PolyGateway/tests/unit/test_telemetry.py

"""遥测子系统测试: SQLiteRecorder(22 列)+ TelemetryEmitter 单一 helper + TelemetryMW。"""

import asyncio
import json
import os
import sqlite3
import subprocess
from pathlib import Path

import pytest

from polygateway.errors import CircuitOpenError, RequestRejectedError
from polygateway.middleware.telemetry import TelemetryEmitter, TelemetryMW
from polygateway.pricing import ModelPrice, PricingTable
from polygateway.telemetry.sqlite import SQLiteRecorder
from polygateway.types import ChatRequest, LLMResponse, SourceConfig

_REQ = ChatRequest(messages=[{"role": "user", "content": "hi"}], session_id="sess-1")

_EXPECTED_COLUMNS = [
    "call_id",
    "parent_call_id",
    "session_id",
    "model",
    "provider",
    "source_name",
    "messages",
    "response",
    "thinking",
    "prompt_tokens",
    "completion_tokens",
    "usage_source",
    "latency_ms",
    "ttft_ms",
    "max_inter_token_ms",
    "cache_hit",
    "error",
    "cost",
    "created_at",
    "cached_prompt_tokens",
    "model_reported",
    "sampling",
    "reasoning_tokens",
    "tenant_id",
    "meta",
]


def _resp(**overrides):
    base = {
        "content": "ok",
        "thinking": "",
        "model": "m",
        "provider": "p",
        "prompt_tokens": 1,
        "completion_tokens": 2,
        "latency_ms": 30,
        "ttft_ms": None,
        "max_inter_token_ms": None,
        "cache_hit": False,
        "call_id": "cid-1",
        "source_name": "s1",
        "usage_source": "measured",
    }
    base.update(overrides)
    return LLMResponse(**base)


def _source(**overrides):
    base = {
        "name": "s1",
        "provider": "p",
        "base_url": "https://gw.example/v1",
        "api_key": "sk",
        "model": "m",
        "timeout_s": 10.0,
    }
    base.update(overrides)
    return SourceConfig(**base)


# 输出单价 8 元/百万: 改前 `unavailable` 行按兜底的 0/4000 换算恰好是 0.032
_PRICING = PricingTable({"m": ModelPrice(input_per_1m=1.0, output_per_1m=8.0)})


async def _record_minimal(recorder, call_id="c1", **overrides):
    fields = {
        "call_id": call_id,
        "parent_call_id": None,
        "session_id": "sess-1",
        "model": "m",
        "provider": "p",
        "source_name": "s1",
        "messages": "[]",
        "response": "ok",
        "thinking": "",
        "prompt_tokens": 1,
        "completion_tokens": 2,
        "usage_source": "measured",
        "latency_ms": 10,
        "ttft_ms": None,
        "max_inter_token_ms": None,
        "cache_hit": False,
        "error": None,
        "cost": None,
        "cached_prompt_tokens": None,
        "model_reported": None,
        "sampling": None,
        "reasoning_tokens": None,
        # 到达 recorder 时已由 emitter 归一化: None → '',空 dict → '{}'
        "tenant_id": "",
        "meta": "{}",
    }
    fields.update(overrides)
    await recorder.record_llm_call(**fields)


@pytest.fixture
def captured_warnings():
    """捕获库发出的 WARNING;loguru 不经标准 logging,pytest 的 caplog 抓不到。

    名字避开裸 `warnings`: 那会遮蔽标准库模块名,本文件将来任何一次
    `import warnings` 都会与它静默互相顶掉,而报错点离真因很远。
    """
    from loguru import logger

    messages: list[str] = []
    sink_id = logger.add(messages.append, level="WARNING")
    yield messages
    logger.remove(sink_id)


# 搬迁前(1.2.1)两个 recorder 各自持有的 INSERT 常量原文,逐字冻结在此。
# 这两条字符串是"纯搬迁不改行为"的机械证据: 构造逻辑换了地方,产物必须一字不差。
_FROZEN_SQLITE_INSERT = (
    "INSERT OR IGNORE INTO llm_calls (call_id, parent_call_id, session_id, model, provider, "
    "source_name, messages, response, thinking, prompt_tokens, completion_tokens, usage_source, "
    "latency_ms, ttft_ms, max_inter_token_ms, cache_hit, error, cost, cached_prompt_tokens, "
    "model_reported, sampling, reasoning_tokens, tenant_id, meta) "
    "VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)"
)
_FROZEN_PG_INSERT = (
    "INSERT INTO llm_calls (call_id, parent_call_id, session_id, model, provider, source_name, "
    "messages, response, thinking, prompt_tokens, completion_tokens, usage_source, latency_ms, "
    "ttft_ms, max_inter_token_ms, cache_hit, error, cost, cached_prompt_tokens, model_reported, "
    "sampling, reasoning_tokens, tenant_id, meta) "
    "VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12, $13, $14, $15, $16, $17, $18, "
    "$19, $20, $21, $22, $23, $24) "
    # 无冲突目标(issue #13 Task 2): 带 `(call_id)` 的版本在按 created_at 分区、
    # 主键为 (call_id, created_at) 的表上匹配不到约束,PG 直接拒收整条写入
    "ON CONFLICT DO NOTHING"
)


def _first_occurrence_order(text: str, names: list[str]) -> list[str]:
    """按各列名在 text 中首次出现的位置排序,用于比对"列名出现顺序"。"""
    found = [(text.index(name), name) for name in names if name in text]
    return [name for _, name in sorted(found)]


class TestSchemaModule:
    """`telemetry/schema.py` 是 schema 单一事实源(issue #13 Task 1)。

    库执行的 DDL 与打印给下游的 SQL 必须同源: 常量分散在两个 recorder 里各存一份时,
    公共函数再写一份就是三份,漂移的表现是"下游照打印的 SQL 建完表,库仍报缺列"。
    """

    def test_columns_and_ddl_are_frozen(self):
        """列序与两端 DDL 逐字未变(搬迁不得改动任何一个字符)。"""
        from polygateway.telemetry.schema import COLUMNS, PG_BACKFILL, PG_DDL, SQLITE_DDL

        # COLUMNS 是 INSERT 字段序,不含数据库自填的 created_at
        assert list(COLUMNS) == [c for c in _EXPECTED_COLUMNS if c != "created_at"]
        assert len(COLUMNS) == 24
        # 两端 DDL 的列出现顺序 == 物理列序(created_at 在第 19 位)
        for ddl in (SQLITE_DDL, PG_DDL):
            assert _first_occurrence_order(ddl, _EXPECTED_COLUMNS) == _EXPECTED_COLUMNS
        assert "CREATE TABLE IF NOT EXISTS llm_calls" in SQLITE_DDL
        assert "created_at         TEXT    NOT NULL DEFAULT (datetime('now'))" in SQLITE_DDL
        assert "created_at         TIMESTAMPTZ NOT NULL DEFAULT now()" in PG_DDL
        assert "meta                 JSONB NOT NULL DEFAULT '{}'::jsonb" in PG_DDL
        # 库内执行的补列语句不带 IF NOT EXISTS(它即便列已存在也先取 ACCESS EXCLUSIVE 锁)
        assert PG_BACKFILL[0] == (
            "cached_prompt_tokens",
            "ALTER TABLE llm_calls ADD COLUMN cached_prompt_tokens INTEGER",
        )
        assert PG_BACKFILL[-1] == (
            "meta",
            "ALTER TABLE llm_calls ADD COLUMN meta JSONB NOT NULL DEFAULT '{}'::jsonb",
        )
        assert all("IF NOT EXISTS" not in stmt for _, stmt in PG_BACKFILL)

    def test_insert_sql_reproduces_the_frozen_statements(self):
        """`insert_sql(backend, COLUMNS)` 与搬迁前的 `_INSERT` 一致(PG 侧去掉冲突目标)。"""
        from polygateway.telemetry.schema import COLUMNS, insert_sql

