"""一条本地采购任务的安全演练流程。

本模块固定为 ``dry_run``。它会核对商品、动态规格、数量和价格，并停在最终
提交订单之前；代码中没有提交订单或付款入口。
"""

from __future__ import annotations

from dataclasses import dataclass
from datetime import datetime, timezone
from typing import Callable, Mapping

from .admin_gateway import AdminGateway, AdminGatewayError, ClientInfo
from .pdd_purchase_adapter import (
    PddPurchaseAdapter,
    PddPurchaseError,
    PurchasePageState,
)
from .task_models import OutboxEventRecord, OutboxEventType, TaskStatus
from .task_repository import TaskRepository


def utc_now_iso() -> str:
    """返回精确到秒的 UTC ISO 8601 时间。"""

    return datetime.now(timezone.utc).isoformat(timespec="seconds").replace(
        "+00:00", "Z"
    )


@dataclass(frozen=True)
class PurchaseTarget:
    """从已领取任务中校验出的采购目标。"""

    goods_id: str
    goods_url: str
    options: Mapping[str, str]
    quantity: int
    max_price_cent: int


@dataclass(frozen=True)
class PurchaseTaskOutcome:
    """采购工作线程返回给协调层的简短结果。"""

    kind: str
    message: str
    task_id: str = ""


PurchaseAdapterFactory = Callable[
    [str, Callable[[], bool]], PddPurchaseAdapter
]


class PurchaseTaskService:
    """只执行本地已保存的采购任务，不领取新任务。"""

    def __init__(
        self,
        gateway: AdminGateway,
        repository: TaskRepository,
        client: ClientInfo,
        device_address: str,
        adapter_factory: PurchaseAdapterFactory,
        *,
        cancelled: Callable[[], bool] = lambda: False,
    ) -> None:
        self._gateway = gateway
        self._repository = repository
        self._client = client
        self._device_address = str(device_address or "").strip()
        self._factory = adapter_factory
        self._cancelled = cancelled

    def execute_one_local(self) -> PurchaseTaskOutcome:
        """先补交结果，再执行最早的本地待执行采购任务。"""

        pending = self._repository.next_pending_outbox()
        if pending is not None:
            return self._submit(pending)
        if not self._device_address:
            raise ValueError("请先在设置页选择并保存 Android 设备")
        task = self._repository.next_purchase_task()
        if task is None:
            return PurchaseTaskOutcome("no_task", "暂无本地待执行的采购任务")
        return self.execute_selected(task.remote_task_id)

    def execute_selected(self, remote_task_id: str) -> PurchaseTaskOutcome:
        """对指定的本地采购任务执行一次演练。"""

        if not self._device_address:
            raise ValueError("请先在设置页选择并保存 Android 设备")
        if self._cancelled():
            return PurchaseTaskOutcome(
                "cancelled", "采购演练已在开始前取消", remote_task_id
            )

        started = self._repository.start_purchase_run(
            remote_task_id, self._device_address
        )
        adapter: PddPurchaseAdapter | None = None
        step = "purchase_prepare"
        try:
            target = self._target_from_task(started.task)
            adapter = self._factory(self._device_address, self._cancelled)

            step = "purchase_open_goods"
            self._enter_step(remote_task_id, started.attempt_id, step)
            adapter.open_goods(target.goods_url)

            step = "purchase_verify_goods"
            self._enter_step(remote_task_id, started.attempt_id, step)
            state = adapter.read_state()
            self._validate_identity(state, target, "goods")

            step = "purchase_select_options"
            self._enter_step(remote_task_id, started.attempt_id, step)
            self._validate_identity(adapter.read_state(), target, "goods")
            adapter.select_options(target.options)

            step = "purchase_verify_options"
            self._enter_step(remote_task_id, started.attempt_id, step)
            state = adapter.read_state()
            self._validate_selected_options(state, target)

            step = "purchase_set_quantity"
            self._enter_step(remote_task_id, started.attempt_id, step)
            self._validate_selected_options(adapter.read_state(), target)
            adapter.set_quantity(target.quantity)

            step = "purchase_verify_quantity_price"
            self._enter_step(remote_task_id, started.attempt_id, step)
            state = adapter.read_state()
            self._validate_checkout_values(state, target)

            step = "purchase_enter_confirmation"
            self._enter_step(remote_task_id, started.attempt_id, step)
            self._validate_checkout_values(adapter.read_state(), target)
            adapter.enter_confirmation()

            step = "purchase_verify_confirmation"
            self._enter_step(remote_task_id, started.attempt_id, step)
            state = adapter.read_state()
            if state.page_kind != "order_confirmation":
                raise PddPurchaseError(
                    "PURCHASE_CONFIRMATION_NOT_REACHED",
                    "没有到达最终提交前确认页，已停止演练",
                    step=step,
                )
            self._validate_checkout_values(state, target)

