"""
角色管理 API (RBAC)
- roles: 租戶層級角色 (不綁定部門)
- role_rights: 角色對系統功能的 CRUD 權限
- user_role_assignments: 使用者角色分配 (直接對人，跨部門有效)
"""
from typing import List, Optional
from fastapi import APIRouter, Depends, HTTPException, Query, status, Request
from sqlalchemy.orm import Session

from app.db.session import get_db
from app.api.deps import get_tenant_id, get_current_tenant
from app.models.role import UserRole, RoleRight, UserRoleAssignment
from app.models.system_function_cache import SystemFunctionCache
from app.schemas.response import MessageResponse
from app.services.audit_service import audit_service

router = APIRouter()


# ========================
# 角色 CRUD
# ========================

@router.get("/")
def get_roles(
    db: Session = Depends(get_db),
    include_inactive: bool = False,
):
    """取得租戶的所有角色"""
    tenant_id = get_current_tenant_id()
    query = db.query(Role).filter(Role.tenant_id == tenant_id)

    if not include_inactive:
        query = query.filter(Role.is_active == True)

    roles = query.order_by(Role.id).all()

    return [
        {
            "id": r.id,
            "role_code": r.role_code,
            "role_name": r.role_name,
            "description": r.description,
            "is_active": r.is_active,
            "rights_count": len(r.rights),
        }
        for r in roles
    ]


@router.get("/{role_id}")
def get_role(
    role_id: int,
    db: Session = Depends(get_db),
):
    """取得角色詳情（含功能權限）"""
    tenant_id = get_current_tenant_id()
    role = db.query(Role).filter(
        Role.id == role_id,
        Role.tenant_id == tenant_id,
    ).first()

    if not role:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail=f"Role with id {role_id} not found"
        )

    return {
        "id": role.id,
        "role_code": role.role_code,
        "role_name": role.role_name,
        "description": role.description,
        "is_active": role.is_active,
        "rights": [
            {
                "function_id": r.function_id,
                "function_code": r.function.function_code if r.function else None,
                "function_name": r.function.function_name if r.function else None,
                "service_code": r.function.service_code if r.function else None,
                "can_read": r.can_read,
                "can_create": r.can_create,
                "can_update": r.can_update,
                "can_delete": r.can_delete,
            }
            for r in role.rights
        ],
    }


@router.post("/", status_code=status.HTTP_201_CREATED)
def create_role(
    data: dict,
    request: Request,
    db: Session = Depends(get_db),
):
    """
    建立角色

    Body: { "role_code": "WAREHOUSE_MANAGER", "role_name": "倉管角色", "description": "..." }
    """
    tenant_id = get_current_tenant_id()
    role_code = data.get("role_code", "").upper()
    role_name = data.get("role_name", "")

    if not role_code or not role_name:
        raise HTTPException(
            status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
            detail="role_code and role_name are required"
        )

    existing = db.query(Role).filter(
        Role.tenant_id == tenant_id,
        Role.role_code == role_code,
    ).first()

    if existing:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail=f"Role code '{role_code}' already exists"
        )

    role = Role(
        tenant_id=tenant_id,
        role_code=role_code,
        role_name=role_name,
        description=data.get("description"),
    )
    db.add(role)
    db.commit()
    db.refresh(role)

    audit_service.log_action(
        request=request, db=db,
        action="create_role", resource_type="role", resource_id=role.id,
        details={"role_code": role_code, "role_name": role_name},
    )

    return {"id": role.id, "role_code": role.role_code, "role_name": role.role_name}


@router.delete("/{role_id}", response_model=MessageResponse)
def deactivate_role(
    role_id: int,
    request: Request,
    db: Session = Depends(get_db),
):
    """停用角色"""
    tenant_id = get_current_tenant_id()
    role = db.query(Role).filter(
        Role.id == role_id,
        Role.tenant_id == tenant_id,
    ).first()

    if not role:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail=f"Role with id {role_id} not found"
        )

    role.is_active = False
    db.commit()

    return MessageResponse(message=f"Role '{role.role_name}' has been deactivated")


# ========================
# 角色功能權限
# ========================

@router.put("/{role_id}/rights")
def set_role_rights(
    role_id: int,
    rights: list,
    request: Request,
    db: Session = Depends(get_db),
):
    """
    設定角色的功能權限 (整體替換)

    Body: [
        {"function_id": 1, "can_read": true, "can_create": false, "can_update": false, "can_delete": false},
        ...
    ]
    """
    tenant_id = get_current_tenant_id()
    role = db.query(Role).filter(
        Role.id == role_id,
        Role.tenant_id == tenant_id,
    ).first()

    if not role:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail=f"Role with id {role_id} not found"
        )

