtime_ns=mtime_ns,
        )

        if info_name:
            info, info_created = get_or_create_asset_info(
                session,
                asset_id=asset.id,
                owner_id=owner_id,
                name=info_name,
                preview_id=preview_id,
            )
            if info_created:
                asset_info_id = info.id
            else:
                update_asset_info_timestamps(session, asset_info=info, preview_id=preview_id)
                asset_info_id = info.id

            norm = normalize_tags(list(tags))
            if norm and asset_info_id:
                if require_existing_tags:
                    _validate_tags_exist(session, norm)
                add_tags_to_asset_info(
                    session,
                    asset_info_id=asset_info_id,
                    tags=norm,
                    origin=tag_origin,
                    create_if_missing=not require_existing_tags,
                )

            if asset_info_id:
                _update_metadata_with_filename(
                    session,
                    asset_info_id=asset_info_id,
                    asset_id=asset.id,
                    info=info,
                    user_metadata=user_metadata,
                )

        try:
            remove_missing_tag_for_asset_id(session, asset_id=asset.id)
        except Exception:
            logging.exception("Failed to clear 'missing' tag for asset %s", asset.id)

        session.commit()

    return IngestResult(
        asset_created=asset_created,
        asset_updated=asset_updated,
        state_created=state_created,
        state_updated=state_updated,
        asset_info_id=asset_info_id,
    )


def register_existing_asset(
    asset_hash: str,
    name: str,
    user_metadata: UserMetadata = None,
    tags: list[str] | None = None,
    tag_origin: str = "manual",
    owner_id: str = "",
) -> RegisterAssetResult:
    with create_session() as session:
        asset = get_asset_by_hash(session, asset_hash=asset_hash)
        if not asset:
            raise ValueError(f"No asset with hash {asset_hash}")

        info, info_created = get_or_create_asset_info(
            session,
            asset_id=asset.id,
            owner_id=owner_id,
            name=name,
            preview_id=None,
        )

        if not info_created:
            tag_names = get_asset_tags(session, asset_info_id=info.id)
            result = RegisterAssetResult(
                info=extract_info_data(info),
                asset=extract_asset_data(asset),
                tags=tag_names,
                created=False,
            )
            session.commit()
            return result

        new_meta = dict(user_metadata or {})
        computed_filename = _compute_filename_for_asset(session, asset.id)
        if computed_filename:
            new_meta["filename"] = computed_filename

        if new_meta:
            set_asset_info_metadata(
                session,
                asset_info_id=info.id,
                user_metadata=new_meta,
            )

        if tags is not None:
            set_asset_info_tags(
                session,
                asset_info_id=info.id,
                tags=tags,
                origin=tag_origin,
            )

        tag_names = get_asset_tags(session, asset_info_id=info.id)
        session.refresh(info)
        result = RegisterAssetResult(
            info=extract_info_data(info),
            asset=extract_asset_data(asset),
            tags=tag_names,
            created=True,
        )
        session.commit()

        return result


def _validate_tags_exist(session: Session, tags: list[str]) -> None:
    existing_tag_names = set(
        name for (name,) in session.execute(select(Tag.name).where(Tag.name.in_(tags))).all()
    )
    missing = [t for t in tags if t not in existing_tag_names]
    if missing:
        raise ValueError(f"Unknown tags: {missing}")


def _compute_filename_for_asset(session: Session, asset_id: str) -> str | None:
    primary_path = select_best_live_path(list_cache_states_by_asset_id(session, asset_id=asset_id))
    return compute_relative_filename(primary_path) if primary_path else None


def _update_metadata_with_filename(
    session: Session,
    asset_info_id: str,
    asset_id: str,
    info: AssetInfo,
    user_metadata: UserMetadata,
) -> None:
    computed_filename = _compute_filename_for_asset(session, asset_id)

    current_meta = info.user_metadata or {}
    new_meta = dict(current_meta)
    if user_metadata:
        for k, v in user_metadata.items():
            new_meta[k] = v
    if computed_filename:
        new_meta["filename"] = computed_filename

    if new_meta != current_meta:
        set_asset_info_metadata(
            session,
            asset_info_id=asset_info_id,
            user_metadata=new_meta,
        )