X-Financial/server/src/app/services/steward_planner.py

from __future__ import annotations

import re
import uuid
from dataclasses import dataclass
from datetime import UTC, date, datetime, timedelta
from typing import Any

from app.schemas.steward import (
    StewardAttachmentGroup,
    StewardAttachmentInput,
    StewardConfirmationAction,
    StewardPlanRequest,
    StewardPlanResponse,
    StewardTask,
    StewardThinkingEvent,
)
from app.services.steward_constants import BUSINESS_CANONICAL_FIELD_ORDER, BUSINESS_CANONICAL_FIELDS
from app.services.ontology_field_registry import normalize_ontology_form_values
from app.services.steward_intent_agent import StewardIntentAgent
from app.services.steward_model_plan_builder import StewardModelPlanBuilder


CITY_NAMES = (
    "北京",
    "上海",
    "广州",
    "深圳",
    "杭州",
    "南京",
    "苏州",
    "成都",
    "重庆",
    "天津",
    "武汉",
    "西安",
    "长沙",
    "郑州",
    "青岛",
    "厦门",
    "福州",
    "合肥",
    "济南",
    "沈阳",
    "大连",
    "宁波",
    "无锡",
)

APPLICATION_SPLIT_PATTERN = re.compile(r"(?:^|[，,。；;])[^，,。；;]*?(?:申请|出差申请|差旅申请)[^，,。；;]*")
REIMBURSEMENT_PATTERN = re.compile(r"(?:我要报销|还需要报销|需要报销|报销)([^，,。；;！？?!\n]+)")
MONTH_DAY_PATTERN = re.compile(r"(?P<month>\d{1,2})\s*月\s*(?P<day>\d{1,2})\s*(?:日|号)?")
ISO_DATE_PATTERN = re.compile(r"(?P<year>\d{4})[-/年](?P<month>\d{1,2})[-/月](?P<day>\d{1,2})(?:日)?")


@dataclass(frozen=True)
class PlannedTaskDraft:
    task_type: str
    segment: str
    index: int


class StewardPlannerService:
    """小财管家第一版规划服务：只生成计划，不执行入库类动作。"""

    def __init__(self, intent_agent: StewardIntentAgent | None = None) -> None:
        self.intent_agent = intent_agent

    def build_plan(self, request: StewardPlanRequest) -> StewardPlanResponse:
        message = self._clean_text(request.message)
        if not message:
            raise ValueError("小财管家需要一段任务描述。")

        base_date = self._resolve_base_date(request.client_now_iso, request.context_json)
        model_call_traces: list[dict[str, Any]] = []
        fallback_reason = ""
        if self.intent_agent is not None:
            try:
                intent_result = self.intent_agent.detect(
                    request,
                    base_date=base_date,
                    canonical_fields=list(BUSINESS_CANONICAL_FIELD_ORDER),
                )
                if intent_result is not None:
                    model_call_traces = intent_result.model_call_traces
                    llm_plan = StewardModelPlanBuilder(self).build(
                        intent_result,
                        request=request,
                        base_date=base_date,
                    )
                    if llm_plan is not None:
                        return llm_plan
                model_call_traces = getattr(self.intent_agent, "last_call_traces", []) or model_call_traces
                fallback_reason = "主模型未返回可用的 function calling 计划，已切换到规则兜底。"
            except Exception as exc:
                model_call_traces = getattr(self.intent_agent, "last_call_traces", []) or model_call_traces
                fallback_reason = f"主模型 function calling 调用失败，已切换到规则兜底：{exc}"

        return self._build_rule_fallback_plan(
            request,
            base_date=base_date,
            model_call_traces=model_call_traces,
            fallback_reason=fallback_reason,
        )

    def _build_rule_fallback_plan(
        self,
        request: StewardPlanRequest,
        *,
        base_date: date,
        model_call_traces: list[dict[str, Any]] | None = None,
        fallback_reason: str = "",
    ) -> StewardPlanResponse:
        message = self._clean_text(request.message)
        task_drafts = self._extract_task_drafts(message)
        tasks = [self._build_task(draft, base_date, request) for draft in task_drafts]
        if not tasks:
            tasks = [self._build_fallback_task(message, base_date, request)]

