"""任务 Pydantic Schemas — 支持无限嵌套子任务、裂变转交、驳回返工"""
from __future__ import annotations
import uuid
from datetime import datetime
from typing import Optional
from pydantic import BaseModel, Field


# ============================================================
# 请求模型
# ============================================================

class TaskCreate(BaseModel):
    """创建任务"""
    product_id: uuid.UUID = Field(..., description="所属产品ID")
    parent_task_id: uuid.UUID | None = Field(None, description="父任务ID(用于嵌套子任务/裂变分支)")
    task_name: str = Field(..., max_length=200, description="任务名称")
    assignee_id: str | None = Field(None, max_length=64, description="负责人ID(逻辑外键→老系统)")
    notify_parent_on_complete: bool = Field(False, description="完成后是否通知父任务")
    is_rework: bool = Field(False, description="是否为返工任务")
    remark: str | None = Field(None, max_length=2000, description="初始描述/交接备注")

    model_config = {"from_attributes": True}


class TaskUpdate(BaseModel):
    """更新任务"""
    task_name: str | None = Field(None, max_length=200)
    assignee_id: str | None = Field(None, max_length=64)
    status: str | None = Field(None, max_length=50, description="任务状态")
    notify_parent_on_complete: bool | None = Field(None)

    model_config = {"from_attributes": True}


class TaskCompleteRequest(BaseModel):
    """完成任务请求 — 携带转交信息（保留兼容旧版单步转交）"""
    operator_id: str | None = Field(None, max_length=64, description="操作人ID")
    next_assignee_id: str | None = Field(None, max_length=64, description="下一步任务负责人ID")
    next_task_name: str | None = Field(None, max_length=200, description="下一步任务名称")
    remark: str | None = Field(None, description="完成备注")


class SubtaskCreate(BaseModel):
    """创建子任务"""
    task_name: str = Field(..., max_length=200, description="子任务名称")
    assignee_id: str | None = Field(None, max_length=64, description="负责人ID")
    notify_parent_on_complete: bool = Field(False, description="完成后是否通知父任务")


class TaskRejectRequest(BaseModel):
    """品质驳回请求"""
    reason: str = Field(..., min_length=1, max_length=500, description="驳回原因（必填）")


class TaskTransferBranch(BaseModel):
    """裂变分支"""
    task_name: str = Field(..., max_length=200, description="工序名称")
    assignees: list[str] = Field(..., min_length=1, description="接收人列表")


class TaskTransferRequest(BaseModel):
    """完工裂变转交请求 — 支持多分支 next_tasks 和旧版单线兼容"""
    next_assignees: list[str] | None = Field(None, description="[旧版] 下一道工序接收人列表")
    next_task_name: str | None = Field(None, max_length=200, description="[旧版] 下一道工序名称")
    next_tasks: list[TaskTransferBranch] | None = Field(None, description="[新版] 多分支任务列表")
    note: str | None = Field(None, description="交接备注")


class TaskRecordCreate(BaseModel):
    """任务进度记录 — 备注 + 图片"""
    remark: str = Field("", max_length=2000, description="备注文本")
    images: list[str] = Field(default_factory=list, description="图片 URL 列表")


class TaskRecordResponse(BaseModel):
    id: int
    task_id: uuid.UUID
    remark: str | None = None
    images: list[str] = []
    created_at: datetime | None = None

    model_config = {"from_attributes": True}

    @classmethod
    def model_validate(cls, obj, **kwargs):
        """处理 DB 中 images 的 JSON 字符串 → list 反序列化"""
        import json
        if hasattr(obj, "images") and isinstance(obj.images, str):
            try:
                obj.images = json.loads(obj.images)
            except (json.JSONDecodeError, TypeError):
                obj.images = []
        elif hasattr(obj, "images") and obj.images is None:
            obj.images = []
        return super().model_validate(obj, **kwargs)


# ============================================================
# 响应模型
# ============================================================

class TaskSummaryResponse(BaseModel):
    """任务摘要 — 扫码时用，不含嵌套子任务"""
    id: uuid.UUID
    product_id: uuid.UUID
    parent_task_id: uuid.UUID | None
    task_name: str
    assignee_id: str | None
    status: str
    notify_parent_on_complete: bool
    is_rework: bool = False
    remark: str | None = None
    reject_reason: str | None = None
    received_at: datetime | None = None
    completed_at: datetime | None = None
    created_at: datetime

    model_config = {"from_attributes": True}


class TaskResponse(BaseModel):
    """任务详情响应 — 递归包含所有子任务"""
    id: uuid.UUID
    product_id: uuid.UUID
    product_sn: str = ""
    product_material: str = ""
    parent_task_id: uuid.UUID | None
    task_name: str
    assignee_id: str | None
    status: str
    notify_parent_on_complete: bool
    is_rework: bool = False
    remark: str | None = None
    reject_reason: str | None = None
    received_at: datetime | None = None
    completed_at: datetime | None = None
    created_at: datetime
    child_tasks: list[TaskResponse] = []
    records: list[TaskRecordResponse] = []

    model_config = {"from_attributes": True}


class TaskCompleteResponse(BaseModel):
    """任务完成响应"""
    completed_task: TaskResponse
    next_task: TaskResponse | None = None
    message: str


class TaskTransferResponse(BaseModel):
    """裂变转交响应"""
    completed_task: TaskResponse
    created_tasks: list[TaskResponse] = []
    message: str


class TaskListResponse(BaseModel):
    """任务列表响应"""
    tasks: list[TaskResponse]
    total: int