        assert insert_sql("sqlite", COLUMNS) == _FROZEN_SQLITE_INSERT
        assert insert_sql("postgres", COLUMNS) == _FROZEN_PG_INSERT
        # 裁剪列表按位置占位符重新编号,不留空洞
        assert insert_sql("postgres", ["call_id", "model"]) == (
            "INSERT INTO llm_calls (call_id, model) VALUES ($1, $2) ON CONFLICT DO NOTHING"
        )
        # 冲突目标不得被"顺手"补回: 分区表上它会让每一条遥测都被 PG 拒收
        assert "ON CONFLICT (" not in insert_sql("postgres", COLUMNS)

    def test_insert_sql_rejects_foreign_columns_and_backends(self):
        """列名来自数据库探测结果而非常量,子集校验是唯一的注入面闸门。"""
        from polygateway.telemetry.schema import COLUMNS, insert_sql

        with pytest.raises(ValueError, match="call_id_x"):
            insert_sql("sqlite", ["call_id_x"])
        with pytest.raises(ValueError):
            insert_sql("sqlite", ["call_id", "meta); DROP TABLE llm_calls; --"])
        with pytest.raises(ValueError, match="mysql"):
            insert_sql("mysql", COLUMNS)

    def test_insert_sql_rejects_an_empty_column_set(self):
        """空列集合两端都拼出语法非法的 SQL,构造器自己拒,不押在调用方的不变量上。

        入参来自数据库探测结果: 探测到一张与本库毫无共同列的同名表,`effective`
        就是空的。真放行会产出 `INSERT OR IGNORE INTO llm_calls () VALUES ()`,
        错误要到执行时才由数据库报,离真因很远。
        """
        from polygateway.telemetry.schema import insert_sql

        for backend in ("sqlite", "postgres"):
            with pytest.raises(ValueError, match="至少需要一列"):
                insert_sql(backend, [])

    def test_schema_sql_is_paste_ready_and_same_source(self):
        """打印给下游的脚本与库执行的 DDL 同源,且对人可重复执行。"""
        from polygateway.telemetry.schema import PG_BACKFILL, SQLITE_BACKFILL, telemetry_schema_sql

        pg = telemetry_schema_sql("postgres")
        lite = telemetry_schema_sql("sqlite")
        for script in (pg, lite):
            # 24 个 INSERT 字段 + created_at 全在,且首次出现顺序与建表 DDL 一致
            assert _first_occurrence_order(script, _EXPECTED_COLUMNS) == _EXPECTED_COLUMNS
            assert "CREATE TABLE IF NOT EXISTS llm_calls" in script
        # 人执行的那份必须幂等: PG 用 ADD COLUMN IF NOT EXISTS(与库内那份有意不同)
        for column, _ in PG_BACKFILL:
            assert f"ALTER TABLE llm_calls ADD COLUMN IF NOT EXISTS {column} " in pg
        # SQLite 无该语法(写上去直接语法错误),只能以注释交代执行前提
        lite_alters = [line for line in lite.splitlines() if line.startswith("ALTER TABLE")]
        assert len(lite_alters) == len(SQLITE_BACKFILL)
        assert all("IF NOT EXISTS" not in line for line in lite_alters)
        for column, _ in SQLITE_BACKFILL:
            assert f"ALTER TABLE llm_calls ADD COLUMN {column} " in lite
        assert "不存在" in lite
        with pytest.raises(ValueError, match="mysql"):
            telemetry_schema_sql("mysql")


class TestBackendColumnParity:
    """两个后端的列清单必须逐字同名同序(issue #11)。

    emitter 只组装一份 `fields`,两个后端各按自己的清单取值;两份清单一旦分叉,
    同一次调用在 SQLite 上写得进、在 PG 上抛 KeyError 被降级吞掉,差异只在换后端时
    才暴露。issue #13 起两端共用 `schema.COLUMNS`,故这里断言的是"共用"本身
    (同一个对象则永远无从分叉),列**序**仍单独断言: INSERT 用位置占位符,
    顺序错位会把值写进错误的列而不报错。
    """

    def test_two_backends_agree_on_columns(self):
        from polygateway.telemetry import postgres, sqlite
        from polygateway.telemetry.schema import COLUMNS

        assert sqlite.COLUMNS is COLUMNS
        assert postgres.COLUMNS is COLUMNS

    def test_caller_dimensions_are_appended_last(self):
        """新列只能追加在末尾: 旧表经 ALTER 补列必落末尾,插在中间会让两条路径分叉。"""
        from polygateway.telemetry.schema import COLUMNS

        assert COLUMNS[-2:] == ("tenant_id", "meta")


class TestSQLiteRecorder:
    async def test_schema_has_frozen_columns(self, tmp_path):
        recorder = SQLiteRecorder(tmp_path / "t.db", auto_migrate=True)
        await _record_minimal(recorder)
        recorder.close()
        cols = [
            r[1] for r in sqlite3.connect(tmp_path / "t.db").execute("PRAGMA table_info(llm_calls)")
        ]
        assert cols == _EXPECTED_COLUMNS

    async def test_call_id_idempotent(self, tmp_path):
        recorder = SQLiteRecorder(tmp_path / "t.db", auto_migrate=True)
        await _record_minimal(recorder, call_id="dup")
        await _record_minimal(recorder, call_id="dup", response="second")
        recorder.close()
        rows = (
            sqlite3.connect(tmp_path / "t.db")
            .execute("SELECT response FROM llm_calls WHERE call_id='dup'")
            .fetchall()
        )
        assert rows == [("ok",)]  # INSERT OR IGNORE: 第二次静默忽略

    async def test_concurrent_writes_all_land(self, tmp_path):
        recorder = SQLiteRecorder(tmp_path / "t.db", auto_migrate=True)
        await asyncio.gather(*(_record_minimal(recorder, call_id=f"c{i}") for i in range(50)))
        recorder.close()
        (count,) = (
            sqlite3.connect(tmp_path / "t.db").execute("SELECT COUNT(*) FROM llm_calls").fetchone()
        )
        assert count == 50

    async def test_unwritable_path_degrades_silently(self):
        recorder = SQLiteRecorder(Path("/nonexistent-root/deep/t.db"), auto_migrate=True)
        await _record_minimal(recorder)  # 不抛
        recorder.close()

    async def test_observability_columns_round_trip(self, tmp_path):
        recorder = SQLiteRecorder(tmp_path / "t.db", auto_migrate=True)
        await _record_minimal(recorder, call_id="c-hit", cached_prompt_tokens=64)
        await _record_minimal(recorder, call_id="c-zero", cached_prompt_tokens=0)
        await _record_minimal(recorder, call_id="c-none", model_reported="MiniMax-Text-01")
        recorder.close()
        rows = dict(
            sqlite3.connect(tmp_path / "t.db")
            .execute("SELECT call_id, cached_prompt_tokens FROM llm_calls")
            .fetchall()
        )
        assert rows["c-hit"] == 64
        assert rows["c-zero"] == 0  # 真实零命中,读回仍是 0 而非 NULL
        assert rows["c-none"] is None

    async def test_reasoning_tokens_column_round_trip(self, tmp_path):
        """issue #6: 7 / 0 / None 三种值各自如实落库,0 与 NULL 不得混同。"""
        recorder = SQLiteRecorder(tmp_path / "t.db", auto_migrate=True)
        await _record_minimal(recorder, call_id="r-some", reasoning_tokens=7)
        await _record_minimal(recorder, call_id="r-zero", reasoning_tokens=0)
        await _record_minimal(recorder, call_id="r-none", reasoning_tokens=None)
        recorder.close()
        rows = dict(
            sqlite3.connect(tmp_path / "t.db")
            .execute("SELECT call_id, reasoning_tokens FROM llm_calls")
            .fetchall()
        )
        assert rows["r-some"] == 7
        assert rows["r-zero"] == 0  # 上报了且确实没推理
        assert rows["r-none"] is None  # 本次调用未上报

    async def test_sampling_column_round_trips(self, tmp_path):
        """issue #4: 采样参数落库,否则事后无法证明某批数据跑在什么温度下。"""
        recorder = SQLiteRecorder(tmp_path / "t.db", auto_migrate=True)
        await _record_minimal(recorder, call_id="c-s", sampling='{"seed": 42, "temperature": 0}')
        await _record_minimal(recorder, call_id="c-plain")
        recorder.close()
        rows = dict(
            sqlite3.connect(tmp_path / "t.db")
            .execute("SELECT call_id, sampling FROM llm_calls")
            .fetchall()
        )
        assert json.loads(rows["c-s"]) == {"seed": 42, "temperature": 0}
        assert rows["c-plain"] is None  # 无采样参数为 NULL,便于 SQL 过滤


class TestSQLiteColumnBackfill:
    """issue #3: 已存在的 18 列旧表必须自动补列,否则每行写入都被丢弃。"""

