DataMate/runtime/datamate-python/app/module/annotation/service/editor.py

"""
标注编辑器（Label Studio Editor）服务

职责：
- 解析 DataMate 标注项目（t_dm_labeling_projects）
- 以“文件下载/预览接口”读取文本内容，构造 Label Studio task
- 以原始 annotation JSON 形式 upsert 最终标注结果（单人单份）
"""

from __future__ import annotations

import uuid
from datetime import datetime
from typing import Any, Dict, List, Optional, Tuple

import hashlib
import httpx
from fastapi import HTTPException
from sqlalchemy import func, select
from sqlalchemy.ext.asyncio import AsyncSession

from app.core.config import settings
from app.core.logging import get_logger
from app.db.models import AnnotationResult, Dataset, DatasetFiles, LabelingProject
from app.module.annotation.schema.editor import (
    EditorProjectInfo,
    EditorTaskListItem,
    EditorTaskListResponse,
    EditorTaskResponse,
    SegmentInfo,
    UpsertAnnotationRequest,
    UpsertAnnotationResponse,
)
from app.module.annotation.service.template import AnnotationTemplateService
from app.module.annotation.service.annotation_text_splitter import AnnotationTextSplitter

logger = get_logger(__name__)


class AnnotationEditorService:
    """Label Studio Editor 集成服务（TEXT POC 版）"""

    # 分段阈值：超过此字符数自动分段
    SEGMENT_THRESHOLD = 200

    def __init__(self, db: AsyncSession):
        self.db = db
        self.template_service = AnnotationTemplateService()

    @staticmethod
    def _stable_ls_id(seed: str) -> int:
        """
        生成稳定的 Label Studio 风格整数 ID（JS 安全整数范围内）。

        说明：
        - Label Studio Frontend 的 mobx-state-tree 模型对 task/annotation 的 id 有类型约束（通常为 number）。
        - DataMate 使用 UUID 作为 file_id/project_id，因此需映射为整数供编辑器使用。
        - 取 sha1 的前 13 个 hex（52bit），落在 JS Number 的安全整数范围。
        """
        digest = hashlib.sha1(seed.encode("utf-8")).hexdigest()
        value = int(digest[:13], 16)
        return value if value > 0 else 1

    def _make_ls_task_id(self, project_id: str, file_id: str) -> int:
        return self._stable_ls_id(f"task:{project_id}:{file_id}")

    def _make_ls_annotation_id(self, project_id: str, file_id: str) -> int:
        # 单人单份最终标签：每个 task 只保留一个 annotation，id 直接与 task 绑定即可
        return self._stable_ls_id(f"annotation:{project_id}:{file_id}")

    async def _get_project_or_404(self, project_id: str) -> LabelingProject:
        result = await self.db.execute(
            select(LabelingProject).where(
                LabelingProject.id == project_id,
                LabelingProject.deleted_at.is_(None),
            )
        )
        project = result.scalar_one_or_none()
        if not project:
            raise HTTPException(status_code=404, detail=f"标注项目不存在: {project_id}")
        return project

    async def _get_dataset_type(self, dataset_id: str) -> Optional[str]:
        result = await self.db.execute(
            select(Dataset.dataset_type).where(Dataset.id == dataset_id)
        )
        return result.scalar_one_or_none()

    async def _get_label_config(self, template_id: Optional[str]) -> Optional[str]:
        if not template_id:
            return None
        template = await self.template_service.get_template(self.db, template_id)
        return getattr(template, "label_config", None) if template else None

    async def get_project_info(self, project_id: str) -> EditorProjectInfo:
        project = await self._get_project_or_404(project_id)

        dataset_type = await self._get_dataset_type(project.dataset_id)
        supported = (dataset_type or "").upper() == "TEXT"
        unsupported_reason = None
        if not supported:
            unsupported_reason = f"当前仅支持 TEXT，项目数据类型为: {dataset_type or 'UNKNOWN'}"