            step = "purchase_dry_run_stopped"
            self._enter_step(remote_task_id, started.attempt_id, step)
            adapter.stop_before_submit()
            result = self._result_data(target, state)
            event = self._repository.save_purchase_result(
                remote_task_id, started.attempt_id, result
            )
        except PddPurchaseError as exc:
            event = self._save_failure(
                remote_task_id,
                started.attempt_id,
                exc.code,
                exc.message,
                exc.retryable,
                exc.step or step,
                exc.diagnostics,
            )
        except Exception as exc:
            event = self._save_failure(
                remote_task_id,
                started.attempt_id,
                "PURCHASE_UNEXPECTED",
                f"采购演练在“{step}”发生未知错误：{exc}",
                False,
                step,
                {},
            )
        finally:
            if adapter is not None:
                adapter.close()
        return self._submit(event)

    def _enter_step(
        self, remote_task_id: str, attempt_id: str, step: str
    ) -> None:
        """先持久化步骤，再检查停止请求。"""

        self._repository.update_purchase_step(
            remote_task_id, attempt_id, step
        )
        if self._cancelled():
            raise PddPurchaseError(
                "PURCHASE_CANCELLED",
                "用户已请求停止采购演练",
                step=step,
            )

    @staticmethod
    def _target_from_task(task: object) -> PurchaseTarget:
        payload_root = getattr(task, "admin_payload", None)
        if not isinstance(payload_root, Mapping):
            raise PddPurchaseError(
                "PURCHASE_TASK_INVALID",
                "采购任务原始数据不是对象",
                step="purchase_prepare",
            )
        payload = payload_root.get("payload")
        if not isinstance(payload, Mapping):
            raise PddPurchaseError(
                "PURCHASE_TASK_INVALID",
                "采购任务缺少 payload 对象",
                step="purchase_prepare",
            )
        goods_url = str(payload.get("goods_url") or "").strip()
        goods_id = str(payload.get("goods_id") or "").strip()
        options = payload.get("options")
        quantity = payload.get("quantity")
        max_price_cent = payload.get("max_price_cent")
        if not goods_url or not goods_id:
            raise PddPurchaseError(
                "PURCHASE_TASK_INVALID",
                "采购任务缺少商品链接或商品编号",
                step="purchase_prepare",
            )
        if not isinstance(options, Mapping) or not options:
            raise PddPurchaseError(
                "PURCHASE_TASK_INVALID",
                "采购任务缺少动态规格 options",
                step="purchase_prepare",
            )
        normalized_options: dict[str, str] = {}
        for key, value in options.items():
            checked_key = str(key or "").strip()
            checked_value = str(value or "").strip()
            if not checked_key or not checked_value:
                raise PddPurchaseError(
                    "PURCHASE_TASK_INVALID",
                    "采购任务 options 的名称和值都不能为空",
                    step="purchase_prepare",
                )
            normalized_options[checked_key] = checked_value
        if isinstance(quantity, bool) or not isinstance(quantity, int) or quantity <= 0:
            raise PddPurchaseError(
                "PURCHASE_TASK_INVALID",
                "采购数量必须是大于 0 的整数",
                step="purchase_prepare",
            )
        if (
            isinstance(max_price_cent, bool)
            or not isinstance(max_price_cent, int)
            or max_price_cent <= 0
        ):
            raise PddPurchaseError(
                "PURCHASE_TASK_INVALID",
                "人民币价格上限必须是大于 0 的整数分",
                step="purchase_prepare",
            )
        return PurchaseTarget(
            goods_id,
            goods_url,
            normalized_options,
            quantity,
            max_price_cent,
        )

    @staticmethod
    def _validate_identity(
        state: PurchasePageState, target: PurchaseTarget, expected_page: str
    ) -> None:
        PurchaseTaskService._validate_common_state(state)
        if state.page_kind != expected_page:
            raise PddPurchaseError(
                "PDD_PAGE_UNKNOWN",
                f"当前页面不是预期的 {expected_page} 页面，已停止演练",
                step="purchase_verify_goods",
            )
        if state.goods_id != target.goods_id:
            raise PddPurchaseError(
                "PURCHASE_GOODS_MISMATCH",
                "当前 PDD 商品与采购任务不一致，已停止演练",
                step="purchase_verify_goods",
            )

    @staticmethod
    def _validate_selected_options(
        state: PurchasePageState, target: PurchaseTarget
    ) -> None:
        PurchaseTaskService._validate_common_state(state)
        if state.goods_id != target.goods_id:
            raise PddPurchaseError(
                "PURCHASE_GOODS_MISMATCH",
                "选择规格后商品编号发生变化，已停止演练",
                step="purchase_verify_options",
            )
        if dict(state.selected_options) != dict(target.options):
            raise PddPurchaseError(
                "PURCHASE_OPTIONS_MISMATCH",
                "当前选中规格与采购任务不完全一致，已停止演练",
                step="purchase_verify_options",
            )