    _LEGACY_DDL = """
    CREATE TABLE llm_calls (
        call_id            TEXT PRIMARY KEY,
        parent_call_id     TEXT,
        session_id         TEXT,
        model              TEXT    NOT NULL,
        provider           TEXT    NOT NULL,
        source_name        TEXT    NOT NULL,
        messages           TEXT    NOT NULL,
        response           TEXT    NOT NULL,
        thinking           TEXT    NOT NULL DEFAULT '',
        prompt_tokens      INTEGER NOT NULL,
        completion_tokens  INTEGER NOT NULL,
        usage_source       TEXT    NOT NULL,
        latency_ms         INTEGER NOT NULL,
        ttft_ms            REAL,
        max_inter_token_ms REAL,
        cache_hit          INTEGER NOT NULL DEFAULT 0,
        error              TEXT,
        cost               REAL,
        created_at         TEXT    NOT NULL DEFAULT (datetime('now'))
    );
    """

    async def test_legacy_table_is_upgraded_in_place(self, tmp_path):
        db = tmp_path / "legacy.db"
        legacy = sqlite3.connect(db)
        legacy.execute(self._LEGACY_DDL)
        legacy.commit()
        legacy.close()

        recorder = SQLiteRecorder(db, auto_migrate=True)
        await _record_minimal(recorder, cached_prompt_tokens=7, model_reported="m-real")
        recorder.close()

        conn = sqlite3.connect(db)
        cols = [r[1] for r in conn.execute("PRAGMA table_info(llm_calls)")]
        assert cols == _EXPECTED_COLUMNS  # ALTER 追加到末尾,与新建库列序一致
        assert conn.execute(
            "SELECT cached_prompt_tokens, model_reported FROM llm_calls"
        ).fetchone() == (7, "m-real")

    async def test_backfill_failure_keeps_the_recorder_usable(self, tmp_path):
        """补列失败只能逐行降级,绝不能把 recorder 整体变成 no-op(设计 D1 纪律)。

        把 llm_calls 建成同名 view: `CREATE TABLE IF NOT EXISTS` 遇 view 静默
        no-op(不抛),随后的 ALTER 才抛 "Cannot add a column to a view"——正是
        补列失败这条分支。`_conn` 必须保持非 None,否则整个 recorder 永久失能。
        """
        db = tmp_path / "view.db"
        conn = sqlite3.connect(db)
        conn.execute("CREATE TABLE real_rows (call_id TEXT)")
        conn.execute("CREATE VIEW llm_calls AS SELECT call_id FROM real_rows")
        conn.commit()
        conn.close()

        recorder = SQLiteRecorder(db, auto_migrate=True)  # 不得抛
        assert recorder._conn is not None  # 补列失败 ≠ recorder 失能(D1 纪律)
        await _record_minimal(recorder)  # 不得抛
        recorder.close()


# issue #11 之前的表形态: 22 个 recorder 字段 + created_at = 23 个物理列,没有任何租户维度
_PRE_TENANT_DDL = """
CREATE TABLE llm_calls (
    call_id            TEXT PRIMARY KEY,
    parent_call_id     TEXT,
    session_id         TEXT,
    model              TEXT    NOT NULL,
    provider           TEXT    NOT NULL,
    source_name        TEXT    NOT NULL,
    messages           TEXT    NOT NULL,
    response           TEXT    NOT NULL,
    thinking           TEXT    NOT NULL DEFAULT '',
    prompt_tokens      INTEGER NOT NULL,
    completion_tokens  INTEGER NOT NULL,
    usage_source       TEXT    NOT NULL,
    latency_ms         INTEGER NOT NULL,
    ttft_ms            REAL,
    max_inter_token_ms REAL,
    cache_hit          INTEGER NOT NULL DEFAULT 0,
    error              TEXT,
    cost               REAL,
    created_at         TEXT    NOT NULL DEFAULT (datetime('now')),
    cached_prompt_tokens INTEGER,
    model_reported       TEXT,
    sampling             TEXT,
    reasoning_tokens     INTEGER
);
"""

_PRE_TENANT_INSERT = (
    "INSERT INTO llm_calls (call_id, model, provider, source_name, messages, response, "
    "prompt_tokens, completion_tokens, usage_source, latency_ms) "
    "VALUES ('old-row', 'm', 'p', 's1', '[]', 'old body', 1, 2, 'measured', 10)"
)


def _make_pre_tenant_db(path: Path) -> None:
    """造一个 issue #11 之前的库: 22 字段旧表 + 一行没有租户归属的历史数据。"""
    conn = sqlite3.connect(path)
    conn.execute(_PRE_TENANT_DDL)
    conn.execute(_PRE_TENANT_INSERT)
    conn.commit()
    conn.close()


class TestSQLiteCallerDimensionsAcceptance:
    """issue #11 的机械化验收(SQLite 侧,真实临时文件): 新建库 / 旧表补列 / 补列失败方向。"""

    async def test_fresh_db_round_trips_the_dimensions(self, tmp_path):
        """新建库: 列齐全,且维度值原样读回——只验列存在会漏掉写错列位的错。"""
        db = tmp_path / "fresh.db"
        recorder = SQLiteRecorder(db, auto_migrate=True)
        await _record_minimal(
            recorder, call_id="c-dim", tenant_id="tenant-a", meta='{"batch": "b7"}'
        )
        recorder.close()

        conn = sqlite3.connect(db)
        assert [r[1] for r in conn.execute("PRAGMA table_info(llm_calls)")] == _EXPECTED_COLUMNS
        row = conn.execute(
            "SELECT tenant_id, meta FROM llm_calls WHERE call_id = 'c-dim'"
        ).fetchone()
        assert row[0] == "tenant-a"
        assert json.loads(row[1]) == {"batch": "b7"}

    async def test_pre_tenant_table_gains_columns_and_old_rows_stay_auditable(self, tmp_path):
        """22 字段旧表补列后,新行带维度,而**老行的 tenant_id 是空串而非 NULL**。

        这条直接验收 issue #11 的核心论点(先启用落库、后加列,补列之前的行没有
        租户归属)。断言方向必须是空串: PG 的 RLS `USING` 表达式对返回 false **或
        NULL** 的行一律隐藏且不报错,故 NULL 的 `tenant_id` 不是"未归属",而是对
        所有人永久不可见的黑洞;哨兵空串则能被一条 `COUNT(*) WHERE tenant_id = ''`
        审计出来,历史欠账是可见、可量化、可补录的。
        """
        db = tmp_path / "pre_tenant.db"
        _make_pre_tenant_db(db)

        recorder = SQLiteRecorder(db, auto_migrate=True)
        await _record_minimal(recorder, call_id="new-row", tenant_id="tenant-a", meta='{"k": 1}')
        recorder.close()

        conn = sqlite3.connect(db)
        cols = [r[1] for r in conn.execute("PRAGMA table_info(llm_calls)")]
        assert cols == _EXPECTED_COLUMNS  # 22 → 24 个 recorder 字段(+ created_at 共 25 物理列)
        rows = dict(conn.execute("SELECT call_id, tenant_id FROM llm_calls").fetchall())
        assert rows["new-row"] == "tenant-a"
        assert rows["old-row"] == ""  # 不是 None: NULL 会被 RLS 静默吞掉
        assert (
            conn.execute("SELECT meta FROM llm_calls WHERE call_id = 'old-row'").fetchone()[0]
            == "{}"
        )

    async def test_readonly_file_backfill_failure_keeps_the_recorder_alive(self, tmp_path):
        """补列失败的降级方向(SQLite 等价构造: 文件只读)。