        # 优先使用项目配置中的label_config（用户编辑版本），其次使用模板默认配置
        label_config = None
        if project.configuration and isinstance(project.configuration, dict):
            label_config = project.configuration.get("label_config")
        if not label_config:
            label_config = await self._get_label_config(project.template_id)

        return EditorProjectInfo(
            projectId=project.id,
            datasetId=project.dataset_id,
            templateId=project.template_id,
            labelConfig=label_config,
            supported=supported,
            unsupportedReason=unsupported_reason,
        )

    async def list_tasks(self, project_id: str, page: int = 0, size: int = 50) -> EditorTaskListResponse:
        project = await self._get_project_or_404(project_id)

        count_result = await self.db.execute(
            select(func.count()).select_from(DatasetFiles).where(
                DatasetFiles.dataset_id == project.dataset_id
            )
        )
        total = int(count_result.scalar() or 0)

        files_result = await self.db.execute(
            select(DatasetFiles)
            .where(DatasetFiles.dataset_id == project.dataset_id)
            .order_by(DatasetFiles.created_at.desc())
            .offset(page * size)
            .limit(size)
        )
        files = files_result.scalars().all()

        file_ids = [str(f.id) for f in files]  # type: ignore[arg-type]
        updated_map: Dict[str, datetime] = {}
        if file_ids:
            ann_result = await self.db.execute(
                select(AnnotationResult.file_id, AnnotationResult.updated_at).where(
                    AnnotationResult.project_id == project_id,
                    AnnotationResult.file_id.in_(file_ids),
                )
            )
            for file_id, updated_at in ann_result.all():
                if file_id and updated_at:
                    updated_map[str(file_id)] = updated_at

        items: List[EditorTaskListItem] = []
        for f in files:
            fid = str(f.id)  # type: ignore[arg-type]
            items.append(
                EditorTaskListItem(
                    fileId=fid,
                    fileName=str(getattr(f, "file_name", "")),
                    fileType=getattr(f, "file_type", None),
                    hasAnnotation=fid in updated_map,
                    annotationUpdatedAt=updated_map.get(fid),
                )
            )

        total_pages = (total + size - 1) // size if size > 0 else 0
        return EditorTaskListResponse(
            content=items,
            totalElements=total,
            totalPages=total_pages,
            page=page,
            size=size,
        )

    async def _fetch_text_content_via_download_api(self, dataset_id: str, file_id: str) -> str:
        base = settings.datamate_backend_base_url.rstrip("/")
        url = f"{base}/data-management/datasets/{dataset_id}/files/{file_id}/download"

        try:
            async with httpx.AsyncClient(timeout=30.0, follow_redirects=True) as client:
                resp = await client.get(url)
                resp.raise_for_status()

                content_length = resp.headers.get("content-length")
                if content_length:
                    try:
                        if int(content_length) > settings.editor_max_text_bytes:
                            raise HTTPException(
                                status_code=413,
                                detail=f"文本文件过大，限制 {settings.editor_max_text_bytes} 字节",
                            )
                    except ValueError:
                        # content-length 非法则忽略，走实际长度判断
                        pass

                data = resp.content
                if len(data) > settings.editor_max_text_bytes:
                    raise HTTPException(
                        status_code=413,
                        detail=f"文本文件过大，限制 {settings.editor_max_text_bytes} 字节",
                    )

                # TEXT POC：默认按 UTF-8 解码，不可解码字符用替换符处理
                return data.decode("utf-8", errors="replace")

        except HTTPException:
            raise
        except httpx.HTTPStatusError as e:
            logger.error(f"读取文本失败: dataset={dataset_id}, file={file_id}, http={e.response.status_code}")
            raise HTTPException(status_code=502, detail="读取文本失败（下载接口返回错误）")
        except Exception as e:
            logger.error(f"读取文本失败: dataset={dataset_id}, file={file_id}, err={e}")
            raise HTTPException(status_code=502, detail="读取文本失败（下载接口调用异常）")

    async def get_task(
        self,
        project_id: str,
        file_id: str,
        segment_index: Optional[int] = None,
    ) -> EditorTaskResponse:
        project = await self._get_project_or_404(project_id)

