"""ORM 模型元数据测试。

建表规范（表小写蛇形复数、字段中文 COMMENT、主键 id、索引 uk_/idx_ 前缀）
属于「红线」，靠人工 review 迟早会漏，这里用测试把它固定下来。
"""

import re

import pytest
from sqlalchemy.dialects import mysql

from app.models import Base

EXPECTED_TABLES = {
    "tplus_automation_states",
    "payroll_months", "payroll_inputs", "payroll_allocations",
    "tplus_source_heads", "tplus_facts", "tplus_source_links", "tplus_work_runs", "tplus_work_lines",
    "users",
    "roles",
    "user_roles",
    "permissions",
    "role_permissions",
    "login_logs",
    "operation_logs",
    "business_roles",
    "system_settings",
    "approval_orders",
    "approval_steps",
    "business_secondary_allocations",
    "param_definitions",
    "param_change_batches",
    "param_values",
    "personnel",
    "personnel_regions",
    "personnel_plans",
    "products",
    "customers",
    "ownership_change_logs",
    "businesses",
    "business_items",
    "business_status_logs",
    "shipments",
    "shipment_items",
    "receipts",
    "customer_rating_grades",
    "performance_ledgers",
    "monthly_settlements",
    "settlement_items",
    "adjustment_orders",
    "tplus_sync_batches",
    "tplus_sync_errors",
    "tplus_sync_records",
    "tplus_sync_watermarks",
}

# 单复数同形的集合名词：本身即复数语义，不受「以 s 结尾」检查约束
PLURAL_EXCEPTIONS = {"personnel"}


def _ddl(table_name: str) -> str:
    """返回某张表的建表 DDL 文本。"""
    from sqlalchemy.schema import CreateTable

    table = Base.metadata.tables[table_name]
    return str(CreateTable(table).compile(dialect=mysql.dialect()))


class TestTableSet:
    """表集合必须完整 —— 漏一张就会让 alembic 生成「删除该表」的迁移。"""

    def test_表集合与预期一致(self) -> None:
        assert set(Base.metadata.tables) == EXPECTED_TABLES

    def test_所有表名均为小写蛇形复数(self) -> None:
        for name in Base.metadata.tables:
            assert re.fullmatch(r"[a-z][a-z0-9_]*", name), f"表名 {name} 不符合小写蛇形"
            # personnel 等集合名词单复数同形，本身即复数语义
            if name not in PLURAL_EXCEPTIONS:
                assert name.endswith("s"), f"表名 {name} 应为复数"


class TestNamingConvention:
    """约束命名：规范要求 uk_表_字段 / idx_表_字段。"""

    @pytest.mark.parametrize("table_name", sorted(EXPECTED_TABLES))
    def test_主键命名为pk_表名(self, table_name: str) -> None:
        pk = Base.metadata.tables[table_name].primary_key
        assert pk.name == f"pk_{table_name}"

    def test_唯一键以uk_开头(self) -> None:
        for table in Base.metadata.tables.values():
            for constraint in table.constraints:
                if constraint.__class__.__name__ == "UniqueConstraint":
                    assert constraint.name.startswith(f"uk_{table.name}_"), constraint.name

    def test_索引以idx_开头(self) -> None:
        for table in Base.metadata.tables.values():
            for index in table.indexes:
                assert index.name.startswith(f"idx_{table.name}_"), index.name

    def test_外键以fk_开头(self) -> None:
        for table in Base.metadata.tables.values():
            for fk in table.foreign_keys:
                assert fk.constraint.name.startswith(f"fk_{table.name}_"), fk.constraint.name

    def test_审批单版本号唯一键覆盖三列(self) -> None:
        """并发提单算重版本号时由 DB 兜底（应用层取号走锁读，见
        approval_service._next_version）；约束名必须与迁移 DDL 严格一致，
        否则 alembic autogenerate 会误判成「约束缺失/多余」。"""
        table = Base.metadata.tables["approval_orders"]
        uks = [c for c in table.constraints if c.__class__.__name__ == "UniqueConstraint"]
        hit = [
            c
            for c in uks
            if {col.name for col in c.columns} == {"order_type", "ref_id", "version_no"}
        ]
        assert hit, "审批单缺 (order_type, ref_id, version_no) 唯一键"
        assert hit[0].name == "uk_approval_orders_order_type_ref_version"


class TestComments:
    """规范红线要求中文 COMMENT。"""

    @pytest.mark.parametrize("table_name", sorted(EXPECTED_TABLES))
    def test_表级中文注释存在(self, table_name: str) -> None:
        assert Base.metadata.tables[table_name].comment, f"{table_name} 缺少表注释"

    @pytest.mark.parametrize("table_name", sorted(EXPECTED_TABLES))
    def test_每列都有中文注释(self, table_name: str) -> None:
        table = Base.metadata.tables[table_name]
        missing = [c.name for c in table.columns if not c.comment]
        assert not missing, f"{table_name} 缺注释的列：{missing}"

    @pytest.mark.parametrize("table_name", sorted(EXPECTED_TABLES))
    def test_注释确实输出到DDL(self, table_name: str) -> None:
        ddl = _ddl(table_name)
        assert "COMMENT '" in ddl
        assert f"COMMENT='{Base.metadata.tables[table_name].comment}'" in ddl


class TestMysqlTableOptions:
    """引擎与字符集：不显式指定则跟随服务端，跨环境可能不一致。"""

    @pytest.mark.parametrize("table_name", sorted(EXPECTED_TABLES))
    def test_显式指定引擎与字符集(self, table_name: str) -> None:
        ddl = _ddl(table_name)
        assert "ENGINE=InnoDB" in ddl
        assert "CHARSET=utf8mb4" in ddl
        assert "utf8mb4_general_ci" in ddl

    @pytest.mark.parametrize("table_name", sorted(EXPECTED_TABLES))
    def test_主键为无符号BIGINT(self, table_name: str) -> None:
        assert "id BIGINT UNSIGNED NOT NULL" in _ddl(table_name)


class TestTimestampColumns:
    """更新时间必须由数据库维护 —— 这是 server_onupdate 做不到的。"""

    @pytest.mark.parametrize("table_name", ["users", "roles", "permissions"])
    def test_带时间戳的表含ON_UPDATE子句(self, table_name: str) -> None:
        assert "ON UPDATE CURRENT_TIMESTAMP" in _ddl(table_name)

    @pytest.mark.parametrize("table_name", ["login_logs", "operation_logs"])
    def test_仅追加的日志表不含ON_UPDATE子句(self, table_name: str) -> None:
        """日志是不可变记录，没有"更新时间"语义。"""
        assert "ON UPDATE CURRENT_TIMESTAMP" not in _ddl(table_name)

    def test_关联表保留create_time便于审计(self) -> None:
        for table_name in ("user_roles", "role_permissions"):
            assert "create_time" in Base.metadata.tables[table_name].columns


class TestEnumColumns:
    """状态类字段的默认值。"""

    def test_用户默认启用且令牌版本为1(self) -> None:
        users = Base.metadata.tables["users"]
        assert users.columns["status"].server_default.arg == "1"
        assert users.columns["token_version"].server_default.arg == "1"

    def test_角色编码唯一(self) -> None:
        ddl = _ddl("roles")
        assert "uk_roles_role_code UNIQUE (role_code)" in ddl

    def test_用户名唯一(self) -> None:
        assert "uk_users_username UNIQUE (username)" in _ddl("users")