"""计提公式模板管理服务。

页面可维护：名称、说明、参数绑定（受骨架角色约束）；公式骨架是受控枚举，
创建后锁定，避免自由表达式注入与执行错位。系统模板随迁移种子初始化，
禁删且骨架/编码/参数锁定；自定义模板无岗位引用才可删除。
"""

from sqlalchemy.exc import IntegrityError

from app.core.constants import ACTION_CREATE, ACTION_DELETE, ACTION_UPDATE
from app.core.exceptions import BadRequestError, ForbiddenError, NotFoundError
from app.core.response import PageResult
from app.models import CalcTemplateDefinition, User
from app.repositories import calc_template_repository
from app.schemas.calc_template import (
    CalcTemplateCreateIn,
    CalcTemplateOut,
    CalcTemplateUpdateIn,
)
from app.services import audit_service
from app.services.audit_service import AuditRecord, RequestMeta
from app.services.calc_templates import FORMULAS, get_formula
from app.services.param_registry import PARAM_REGISTRY

MODULE_CALC_TEMPLATE = "公式模板"


def _to_out(row: CalcTemplateDefinition, role_count: int = 0) -> CalcTemplateOut:
    return CalcTemplateOut(
        id=row.id,
        template_code=row.template_code,
        template_name=row.template_name,
        formula_type=row.formula_type,
        params=dict(row.params_json or {}),
        description=row.description,
        sort_order=row.sort_order,
        status=row.status,
        is_system=row.is_system,
        role_count=role_count,
    )


def _validate_params(formula_type: str, params: dict[str, str]) -> dict[str, str]:
    """骨架角色必须全覆盖且不引入多余角色；目标参数必须已注册。"""
    spec = get_formula(formula_type)
    expected = set(spec.roles)
    provided = set(params)
    if provided != expected:
        missing = sorted(expected - provided)
        extra = sorted(provided - expected)
        details = []
        if missing:
            details.append("缺少参数角色：" + "、".join(missing))
        if extra:
            details.append("多余参数角色：" + "、".join(extra))
        raise BadRequestError("；".join(details))
    unknown = sorted(code for code in params.values() if code not in PARAM_REGISTRY)
    if unknown:
        raise BadRequestError("参数编码未注册：" + "、".join(unknown))
    return {role: params[role] for role in spec.roles}


def list_templates(session) -> PageResult[CalcTemplateOut]:
    """模板列表（含停用与引用计数，供管理页）。"""
    rows = calc_template_repository.list_all(session)
    counts = calc_template_repository.count_roles_by_codes(session, [r.template_code for r in rows])
    return PageResult[CalcTemplateOut](
        records=[_to_out(row, counts.get(row.template_code, 0)) for row in rows],
        total=len(rows),
        page_num=1,
        page_size=max(len(rows), 1),
    )


def list_formula_options() -> list[dict]:
    """骨架下拉（受控集合）。"""
    return [
        {"code": spec.code, "name": spec.name, "description": spec.description, "roles": list(spec.roles)}
        for spec in FORMULAS.values()
    ]


def create_template(
    session,
    payload: CalcTemplateCreateIn,
    *,
    operator: User,
    meta: RequestMeta,
) -> CalcTemplateOut:
    """新增模板。编码唯一；骨架受控；参数绑定按骨架角色校验。"""
    if calc_template_repository.get_by_code(session, payload.template_code) is not None:
        raise BadRequestError(f"模板编码 {payload.template_code} 已存在")
    try:
        get_formula(payload.formula_type)
    except ValueError as exc:
        raise BadRequestError(str(exc)) from exc
    params = _validate_params(payload.formula_type, payload.params)
    row = CalcTemplateDefinition(
        template_code=payload.template_code,
        template_name=payload.template_name,
        formula_type=payload.formula_type,
        params_json=params,
        description=payload.description,
        sort_order=payload.sort_order,
        status=1,
        is_system=0,
    )
    try:
        calc_template_repository.create(session, row)
        session.commit()
    except IntegrityError as exc:
        session.rollback()
        raise BadRequestError(f"模板编码 {payload.template_code} 已存在") from exc
    with audit_service.audit(
        session,
        operator=operator,
        record=AuditRecord(
            module=MODULE_CALC_TEMPLATE,
            action=ACTION_CREATE,
            target=payload.template_code,
            summary=f"新增计提公式模板 {payload.template_name}",
            detail={"formula_type": payload.formula_type, "params": params},
        ),
        meta=meta,
    ):
        pass
    return _to_out(row)


def update_template(
    session,
    template_id: int,
    payload: CalcTemplateUpdateIn,
    *,
    operator: User,
    meta: RequestMeta,
) -> CalcTemplateOut:
    """编辑模板。系统模板参数锁定；自定义模板参数仍按骨架角色校验。"""
    row = calc_template_repository.get_by_id(session, template_id, for_update=True)
    if row is None:
        raise NotFoundError("模板不存在")
    params = dict(row.params_json or {})
    if row.is_system != 1:
        params = _validate_params(row.formula_type, payload.params)
    row.template_name = payload.template_name
    row.description = payload.description
    row.sort_order = payload.sort_order
    row.params_json = params
    session.commit()
    with audit_service.audit(
        session,
        operator=operator,
        record=AuditRecord(
            module=MODULE_CALC_TEMPLATE,
            action=ACTION_UPDATE,
            target=row.template_code,
            summary=f"修改计提公式模板 {row.template_name}",
            detail={"params": params},
        ),
        meta=meta,
    ):
        pass
    return _to_out(row)


def delete_template(
    session,
    template_id: int,
    *,
    operator: User,
    meta: RequestMeta,
) -> None:
    """删除模板。系统模板禁删；被岗位引用禁删。"""
    row = calc_template_repository.get_by_id(session, template_id, for_update=True)
    if row is None:
        raise NotFoundError("模板不存在")
    if row.is_system == 1:
        raise ForbiddenError("系统内置模板不可删除")
    counts = calc_template_repository.count_roles_by_codes(session, [row.template_code])
    if counts.get(row.template_code):
        raise BadRequestError("模板已被岗位引用，不能删除；可先调整岗位模板后再删除")
    calc_template_repository.delete(session, row)
    session.commit()
    with audit_service.audit(
        session,
        operator=operator,
        record=AuditRecord(
            module=MODULE_CALC_TEMPLATE,
            action=ACTION_DELETE,
            target=row.template_code,
            summary=f"删除计提公式模板 {row.template_name}",
        ),
        meta=meta,
    ):
        pass