"""kb 域纯逻辑单测（不连库）：状态机全跃迁矩阵、12 类 Literal、色板格式校验。

repo / service 的 DB 路径由 ``tests/integration/test_kb_entity.py`` 覆盖，
这里只钉死「规则本身」：哪条跃迁合法、哪类实体名合法、什么 hex 合法。
"""

from __future__ import annotations

from itertools import product
from typing import get_args

import pytest
from pydantic import ValidationError

from packages.kb.schemas import (
    ENTITY_STATUSES,
    ENTITY_TYPES,
    MAX_GRAPH_HOPS,
    ColorRole,
    EntityCreate,
    EntityUpdate,
    GraphHop,
    GraphNode,
    GraphPath,
    RelationCreate,
)
from packages.kb.service import (
    CONTENT_EDITABLE_STATUSES,
    LEGAL_TRANSITIONS,
    assert_transition,
    can_transition,
    ensure_content_editable,
    ensure_valid_color_role,
    ensure_valid_hex,
    ensure_valid_hops,
)
from packages.shared.errors import AppError, ErrorCode

# 12 类本体（知识库文档 §3.1）。这里刻意不引用 ENTITY_TYPES 常量本身，
# 而是手写清单——常量抄错时测试必须能抓住。
_EXPECTED_12_TYPES = (
    "item",
    "color",
    "style",
    "body_shape",
    "face_hair",
    "occasion",
    "material",
    "accessory",
    "makeup",
    "rule",
    "outfit",
    "trend",
)

#: 状态机合法跃迁（draft→reviewing→published→published 后归档 + 撤稿支线）。
#: published→draft 不在其中：改已发布内容 = 撤稿归档后重录新草稿。
_LEGAL_PAIRS = {
    ("draft", "reviewing"),
    ("reviewing", "published"),
    ("published", "archived"),
    ("draft", "archived"),
    ("reviewing", "archived"),
}


class TestStateMachineMatrix:
    """全跃迁矩阵：4 态 × 4 态共 16 组合，合法 5 条，其余 11 条全部拦下。"""

    @pytest.mark.parametrize(("current", "target"), list(product(ENTITY_STATUSES, repeat=2)))
    def test_matrix(self, current: str, target: str) -> None:
        expected = (current, target) in _LEGAL_PAIRS
        assert can_transition(current, target) is expected
        if expected:
            assert_transition(current, target)  # 不抛即合法
        else:
            with pytest.raises(AppError) as exc_info:
                assert_transition(current, target)
            assert exc_info.value.code == ErrorCode.STATE_CONFLICT
            assert exc_info.value.http_status == 409
            assert exc_info.value.data == {"current": current, "target": target}

    def test_matrix_definition_is_exact(self) -> None:
        """合法性来源是 LEGAL_TRANSITIONS 常量：常量与期望集合互为镜像。"""
        assert frozenset(_LEGAL_PAIRS) == LEGAL_TRANSITIONS
        assert len(_LEGAL_PAIRS) == 5

    @pytest.mark.parametrize("status", ["draft", "reviewing"])
    def test_content_editable_in(self, status: str) -> None:
        ensure_content_editable(status)  # 不抛即可编辑

    @pytest.mark.parametrize("status", ["published", "archived"])
    def test_content_frozen_outside_draft_reviewing(self, status: str) -> None:
        with pytest.raises(AppError) as exc_info:
            ensure_content_editable(status)
        assert exc_info.value.code == ErrorCode.STATE_CONFLICT
        assert frozenset({"draft", "reviewing"}) == CONTENT_EDITABLE_STATUSES


class TestEntitySchemas:
    @pytest.mark.parametrize("entity_type", _EXPECTED_12_TYPES)
    def test_all_12_entity_types_accepted(self, entity_type: str) -> None:
        payload = EntityCreate(entity_type=entity_type, name="白衬衫", attrs={"sleeve": "long"})
        assert payload.entity_type == entity_type
        assert ENTITY_TYPES == _EXPECTED_12_TYPES
        assert len(_EXPECTED_12_TYPES) == 12

    @pytest.mark.parametrize("entity_type", ["garbage", "Item", "items", "", "user"])
    def test_invalid_entity_type_rejected(self, entity_type: str) -> None:
        with pytest.raises(ValidationError):
            EntityCreate(entity_type=entity_type, name="白衬衫")  # type: ignore[arg-type]