        attachment_groups = self._build_attachment_groups(request.attachments, tasks)
        confirmation_groups = self._build_confirmation_actions(tasks, attachment_groups)
        thinking_events = self._build_thinking_events(tasks, attachment_groups, request.attachments)
        if fallback_reason:
            thinking_events.insert(
                0,
                StewardThinkingEvent(
                    event_id="intent_agent_rule_fallback",
                    stage="rule_fallback",
                    title="意图识别智能体进入兜底模式",
                    content=fallback_reason,
                ),
            )
        plan_id = f"steward_plan_{uuid.uuid4().hex[:12]}"

        return StewardPlanResponse(
            plan_id=plan_id,
            plan_status="needs_confirmation" if confirmation_groups else "ready_to_delegate",
            planning_source="rule_fallback",
            summary=self._build_summary(tasks, attachment_groups),
            thinking_events=thinking_events,
            tasks=tasks,
            attachment_groups=attachment_groups,
            confirmation_groups=confirmation_groups,
            model_call_traces=model_call_traces or [],
        )

    def _extract_task_drafts(self, message: str) -> list[PlannedTaskDraft]:
        drafts: list[PlannedTaskDraft] = []
        first_reimbursement = self._find_first_reimbursement_index(message)
        application_source = message[:first_reimbursement] if first_reimbursement >= 0 else message
        if self._looks_like_application(application_source) or self._looks_like_future_travel_application(application_source):
            drafts.append(
                PlannedTaskDraft(
                    task_type="expense_application",
                    segment=application_source.strip("，,。；; "),
                    index=len(drafts) + 1,
                )
            )

        for match in REIMBURSEMENT_PATTERN.finditer(message):
            segment = f"报销{match.group(1)}"
            drafts.append(
                PlannedTaskDraft(
                    task_type="reimbursement",
                    segment=segment.strip("，,。；; "),
                    index=len(drafts) + 1,
                )
            )

        return drafts

    @staticmethod
    def _find_first_reimbursement_index(message: str) -> int:
        candidates = [message.find(item) for item in ("我要报销", "还需要报销", "需要报销", "报销")]
        positives = [item for item in candidates if item >= 0]
        return min(positives) if positives else -1

    @staticmethod
    def _looks_like_application(text: str) -> bool:
        compact = re.sub(r"\s+", "", text)
        return bool(compact) and "申请" in compact and bool(re.search(r"出差|差旅|费用|交通|住宿|采购|会务|会议", compact))

    @staticmethod
    def _looks_like_future_travel_application(text: str) -> bool:
        compact = re.sub(r"\s+", "", text)
        if not compact or "报销" in compact:
            return False
        business_signal = re.search(
            r"出差|差旅|客户现场|项目|部署|实施|支撑|支持|协助|拜访|调研|培训|会议|驻场|上线|验收",
            compact,
        )
        route_signal = re.search(
            fr"(?:去|到|赴|前往)({'|'.join(CITY_NAMES)})",
            compact,
        )
        time_signal = re.search(
            r"明天|后天|下周|下月|近期|月底|\d{1,2}月\d{1,2}(?:日|号)?|"
            r"\d{4}[-/年]\d{1,2}[-/月]\d{1,2}(?:日)?|[0-9一二两三四五六七八九十]+天",
            compact,
        )
        planned_route_signal = re.search(
            r"(?:去|到|赴|前往).{0,24}(?:出差|差旅|客户|现场|项目|部署|实施|支撑|支持|协助|拜访|调研|培训|会议|驻场|上线|验收)|"
            r"(?:出差|差旅).{0,24}(?:[0-9一二两三四五六七八九十]+天|客户|现场|项目|部署|实施|支撑|支持|协助|拜访|调研|培训|会议|驻场|上线|验收)",
            compact,
        )
        return bool((business_signal or route_signal) and (time_signal or planned_route_signal))

    def _build_task(
        self,
        draft: PlannedTaskDraft,
        base_date: date,
        request: StewardPlanRequest,
    ) -> StewardTask:
        fields = self._extract_ontology_fields(draft.segment, draft.task_type, base_date, request)
        missing_fields = self._resolve_missing_fields(draft.task_type, fields)
        task_id = f"task_{'app' if draft.task_type == 'expense_application' else 'reim'}_{draft.index:03d}"
        assigned_agent = (
            "application_assistant"
            if draft.task_type == "expense_application"
            else "reimbursement_assistant"
        )
        title_prefix = "费用申请" if draft.task_type == "expense_application" else "费用报销"
        title = self._build_task_title(title_prefix, fields, draft.index)
        return StewardTask(
            task_id=task_id,
            task_type=draft.task_type,  # type: ignore[arg-type]
            assigned_agent=assigned_agent,  # type: ignore[arg-type]
            title=title,
            summary=self._build_task_summary(draft.segment, fields),
            status="needs_confirmation",
            confidence=self._resolve_task_confidence(draft.segment, fields, draft.task_type),
            ontology_fields=fields,
            missing_fields=missing_fields,
            confirmation_required=True,
        )