        SQLite 没有角色权限模型,与 PG「只有 SELECT/INSERT 权限的角色」等价的构造
        是文件本身只读。库文件必须**预先置为 WAL 且干净关闭**,否则 `__init__` 的
        `PRAGMA journal_mode=WAL` 会先撞上只读而让失败点跑到补列之前,测不到本用例
        要测的那条分支(实测: 非 WAL 库 chmod 444 后该 PRAGMA 报 readonly database)。
        只读库连 INSERT 都做不了,故这里**只断言**补列失败不清空 `_conn`、不抛出
        `__init__`(sqlite.py `_backfill_columns` 那条纪律),不断言"写入仍成功"。
        """
        if os.geteuid() == 0:
            pytest.skip("root 无视文件权限位,只读构造不成立")
        db = tmp_path / "readonly.db"
        conn = sqlite3.connect(db)
        conn.execute("PRAGMA journal_mode=WAL")  # 预置 WAL: 让只读连接不必改日志模式
        conn.execute(_PRE_TENANT_DDL)
        conn.execute(_PRE_TENANT_INSERT)
        conn.commit()
        conn.close()
        db.chmod(0o444)

        # finally 还原权限位: 任一断言先失败时,不还原会让 tmp_path 清理连带报错,
        # 把"某条断言失败"的真因盖成一个无关的 PermissionError
        try:
            recorder = SQLiteRecorder(db, auto_migrate=True)  # 不得抛
            assert recorder._conn is not None  # 补列失败 ≠ recorder 失能
            await _record_minimal(recorder, call_id="doomed")  # 只读库写不进,但不得抛
            recorder.close()
        finally:
            db.chmod(0o644)

        stale = sqlite3.connect(db)
        assert [r[1] for r in stale.execute("PRAGMA table_info(llm_calls)")] == (
            _EXPECTED_COLUMNS[:-2]
        )  # 补列确实没成功,用例不是在只读库上空转


class TestSQLiteSchemaMode:
    """issue #13: `auto_migrate` 两档——auto 保持自动补列,manual 只裁剪写入不发 DDL。

    列数断言一律按**物理列数**写: 旧表 22 个 INSERT 字段 + `created_at` = 23,
    补齐后 24 + `created_at` = 25。混用 INSERT 字段数与物理列数是本处最易错的地方。
    """

    def _physical_columns(self, db: Path) -> list[str]:
        conn = sqlite3.connect(db)
        try:
            return [r[1] for r in conn.execute("PRAGMA table_info(llm_calls)")]
        finally:
            conn.close()

    async def test_manual_mode_trims_the_insert_instead_of_altering(
        self, tmp_path, captured_warnings
    ):
        """manual + 22 字段旧表: 一条 ALTER 都不发,写入按现有列裁剪后照样落库。

        裁剪是关掉 ALTER 的前提: 不裁剪的话每行 INSERT 都撞 `no column named
        tenant_id` 而被整行丢弃——那是把自动补列换成静默全失能。
        """
        db = tmp_path / "manual_legacy.db"
        _make_pre_tenant_db(db)

        recorder = SQLiteRecorder(db, auto_migrate=False)
        await _record_minimal(recorder, call_id="new-row", tenant_id="tenant-a", meta='{"k": 1}')
        recorder.close()

        assert len(self._physical_columns(db)) == 23  # 未 ALTER: 物理列数原封不动
        conn = sqlite3.connect(db)
        assert conn.execute(
            "SELECT response, model FROM llm_calls WHERE call_id = 'new-row'"
        ).fetchone() == ("ok", "m")  # 裁剪后的列值仍对得上位
        conn.close()

        assert len(captured_warnings) == 1  # 缺列只讲一次,不逐行刷屏
        message = captured_warnings[0]
        assert "tenant_id" in message and "meta" in message  # 逐列点名
        assert "不会被记录" in message  # 讲清后果
        assert "ALTER TABLE" in message  # 给出可直接执行的补列 SQL

    async def test_auto_mode_still_upgrades_the_legacy_table(self, tmp_path):
        """auto + 同款旧表: 现状回归,补列后物理列数 23 → 25。"""
        db = tmp_path / "auto_legacy.db"
        _make_pre_tenant_db(db)

        recorder = SQLiteRecorder(db, auto_migrate=True)
        await _record_minimal(recorder, call_id="new-row", tenant_id="tenant-a")
        recorder.close()

        assert self._physical_columns(db) == _EXPECTED_COLUMNS
        assert len(self._physical_columns(db)) == 25

    async def test_manual_mode_still_creates_a_fresh_table(self, tmp_path):
        """manual 只管 ALTER,不管 CREATE: 全新库照建,25 个物理列齐全(设计 §4.2)。"""
        db = tmp_path / "manual_fresh.db"
        recorder = SQLiteRecorder(db, auto_migrate=False)
        await _record_minimal(recorder, call_id="c-fresh", tenant_id="tenant-a")
        recorder.close()

        assert self._physical_columns(db) == _EXPECTED_COLUMNS
        conn = sqlite3.connect(db)
        assert (
            conn.execute("SELECT tenant_id FROM llm_calls WHERE call_id = 'c-fresh'").fetchone()[0]
            == "tenant-a"
        )
        conn.close()

    async def test_table_without_call_id_escalates_the_wording(self, tmp_path, captured_warnings):
        """缺主键列 call_id = 该表压根不是本库的 llm_calls: 措辞升级,但库不做二次判定。"""
        db = tmp_path / "alien.db"
        conn = sqlite3.connect(db)
        conn.execute("CREATE TABLE llm_calls (model TEXT, provider TEXT)")
        conn.commit()
        conn.close()

        recorder = SQLiteRecorder(db, auto_migrate=False)  # 不得抛
        await _record_minimal(recorder)  # 照常尝试写入
        recorder.close()

        message = "\n".join(captured_warnings)
        assert "call_id" in message
        assert "不是本库" in message

    async def test_no_recognizable_column_falls_back_to_the_full_column_set(
        self, tmp_path, captured_warnings
    ):
        """探测结果与 COLUMNS 毫无交集视同探测异常: 保守回落全量列。

        `insert_sql` 自己拒空列集合(见 `test_insert_sql_rejects_an_empty_column_set`),
        故这里回落不发生就不是"拼出空语句",而是 ValueError 逃出 `__init__` ——
        遥测初始化失败必须静默降级,崩溃比丢维度严重得多。
        """
        from polygateway.telemetry.schema import COLUMNS

        db = tmp_path / "foreign.db"
        conn = sqlite3.connect(db)
        conn.execute("CREATE TABLE llm_calls (foo TEXT, bar TEXT)")
        conn.commit()
        conn.close()

        recorder = SQLiteRecorder(db, auto_migrate=False)  # 不得抛
        assert recorder._columns == COLUMNS
        await _record_minimal(recorder)  # 写不进去,但只逐行 warning,不抛
        recorder.close()
        assert captured_warnings  # 沉默地退化成空语句是最坏结果,必须有声

    async def test_empty_probe_result_degrades_instead_of_raising(
        self, tmp_path, captured_warnings
    ):
        """探测返回空集合时走回落,绝不让 `insert_sql` 的 ValueError 逃出去。