        # TEXT 支持校验
        dataset_type = await self._get_dataset_type(project.dataset_id)
        if (dataset_type or "").upper() != "TEXT":
            raise HTTPException(status_code=400, detail="当前仅支持 TEXT 项目的内嵌编辑器")

        file_result = await self.db.execute(
            select(DatasetFiles).where(
                DatasetFiles.id == file_id,
                DatasetFiles.dataset_id == project.dataset_id,
            )
        )
        file_record = file_result.scalar_one_or_none()
        if not file_record:
            raise HTTPException(status_code=404, detail=f"文件不存在或不属于该项目: {file_id}")

        text_content = await self._fetch_text_content_via_download_api(project.dataset_id, file_id)

        # 获取现有标注
        ann_result = await self.db.execute(
            select(AnnotationResult).where(
                AnnotationResult.project_id == project_id,
                AnnotationResult.file_id == file_id,
            )
        )
        ann = ann_result.scalar_one_or_none()

        ls_task_id = self._make_ls_task_id(project_id, file_id)

        # 判断是否需要分段
        needs_segmentation = len(text_content) > self.SEGMENT_THRESHOLD
        segments: Optional[List[SegmentInfo]] = None
        current_segment_index = 0
        display_text = text_content

        if needs_segmentation:
            splitter = AnnotationTextSplitter(max_chars=self.SEGMENT_THRESHOLD)
            raw_segments = splitter.split(text_content)
            current_segment_index = segment_index if segment_index is not None else 0

            # 校验段落索引
            if current_segment_index < 0 or current_segment_index >= len(raw_segments):
                current_segment_index = 0

            # 标记每个段落是否已有标注
            segment_annotations: Dict[str, Any] = {}
            if ann and ann.annotation and ann.annotation.get("segmented"):
                segment_annotations = ann.annotation.get("segments", {})

            segments = []
            for seg in raw_segments:
                segments.append(SegmentInfo(
                    idx=seg["idx"],
                    text=seg["text"],
                    start=seg["start"],
                    end=seg["end"],
                    hasAnnotation=str(seg["idx"]) in segment_annotations,
                ))

            # 当前段落文本用于 task.data.text
            display_text = raw_segments[current_segment_index]["text"]

        # 构造 task 对象
        task: Dict[str, Any] = {
            "id": ls_task_id,
            "data": {
                "text": display_text,
                "file_id": file_id,
                "dataset_id": project.dataset_id,
                "file_name": getattr(file_record, "file_name", ""),
            },
            "annotations": [],
        }

        annotation_updated_at = None
        if ann:
            annotation_updated_at = ann.updated_at

            if needs_segmentation and ann.annotation and ann.annotation.get("segmented"):
                # 分段模式：获取当前段落的标注
                segment_annotations = ann.annotation.get("segments", {})
                seg_ann = segment_annotations.get(str(current_segment_index), {})
                stored = {
                    "id": self._make_ls_annotation_id(project_id, file_id) + current_segment_index,
                    "task": ls_task_id,
                    "result": seg_ann.get("result", []),
                    "created_at": seg_ann.get("created_at", datetime.utcnow().isoformat() + "Z"),
                    "updated_at": seg_ann.get("updated_at", datetime.utcnow().isoformat() + "Z"),
                }
                task["annotations"] = [stored]
            elif not needs_segmentation:
                # 非分段模式：直接返回存储的 annotation 原始对象
                stored = dict(ann.annotation or {})
                stored["task"] = ls_task_id
                if not isinstance(stored.get("id"), int):
                    stored["id"] = self._make_ls_annotation_id(project_id, file_id)
                task["annotations"] = [stored]
            else:
                # 首次从非分段切换到分段：提供空标注
                empty_ann_id = self._make_ls_annotation_id(project_id, file_id) + current_segment_index
                task["annotations"] = [
                    {
                        "id": empty_ann_id,
                        "task": ls_task_id,
                        "result": [],
                        "created_at": datetime.utcnow().isoformat() + "Z",
                        "updated_at": datetime.utcnow().isoformat() + "Z",
                    }
                ]
        else:
            # 提供一个空 annotation，避免前端在没有选中 annotation 时无法产生 result
            empty_ann_id = self._make_ls_annotation_id(project_id, file_id)
            if needs_segmentation:
                empty_ann_id += current_segment_index
            task["annotations"] = [
                {
                    "id": empty_ann_id,
                    "task": ls_task_id,
                    "result": [],
                    "created_at": datetime.utcnow().isoformat() + "Z",
                    "updated_at": datetime.utcnow().isoformat() + "Z",
                }
            ]

