"""Tests for the backfill_embeddings script (T112, Phase 4.5).

Phase 4 shipped a backfill that walked memories *without* an embedding
row and produced a vector for each (deterministic pseudo path). T112
adds a ``--re-embed-all`` flag that walks **every** memory regardless
of whether it already has an embeddings row, so operators can swap
embedding models and have the existing rows replaced (the
``embedding_indexed`` projector is INSERT OR REPLACE).

These tests exercise the script's ``main()`` directly via asyncio —
shell-out via subprocess would also work but importing keeps the
fixture surface small and the failure mode clearer.
"""

from __future__ import annotations

from pathlib import Path
from unittest.mock import patch

import pytest

from chat.db.connection import open_db
from chat.db.migrate import apply_migrations
from chat.eventlog.log import append_and_apply, append_event
from chat.eventlog.projector import project
from chat.services.embeddings import DEFAULT_EMBEDDING_MODEL

# Trigger handler registration for projection.
import chat.state.embeddings  # noqa: F401
import chat.state.entities  # noqa: F401
import chat.state.memory  # noqa: F401
import chat.state.world  # noqa: F401

import scripts.backfill_embeddings as backfill


def _seed(db_path: Path, count: int) -> list[int]:
    """Seed ``count`` memory rows for ``bot_a``; return their ids."""
    with open_db(db_path) as conn:
        append_event(
            conn,
            kind="bot_authored",
            payload={
                "id": "bot_a",
                "name": "BotA",
                "persona": "...",
                "voice_samples": [],
                "traits": [],
                "backstory": "",
                "initial_relationship_to_you": "",
                "kickoff_prose": "",
            },
        )
        append_event(
            conn,
            kind="chat_created",
            payload={
                "id": "chat_bot_a",
                "host_bot_id": "bot_a",
                "initial_time": "2026-04-26T20:00:00+00:00",
                "narrative_anchor": "Day 1",
                "weather": "",
            },
        )
        for i in range(count):
            append_event(
                conn,
                kind="memory_written",
                payload={
                    "owner_id": "bot_a",
                    "chat_id": "chat_bot_a",
                    "pov_summary": f"memory text {i}",
                    "witness_you": 1,
                    "witness_host": 1,
                    "witness_guest": 0,
                    "source": "direct",
                    "reliability": 1.0,
                    "significance": 1,
                    "pinned": 0,
                    "auto_pinned": 0,
                },
            )
        project(conn)
        return [
            r[0]
            for r in conn.execute(
                "SELECT id FROM memories WHERE owner_id = 'bot_a' ORDER BY id"
            ).fetchall()
        ]


def _seed_embedding(db_path: Path, memory_id: int, model: str = "stale-model") -> None:
    """Insert a stale ``embedding_indexed`` event so the row already
    exists in ``embeddings`` (and the default backfill would skip it)."""
    with open_db(db_path) as conn:
        append_and_apply(
            conn,
            kind="embedding_indexed",
            payload={
                "memory_id": memory_id,
                "model": model,
                "dim": 3,
                "vector": [0.0, 0.0, 0.0],
            },
        )


@pytest.mark.asyncio
async def test_re_embed_all_walks_every_memory(tmp_path, monkeypatch, capsys):
    """``--re-embed-all`` re-embeds memories that already have rows in
    ``embeddings`` (default mode skips them). After the run, every
    memory should have an updated embedding tagged with the configured
    model (the projector replaces stale rows in place)."""
    db = tmp_path / "t.db"
    apply_migrations(db)
    memory_ids = _seed(db, count=3)
    # Pre-seed stale embeddings on two of the three memories so the
    # default path would skip them and only ``--re-embed-all`` covers
    # everything.
    _seed_embedding(db, memory_ids[0])
    _seed_embedding(db, memory_ids[1])

    cfg = tmp_path / "config.toml"
    cfg.write_text(
        f'featherless_api_key = "x"\n'
        f'db_path = "{db}"\n'
        f'data_dir = "{tmp_path}"\n'
    )
    monkeypatch.setenv("CHAT_CONFIG_PATH", str(cfg))
    monkeypatch.setenv("CHAT_DB_PATH", str(db))

    with patch("sys.argv", ["backfill_embeddings.py", "--re-embed-all"]):
        await backfill.main()

    # All three memories now have a fresh embedding tagged with the
    # default pseudo model (replacing the stale rows).
    with open_db(db) as conn:
        rows = conn.execute(
            "SELECT memory_id, model FROM embeddings ORDER BY memory_id"
        ).fetchall()
        assert len(rows) == 3
        for mid, model in rows:
            assert mid in memory_ids
            assert model == DEFAULT_EMBEDDING_MODEL


@pytest.mark.asyncio
async def test_default_backfill_only_walks_missing(tmp_path, monkeypatch):
    """Without ``--re-embed-all``, the script keeps the Phase 4
    behavior — memories with an existing embedding row are left
    alone (their stale-model tag survives)."""
    db = tmp_path / "t.db"
    apply_migrations(db)
    memory_ids = _seed(db, count=2)
    _seed_embedding(db, memory_ids[0], model="stale-model")
    # memory_ids[1] has no embedding yet.

    cfg = tmp_path / "config.toml"
    cfg.write_text(
        f'featherless_api_key = "x"\n'
        f'db_path = "{db}"\n'
        f'data_dir = "{tmp_path}"\n'
    )
    monkeypatch.setenv("CHAT_CONFIG_PATH", str(cfg))
    monkeypatch.setenv("CHAT_DB_PATH", str(db))

    with patch("sys.argv", ["backfill_embeddings.py"]):
        await backfill.main()

    with open_db(db) as conn:
        rows = dict(
            conn.execute(
                "SELECT memory_id, model FROM embeddings ORDER BY memory_id"
            ).fetchall()
        )
        # Stale row preserved; only the missing one was filled.
        assert rows[memory_ids[0]] == "stale-model"
        assert rows[memory_ids[1]] == DEFAULT_EMBEDDING_MODEL


@pytest.mark.asyncio
async def test_re_embed_all_respects_model_arg(tmp_path, monkeypatch):
    """The ``--model`` flag overrides ``Settings.embedding_model``.
    With a non-default model and a client that returns canned vectors,
    every memory is re-embedded with the supplied model tag."""
    db = tmp_path / "t.db"
    apply_migrations(db)
    memory_ids = _seed(db, count=2)
    _seed_embedding(db, memory_ids[0])

    cfg = tmp_path / "config.toml"
    cfg.write_text(
        f'featherless_api_key = "x"\n'
        f'db_path = "{db}"\n'
        f'data_dir = "{tmp_path}"\n'
    )
    monkeypatch.setenv("CHAT_CONFIG_PATH", str(cfg))
    monkeypatch.setenv("CHAT_DB_PATH", str(db))

    # Patch the client factory the script uses to produce a Mock with
    # canned embeddings — one per memory.
    from chat.llm.mock import MockLLMClient

    canned_vec = [0.1] * 384

    def _factory(_settings):
        return MockLLMClient(
            canned=[],
            canned_embeddings=[list(canned_vec) for _ in memory_ids],
        )

    monkeypatch.setattr(backfill, "_build_client", _factory)

    with patch(
        "sys.argv",
        [
            "backfill_embeddings.py",
            "--re-embed-all",
            "--model",
            "bge-small-en-v1.5",
        ],
    ):
        await backfill.main()

    with open_db(db) as conn:
        rows = conn.execute(
            "SELECT memory_id, model FROM embeddings ORDER BY memory_id"
        ).fetchall()
        assert len(rows) == 2
        for _, model in rows:
            assert model == "bge-small-en-v1.5"