        SQLite 建不出零列的表,故直接喂空探测结果调那条分支——它正是
        `insert_sql` 拒空之后唯一可能把"静默降级"变成崩溃的入口。
        """
        from polygateway.telemetry.schema import COLUMNS

        db = tmp_path / "empty_probe.db"
        recorder = SQLiteRecorder(db, auto_migrate=False)
        recorder._adopt_existing_columns(set())  # 不得抛
        assert recorder._columns == COLUMNS
        await _record_minimal(recorder, call_id="c-after")  # 写入照常
        recorder.close()

        conn = sqlite3.connect(db)
        assert conn.execute(
            "SELECT response FROM llm_calls WHERE call_id = 'c-after'"
        ).fetchone() == ("ok",)
        conn.close()
        assert [m for m in captured_warnings if "没有任何本库认识的列" in m]  # 只有 warning

    async def test_auto_migrate_is_required_keyword_only(self, tmp_path):
        """关键行为参数不给默认值(P4): 缺省规则只写在 config 一处,不与类签名漂移。"""
        with pytest.raises(TypeError):
            SQLiteRecorder(tmp_path / "t.db")  # type: ignore[call-arg]


class _FakePgConn:
    """记录执行过的语句;可让 ALTER/CREATE/探测抛错以模拟权限不足与抖动。

    `existing` 为空列表即表示**表不存在**(与真实 PG 一致: `to_regclass` 为 NULL
    时列探测必然零行),故 `fetchval` 与 `fetch` 共用同一份事实。
    """

    def __init__(
        self,
        existing: list[str],
        *,
        fail_alter: bool = False,
        fail_create: bool = False,
        probe_errors: int = 0,
    ):
        self.existing = existing
        self.fail_alter = fail_alter
        self.fail_create = fail_create
        self.probe_errors = probe_errors
        self.statements: list[str] = []

    async def execute(self, sql, *args):
        self.statements.append(sql)
        if sql.startswith("ALTER TABLE") and self.fail_alter:
            raise RuntimeError("must be owner of table llm_calls")
        if sql.lstrip().startswith("CREATE TABLE"):
            if self.fail_create:
                raise RuntimeError("permission denied for schema public")
            self.existing = list(_EXPECTED_COLUMNS)

    async def fetchval(self, sql, *args):
        self.statements.append(sql)
        if self.probe_errors > 0:
            self.probe_errors -= 1
            raise RuntimeError("connection was closed in the middle of operation")
        return "llm_calls" if self.existing else None

    async def fetch(self, sql, *args):
        self.statements.append(sql)
        return [{"attname": name} for name in self.existing]


class _FakePgPool:
    def __init__(self, conn):
        self._conn = conn

    def acquire(self):
        conn = self._conn

        class _Ctx:
            async def __aenter__(self):
                return conn

            async def __aexit__(self, *exc):
                return False

        return _Ctx()


class TestPostgresBackfillDiscipline:
    """PG 补列必须与 SQLite 侧对称: 失败只逐行降级,且稳态不抢排他锁(issue #3)。"""

    _LEGACY = ["call_id", "cost", "created_at"]
    _CURRENT = [
        "call_id",
        "cost",
        "created_at",
        "cached_prompt_tokens",
        "model_reported",
        "sampling",
        "reasoning_tokens",
        "tenant_id",
        "meta",
    ]

    def _recorder(self, conn):
        from polygateway.telemetry.postgres import PostgresRecorder

        return PostgresRecorder(
            "postgresql://u:p@h:5432/polygateway", pool=_FakePgPool(conn), auto_migrate=True
        )

    async def test_alter_failure_does_not_disable_the_recorder(self):
        """ALTER 失败(如账号只有 INSERT 权限)不得置 _failed —— 那会让遥测全灭。"""
        conn = _FakePgConn(self._LEGACY, fail_alter=True)
        recorder = self._recorder(conn)
        await _record_minimal(recorder)  # 不得抛
        assert recorder._failed is False
        assert any(s.startswith("INSERT INTO llm_calls") for s in conn.statements)

    async def test_no_alter_when_columns_already_exist(self):
        """ADD COLUMN IF NOT EXISTS 即使列已存在也会先抢 ACCESS EXCLUSIVE 锁,

        而遥测是内联 await——稳态下必须一条 ALTER 都不发,否则每个进程的首次
        写入都会去锁共享审计表。
        """
        conn = _FakePgConn(self._CURRENT)
        await _record_minimal(self._recorder(conn))
        assert not [s for s in conn.statements if s.startswith("ALTER TABLE")]

    async def test_missing_columns_are_added_once(self):
        conn = _FakePgConn(self._LEGACY)
        await _record_minimal(self._recorder(conn))
        from polygateway.telemetry.schema import PG_BACKFILL

        altered = [s for s in conn.statements if s.startswith("ALTER TABLE")]
        assert len(altered) == len(PG_BACKFILL)  # 旧表缺全部补列,故一列一条 ALTER
        assert all("IF NOT EXISTS" not in s for s in altered)  # 探测已确认缺列,无需再判


class TestPostgresTableProbe:
    """建表必须先探测,且"判死"只认"确定写不进去"(issue #9)。

    实测(PostgreSQL 16.14,只有表级 SELECT/INSERT 的角色): `CREATE TABLE IF NOT
    EXISTS` 被拒 permission denied for schema,而同一连接的 `INSERT` 通过——
    PG 对 schema 的 CREATE 权限检查早于 `IF NOT EXISTS` 的存在性判断。无条件发
    DDL 会让这类最小权限部署的整个进程静默失遥测。
    """

    _CURRENT = [
        "call_id",
        "cost",
        "created_at",
        "cached_prompt_tokens",
        "model_reported",
        "sampling",
        "reasoning_tokens",
        "tenant_id",
        "meta",
    ]

    def _recorder(self, conn):
        from polygateway.telemetry.postgres import PostgresRecorder

        return PostgresRecorder(
            "postgresql://u:p@h:5432/polygateway", pool=_FakePgPool(conn), auto_migrate=True
        )

    def _created(self, conn):
        return [s for s in conn.statements if s.lstrip().startswith("CREATE TABLE")]

    async def test_existing_table_is_never_recreated(self):
        """表已存在就一条 DDL 都不发——这是权限被拒的唯一根治办法。"""
        conn = _FakePgConn(self._CURRENT)
        await _record_minimal(self._recorder(conn))
        assert not self._created(conn)

    async def test_create_denied_on_existing_table_keeps_recording(self):
        """就算 DDL 仍被发出并被拒,表存在时也不得判死整个 recorder。"""
        conn = _FakePgConn(self._CURRENT, fail_create=True)
        recorder = self._recorder(conn)
        await _record_minimal(recorder)  # 不得抛
        assert recorder._failed is False
        assert any(s.startswith("INSERT INTO llm_calls") for s in conn.statements)

    async def test_missing_table_is_created_and_not_backfilled(self):
        """表不存在→建表;新建表列已齐全,不得再发补列 ALTER。"""
        conn = _FakePgConn([])
        recorder = self._recorder(conn)
        await _record_minimal(recorder)
        assert len(self._created(conn)) == 1
        assert not [s for s in conn.statements if s.startswith("ALTER TABLE")]
        assert recorder._failed is False
        assert any(s.startswith("INSERT INTO llm_calls") for s in conn.statements)

    async def test_create_failure_on_missing_table_degrades_to_noop(self):
        """表确定不存在且建不出来 = 确定写不进去: 此时才允许永久 no-op。"""
        conn = _FakePgConn([], fail_create=True)
        recorder = self._recorder(conn)
        await _record_minimal(recorder)  # 不得抛
        assert recorder._failed is True
        assert not [s for s in conn.statements if s.startswith("INSERT INTO llm_calls")]

    async def test_probe_failure_is_transient_not_terminal(self):
        """探测失败多为连接抖动: 跳过本次,下次调用必须重试,绝不永久判死。"""
        conn = _FakePgConn(self._CURRENT, probe_errors=1)
        recorder = self._recorder(conn)
        await _record_minimal(recorder, call_id="first")  # 不得抛
        assert recorder._failed is False
        assert not [s for s in conn.statements if s.startswith("INSERT INTO llm_calls")]
        await _record_minimal(recorder, call_id="second")
        assert [s for s in conn.statements if s.startswith("INSERT INTO llm_calls")]


class TestPostgresSchemaMode:
    """issue #13: PG 侧 manual 档一条 ALTER 都不发,改按现有列裁剪 INSERT。

    真实 PG 的验收在 `tests/integration/test_postgres_telemetry.py`;这里用 fake 连接
    锁住"发了哪些语句",无 DSN 环境下集成用例被 skip 时仍有回归保护。
    """

