"""Unit tests for timmy.memory.unified — schema, migration, and dataclasses."""

import sqlite3
import uuid
from unittest.mock import patch

import pytest

from timmy.memory.unified import (
    MemoryChunk,
    MemoryEntry,
    _ensure_schema,
    _get_table_columns,
    _migrate_schema,
    get_conn,
    get_connection,
)

# ── Helpers ──────────────────────────────────────────────────────────────────


def _make_conn() -> sqlite3.Connection:
    """Return an in-memory SQLite connection with row_factory set."""
    conn = sqlite3.connect(":memory:")
    conn.row_factory = sqlite3.Row
    return conn


# ── get_connection / get_conn ────────────────────────────────────────────────


class TestGetConnection:
    """Tests for get_connection context manager."""

    def test_returns_connection(self, tmp_path):
        """get_connection yields a usable sqlite3 connection."""
        db = tmp_path / "mem.db"
        with patch("timmy.memory.unified.DB_PATH", db):
            with get_connection() as conn:
                assert isinstance(conn, sqlite3.Connection)
                # Schema should already be created
                cur = conn.execute(
                    "SELECT name FROM sqlite_master WHERE type='table' AND name='memories'"
                )
                assert cur.fetchone() is not None

    def test_creates_parent_directory(self, tmp_path):
        """get_connection creates parent dirs if missing."""
        db = tmp_path / "sub" / "dir" / "mem.db"
        with patch("timmy.memory.unified.DB_PATH", db):
            with get_connection() as conn:
                conn.execute("SELECT 1")
        assert db.parent.exists()

    def test_get_conn_alias(self):
        """get_conn is the same object as get_connection."""
        assert get_conn is get_connection

    def test_connection_has_row_factory(self, tmp_path):
        """Connection should use sqlite3.Row factory."""
        db = tmp_path / "mem.db"
        with patch("timmy.memory.unified.DB_PATH", db):
            with get_connection() as conn:
                assert conn.row_factory is sqlite3.Row

    def test_wal_mode_enabled(self, tmp_path):
        """Connection enables WAL journal mode."""
        db = tmp_path / "mem.db"
        with patch("timmy.memory.unified.DB_PATH", db):
            with get_connection() as conn:
                cur = conn.execute("PRAGMA journal_mode")
                mode = cur.fetchone()[0]
                assert mode == "wal"


# ── _ensure_schema ───────────────────────────────────────────────────────────


class TestEnsureSchema:
    """Tests for _ensure_schema."""

    def test_creates_memories_table(self):
        """Memories table should be created with correct columns."""
        conn = _make_conn()
        _ensure_schema(conn)
        cols = _get_table_columns(conn, "memories")
        expected = {
            "id",
            "content",
            "memory_type",
            "source",
            "embedding",
            "metadata",
            "source_hash",
            "agent_id",
            "task_id",
            "session_id",
            "confidence",
            "tags",
            "created_at",
            "last_accessed",
            "access_count",
        }
        assert cols == expected
        conn.close()

    def test_creates_indexes(self):
        """Expected indexes should exist after schema creation."""
        conn = _make_conn()
        _ensure_schema(conn)
        cur = conn.execute("SELECT name FROM sqlite_master WHERE type='index'")
        indexes = {row[0] for row in cur.fetchall()}
        for idx in [
            "idx_memories_type",
            "idx_memories_time",
            "idx_memories_session",
            "idx_memories_agent",
            "idx_memories_source",
        ]:
            assert idx in indexes, f"Missing index: {idx}"
        conn.close()

    def test_idempotent(self):
        """Calling _ensure_schema twice should not error."""
        conn = _make_conn()
        _ensure_schema(conn)
        _ensure_schema(conn)  # no error
        conn.close()

    def test_default_values(self):
        """Inserted row should have correct defaults."""
        conn = _make_conn()
        _ensure_schema(conn)
        conn.execute(
            "INSERT INTO memories (id, content, created_at) VALUES (?, ?, ?)",
            ("test-1", "hello", "2025-01-01T00:00:00"),
        )
        conn.commit()
        row = conn.execute("SELECT * FROM memories WHERE id='test-1'").fetchone()
        assert row["memory_type"] == "fact"
        assert row["source"] == "agent"
        assert row["confidence"] == 0.8
        assert row["tags"] == "[]"
        assert row["access_count"] == 0
        conn.close()


# ── _get_table_columns ───────────────────────────────────────────────────────


class TestGetTableColumns:
    """Tests for _get_table_columns helper."""

    def test_returns_column_names(self):
        conn = _make_conn()
        conn.execute("CREATE TABLE t (a TEXT, b INTEGER, c REAL)")
        assert _get_table_columns(conn, "t") == {"a", "b", "c"}
        conn.close()

    def test_empty_for_missing_table(self):
        """PRAGMA table_info on non-existent table returns empty set."""
        conn = _make_conn()
        assert _get_table_columns(conn, "nonexistent") == set()
        conn.close()


