import sqlite3

import pytest

from pipeline import FakeSource, FatalError, RetryableError, TokenBucket, run_sync, with_retry


def make_rows(n, start=0, ts_prefix="2026-10-23T10:00:", status="paid"):
    return [{"id": f"o{i:03d}", "amount_cents": i, "status": status, "updated_at": f"{ts_prefix}{i:02d}"} for i in range(start, start + n)]


def test_resume_from_watermark_and_idempotent():
    conn = sqlite3.connect(":memory:")
    src = FakeSource(make_rows(30))
    assert run_sync(conn, src, page_size=10, sleep=lambda s: None).written == 30
    again = run_sync(conn, src, page_size=10, sleep=lambda s: None)
    assert again.fetched == 0                                       # 水位线生效，不重复拉取
    src.rows += make_rows(5, start=30)
    assert run_sync(conn, src, page_size=10, sleep=lambda s: None).written == 5
    assert conn.execute("SELECT COUNT(*) FROM orders").fetchone()[0] == 35


def test_older_version_does_not_overwrite_newer():
    conn = sqlite3.connect(":memory:")
    run_sync(conn, FakeSource([{"id": "a", "amount_cents": 1, "status": "refunded", "updated_at": "2026-10-23T12:00:00"}]), job="j1")
    # 另一个来源（或重放）送来旧版本
    run_sync(conn, FakeSource([{"id": "a", "amount_cents": 1, "status": "paid", "updated_at": "2026-10-23T09:00:00"}]), job="j2")
    assert conn.execute("SELECT status FROM orders WHERE id='a'").fetchone()[0] == "refunded"


def test_quality_gate_rolls_back_and_alerts():
    conn = sqlite3.connect(":memory:")
    rows = make_rows(10) + make_rows(3, start=10, status="???")    # 3/13 坏数据，超过 5%
    alerts = []
    r = run_sync(conn, FakeSource(rows), max_dead_ratio=0.05, alert=alerts.append)
    assert not r.committed and alerts
    assert conn.execute("SELECT COUNT(*) FROM orders").fetchone()[0] == 0           # 整批回滚
    assert conn.execute("SELECT COUNT(*) FROM watermarks").fetchone()[0] == 0       # 水位线没动


def test_retry_only_retryable_and_respects_retry_after():
    sleeps = []
    calls = iter([RetryableError("429", retry_after=2.0), RetryableError("timeout"), ["ok"]])

    def fn():
        v = next(calls)
        if isinstance(v, Exception):
            raise v
        return v

    assert with_retry(fn, sleep=sleeps.append) == ["ok"]
    assert sleeps[0] == 2.0 and 0 <= sleeps[1] <= 0.4

    def fatal():
        raise FatalError("401")

    with pytest.raises(FatalError):
        with_retry(fatal, sleep=sleeps.append)


def test_retry_gives_up():
    def always():
        raise RetryableError("503")

    with pytest.raises(RetryableError):
        with_retry(always, attempts=3, sleep=lambda s: None)


def test_token_bucket_limits_rate():
    clock = [0.0]
    slept = []

    def sleep(s):
        slept.append(s)
        clock[0] += s

    b = TokenBucket(rate=2, capacity=2, now=lambda: clock[0], sleep=sleep)
    for _ in range(6):
        b.acquire()
    assert clock[0] == pytest.approx(2.0)            # 2 个初始令牌 + 4 个以每秒 2 个的速度补充 = 2 秒