    _LEGACY = ["call_id", "cost", "created_at"]

    def _recorder(self, conn, *, auto_migrate):
        from polygateway.telemetry.postgres import PostgresRecorder

        return PostgresRecorder(
            "postgresql://u:p@h:5432/polygateway", pool=_FakePgPool(conn), auto_migrate=auto_migrate
        )

    async def test_manual_mode_trims_the_insert_instead_of_altering(self, captured_warnings):
        conn = _FakePgConn(self._LEGACY)
        recorder = self._recorder(conn, auto_migrate=False)
        await _record_minimal(recorder)

        assert not [s for s in conn.statements if s.startswith("ALTER TABLE")]
        assert "INSERT INTO llm_calls (call_id, cost) VALUES ($1, $2) ON CONFLICT DO NOTHING" in (
            conn.statements
        )
        assert recorder._columns == ("call_id", "cost")
        message = "\n".join(captured_warnings)
        assert "tenant_id" in message and "meta" in message  # 逐列点名
        assert "不会被记录" in message  # 讲清后果
        assert "ALTER TABLE llm_calls ADD COLUMN tenant_id" in message  # 可直接执行的 SQL

    async def test_manual_mode_still_creates_a_missing_table(self):
        """manual 只管 ALTER 不管 CREATE: 新建表列已齐全,写入照发全量列。"""
        from polygateway.telemetry.schema import COLUMNS

        conn = _FakePgConn([])
        recorder = self._recorder(conn, auto_migrate=False)
        await _record_minimal(recorder)

        assert [s for s in conn.statements if s.lstrip().startswith("CREATE TABLE")]
        assert recorder._columns == COLUMNS

    async def test_no_recognizable_column_falls_back_to_the_full_column_set(
        self, captured_warnings
    ):
        """PG 侧同款回落(SQLite 侧对称用例见 TestSQLiteSchemaMode)。

        表存在(`to_regclass` 非空)但列与 `COLUMNS` 毫无交集: 裁剪结果为空,
        必须回落全量而不是把空列集交给 `insert_sql`——`_prepare_schema` 里那次
        调用在 try 之外,ValueError 会顺着 `record_llm_call` 冒给业务调用方。
        """
        from polygateway.telemetry.schema import COLUMNS

        conn = _FakePgConn(["foo", "bar"])
        recorder = self._recorder(conn, auto_migrate=False)
        await _record_minimal(recorder)  # 不得抛

        assert recorder._columns == COLUMNS
        assert not [s for s in conn.statements if s.startswith("ALTER TABLE")]
        assert [m for m in captured_warnings if "没有任何本库认识的列" in m]

    async def test_auto_mode_still_backfills(self):
        """auto 档现状回归: 缺列照补,补完写全量列。"""
        from polygateway.telemetry.schema import COLUMNS, PG_BACKFILL

        conn = _FakePgConn(self._LEGACY)
        recorder = self._recorder(conn, auto_migrate=True)
        await _record_minimal(recorder)

        assert len([s for s in conn.statements if s.startswith("ALTER TABLE")]) == len(PG_BACKFILL)
        assert recorder._columns == COLUMNS


class _MemoryRecorder:
    def __init__(self):
        self.rows = []

    async def record_llm_call(self, **fields):
        self.rows.append(fields)


class TestEmitterRecorderContract:
    """emitter 的实参键集合必须与后端的 `schema.COLUMNS` 完全一致(issue #3)。

    两个后端的 `row = tuple(fields[col] for col in COLUMNS)` 都在 try **之外**,
    emitter 漏传一个键就抛 KeyError,被 `_record` 的 except Exception 吞成 warning
    → 遥测静默全丢。而 8 个 `**fields` 形态的 fake 一个都拦不住,故显式断言。
    """

    async def test_emitter_supplies_exactly_the_backend_columns(self):
        from polygateway.telemetry.schema import COLUMNS

        rec = _MemoryRecorder()
        await TelemetryEmitter(rec).emit_attempt(
            request=_REQ,
            source=_source(),
            call_id="cid-1",
            latency_ms=42,
            response=_resp(),
            error=None,
        )
        assert set(rec.rows[0]) == set(COLUMNS)

    @pytest.mark.parametrize("emit", ["attempt", "cache_hit", "terminal_failure"])
    async def test_every_entry_point_supplies_the_same_keys(self, emit):
        from polygateway.telemetry.schema import COLUMNS

        rec = _MemoryRecorder()
        emitter = TelemetryEmitter(rec)
        if emit == "attempt":
            await emitter.emit_attempt(
                request=_REQ,
                source=_source(),
                call_id="c",
                latency_ms=1,
                response=None,
                error="boom",
            )
        elif emit == "cache_hit":
            await emitter.emit_cache_hit(request=_REQ, response=_resp())
        else:
            await emitter.emit_terminal_failure(
                request=_REQ, call_id="c", latency_ms=1, error="dead"
            )
        assert set(rec.rows[0]) == set(COLUMNS)


class TestEmitterObservabilityFields:
    """issue #3: 三个入口各自的取值口径(设计 §5 表)。"""

    async def test_attempt_carries_the_response_values(self):
        rec = _MemoryRecorder()
        await TelemetryEmitter(rec).emit_attempt(
            request=_REQ,
            source=_source(),
            call_id="cid-1",
            latency_ms=42,
            response=_resp(cached_prompt_tokens=64, model_reported="m-real", reasoning_tokens=7),
            error=None,
        )
        assert rec.rows[0]["cached_prompt_tokens"] == 64
        assert rec.rows[0]["model_reported"] == "m-real"
        assert rec.rows[0]["reasoning_tokens"] == 7

    async def test_failed_attempt_has_no_provider_facts(self):
        rec = _MemoryRecorder()
        await TelemetryEmitter(rec).emit_attempt(
            request=_REQ,
            source=_source(),
            call_id="cid-2",
            latency_ms=7,
            response=None,
            error="boom",
        )
        assert rec.rows[0]["cached_prompt_tokens"] is None
        assert rec.rows[0]["model_reported"] is None
        assert rec.rows[0]["reasoning_tokens"] is None

    async def test_cache_hit_replays_the_recorded_values(self):
        """决策 B1: 命中行原样回放,故命中率统计必须带 WHERE cache_hit = false。"""
        rec = _MemoryRecorder()
        await TelemetryEmitter(rec).emit_cache_hit(
            request=_REQ,
            response=_resp(cached_prompt_tokens=64, model_reported="m-real", reasoning_tokens=7),
        )
        row = rec.rows[0]
        assert row["cache_hit"] is True
        assert row["cached_prompt_tokens"] == 64 and row["model_reported"] == "m-real"
        assert row["reasoning_tokens"] == 7  # 与 cached 同口径原样回放

    async def test_terminal_failure_records_none(self):
        rec = _MemoryRecorder()
        await TelemetryEmitter(rec).emit_terminal_failure(
            request=_REQ, call_id="c", latency_ms=1, error="dead"
        )
        assert rec.rows[0]["cached_prompt_tokens"] is None
        assert rec.rows[0]["model_reported"] is None
        assert rec.rows[0]["reasoning_tokens"] is None


class TestEmitterSamplingColumn:
    """issue #4: sampling 列在三个入口的口径(设计决策 D 表格)。

    列语义 = 「调用方采样意图 ⊎ 生效源 extra_body」,**不含**结构化注入的
    response_format(列名是采样参数,schema 不是;且数 KB schema 逐行落库会让
    审计表无谓膨胀)。三入口若各读各的层,同一列在不同行含义就不同。
    """

    _SAMPLED = ChatRequest(
        messages=[{"role": "user", "content": "hi"}],
        sampling={"seed": 42},
        overlay={"seed": 42, "response_format": {"type": "json_object"}},
    )

    async def test_attempt_merges_source_extra_body(self):
        rec = _MemoryRecorder()
        await TelemetryEmitter(rec).emit_attempt(
            request=self._SAMPLED,
            source=_source(extra_body={"temperature": 0}),
            call_id="c",
            latency_ms=1,
            response=_resp(),
            error=None,
        )
        assert json.loads(rec.rows[0]["sampling"]) == {"seed": 42, "temperature": 0}

    async def test_response_format_never_leaks_into_the_column(self):
        """三行都不得出现 response_format——它不是采样参数。"""
        rec = _MemoryRecorder()
        emitter = TelemetryEmitter(rec)
        await emitter.emit_attempt(
            request=self._SAMPLED,
            source=_source(),
            call_id="c",
            latency_ms=1,
            response=_resp(),
            error=None,
        )
        await emitter.emit_cache_hit(request=self._SAMPLED, response=_resp())
        await emitter.emit_terminal_failure(
            request=self._SAMPLED, call_id="c", latency_ms=1, error="dead"
        )
        assert len(rec.rows) == 3
        for row in rec.rows:
            assert "response_format" not in row["sampling"]