        return EditorTaskResponse(
            task=task,
            annotationUpdatedAt=annotation_updated_at,
            segmented=needs_segmentation,
            segments=segments,
            totalSegments=len(segments) if segments else 1,
            currentSegmentIndex=current_segment_index,
        )

    async def upsert_annotation(self, project_id: str, file_id: str, request: UpsertAnnotationRequest) -> UpsertAnnotationResponse:
        project = await self._get_project_or_404(project_id)

        # 校验文件归属
        file_check = await self.db.execute(
            select(DatasetFiles.id).where(
                DatasetFiles.id == file_id,
                DatasetFiles.dataset_id == project.dataset_id,
            )
        )
        if not file_check.scalar_one_or_none():
            raise HTTPException(status_code=404, detail=f"文件不存在或不属于该项目: {file_id}")

        annotation_payload = dict(request.annotation or {})
        result = annotation_payload.get("result")
        if not isinstance(result, list):
            raise HTTPException(status_code=400, detail="annotation.result 必须为数组")

        ls_task_id = self._make_ls_task_id(project_id, file_id)

        existing_result = await self.db.execute(
            select(AnnotationResult).where(
                AnnotationResult.project_id == project_id,
                AnnotationResult.file_id == file_id,
            )
        )
        existing = existing_result.scalar_one_or_none()

        now = datetime.utcnow()

        # 判断是否为分段保存模式
        if request.segment_index is not None:
            # 分段模式：合并段落标注到整体结构
            final_payload = self._merge_segment_annotation(
                existing.annotation if existing else None,
                request.segment_index,
                annotation_payload,
            )
        else:
            # 非分段模式：直接使用传入的 annotation
            annotation_payload["task"] = ls_task_id
            if not isinstance(annotation_payload.get("id"), int):
                annotation_payload["id"] = self._make_ls_annotation_id(project_id, file_id)
            final_payload = annotation_payload

        if existing:
            if request.expected_updated_at and existing.updated_at:
                if existing.updated_at != request.expected_updated_at.replace(tzinfo=None):
                    raise HTTPException(status_code=409, detail="标注已被更新，请刷新后重试")

            existing.annotation = final_payload  # type: ignore[assignment]
            existing.updated_at = now  # type: ignore[assignment]
            await self.db.commit()
            await self.db.refresh(existing)

            return UpsertAnnotationResponse(
                annotationId=existing.id,
                updatedAt=existing.updated_at or now,
            )

        new_id = str(uuid.uuid4())
        record = AnnotationResult(
            id=new_id,
            project_id=project_id,
            file_id=file_id,
            annotation=final_payload,
            created_at=now,
            updated_at=now,
        )
        self.db.add(record)
        await self.db.commit()
        await self.db.refresh(record)

        return UpsertAnnotationResponse(
            annotationId=record.id,
            updatedAt=record.updated_at or now,
        )

    def _merge_segment_annotation(
        self,
        existing: Optional[Dict[str, Any]],
        segment_index: int,
        new_annotation: Dict[str, Any],
    ) -> Dict[str, Any]:
        """
        合并段落标注到整体结构

        Args:
            existing: 现有的 annotation 数据
            segment_index: 段落索引
            new_annotation: 新的段落标注数据

        Returns:
            合并后的 annotation 结构
        """
        if not existing or not existing.get("segmented"):
            # 初始化分段结构
            base: Dict[str, Any] = {
                "segmented": True,
                "version": 1,
                "segments": {},
            }
        else:
            base = dict(existing)

        # 更新指定段落的标注
        base["segments"][str(segment_index)] = {
            "result": new_annotation.get("result", []),
            "created_at": new_annotation.get("created_at", datetime.utcnow().isoformat() + "Z"),
            "updated_at": datetime.utcnow().isoformat() + "Z",
        }

        return base