"""指导成本解析只认已登记事实：多条候选不猜、单位与封存状态必须显式匹配。"""

from decimal import Decimal

import pytest

from app.core.exceptions import BadRequestError
from app.services.tplus.guidance import check_unit_guidance_conflicts, resolve_guidance


class Fact:
    """最小事实替身：resolve_guidance 只读取 kind 与 data_json。"""

    def __init__(self, data_json):
        self.kind = "GUIDANCE"
        self.data_json = data_json


def facts_of(*rows):
    """按 (kind, fact_key) 组装成 latest_guidance_facts 的返回结构。"""
    return {("GUIDANCE", str(index)): Fact(row) for index, row in enumerate(rows)}


def final_row(**overrides):
    row = {
        "product_id": 9,
        "month": "2026-03",
        "basis": "UNIT",
        "unit": "根",
        "is_finalized": True,
    }
    row.update(overrides)
    return row


def test_没有匹配事实时返回缺失():
    state, guidance = resolve_guidance(facts_of(), 9, "line-1", "2026-03", "根")
    assert state == "MISSING"
    assert guidance is None


def test_多条候选时不选择其中一条():
    rows = facts_of(final_row(), final_row(shipment_line_id="line-1"))
    state, guidance = resolve_guidance(rows, 9, "line-1", "2026-03", "根")
    assert state == "AMBIGUOUS"
    assert guidance is None


def test_唯一候选且单位一致时返回已封存事实():
    row = final_row()
    state, guidance = resolve_guidance(facts_of(row), 9, "line-1", "2026-03", "根")
    assert state == "FINALIZED"
    assert guidance is row


def test_单位不一致时不采用该事实():
    state, guidance = resolve_guidance(facts_of(final_row(unit="吨")), 9, "line-1", "2026-03", "根")
    assert state == "UNIT_MISMATCH"
    assert guidance is None


def test_未封存事实不能作为指导价依据():
    state, guidance = resolve_guidance(facts_of(final_row(is_finalized=False)), 9, "line-1", "2026-03", "根")
    assert state == "UNFINALIZED"
    assert guidance is None


def test_按明细行登记的指导价只对该行生效():
    rows = facts_of(final_row(basis="LINE", shipment_line_id="line-1"))
    assert resolve_guidance(rows, 9, "line-1", "2026-03", "根")[0] == "FINALIZED"
    assert resolve_guidance(rows, 9, "line-2", "2026-03", "根")[0] == "MISSING"


def test_同一产品同月已有事实时拒绝重复登记():
    with pytest.raises(BadRequestError, match="重叠"):
        check_unit_guidance_conflicts(facts_of(final_row()), 9, "2026-03", "根", "10", [])


def test_历史封存明细的成本或单位不一致时拒绝():
    with pytest.raises(BadRequestError, match="不一致"):
        check_unit_guidance_conflicts(
            facts_of(), 9, "2026-03", "根", "10",
            [{"unit_cost": "11", "unit": "根"}],
        )
    with pytest.raises(BadRequestError, match="不一致"):
        check_unit_guidance_conflicts(
            facts_of(), 9, "2026-03", "根", "10",
            [{"unit_cost": "10", "unit": "吨"}],
        )


def test_事实为空且历史一致时放行():
    check_unit_guidance_conflicts(
        facts_of(), 9, "2026-03", "根", Decimal("10"),
        [{"unit_cost": "10", "unit": "根"}, {"unit_cost": "10.00", "unit": "根"}],
    )


def test_金额非法时拒绝():
    for bad in ("abc", "-1", "nan"):
        with pytest.raises(BadRequestError, match="不一致"):
            check_unit_guidance_conflicts(facts_of(), 9, "2026-03", "根", bad, [])