# ── _migrate_schema ──────────────────────────────────────────────────────────


class TestMigrateSchema:
    """Tests for _migrate_schema — old table migration."""

    def _setup_memories_table(self, conn):
        """Create the unified memories table for migration tests."""
        _ensure_schema(conn)

    def test_no_old_tables_is_noop(self):
        """Migration with only memories table does nothing."""
        conn = _make_conn()
        self._setup_memories_table(conn)
        # Should not raise
        _migrate_schema(conn)
        conn.close()

    def test_migrates_episodes_with_context_type(self):
        """Episodes rows migrate to memories with context_type as memory_type."""
        conn = _make_conn()
        self._setup_memories_table(conn)
        conn.execute("""
            CREATE TABLE episodes (
                id TEXT PRIMARY KEY,
                content TEXT,
                context_type TEXT,
                source TEXT,
                embedding TEXT,
                metadata TEXT,
                agent_id TEXT,
                task_id TEXT,
                session_id TEXT,
                timestamp TEXT
            )
        """)
        conn.execute(
            "INSERT INTO episodes VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)",
            (
                "ep-1",
                "test content",
                "conversation",
                "agent",
                None,
                None,
                "a1",
                "t1",
                "s1",
                "2025-01-01T00:00:00",
            ),
        )
        conn.commit()

        _migrate_schema(conn)

        # Episodes table should be dropped
        tables = {
            r[0]
            for r in conn.execute("SELECT name FROM sqlite_master WHERE type='table'").fetchall()
        }
        assert "episodes" not in tables

        # Data should be in memories
        row = conn.execute("SELECT * FROM memories WHERE id='ep-1'").fetchone()
        assert row is not None
        assert row["content"] == "test content"
        assert row["memory_type"] == "conversation"
        assert row["source"] == "agent"
        conn.close()

    def test_migrates_episodes_without_context_type(self):
        """Episodes without context_type column default to 'conversation'."""
        conn = _make_conn()
        self._setup_memories_table(conn)
        conn.execute("""
            CREATE TABLE episodes (
                id TEXT PRIMARY KEY,
                content TEXT,
                source TEXT,
                embedding TEXT,
                metadata TEXT,
                agent_id TEXT,
                task_id TEXT,
                session_id TEXT,
                timestamp TEXT
            )
        """)
        conn.execute(
            "INSERT INTO episodes VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)",
            ("ep-2", "no type", "user", None, None, None, None, None, "2025-02-01"),
        )
        conn.commit()

        _migrate_schema(conn)
        row = conn.execute("SELECT * FROM memories WHERE id='ep-2'").fetchone()
        assert row["memory_type"] == "conversation"
        conn.close()

    def test_migrates_chunks(self):
        """Chunks table migrates to memories as vault_chunk type."""
        conn = _make_conn()
        self._setup_memories_table(conn)
        conn.execute("""
            CREATE TABLE chunks (
                id TEXT PRIMARY KEY,
                content TEXT,
                filepath TEXT,
                embedding TEXT,
                created_at TEXT
            )
        """)
        conn.execute(
            "INSERT INTO chunks VALUES (?, ?, ?, ?, ?)",
            ("ch-1", "chunk text", "/vault/note.md", None, "2025-03-01"),
        )
        conn.commit()

        _migrate_schema(conn)

        tables = {
            r[0]
            for r in conn.execute("SELECT name FROM sqlite_master WHERE type='table'").fetchall()
        }
        assert "chunks" not in tables

        row = conn.execute("SELECT * FROM memories WHERE id='ch-1'").fetchone()
        assert row is not None
        assert row["memory_type"] == "vault_chunk"
        assert row["source"] == "/vault/note.md"
        conn.close()

    def test_migrates_chunks_minimal_columns(self):
        """Chunks with minimal columns (text instead of content, no id)."""
        conn = _make_conn()
        self._setup_memories_table(conn)
        conn.execute("CREATE TABLE chunks (text TEXT, source TEXT)")
        conn.execute("INSERT INTO chunks VALUES (?, ?)", ("minimal chunk", "vault"))
        conn.commit()

        _migrate_schema(conn)

        rows = conn.execute("SELECT * FROM memories WHERE memory_type='vault_chunk'").fetchall()
        assert len(rows) == 1
        assert rows[0]["content"] == "minimal chunk"
        assert rows[0]["source"] == "vault"
        conn.close()

    def test_drops_facts_table(self):
        """Old facts table is dropped during migration."""
        conn = _make_conn()
        self._setup_memories_table(conn)
        conn.execute("CREATE TABLE facts (id TEXT PRIMARY KEY, content TEXT)")
        conn.commit()