    @pytest.mark.parametrize("emit", ["cache_hit", "terminal_failure"])
    async def test_sourceless_entries_record_call_level_only(self, emit):
        """两个最外层入口没有"生效源"可言,与 model/source_name 置空同一先例。"""
        rec = _MemoryRecorder()
        emitter = TelemetryEmitter(rec)
        if emit == "cache_hit":
            await emitter.emit_cache_hit(request=self._SAMPLED, response=_resp())
        else:
            await emitter.emit_terminal_failure(
                request=self._SAMPLED, call_id="c", latency_ms=1, error="dead"
            )
        assert json.loads(rec.rows[0]["sampling"]) == {"seed": 42}

    async def test_absent_sampling_is_null(self):
        """无采样参数时为 NULL,而非空字符串或 "{}"——便于 SQL 过滤。"""
        rec = _MemoryRecorder()
        await TelemetryEmitter(rec).emit_attempt(
            request=_REQ,
            source=_source(),
            call_id="c",
            latency_ms=1,
            response=_resp(),
            error=None,
        )
        assert rec.rows[0]["sampling"] is None


class TestEmitterCallerDimensions:
    """issue #11: 三个 emit 入口统一从 `request` 读维度,`_record` 落库前归一化。

    维度只有一个读取点(`request`),否则同一列在三种行里口径分叉——那正是
    "遥测调用点收敛为单一 helper"这条铁律要防的形态。
    """

    _META = {"z_last": "z", "a_first": 1, "m_mid": True}
    _REQ_A = ChatRequest(
        messages=[{"role": "user", "content": "hi"}],
        session_id="sess-1",
        tenant_id="tenant-a",
        meta=_META,
    )

    @pytest.mark.parametrize("emit", ["attempt", "cache_hit", "terminal_failure"])
    async def test_every_entry_point_carries_the_dimensions(self, emit):
        """三条路径写出的行都必须带维度: 漏掉任一条,该租户的账就永远对不上。"""
        rec = _MemoryRecorder()
        emitter = TelemetryEmitter(rec)
        if emit == "attempt":
            await emitter.emit_attempt(
                request=self._REQ_A,
                source=_source(),
                call_id="c",
                latency_ms=1,
                response=_resp(),
                error=None,
            )
        elif emit == "cache_hit":
            await emitter.emit_cache_hit(request=self._REQ_A, response=_resp(cache_hit=True))
        else:
            await emitter.emit_terminal_failure(
                request=self._REQ_A, call_id="c", latency_ms=1, error="dead"
            )
        row = rec.rows[0]
        assert row["tenant_id"] == "tenant-a"
        assert json.loads(row["meta"]) == self._META

    async def test_cache_hit_records_the_current_caller_not_the_cached_one(self):
        """缓存命中行的维度是"本次由谁发起",不是历史那次——最容易实现反的一处。

        历史那次由租户 B 发起并把响应留在了缓存里;本次由租户 A 发起并命中。
        若读了历史那次的归属,租户 A 的调用会记到 B 头上,而 A 的账面凭空少一行
        ——两个租户的账同时错,且错得没有任何报错。
        """
        historical = ChatRequest(
            messages=[{"role": "user", "content": "hi"}],
            tenant_id="tenant-b",
            meta={"batch": "old-batch"},
        )
        rec = _MemoryRecorder()
        mw = TelemetryMW(TelemetryEmitter(rec))

        async def terminal(request):
            # 缓存层回放的是历史那次的响应对象(其 call_id 属于 historical 那次)
            return _resp(cache_hit=True, latency_ms=0, call_id="cache-cid")

        assert historical.tenant_id == "tenant-b"  # 历史归属确实不同,否则本用例是空转
        await mw(self._REQ_A, terminal)

        row = rec.rows[0]
        assert row["cache_hit"] is True
        assert row["tenant_id"] == "tenant-a"
        assert "old-batch" not in row["meta"]

    async def test_absent_dimensions_land_as_sentinels(self):
        """未传维度落哨兵值: `tenant_id` 空串、`meta` 字面量 `'{}'`,都不是 NULL。

        NULL 的 `tenant_id` 在 PG 的 RLS policy 下对所有人永久不可见(设计 §4.4),
        空串则可用一条 SQL 审计出还有多少行未归属;`meta` 同理,`'{}'` 可被
        JSON 函数直接查询,NULL 则要每条查询都额外判空。
        """
        rec = _MemoryRecorder()
        await TelemetryEmitter(rec).emit_attempt(
            request=_REQ,  # tenant_id=None, meta={}
            source=_source(),
            call_id="c",
            latency_ms=1,
            response=_resp(),
            error=None,
        )
        row = rec.rows[0]
        assert row["tenant_id"] == ""
        assert row["meta"] == "{}"

    async def test_meta_is_serialized_with_sorted_keys(self):
        """键序固定,同一份维度在任意两行里字节一致,可直接做等值比对与去重。"""
        rec = _MemoryRecorder()
        await TelemetryEmitter(rec).emit_terminal_failure(
            request=self._REQ_A, call_id="c", latency_ms=1, error="dead"
        )
        assert list(json.loads(rec.rows[0]["meta"])) == ["a_first", "m_mid", "z_last"]

    async def test_non_ascii_meta_stays_readable(self):
        """`ensure_ascii=False`: 中文维度按原文落库,而非 `\\uXXXX` 转义串。"""
        rec = _MemoryRecorder()
        req = ChatRequest(messages=[{"role": "user", "content": "hi"}], meta={"dept": "研发"})
        await TelemetryEmitter(rec).emit_terminal_failure(
            request=req, call_id="c", latency_ms=1, error="dead"
        )
        assert "研发" in rec.rows[0]["meta"]

    async def test_non_finite_meta_value_drops_the_row_instead_of_poisoning_it(self):
        """入口失守时 `allow_nan=False` 的真实结果: 整行降级丢弃,且不抛给调用方。

        直接构造带 `nan` 的 `ChatRequest`(绕过 `validate_caller_dimensions` 这道
        主防线,模拟将来某个新入口忘记校验)。没有 `allow_nan=False` 时,
        `json.dumps` 会写出裸 `NaN` 字面量——PG 的 JSONB 会拒收,但 **SQLite 的
        `meta` 是 TEXT 列不做校验**,那串非法 JSON 会被静默存进去,污染此后一切
        按 JSON 解析 meta 的分析。宁可丢一行遥测,也不要一行毒数据。

        同时断言不抛: 遥测的降级方向是"静默降级"(铁律),把调用方的一次正常
        业务调用因为一个维度值炸掉,方向反了。
        """
        rec = _MemoryRecorder()
        req = ChatRequest(messages=[{"role": "user", "content": "hi"}], meta={"k": float("nan")})
        await TelemetryEmitter(rec).emit_terminal_failure(
            request=req, call_id="c", latency_ms=1, error="dead"
        )
        assert rec.rows == []


class TestCostWithCachedTier:
    """issue #3: 命中部分按缓存单价计费,避免 cost 系统性高估。"""