    def _build_fallback_task(
        self,
        message: str,
        base_date: date,
        request: StewardPlanRequest,
    ) -> StewardTask:
        task_type = "reimbursement" if "报销" in message or request.attachments else "expense_application"
        draft = PlannedTaskDraft(task_type=task_type, segment=message, index=1)
        task = self._build_task(draft, base_date, request)
        return task.model_copy(update={"confidence": min(task.confidence, 0.58)})

    def _extract_ontology_fields(
        self,
        segment: str,
        task_type: str,
        base_date: date,
        request: StewardPlanRequest,
    ) -> dict[str, str]:
        normalized_context = normalize_ontology_form_values(request.context_json.get("review_form_values"))
        fields: dict[str, str] = {
            key: value
            for key, value in normalized_context.items()
            if key in BUSINESS_CANONICAL_FIELDS and str(value or "").strip()
        }
        expense_type = self._infer_expense_type(segment, task_type)
        if expense_type and not fields.get("expense_type"):
            fields["expense_type"] = expense_type
        time_range = self._extract_time_range(segment, base_date)
        if time_range and not fields.get("time_range"):
            fields["time_range"] = time_range
        location = self._extract_location(segment)
        if location and not fields.get("location"):
            fields["location"] = location
        reason = self._extract_reason(segment, task_type)
        if reason and not fields.get("reason"):
            fields["reason"] = reason
        transport_mode = self._extract_transport_mode(segment)
        if transport_mode and not fields.get("transport_mode"):
            fields["transport_mode"] = transport_mode
        if request.attachments:
            fields["attachments"] = "、".join(item.name for item in request.attachments if item.name)

        return {key: value for key, value in fields.items() if key in BUSINESS_CANONICAL_FIELDS and value}

    @staticmethod
    def _infer_expense_type(segment: str, task_type: str) -> str:
        compact = re.sub(r"\s+", "", segment)
        if re.search(r"招待|接待|餐饮|宴请|客户吃饭|业务餐", compact):
            return "entertainment"
        if re.search(r"出差|差旅|住宿|酒店|机票|航班|高铁|火车", compact):
            return "travel"
        if re.search(r"交通|出租车|的士|网约车|打车|地铁|公交", compact):
            return "transport" if task_type == "reimbursement" else "travel"
        return "travel" if task_type == "expense_application" else "other"

    def _extract_time_range(self, segment: str, base_date: date) -> str:
        compact = re.sub(r"\s+", "", segment)
        if "昨天" in compact:
            return (base_date - timedelta(days=1)).isoformat()
        if "前天" in compact:
            return (base_date - timedelta(days=2)).isoformat()
        if "明天" in compact:
            return (base_date + timedelta(days=1)).isoformat()
        if "后天" in compact:
            return (base_date + timedelta(days=2)).isoformat()

        iso_match = ISO_DATE_PATTERN.search(compact)
        if iso_match:
            return self._safe_date(
                int(iso_match.group("year")),
                int(iso_match.group("month")),
                int(iso_match.group("day")),
            )

        month_day = MONTH_DAY_PATTERN.search(compact)
        if month_day:
            return self._safe_date(
                base_date.year,
                int(month_day.group("month")),
                int(month_day.group("day")),
            )
        return ""

    @staticmethod
    def _safe_date(year: int, month: int, day: int) -> str:
        try:
            return date(year, month, day).isoformat()
        except ValueError:
            return ""

    @staticmethod
    def _extract_location(segment: str) -> str:
        compact = re.sub(r"\s+", "", segment)
        for prefix in ("去", "到", "赴", "前往"):
            match = re.search(fr"{prefix}({'|'.join(CITY_NAMES)})", compact)
            if match:
                return match.group(1)
        for city in CITY_NAMES:
            if city in compact:
                return city
        return ""

