"""整批模拟执行：新增组件补全物料默认配置，再按顺序在大屏副本上执行，遇到第一个错误即停止

纯函数，不依赖 agent；agent 的 apply_actions 工具和测试共用
"""

from copy import deepcopy

from app.actions.layout import EXPANDERS
from app.actions.registry import apply_action
from app.actions.update import fit_existing_path
from app.resources.material_fields import check_update_field, find_material
from app.schemas.actions import Action, AddAction, AgentAction, UpdateAction
from app.schemas.capabilities import DATA_BINDING_ERROR, DATA_BINDING_SUPPORTED
from app.schemas.component_resource import ComponentCatalog
from app.schemas.screen import Screen, ScreenNode


class BatchError(ValueError):
    """整批中第 index 个动作（从 0 开始）失败，消息里带上序号和目标，模型据此修正"""

    def __init__(self, index: int, action: AgentAction, reason: str):
        self.index = index
        self.reason = reason
        if isinstance(action, AddAction):
            target = action.node.id
        elif ids := getattr(action, "target_ids", None):
            target = "、".join(ids)
        else:
            target = getattr(action, "target_id", "画布")
        super().__init__(f"第 {index + 1} 个动作（{action.type} {target}）：{reason}")


def merge_config(defaults: dict, overrides: dict) -> dict:
    """对象逐层覆盖，数组和标量整体替换，不修改传入的数据"""
    result = deepcopy(defaults)
    for key, value in overrides.items():
        result[key] = (
            merge_config(result[key], value)
            if isinstance(result.get(key), dict) and isinstance(value, dict)
            else deepcopy(value)
        )
    return result


def complete_add(action: AddAction, catalog: ComponentCatalog) -> AddAction:
    """按 node.type 找物料补全新增组件，模型显式写出的字段优先

    sample_data 模型写了就以模型为准（只有它知道是否换成了自己的数据），没写时按物料设置
    """
    material = find_material(catalog, action.node.type)
    if not DATA_BINDING_SUPPORTED and action.node.model_extra.get("dataId"):
        raise ValueError(DATA_BINDING_ERROR)
    overrides = action.node.model_dump(mode="json", exclude_unset=True)
    node = ScreenNode.model_validate(merge_config(material.template(), overrides))
    sample_data = (
        action.sample_data
        if "sample_data" in action.model_fields_set
        else material.sample_data
    )
    return action.model_copy(update={"node": node, "sample_data": sample_data})


def run_batch(
    screen: Screen, catalog: ComponentCatalog, actions: list[AgentAction]
) -> tuple[list[Action], Screen]:
    """从原始大屏开始按顺序模拟执行，返回前端要执行的动作和执行后的大屏；第一个错误抛 BatchError

    布局意图（arrange、align、distribute、set_layout）在这里按当时的大屏展开成 move 和 resize
    """
    current = screen.model_copy(deep=True)
    completed: list[Action] = []
    for index, action in enumerate(actions):
        try:
            if expander := EXPANDERS.get(action.type):
                expanded = expander(current, action)
                for primitive in expanded:
                    current = apply_action(current, primitive)
                completed.extend(expanded)
                continue
            if isinstance(action, AddAction):
                action = complete_add(action, catalog)
            elif isinstance(action, UpdateAction):
                # 目标不存在时交给执行器报错
                node = next(
                    (item for item in current.nodes if item.id == action.target_id),
                    None,
                )
                if node is not None:
                    check_update_field(catalog, node.type, action)
                    # 字段定义允许、但组件中还没有的中间对象，折叠进值里再执行
                    action = fit_existing_path(node, action)
            current = apply_action(current, action)
        except ValueError as error:  # 含 pydantic ValidationError
            raise BatchError(index, action, str(error)) from error
        completed.append(action)
    return completed, current