"""
Per-account blobs on the node — the playlist store (docs/playlists.md §3.3, §8.2).

The node holds bytes it cannot read, one row per playlist plus a manifest, and
hands them back to the account that wrote them. Three things have to hold, and
only the first is obvious:

  - a blob round-trips through the process, byte for byte, as **bytes** — the
    column is a BLOB rather than base64 TEXT because these run to hundreds of
    kilobytes and base64 is a third of every write;
  - the plaintext is never in the file, which is the whole claim; and
  - every cap **refuses** rather than truncating. A truncating cap silently
    loses tracks, which is the failure the whole design exists to prevent.
"""

import pytest
from meshbay_node.bundle_store import BundleStore


@pytest.mark.asyncio
async def test_a_blob_round_trips_as_bytes(tmp_path):
    store = BundleStore(db_path=tmp_path / "bundles.db")
    await store.open()

    # Every byte value, so a text column or an encoding step anywhere in the
    # path shows up as a difference rather than surviving by luck.
    sealed = bytes(range(256)) * 8
    await store.store_user_blob("u1", "playlists", 3, sealed)

    row = await store.fetch_user_blob("u1", "playlists")
    assert row == {"rev": 3, "blob_enc": sealed}
    assert isinstance(row["blob_enc"], bytes)
    await store.close()


@pytest.mark.asyncio
async def test_a_blob_survives_the_process(tmp_path):
    """Reopened from disk, not read back out of the same connection."""
    db = tmp_path / "bundles.db"
    sealed = b"\x00\x01sealed-body\xff"

    store = BundleStore(db_path=db)
    await store.open()
    await store.store_user_blob("u1", "playlist:abc-123", 41, sealed)
    await store.close()

    again = BundleStore(db_path=db)
    await again.open()
    assert (await again.fetch_user_blob("u1", "playlist:abc-123"))["blob_enc"] == sealed
    await again.close()


@pytest.mark.asyncio
async def test_one_playlist_is_one_row(tmp_path):
    """The point of the split: rewriting Favourites must not touch the rest."""
    store = BundleStore(db_path=tmp_path / "bundles.db")
    await store.open()

    await store.store_user_blob("u1", "playlists", 1, b"manifest")
    await store.store_user_blob("u1", "playlist:favorites", 1, b"fav-v1")
    await store.store_user_blob("u1", "playlist:evening", 1, b"evening-v1")

    await store.store_user_blob("u1", "playlist:favorites", 2, b"fav-v2")

    assert (await store.fetch_user_blob("u1", "playlist:favorites"))["rev"] == 2
    assert (await store.fetch_user_blob("u1", "playlist:evening"))["blob_enc"] == b"evening-v1"
    assert (await store.fetch_user_blob("u1", "playlists"))["blob_enc"] == b"manifest"
    await store.close()


@pytest.mark.asyncio
async def test_an_unwritten_kind_is_absent_not_an_error(tmp_path):
    """"No playlist here yet" is the ordinary state of a fresh node."""
    store = BundleStore(db_path=tmp_path / "bundles.db")
    await store.open()
    assert await store.fetch_user_blob("u1", "playlists") is None
    assert await store.list_user_blobs("u1") == []
    await store.close()


@pytest.mark.asyncio
async def test_listing_reports_kinds_and_revisions_and_no_payload(tmp_path):
    """What a client that lost its local state needs, and nothing more: the
    kinds carry client-generated UUIDs and cannot be guessed."""
    store = BundleStore(db_path=tmp_path / "bundles.db")
    await store.open()
    await store.store_user_blob("u1", "playlists", 7, b"m")
    await store.store_user_blob("u1", "playlist:aaa", 2, b"secret-body")

    listing = await store.list_user_blobs("u1")
    assert listing == [{"kind": "playlist:aaa", "rev": 2},
                       {"kind": "playlists", "rev": 7}]
    assert "blob_enc" not in listing[0]
    await store.close()


@pytest.mark.asyncio
async def test_one_account_never_sees_another(tmp_path):
    """`user_id` comes from the authenticated session; this is what that buys."""
    store = BundleStore(db_path=tmp_path / "bundles.db")
    await store.open()
    await store.store_user_blob("alice", "playlists", 1, b"alice")
    await store.store_user_blob("bob", "playlists", 1, b"bob")

    assert (await store.fetch_user_blob("alice", "playlists"))["blob_enc"] == b"alice"
    assert await store.list_user_blobs("bob") == [{"kind": "playlists", "rev": 1}]

    await store.delete_user_blob("alice", "playlists")
    assert await store.fetch_user_blob("alice", "playlists") is None
    assert await store.fetch_user_blob("bob", "playlists") is not None
    await store.close()


@pytest.mark.asyncio
async def test_deleting_something_absent_says_so_rather_than_raising(tmp_path):
    store = BundleStore(db_path=tmp_path / "bundles.db")
    await store.open()
    assert await store.delete_user_blob("u1", "playlist:gone") is False
    await store.store_user_blob("u1", "playlist:gone", 1, b"x")
    assert await store.delete_user_blob("u1", "playlist:gone") is True
    await store.close()


@pytest.mark.asyncio
async def test_the_account_total_is_what_the_cap_is_checked_against(tmp_path):
    """The per-blob caps bound one playlist; only this bounds the account, and
    an unbounded write primitive pointed at somebody else's disk needs it."""
    store = BundleStore(db_path=tmp_path / "bundles.db")
    await store.open()
    assert await store.user_blob_total_bytes("u1") == 0

    await store.store_user_blob("u1", "playlists", 1, b"x" * 100)
    await store.store_user_blob("u1", "playlist:a", 1, b"y" * 250)
    assert await store.user_blob_total_bytes("u1") == 350

    # Replacing a blob replaces its contribution rather than adding to it.
    await store.store_user_blob("u1", "playlist:a", 2, b"y" * 50)
    assert await store.user_blob_total_bytes("u1") == 150

    await store.delete_user_blob("u1", "playlist:a")
    assert await store.user_blob_total_bytes("u1") == 100
    await store.close()


@pytest.mark.asyncio
async def test_the_plaintext_is_not_in_the_file(tmp_path):
    """The same check test_chat_key_storage.py makes for epoch keys, for the
    same reason: a plaintext column beside the sealed one is the obvious thing
    to write and would collapse the whole claim, silently."""
    db = tmp_path / "bundles.db"
    store = BundleStore(db_path=db)
    await store.open()
    await store.store_user_blob(
        "u1", "playlist:abc", 1, b"SEALED-CIPHERTEXT-ONLY")
    await store.close()

    raw = db.read_bytes()
    assert b"SEALED-CIPHERTEXT-ONLY" in raw, (
        "the sealed bytes should be there — this test is only meaningful if it "
        "is actually reading the right file")
    # What must never be: a track title, an artist, a path. The store is handed
    # ciphertext and stores exactly that; anything readable here would mean the
    # client sealed nothing or the node unwrapped it.
    for leak in (b"Un titre", b"tracks", b"artist", b"favorites"):
        assert leak not in raw, f"{leak!r} is in bundles.db in clear"