    @staticmethod
    def _extract_reason(segment: str, task_type: str) -> str:
        cleaned = re.sub(r"\s+", "", segment).strip("，,。；; ")
        if task_type == "expense_application":
            match = re.search(r"(辅助|支持|协助|支撑|参加|拜访|调研|实施|部署|审核).+", cleaned)
            if match:
                return StewardPlannerService._strip_trailing_connectors(match.group(0))
            reason = re.sub(r"^.*?(?:出差|差旅)", "", cleaned).strip("，,。；;的费用")
            return StewardPlannerService._strip_trailing_connectors(reason) or cleaned
        cleaned = re.sub(r"^报销", "", cleaned)
        cleaned = re.sub(r"^(?:昨天|前天|明天|后天|\d{1,2}月\d{1,2}(?:日|号)?)的?", "", cleaned)
        return cleaned.strip("，,。；; ") or segment.strip()

    @staticmethod
    def _strip_trailing_connectors(value: str) -> str:
        cleaned = str(value or "").strip("，,。；; ")
        return re.sub(r"(?:并且|而且|同时|另外|还需要|需要)$", "", cleaned).strip("，,。；; ")

    @staticmethod
    def _extract_transport_mode(segment: str) -> str:
        compact = re.sub(r"\s+", "", segment)
        if re.search(r"高铁|动车|火车", compact):
            return "train"
        if re.search(r"飞机|机票|航班", compact):
            return "flight"
        if re.search(r"出租车|的士|网约车|打车", compact):
            return "taxi"
        if "交通" in compact:
            return "other"
        return ""

    @staticmethod
    def _resolve_missing_fields(task_type: str, fields: dict[str, str]) -> list[str]:
        required = ["expense_type", "time_range", "reason"]
        if task_type == "expense_application":
            required.append("location")
        return [key for key in required if not str(fields.get(key) or "").strip()]

    @staticmethod
    def _resolve_task_confidence(segment: str, fields: dict[str, str], task_type: str) -> float:
        compact = re.sub(r"\s+", "", segment)
        if task_type == "expense_application":
            intent_score = 1.0 if (
                "申请" in compact or StewardPlannerService._looks_like_future_travel_application(compact)
            ) else 0.45
        else:
            intent_score = 1.0 if "报销" in compact else 0.45
        time_score = 1.0 if fields.get("time_range") else 0.0
        location_score = 1.0 if fields.get("location") else 0.2
        scene_score = 1.0 if fields.get("expense_type") and fields["expense_type"] != "other" else 0.35
        confidence = min(1.0, 0.35 * intent_score + 0.25 * time_score + 0.2 * location_score + 0.2 * scene_score)
        return round(max(0.45, confidence), 2)

    def _build_attachment_groups(
        self,
        attachments: list[StewardAttachmentInput],
        tasks: list[StewardTask],
    ) -> list[StewardAttachmentGroup]:
        if not attachments:
            return []

        classified = [(item, self._classify_attachment(item)) for item in attachments if item.name]
        travel_related = [item.name for item, scene in classified if scene in {"travel", "transport"}]
        excluded = [item.name for item, scene in classified if scene not in {"travel", "transport"}]
        target_task = self._resolve_attachment_target_task(tasks)

        groups: list[StewardAttachmentGroup] = []
        if travel_related:
            confidence = 0.72 + min(0.18, len(travel_related) * 0.04)
            groups.append(
                StewardAttachmentGroup(
                    group_id="ag_travel_001",
                    target_task_id=target_task.task_id if target_task else None,
                    scene="travel",
                    scene_label="差旅相关费用",
                    attachment_names=travel_related,
                    excluded_attachment_names=excluded,
                    confidence=round(confidence, 2),
                    rationale="附件名称或 OCR 摘要中包含差旅、交通、住宿、火车、机票等线索。",
                    confirmation_required=True,
                )
            )
        elif excluded:
            groups.append(
                StewardAttachmentGroup(
                    group_id="ag_other_001",
                    target_task_id=None,
                    scene="other",
                    scene_label="待人工确认费用",
                    attachment_names=excluded,
                    excluded_attachment_names=[],
                    confidence=0.5,
                    rationale="当前附件缺少可稳定归属到申请或报销任务的差旅线索。",
                    confirmation_required=True,
                )
            )
        return groups

    @staticmethod
    def _resolve_attachment_target_task(tasks: list[StewardTask]) -> StewardTask | None:
        reimbursement_tasks = [item for item in tasks if item.task_type == "reimbursement"]
        for task in reimbursement_tasks:
            if task.ontology_fields.get("expense_type") == "travel":
                return task
        return reimbursement_tasks[0] if reimbursement_tasks else None

