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 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",
]


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,
    }
    fields.update(overrides)
    await recorder.record_llm_call(**fields)


class TestSQLiteRecorder:
    async def test_schema_has_frozen_columns(self, tmp_path):
        recorder = SQLiteRecorder(tmp_path / "t.db")
        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")
        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")
        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"))
        await _record_minimal(recorder)  # 不抛
        recorder.close()

    async def test_observability_columns_round_trip(self, tmp_path):
        recorder = SQLiteRecorder(tmp_path / "t.db")
        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")
        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")
        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)
        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)  # 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()


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",
    ]

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

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

    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.postgres import _BACKFILL

        altered = [s for s in conn.statements if s.startswith("ALTER TABLE")]
        assert len(altered) == len(_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",
    ]

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

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

    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 _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两个后端的 _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.postgres import _COLUMNS as PG_COLUMNS
        from polygateway.telemetry.sqlite import _COLUMNS as SQLITE_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(SQLITE_COLUMNS) == set(PG_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.sqlite import _COLUMNS as SQLITE_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(SQLITE_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 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"]