    @staticmethod
    def _validate_checkout_values(
        state: PurchasePageState, target: PurchaseTarget
    ) -> None:
        PurchaseTaskService._validate_selected_options(state, target)
        if state.quantity != target.quantity:
            raise PddPurchaseError(
                "PURCHASE_QUANTITY_MISMATCH",
                "当前数量与采购任务不一致，已停止演练",
                step="purchase_verify_quantity_price",
            )
        if state.price_cent <= 0:
            raise PddPurchaseError(
                "PURCHASE_PRICE_MISSING",
                "无法读取稳定的当前人民币价格，已停止演练",
                step="purchase_verify_quantity_price",
            )
        if state.price_cent > target.max_price_cent:
            raise PddPurchaseError(
                "PURCHASE_PRICE_EXCEEDED",
                (
                    f"当前价格 {state.price_cent} 分超过上限 "
                    f"{target.max_price_cent} 分，已停止演练"
                ),
                step="purchase_verify_quantity_price",
            )

    @staticmethod
    def _validate_common_state(state: PurchasePageState) -> None:
        if state.page_kind == "captcha":
            raise PddPurchaseError(
                "PDD_PAGE_CAPTCHA",
                "PDD 出现安全验证，请人工处理",
                step="purchase_page_check",
            )
        if state.page_kind == "login_required":
            raise PddPurchaseError(
                "PDD_PAGE_LOGIN_REQUIRED",
                "PDD 登录状态失效，请人工登录后再处理",
                step="purchase_page_check",
            )
        if state.page_kind in {"unknown", "risk_control", "payment"}:
            raise PddPurchaseError(
                "PDD_PAGE_UNKNOWN",
                "PDD 出现未知、风控或支付页面，已停止演练",
                step="purchase_page_check",
            )
        if state.candidate_count != 1:
            raise PddPurchaseError(
                "PURCHASE_AMBIGUOUS_TARGET",
                "页面存在多个候选目标，无法安全确认，已停止演练",
                step="purchase_page_check",
            )

    def _save_failure(
        self,
        remote_task_id: str,
        attempt_id: str,
        code: str,
        message: str,
        retryable: bool,
        step: str,
        diagnostics: Mapping[str, object],
    ) -> OutboxEventRecord:
        if code == "PURCHASE_CANCELLED":
            status = TaskStatus.CANCELLED
        elif retryable:
            status = TaskStatus.RETRY_WAIT
        else:
            status = TaskStatus.MANUAL_REVIEW
        return self._repository.save_purchase_failure(
            remote_task_id,
            attempt_id,
            status,
            code,
            message,
            retryable,
            step,
            dict(diagnostics),
        )

    def _submit(self, event: OutboxEventRecord) -> PurchaseTaskOutcome:
        task_id = self._repository.outbox_task_id(event.id)
        self._repository.mark_outbox_sending(event.id)
        try:
            if event.event_type is OutboxEventType.TASK_FAILURE:
                receipt = self._gateway.submit_failure(
                    task_id, event.idempotency_key, event.payload_json
                )
            else:
                receipt = self._gateway.submit_result(
                    task_id, event.idempotency_key, event.payload_json
                )
            if not receipt.accepted:
                raise AdminGatewayError(
                    "ADMIN_RESULT_NOT_ACCEPTED",
                    "Admin 未确认接收采购演练结果",
                    False,
                )
        except AdminGatewayError as exc:
            message = str(exc)
            if exc.retryable:
                self._repository.mark_outbox_retry(event.id, message)
                return PurchaseTaskOutcome(
                    "result_pending",
                    f"任务 {task_id} 演练结果已保存在本地，等待提交 Admin：{message}",
                    task_id,
                )
            self._repository.mark_outbox_failed(event.id, message)
            return PurchaseTaskOutcome(
                "manual_review",
                f"任务 {task_id} 演练结果被 Admin 拒绝：{message}",
                task_id,
            )

        self._repository.mark_outbox_sent(event.id)
        if event.event_type is OutboxEventType.TASK_FAILURE:
            return PurchaseTaskOutcome(
                "failed",
                f"任务 {task_id} 采购演练未完成，失败信息已提交 Admin",
                task_id,
            )
        return PurchaseTaskOutcome(
            "succeeded",
            f"任务 {task_id} 演练完成并已提交 Admin；没有提交订单",
            task_id,
        )

    def _result_data(
        self, target: PurchaseTarget, state: PurchasePageState
    ) -> dict[str, object]:
        return {
            "schema_version": 1,
            "goods_id": target.goods_id,
            "goods_url": target.goods_url,
            "purchase": {
                "mode": "dry_run",
                "requested": {
                    "options": dict(target.options),
                    "quantity": target.quantity,
                    "max_price_cent": target.max_price_cent,
                },
                "confirmed": {
                    "options": dict(state.selected_options),
                    "quantity": state.quantity,
                    "unit_price_cent": state.price_cent,
                    "total_price_cent": state.price_cent * state.quantity,
                },
                "confirmation_reached": True,
                "order_submitted": False,
                "payment_attempted": False,
                "order_no": None,
                "ordered_at": None,
                "ordered_at_raw": None,
                "match_status": "not_submitted",
            },
            "captured_at": utc_now_iso(),
            "source": {
                "client_id": self._client.client_id,
                "device_address": self._device_address,
                "mode": "dry_run",
            },
        }