    @staticmethod
    def _classify_attachment(attachment: StewardAttachmentInput) -> str:
        text = " ".join(
            [
                attachment.name,
                attachment.media_type,
                attachment.ocr_summary,
                " ".join(f"{key}:{value}" for key, value in attachment.ocr_fields.items()),
            ]
        )
        compact = re.sub(r"\s+", "", text).lower()
        if re.search(r"招待|接待|餐饮|宴请|客户|meal|entertainment", compact):
            return "entertainment"
        if re.search(r"酒店|住宿|差旅|出差|高铁|火车|动车|机票|航班|train|flight|hotel|travel", compact):
            return "travel"
        if re.search(r"出租车|的士|网约车|打车|交通|taxi|transport", compact):
            return "transport"
        return "other"

    def _build_confirmation_actions(
        self,
        tasks: list[StewardTask],
        attachment_groups: list[StewardAttachmentGroup],
    ) -> list[StewardConfirmationAction]:
        actions: list[StewardConfirmationAction] = []
        for task in tasks:
            if task.task_type == "expense_application":
                action_type = "confirm_create_application"
                label = "确认创建申请单"
            else:
                action_type = "confirm_create_reimbursement_draft"
                label = "确认创建报销草稿"
            actions.append(
                StewardConfirmationAction(
                    confirmation_id=f"confirm_{task.task_id}",
                    action_type=action_type,
                    label=label,
                    description=f"确认后把“{task.title}”交给{self._agent_label(task.assigned_agent)}继续核对。",
                    target_task_id=task.task_id,
                    payload={
                        "task_id": task.task_id,
                        "task_type": task.task_type,
                        "assigned_agent": task.assigned_agent,
                        "ontology_fields": task.ontology_fields,
                    },
                )
            )

        for group in attachment_groups:
            actions.append(
                StewardConfirmationAction(
                    confirmation_id=f"confirm_{group.group_id}",
                    action_type="confirm_attachment_group",
                    label="确认附件归集",
                    description=f"确认后将 {len(group.attachment_names)} 份附件按“{group.scene_label}”归集。",
                    target_task_id=group.target_task_id,
                    attachment_group_id=group.group_id,
                    payload={
                        "attachment_group_id": group.group_id,
                        "target_task_id": group.target_task_id,
                        "attachment_names": group.attachment_names,
                        "excluded_attachment_names": group.excluded_attachment_names,
                    },
                )
            )
        return actions

    @staticmethod
    def _agent_label(assigned_agent: str) -> str:
        return "申请助手" if assigned_agent == "application_assistant" else "报销助手"

    def _build_thinking_events(
        self,
        tasks: list[StewardTask],
        attachment_groups: list[StewardAttachmentGroup],
        attachments: list[StewardAttachmentInput],
    ) -> list[StewardThinkingEvent]:
        application_count = sum(1 for item in tasks if item.task_type == "expense_application")
        reimbursement_count = sum(1 for item in tasks if item.task_type == "reimbursement")
        task_intent_summary = self._summarize_task_intents(tasks)
        ontology_summary = self._summarize_ontology_coverage(tasks)
        delegation_summary = self._summarize_delegation_targets(tasks)
        events = [
            StewardThinkingEvent(
                event_id="intent_agent_entry",
                stage="intent_agent",
                title="意图识别智能体接管",
                content=(
                    f"检测到复合财务话术，当前不是单一助手会话；"
                    f"已进入小财管家编排模式，候选任务共 {len(tasks)} 个。"
                ),
            ),
            StewardThinkingEvent(
                event_id="intent_task_split",
                stage="task_split",
                title=f"拆分申请 {application_count} 个、报销 {reimbursement_count} 个",
                content=task_intent_summary,
            ),
            StewardThinkingEvent(
                event_id="intent_ontology_mapping",
                stage="ontology_mapping",
                title="映射业务本体字段",
                content=ontology_summary,
            ),
        ]
        if attachments:
            events.append(
                StewardThinkingEvent(
                    event_id="intent_attachment_correlation",
                    stage="attachment_correlation",
                    title="关联附件与任务线索",
                    content=self._summarize_attachment_correlation(attachment_groups, len(attachments)),
                )
            )
        events.append(
            StewardThinkingEvent(
                event_id="intent_delegation_gate",
                stage="delegation_gate",
                title="生成确认点并准备分派",
                content=f"{delegation_summary} 创建单据、生成草稿、绑定附件和提交审批都会等待用户确认。",
            )
        )
        return events