    @pytest.mark.parametrize("name", ["", "x" * 129])
    def test_name_length_enforced(self, name: str) -> None:
        with pytest.raises(ValidationError):
            EntityCreate(entity_type="item", name=name)

    def test_attrs_default_empty_and_optional_fields(self) -> None:
        payload = EntityCreate(entity_type="style", name="通勤风")
        assert payload.attrs == {}
        assert payload.source is None
        assert payload.license is None

    def test_entity_update_defaults_and_status_literal(self) -> None:
        assert EntityUpdate().content_fields() == {}
        assert EntityUpdate(attrs={"a": 1}).content_fields() == {"attrs": {"a": 1}}
        # status 不是内容字段：纯跃迁请求不该引起 version 变化
        assert EntityUpdate(status="published").content_fields() == {}
        with pytest.raises(ValidationError):
            EntityUpdate(status="frozen")  # type: ignore[arg-type]

    def test_entity_update_distinguishes_unset_and_null(self) -> None:
        """PATCH 语义：显式传 null 清空字段，未传不动字段。"""
        payload = EntityUpdate.model_validate({"source": None})
        assert payload.content_fields() == {"source": None}
        assert EntityUpdate.model_validate({}).content_fields() == {}

    def test_status_literal_matches_state_machine(self) -> None:
        assert set(ENTITY_STATUSES) == {"draft", "reviewing", "published", "archived"}


class TestRelationAndGraphSchemas:
    def test_relation_create_defaults(self) -> None:
        payload = RelationCreate(from_entity_id=1, to_entity_id=2, rel_type="suits")
        assert payload.weight == payload.confidence  # 默认 1
        assert str(payload.weight) == "1"

    @pytest.mark.parametrize(
        ("rel_type", "weight"),
        [("", 1), ("x" * 65, 1), ("suits", -0.1), ("suits", 10)],
    )
    def test_relation_create_rejects_bad_shape(self, rel_type: str, weight: float) -> None:
        with pytest.raises(ValidationError):
            RelationCreate(from_entity_id=1, to_entity_id=2, rel_type=rel_type, weight=weight)

    def test_graph_path_shape_invariants(self) -> None:
        """可解释路径的结构不变式：len(hops) == len(nodes) - 1，逐跳有 rel_type。"""
        path = GraphPath(
            nodes=[
                GraphNode(entity_id="1", entity_type="item", name="白衬衫", status="published"),
                GraphNode(entity_id="2", entity_type="style", name="通勤风", status="published"),
                GraphNode(entity_id="3", entity_type="occasion", name="面试", status="published"),
            ],
            hops=[
                GraphHop(from_entity_id="1", rel_type="suits", to_entity_id="2"),
                GraphHop(from_entity_id="2", rel_type="fits", to_entity_id="3"),
            ],
        )
        assert len(path.hops) == len(path.nodes) - 1
        assert [hop.rel_type for hop in path.hops] == ["suits", "fits"]


class TestColorValidation:
    @pytest.mark.parametrize("hex_code", ["#A1B2C3", "#a1b2c3", "#000000", "#FFFFFF"])
    def test_valid_hex(self, hex_code: str) -> None:
        ensure_valid_hex(hex_code)  # 不抛即合法

    @pytest.mark.parametrize(
        "hex_code",
        [
            "A1B2C3",  # 缺 #
            "#A1B2C",  # 5 位
            "#A1B2C3D",  # 7 位
            "#G1H2J3",  # 非 hex 字符
            " #A1B2C3",  # 前导空格
            "#A1B2C3\n",  # 尾部换行：fullmatch 必须拦
            "#Z9",
            "",
        ],
    )
    def test_invalid_hex(self, hex_code: str) -> None:
        with pytest.raises(AppError) as exc_info:
            ensure_valid_hex(hex_code)
        assert exc_info.value.code == ErrorCode.BAD_REQUEST
        assert exc_info.value.http_status == 400

    @pytest.mark.parametrize("role", ["base", "accent", "avoid"])
    def test_valid_roles(self, role: str) -> None:
        ensure_valid_color_role(role)

    @pytest.mark.parametrize("role", ["primary", "BASE", "", "main"])
    def test_invalid_roles(self, role: str) -> None:
        with pytest.raises(AppError) as exc_info:
            ensure_valid_color_role(role)
        assert exc_info.value.code == ErrorCode.BAD_REQUEST

    def test_color_role_literal_matches_guard(self) -> None:
        assert set(get_args(ColorRole)) == {"base", "accent", "avoid"}


class TestHopsBound:
    """1~3 跳：超界 400（HTTP 入口由 Query ge/le 先行拦成 422，service 兜底）。"""

    @pytest.mark.parametrize("max_hops", [1, 2, MAX_GRAPH_HOPS])
    def test_valid_hops(self, max_hops: int) -> None:
        ensure_valid_hops(max_hops)

    @pytest.mark.parametrize("max_hops", [0, -1, 4, 99])
    def test_out_of_range_hops(self, max_hops: int) -> None:
        with pytest.raises(AppError) as exc_info:
            ensure_valid_hops(max_hops)
        assert exc_info.value.code == ErrorCode.BAD_REQUEST