    _TABLE = PricingTable(
        {"m": ModelPrice(input_per_1m=10.0, output_per_1m=20.0, cached_input_per_1m=2.0)}
    )

    async def test_cached_hit_lowers_the_recorded_cost(self):
        rec = _MemoryRecorder()
        emitter = TelemetryEmitter(rec, pricing=self._TABLE)
        full = _resp(prompt_tokens=1_000_000, completion_tokens=0)
        await emitter.emit_attempt(
            request=_REQ,
            source=_source(),
            call_id="c1",
            latency_ms=1,
            response=full,
            error=None,
        )
        await emitter.emit_attempt(
            request=_REQ,
            source=_source(),
            call_id="c2",
            latency_ms=1,
            response=_resp(
                prompt_tokens=1_000_000, completion_tokens=0, cached_prompt_tokens=600_000
            ),
            error=None,
        )
        assert rec.rows[0]["cost"] == pytest.approx(10.0)
        assert rec.rows[1]["cost"] == pytest.approx(5.2)  # 400k×10 + 600k×2

    async def test_cache_hit_row_still_costs_zero(self):
        """缓存命中未产生新调用 → cost 恒 0.0,该短路必须排在任何换算之前。"""
        rec = _MemoryRecorder()
        await TelemetryEmitter(rec, pricing=self._TABLE).emit_cache_hit(
            request=_REQ,
            response=_resp(prompt_tokens=1_000_000, cached_prompt_tokens=600_000),
        )
        assert rec.rows[0]["cost"] == 0.0

    async def test_unavailable_usage_still_costs_none(self):
        rec = _MemoryRecorder()
        await TelemetryEmitter(rec, pricing=self._TABLE).emit_attempt(
            request=_REQ,
            source=_source(),
            call_id="c",
            latency_ms=1,
            response=_resp(usage_source="unavailable", cached_prompt_tokens=5),
            error=None,
        )
        assert rec.rows[0]["cost"] is None


class TestEmitter:
    async def test_attempt_success_row(self):
        rec = _MemoryRecorder()
        emitter = TelemetryEmitter(rec)
        await emitter.emit_attempt(
            request=_REQ,
            source=_source(),
            call_id="cid-1",
            latency_ms=42,
            response=_resp(),
            error=None,
        )
        row = rec.rows[0]
        assert row["call_id"] == "cid-1" and row["error"] is None
        assert row["session_id"] == "sess-1" and row["source_name"] == "s1"
        assert row["response"] == "ok" and row["cost"] is None

    async def test_attempt_failure_row(self):
        rec = _MemoryRecorder()
        emitter = TelemetryEmitter(rec)
        await emitter.emit_attempt(
            request=_REQ,
            source=_source(),
            call_id="cid-2",
            latency_ms=7,
            response=None,
            error="TransientError: boom",
        )
        row = rec.rows[0]
        assert row["error"].startswith("TransientError")
        # 失败尝试没有任何用量信息可言 → unavailable(设计 §3.2 #6)
        assert row["response"] == "" and row["usage_source"] == "unavailable"
        assert row["cost"] is None

    async def test_terminal_failure_row_is_unavailable(self):
        rec = _MemoryRecorder()
        await TelemetryEmitter(rec, pricing=_PRICING).emit_terminal_failure(
            request=_REQ, call_id="cid-t", latency_ms=5, error="cancelled"
        )
        row = rec.rows[0]
        assert row["usage_source"] == "unavailable" and row["cost"] is None

    @pytest.mark.parametrize(("prompt", "completion"), [(0, 0), (0, 4000)])
    async def test_unavailable_success_row_has_null_cost(self, prompt, completion):
        """产生了真实调用但用量不可得 → cost 记 NULL(设计 §3.1 不变式)。

        参数第二组是改前兜底写出的 `0/4000` 形态: 那时换算出 0.032 的假金额。
        """
        rec = _MemoryRecorder()
        await TelemetryEmitter(rec, pricing=_PRICING).emit_attempt(
            request=_REQ,
            source=_source(),
            call_id="cid-u",
            latency_ms=42,
            response=_resp(
                usage_source="unavailable", prompt_tokens=prompt, completion_tokens=completion
            ),
            error=None,
        )
        assert rec.rows[0]["cost"] is None

    async def test_measured_row_still_priced(self):
        """对照组: 同一价格表下 measured 行照常换算,证明 None 不是价格表没接上。"""
        rec = _MemoryRecorder()
        await TelemetryEmitter(rec, pricing=_PRICING).emit_attempt(
            request=_REQ,
            source=_source(),
            call_id="cid-m",
            latency_ms=42,
            response=_resp(prompt_tokens=0, completion_tokens=4000),
            error=None,
        )
        assert rec.rows[0]["cost"] == pytest.approx(0.032)

    async def test_cache_hit_keeps_zero_cost_even_when_unavailable(self):
        """缓存命中未产生新调用,0.0 是事实而非未知 → 短路必须排在 cache_hit 之后。"""
        rec = _MemoryRecorder()
        await TelemetryEmitter(rec, pricing=_PRICING).emit_cache_hit(
            request=_REQ,
            response=_resp(cache_hit=True, usage_source="unavailable", completion_tokens=4000),
        )
        assert rec.rows[0]["cache_hit"] is True and rec.rows[0]["cost"] == 0.0

    async def test_multimodal_messages_digested_before_storage(self):
        rec = _MemoryRecorder()
        emitter = TelemetryEmitter(rec)
        big = "data:image/png;base64," + "A" * 100_000
        req = ChatRequest(
            messages=[
                {
                    "role": "user",
                    "content": [
                        {"type": "image_url", "image_url": {"url": big}},
                    ],
                }
            ]
        )
        await emitter.emit_attempt(
            request=req,
            source=_source(),
            call_id="c",
            latency_ms=1,
            response=None,
            error="x",
        )
        assert len(rec.rows[0]["messages"]) < 500  # base64 不整段进库(VT R12)

    async def test_recorder_failure_swallowed(self):
        class Broken:
            async def record_llm_call(self, **fields):
                raise OSError("disk full")

        emitter = TelemetryEmitter(Broken())
        await emitter.emit_attempt(
            request=_REQ,
            source=_source(),
            call_id="c",
            latency_ms=1,
            response=_resp(),
            error=None,
        )  # 不抛(降级不冒泡)


class TestTelemetryMW:
    async def test_cache_hit_recorded(self):
        rec = _MemoryRecorder()
        mw = TelemetryMW(TelemetryEmitter(rec))

        async def terminal(request):
            return _resp(cache_hit=True, latency_ms=0, call_id="cache-cid")

        resp = await mw(_REQ, terminal)
        assert resp.cache_hit
        assert len(rec.rows) == 1
        assert rec.rows[0]["cache_hit"] is True and rec.rows[0]["latency_ms"] == 0

    async def test_normal_success_not_double_recorded(self):
        """成功尝试由 RetryMW 逐次记录;最外层不得重复记。"""
        rec = _MemoryRecorder()
        mw = TelemetryMW(TelemetryEmitter(rec))

        async def terminal(request):
            return _resp(cache_hit=False)

        await mw(_REQ, terminal)
        assert rec.rows == []

    async def test_scope_level_failure_recorded(self):
        rec = _MemoryRecorder()
        mw = TelemetryMW(TelemetryEmitter(rec))

        async def terminal(request):
            raise CircuitOpenError(scope="llm", retry_after_s=30.0)

        with pytest.raises(CircuitOpenError):
            await mw(_REQ, terminal)
        assert len(rec.rows) == 1 and "circuit_open" in rec.rows[0]["error"]

    async def test_attempt_level_failure_not_double_recorded(self):
        """RequestRejected 已被 RetryMW 逐次记录 → 最外层跳过。"""
        rec = _MemoryRecorder()
        mw = TelemetryMW(TelemetryEmitter(rec))

        async def terminal(request):
            raise RequestRejectedError("400")

        with pytest.raises(RequestRejectedError):
            await mw(_REQ, terminal)
        assert rec.rows == []


def test_single_emitter_discipline():
    """铁律执法: record_llm_call 在 src/ 的调用点只允许出现在 telemetry emitter。"""
    out = subprocess.run(
        ["grep", "-rln", "record_llm_call(", "src/polygateway"],
        capture_output=True,
        text=True,
        cwd=Path(__file__).resolve().parents[2],
    ).stdout.splitlines()
    callers = [
        p
        for p in out
        if not p.endswith(("ports.py", "telemetry/sqlite.py", "telemetry/postgres.py"))
    ]
    assert callers == ["src/polygateway/middleware/telemetry.py"]