"""标签+校准测试（T-G3）：四条推导规则 / T3 保持 / 180d 清理 / conformal 覆盖 / last-good。"""
import json
import time

from gateway.sense.calibrate import (
    compute_thresholds,
    load_active,
    save_thresholds,
)
from gateway.sense.labeler import derive_true_tier, derive_true_tiers
from gateway.sense.store import SenseStore


def _obs(rid, executed, outcome, probs=None, features=None, override="", true_tier=""):
    return {"request_id": rid, "consumer": "pipeline", "decided_tier": executed,
            "executed_tier": executed, "probs": probs or "{}", "outcome": outcome,
            "features": features or "{}", "human_override": override,
            "true_tier": true_tier}


# ---------------- derive_true_tier 纯函数 ----------------

def test_rule1_success_t1():
    assert derive_true_tier(_obs("r", "T1", "ok")) == "T1"
    assert derive_true_tier(_obs("r", "T1", "verified")) == "T1"


def test_rule2_failure_next_tier_and_t3_stays():
    assert derive_true_tier(_obs("r", "T1", "failed")) == "T2"
    assert derive_true_tier(_obs("r", "T2", "user_retry")) == "T3"
    assert derive_true_tier(_obs("r", "T3", "timeout")) == "T3"     # T3 保持 T3


def test_rule3_plan_multi_signals_t3():
    row = _obs("r", "T2", "ok", features=json.dumps({"plan_multi": True}))
    assert derive_true_tier(row) == "T3"


def test_rule4_human_override_wins():
    row = _obs("r", "T1", "failed", override="T3")
    assert derive_true_tier(row) == "T3"


def test_empty_outcome_skipped():
    assert derive_true_tier(_obs("r", "T1", "")) is None


# ---------------- derive_true_tiers 批量 + 清理 ----------------

def test_batch_derive_and_purge(tmp_path):
    store = SenseStore.init_db(tmp_path / "s.sqlite3")
    now = time.time()
    for rid, outcome in [("a", "ok"), ("b", "failed"), ("c", "")]:
        store.insert_observation(_obs(rid, "T2", outcome))
    # 一条 200 天前的旧数据（先推导后清理）
    store.insert_observation({**_obs("old", "T1", "ok"), "ts": now - 200 * 86400})
    count = derive_true_tiers(store, now=now, retention_days=180)
    assert count == 3                                   # a→T2, b→T3, old→T1
    rows = {r["request_id"]: r for r in store.all_observations()}
    assert rows["a"]["true_tier"] == "T2"
    assert rows["b"]["true_tier"] == "T3"
    assert "old" not in rows                            # 180d 清理生效（推导后删除）


# ---------------- compute_thresholds ----------------

def test_conformal_threshold_coverage():
    """合成分布：T1 高分样本真为 T1 -> τ1 满足精度 >= 1-α；τ3 同理（需真 T3 样本）。"""
    rows = []
    for i in range(40):
        rows.append({"probs": json.dumps({"t1": 0.95 - i * 0.001, "t3": 0.01}),
                     "true_tier": "T1"})
    for i in range(10):
        rows.append({"probs": json.dumps({"t1": 0.3, "t3": 0.3}),
                     "true_tier": "T2"})
    for i in range(5):
        rows.append({"probs": json.dumps({"t3": 0.9, "t1": 0.02}),
                     "true_tier": "T3"})
    th = compute_thresholds(rows, alpha=0.05, min_labels=10)
    assert th["ok"] is True and th["n"] == 55
    kept = [r for r in rows if json.loads(r["probs"])["t1"] >= th["t1"]]
    precision = sum(1 for r in kept if r["true_tier"] == "T1") / len(kept)
    assert precision >= 0.95


def test_min_labels_not_met_returns_not_ok():
    rows = [{"probs": json.dumps({"t1": 0.9, "t3": 0.05}), "true_tier": "T1"}]
    th = compute_thresholds(rows, alpha=0.05, min_labels=500)
    assert th["ok"] is False and th["t1"] is None


def test_threshold_artifact_roundtrip_and_last_good(tmp_path):
    """工件读写 + active 切换 + last-good 回退链。"""
    store = SenseStore.init_db(tmp_path / "s.sqlite3")
    th = {"t1": 0.8, "t3": 0.85, "coverage": 0.9, "n": 500, "ok": True}
    path = save_thresholds(store, tmp_path, "v1", th, activate=True)
    assert "thresholds.json" in path
    loaded = load_active(store, tmp_path)
    assert loaded["t1"] == 0.8 and loaded["version"] == "v1"
    # 保存 v2 不激活 -> 仍 v1；激活 v2 -> 切换；v2 文件损坏 -> 扫描回退 v1
    save_thresholds(store, tmp_path, "v2", {"t1": 0.7, "t3": 0.7,
                                            "coverage": 0.9, "n": 500})
    assert load_active(store, tmp_path)["version"] == "v1"     # v2 未激活
    store.activate_artifact("v2", "thresholds")
    assert load_active(store, tmp_path)["version"] == "v2"
    (tmp_path / "v2" / "thresholds.json").unlink()
    loaded = load_active(store, tmp_path)
    assert loaded["version"] == "v1" and loaded["t1"] == 0.8   # last-good 扫描回退
    # 全新 store（无任何工件登记）-> 保守值
    fresh_store = SenseStore.init_db(tmp_path / "fresh.sqlite3")
    fresh = load_active(fresh_store, tmp_path / "fresh")
    assert fresh["version"] == "conservative"