    # 刪除舊的權限
    db.query(RoleRight).filter(RoleRight.role_id == role_id).delete()

    # 新增新的權限
    for r in rights:
        function_id = r.get("function_id")
        fn = db.query(SystemFunctionCache).filter(
            SystemFunctionCache.id == function_id
        ).first()

        if not fn:
            continue

        right = RoleRight(
            role_id=role_id,
            function_id=function_id,
            can_read=r.get("can_read", False),
            can_create=r.get("can_create", False),
            can_update=r.get("can_update", False),
            can_delete=r.get("can_delete", False),
        )
        db.add(right)

    db.commit()

    audit_service.log_action(
        request=request, db=db,
        action="update_role_rights", resource_type="role", resource_id=role_id,
        details={"rights_count": len(rights)},
    )

    return {"message": f"Role rights updated", "rights_count": len(rights)}


# ========================
# 使用者角色分配
# ========================

@router.get("/user-assignments/")
def get_user_role_assignments(
    db: Session = Depends(get_db),
    keycloak_user_id: Optional[str] = Query(None, description="Keycloak User UUID"),
):
    """取得使用者角色分配"""
    tenant_id = get_current_tenant_id()
    query = db.query(UserRoleAssignment).filter(
        UserRoleAssignment.tenant_id == tenant_id,
        UserRoleAssignment.is_active == True,
    )

    if keycloak_user_id:
        query = query.filter(UserRoleAssignment.keycloak_user_id == keycloak_user_id)

    assignments = query.all()

    return [
        {
            "id": a.id,
            "keycloak_user_id": a.keycloak_user_id,
            "role_id": a.role_id,
            "role_code": a.role.role_code if a.role else None,
            "role_name": a.role.role_name if a.role else None,
            "assigned_at": a.assigned_at,
        }
        for a in assignments
    ]


@router.post("/user-assignments/", status_code=status.HTTP_201_CREATED)
def assign_role_to_user(
    data: dict,
    request: Request,
    db: Session = Depends(get_db),
):
    """
    分配角色給使用者 (直接對人，跨部門有效)

    Body: { "keycloak_user_id": "uuid", "role_id": 1 }
    """
    tenant_id = get_current_tenant_id()
    keycloak_user_id = data.get("keycloak_user_id")
    role_id = data.get("role_id")

    if not keycloak_user_id or not role_id:
        raise HTTPException(
            status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
            detail="keycloak_user_id and role_id are required"
        )

    role = db.query(Role).filter(
        Role.id == role_id,
        Role.tenant_id == tenant_id,
    ).first()

    if not role:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail=f"Role with id {role_id} not found"
        )

    existing = db.query(UserRoleAssignment).filter(
        UserRoleAssignment.keycloak_user_id == keycloak_user_id,
        UserRoleAssignment.role_id == role_id,
    ).first()

    if existing:
        if existing.is_active:
            raise HTTPException(
                status_code=status.HTTP_400_BAD_REQUEST,
                detail="User already has this role assigned"
            )
        existing.is_active = True
        db.commit()
        return {"message": "Role assignment reactivated", "id": existing.id}

    assignment = UserRoleAssignment(
        tenant_id=tenant_id,
        keycloak_user_id=keycloak_user_id,
        role_id=role_id,
    )
    db.add(assignment)
    db.commit()
    db.refresh(assignment)

    audit_service.log_action(
        request=request, db=db,
        action="assign_role", resource_type="user_role_assignment", resource_id=assignment.id,
        details={"keycloak_user_id": keycloak_user_id, "role_id": role_id, "role_code": role.role_code},
    )

    return {"id": assignment.id, "keycloak_user_id": keycloak_user_id, "role_id": role_id}


@router.delete("/user-assignments/{assignment_id}", response_model=MessageResponse)
def revoke_role_from_user(
    assignment_id: int,
    request: Request,
    db: Session = Depends(get_db),
):
    """撤銷使用者角色"""
    tenant_id = get_current_tenant_id()
    assignment = db.query(UserRoleAssignment).filter(
        UserRoleAssignment.id == assignment_id,
        UserRoleAssignment.tenant_id == tenant_id,
    ).first()

    if not assignment:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail=f"Assignment with id {assignment_id} not found"
        )

    assignment.is_active = False
    db.commit()

    audit_service.log_action(
        request=request, db=db,
        action="revoke_role", resource_type="user_role_assignment", resource_id=assignment_id,
        details={"keycloak_user_id": assignment.keycloak_user_id, "role_id": assignment.role_id},
    )

    return MessageResponse(message="Role assignment revoked")


# ========================
# 系統功能查詢
# ========================

@router.get("/system-functions/")
def get_system_functions(
    db: Session = Depends(get_db),
    service_code: Optional[str] = Query(None, description="服務代碼篩選: hr/erp/mail/ai"),
):
    """取得系統功能清單 (從快取表)"""
    query = db.query(SystemFunctionCache).filter(SystemFunctionCache.is_active == True)

    if service_code:
        query = query.filter(SystemFunctionCache.service_code == service_code)

    functions = query.order_by(SystemFunctionCache.service_code, SystemFunctionCache.id).all()

    return [
        {
            "id": f.id,
            "service_code": f.service_code,
            "function_code": f.function_code,
            "function_name": f.function_name,
            "function_category": f.function_category,
        }
        for f in functions
    ]