        _migrate_schema(conn)

        tables = {
            r[0]
            for r in conn.execute("SELECT name FROM sqlite_master WHERE type='table'").fetchall()
        }
        assert "facts" not in tables
        conn.close()

    def test_migration_handles_episode_error_gracefully(self):
        """If episode migration fails, it logs warning but continues."""
        conn = _make_conn()
        self._setup_memories_table(conn)
        # Create episodes with a column that will cause a conflict
        conn.execute("CREATE TABLE episodes (id TEXT PRIMARY KEY, content TEXT)")
        # Insert a row with the same ID already in memories to trigger conflict
        conn.execute(
            "INSERT INTO memories (id, content, created_at) VALUES (?, ?, ?)",
            ("dup-id", "existing", "2025-01-01"),
        )
        conn.execute("INSERT INTO episodes VALUES (?, ?)", ("dup-id", "duplicate"))
        conn.commit()

        # Should not raise — logs warning instead
        _migrate_schema(conn)
        conn.close()

    def test_full_migration_all_old_tables(self):
        """All three old tables migrate in a single pass."""
        conn = _make_conn()
        self._setup_memories_table(conn)

        conn.execute("""
            CREATE TABLE episodes (
                id TEXT, content TEXT, context_type TEXT, source TEXT,
                embedding TEXT, metadata TEXT, agent_id TEXT, task_id TEXT,
                session_id TEXT, timestamp TEXT
            )
        """)
        conn.execute(
            "CREATE TABLE chunks (id TEXT, content TEXT, filepath TEXT, embedding TEXT, created_at TEXT)"
        )
        conn.execute("CREATE TABLE facts (id TEXT, content TEXT)")
        conn.execute(
            "INSERT INTO episodes VALUES ('e1','ep','conv','agent',NULL,NULL,NULL,NULL,NULL,'2025-01-01')"
        )
        conn.execute("INSERT INTO chunks VALUES ('c1','chunk','/f.md',NULL,'2025-01-01')")
        conn.commit()

        _migrate_schema(conn)

        tables = {
            r[0]
            for r in conn.execute("SELECT name FROM sqlite_master WHERE type='table'").fetchall()
        }
        assert "episodes" not in tables
        assert "chunks" not in tables
        assert "facts" not in tables
        assert "memories" in tables

        assert conn.execute("SELECT COUNT(*) FROM memories").fetchone()[0] >= 2
        conn.close()


# ── MemoryEntry dataclass ────────────────────────────────────────────────────


class TestMemoryEntry:
    """Tests for the MemoryEntry dataclass."""

    def test_defaults(self):
        entry = MemoryEntry()
        assert entry.content == ""
        assert entry.source == ""
        assert entry.context_type == "conversation"
        assert entry.agent_id is None
        assert entry.task_id is None
        assert entry.session_id is None
        assert entry.metadata is None
        assert entry.embedding is None
        assert entry.relevance_score is None
        # ID should be a valid UUID
        uuid.UUID(entry.id)
        # Timestamp should be ISO format
        assert "T" in entry.timestamp

    def test_custom_values(self):
        entry = MemoryEntry(
            id="custom-id",
            content="hello world",
            source="user",
            context_type="fact",
            agent_id="agent-1",
            task_id="task-1",
            session_id="sess-1",
            metadata={"key": "value"},
            embedding=[0.1, 0.2, 0.3],
            timestamp="2025-06-01T00:00:00",
            relevance_score=0.95,
        )
        assert entry.id == "custom-id"
        assert entry.content == "hello world"
        assert entry.source == "user"
        assert entry.context_type == "fact"
        assert entry.agent_id == "agent-1"
        assert entry.metadata == {"key": "value"}
        assert entry.embedding == [0.1, 0.2, 0.3]
        assert entry.relevance_score == 0.95

    def test_unique_ids(self):
        """Each MemoryEntry gets a unique default ID."""
        a = MemoryEntry()
        b = MemoryEntry()
        assert a.id != b.id


# ── MemoryChunk dataclass ────────────────────────────────────────────────────


class TestMemoryChunk:
    """Tests for the MemoryChunk dataclass."""

    def test_fields(self):
        chunk = MemoryChunk(
            id="ch-1",
            source="/vault/file.md",
            content="some text",
            embedding=[0.5, 0.6],
            created_at="2025-01-01T00:00:00",
        )
        assert chunk.id == "ch-1"
        assert chunk.source == "/vault/file.md"
        assert chunk.content == "some text"
        assert chunk.embedding == [0.5, 0.6]
        assert chunk.created_at == "2025-01-01T00:00:00"

    def test_required_fields(self):
        """MemoryChunk requires all fields — no defaults."""
        with pytest.raises(TypeError):
            MemoryChunk()  # type: ignore[call-arg]