    @staticmethod
    def _summarize_task_intents(tasks: list[StewardTask]) -> str:
        if not tasks:
            return "当前输入尚未形成稳定任务，先保留为待确认财务事项。"
        parts = []
        for task in tasks:
            task_label = "申请" if task.task_type == "expense_application" else "报销"
            fields = task.ontology_fields
            anchors = []
            if fields.get("time_range"):
                anchors.append(fields["time_range"])
            if fields.get("location"):
                anchors.append(fields["location"])
            if fields.get("expense_type"):
                anchors.append(fields["expense_type"])
            anchor_text = "、".join(anchors) if anchors else "待补充关键字段"
            parts.append(f"{task_label}：{task.title}（{anchor_text}）")
        return "；".join(parts)

    @staticmethod
    def _summarize_ontology_coverage(tasks: list[StewardTask]) -> str:
        canonical_keys = []
        missing_keys = []
        for task in tasks:
            canonical_keys.extend(task.ontology_fields.keys())
            missing_keys.extend(task.missing_fields)
        unique_keys = sorted({item for item in canonical_keys if item})
        unique_missing = sorted({item for item in missing_keys if item})
        mapped = "、".join(unique_keys) if unique_keys else "暂无稳定字段"
        missing = "；缺失字段：" + "、".join(unique_missing) if unique_missing else ""
        return f"已使用 canonical ontology fields：{mapped}{missing}。兼容字段只作为输入别名，不直接进入业务逻辑。"

    @staticmethod
    def _summarize_attachment_correlation(
        attachment_groups: list[StewardAttachmentGroup],
        total_attachment_count: int,
    ) -> str:
        grouped_names = []
        excluded_names = []
        for group in attachment_groups:
            grouped_names.extend(group.attachment_names)
            excluded_names.extend(group.excluded_attachment_names)
        grouped_text = "、".join(grouped_names) if grouped_names else "暂无可稳定归集附件"
        excluded_text = "；排除或单独确认：" + "、".join(excluded_names) if excluded_names else ""
        return f"已核对 {total_attachment_count} 份附件，建议归集：{grouped_text}{excluded_text}。"

    @staticmethod
    def _summarize_delegation_targets(tasks: list[StewardTask]) -> str:
        application_count = sum(1 for item in tasks if item.assigned_agent == "application_assistant")
        reimbursement_count = sum(1 for item in tasks if item.assigned_agent == "reimbursement_assistant")
        parts = []
        if application_count:
            parts.append(f"{application_count} 个申请任务交给申请助手")
        if reimbursement_count:
            parts.append(f"{reimbursement_count} 个报销任务交给报销助手")
        return "；".join(parts) + "。" if parts else "尚无可分派任务。"

    @staticmethod
    def _build_summary(tasks: list[StewardTask], attachment_groups: list[StewardAttachmentGroup]) -> str:
        parts = [f"我识别到 {len(tasks)} 个待处理任务"]
        if attachment_groups:
            grouped = sum(len(item.attachment_names) for item in attachment_groups)
            parts.append(f"并形成 {grouped} 份附件的归集建议")
        parts.append("，请确认后我再分派给对应助手执行。")
        return "".join(parts)

    @staticmethod
    def _build_task_title(prefix: str, fields: dict[str, str], index: int) -> str:
        location = fields.get("location", "")
        time_range = fields.get("time_range", "")
        expense_type = fields.get("expense_type", "")
        subject = location or {"travel": "差旅", "transport": "交通", "entertainment": "招待"}.get(expense_type, "")
        if subject and time_range:
            return f"{prefix} {time_range} {subject}"
        if subject:
            return f"{prefix} {subject}"
        return f"{prefix} {index}"

    @staticmethod
    def _build_task_summary(segment: str, fields: dict[str, str]) -> str:
        field_parts = []
        for key, label in (
            ("time_range", "时间"),
            ("location", "地点"),
            ("expense_type", "费用类型"),
            ("reason", "事由"),
            ("transport_mode", "交通方式"),
        ):
            value = fields.get(key)
            if value:
                field_parts.append(f"{label}：{value}")
        return "；".join(field_parts) or segment

    @staticmethod
    def _resolve_base_date(client_now_iso: str | None, context_json: dict[str, Any]) -> date:
        raw_value = client_now_iso or str(context_json.get("client_now_iso") or "").strip()
        if raw_value:
            try:
                parsed = datetime.fromisoformat(raw_value.replace("Z", "+00:00"))
                return parsed.date()
            except ValueError:
                pass
        return datetime.now(UTC).date()

    @staticmethod
    def _clean_text(value: Any) -> str:
        return re.sub(r"\s+", " ", str(value or "")).strip()