"""KPI模板库 API — 管理会计OS
支持系统预置模板 + 用户自定义模板
从模板实例化创建KPI时，复制模板快照到kpi_definitions"""
from fastapi import APIRouter, Depends, HTTPException, Query
from sqlalchemy.orm import Session
from typing import Optional
from datetime import datetime

from app.database import get_db
from app.auth_middleware import require_role
from app.models import KPITemplate, KPIDefinition, OperationLog

router = APIRouter(prefix="/api/cma/templates", tags=["KPI模板库"],
    dependencies=[Depends(require_role("ceo", "finance", "business", "it"))],
)

WRITE_ROLES = Depends(require_role("ceo", "finance", "it"))


def template_to_dict(t):
    return {c.name: getattr(t, c.name) for c in t.__table__.columns}


@router.get("")
def list_templates(
    dimension: Optional[str] = None,
    category: Optional[str] = None,
    keyword: Optional[str] = None,
    is_system: Optional[int] = None,
    db: Session = Depends(get_db),
):
    """获取模板列表，支持按维度/类别/关键字筛选"""
    query = db.query(KPITemplate)
    if dimension:
        query = query.filter(KPITemplate.dimension == dimension)
    if category:
        query = query.filter(KPITemplate.category == category)
    if keyword:
        query = query.filter(KPITemplate.kpi_name.contains(keyword))
    if is_system is not None:
        query = query.filter(KPITemplate.is_system == is_system)
    templates = query.order_by(KPITemplate.is_system.desc(), KPITemplate.kpi_code).all()
    return {"total": len(templates), "data": [template_to_dict(t) for t in templates]}


@router.get("/{template_id}")
def get_template(template_id: int, db: Session = Depends(get_db)):
    t = db.query(KPITemplate).filter(KPITemplate.id == template_id).first()
    if not t:
        raise HTTPException(404, "模板不存在")
    return template_to_dict(t)


@router.post("")
def create_template(data: dict, db: Session = Depends(get_db), user=WRITE_ROLES):
    """用户创建自定义模板"""
    existing = db.query(KPITemplate).filter(KPITemplate.kpi_code == data.get("kpi_code", "")).first()
    if existing:
        raise HTTPException(400, f"模板编码 {data['kpi_code']} 已存在")
    t = KPITemplate(
        kpi_code=data.get("kpi_code"),
        kpi_name=data.get("kpi_name"),
        dimension=data.get("dimension"),
        category=data.get("category"),
        formula=data.get("formula"),
        formula_desc=data.get("formula_desc"),
        unit=data.get("unit", "%"),
        target_value=data.get("target_value"),
        description=data.get("description"),
        is_system=0,  # 用户创建的永远不是系统模板
        usage_count=0,
    )
    db.add(t)
    db.commit()
    db.refresh(t)
    _log(db, 1, "create", "template", t.id, {"kpi_code": t.kpi_code, "kpi_name": t.kpi_name})
    return template_to_dict(t)


@router.put("/{template_id}")
def update_template(template_id: int, data: dict, db: Session = Depends(get_db), user=WRITE_ROLES):
    """修改自定义模板（系统预置不可修改）"""
    t = db.query(KPITemplate).filter(KPITemplate.id == template_id).first()
    if not t:
        raise HTTPException(404, "模板不存在")
    if t.is_system:
        raise HTTPException(403, "系统预置模板不可修改")
    for k, v in data.items():
        if hasattr(t, k) and v is not None:
            setattr(t, k, v)
    db.commit()
    return template_to_dict(t)


@router.delete("/{template_id}")
def delete_template(template_id: int, db: Session = Depends(get_db), user=WRITE_ROLES):
    """删除自定义模板（系统预置不可删除）"""
    t = db.query(KPITemplate).filter(KPITemplate.id == template_id).first()
    if not t:
        raise HTTPException(404, "模板不存在")
    if t.is_system:
        raise HTTPException(403, "系统预置模板不可删除")
    db.delete(t)
    db.commit()
    return {"message": "模板已删除"}


@router.post("/{template_id}/instantiate")
def instantiate_template(template_id: int, data: dict, db: Session = Depends(get_db), user=WRITE_ROLES):
    """从模板实例化创建KPI，复制模板快照到kpi_definitions"""
    t = db.query(KPITemplate).filter(KPITemplate.id == template_id).first()
    if not t:
        raise HTTPException(404, "模板不存在")

    kpi_code = data.get("kpi_code", t.kpi_code)
    kpi_name = data.get("kpi_name", t.kpi_name)

    # 检查编码唯一性
    existing = db.query(KPIDefinition).filter(KPIDefinition.kpi_code == kpi_code).first()
    if existing:
        raise HTTPException(400, f"KPI编码 {kpi_code} 已存在，请修改")

    kpi = KPIDefinition(
        template_id=t.id,
        is_system=0,  # 从模板实例化的KPI不是系统预置
        kpi_code=kpi_code,
        kpi_name=kpi_name,
        dimension=data.get("dimension", t.dimension),
        category=data.get("category", t.category),
        formula=data.get("formula", t.formula),
        formula_desc=data.get("formula_desc", t.formula_desc),
        unit=data.get("unit", t.unit or "%"),
        target_value=data.get("target_value", t.target_value),
        objective=data.get("objective"),
        data_source_type=data.get("data_source_type", "manual"),
        frequency=data.get("frequency", "monthly"),
        responsible_dept=data.get("responsible_dept"),
        responsible_user=data.get("responsible_user"),
        status="active",
    )
    db.add(kpi)
    db.commit()
    db.refresh(kpi)

    # 更新模板使用计数
    t.usage_count = (t.usage_count or 0) + 1
    db.commit()

    _log(db, 1, "create", "kpi", kpi.id, {"from_template": template_id, "kpi_code": kpi.kpi_code})
    return {c.name: getattr(kpi, c.name) for c in kpi.__table__.columns}


def _log(db, user_id, action, target_type, target_id, detail):
    import json
    log = OperationLog(user_id=user_id, action=action, target_type=target_type,
                       target_id=target_id, detail=json.dumps(detail, ensure_ascii=False) if detail else None)
    db.add(log)
    db.commit()