95 lines
3.0 KiB
Python
95 lines
3.0 KiB
Python
"""Helpers for converting uploaded documents into markdown snippets."""
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from __future__ import annotations
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import uuid
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from dataclasses import dataclass
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from pathlib import Path
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import aiofiles
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from fastapi import UploadFile
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from yuxi.config import config as app_config
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from yuxi.plugins.parser import Parser
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from yuxi.utils import logger
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ATTACHMENT_ALLOWED_EXTENSIONS: tuple[str, ...] = ()
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MAX_ATTACHMENT_SIZE_BYTES = 5 * 1024 * 1024 # 5 MB
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MAX_ATTACHMENT_MARKDOWN_CHARS = 32_000
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@dataclass(slots=True)
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class ConversionResult:
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"""Represents the normalized output of an uploaded attachment."""
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file_id: str
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file_name: str
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file_type: str | None
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file_size: int
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markdown: str
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truncated: bool
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def _ensure_workdir() -> Path:
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workdir = Path(app_config.save_dir) / "uploads" / "chat_attachments"
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workdir.mkdir(parents=True, exist_ok=True)
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return workdir
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async def _write_upload_to_disk(upload: UploadFile, dest: Path) -> int:
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await upload.seek(0)
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written = 0
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chunk_size = 1024 * 1024
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async with aiofiles.open(dest, "wb") as buffer:
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while True:
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chunk = await upload.read(chunk_size)
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if not chunk:
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break
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written += len(chunk)
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if written > MAX_ATTACHMENT_SIZE_BYTES:
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raise ValueError("附件过大，当前仅支持 5 MB 以内的文件")
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await buffer.write(chunk)
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return written
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def _truncate_markdown(markdown: str) -> tuple[str, bool]:
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if len(markdown) <= MAX_ATTACHMENT_MARKDOWN_CHARS:
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return markdown, False
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truncated_content = markdown[: MAX_ATTACHMENT_MARKDOWN_CHARS - 100].rstrip()
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truncated_content = f"{truncated_content}\n\n[内容已截断，超出 {MAX_ATTACHMENT_MARKDOWN_CHARS} 字符限制]"
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return truncated_content, True
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async def convert_upload_to_markdown(upload: UploadFile) -> ConversionResult:
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"""Persist an UploadFile temporarily, convert it to markdown, and clean up."""
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if not upload.filename:
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raise ValueError("无法识别的文件名")
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file_name = Path(upload.filename).name
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suffix = Path(file_name).suffix.lower()
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if ATTACHMENT_ALLOWED_EXTENSIONS and suffix not in ATTACHMENT_ALLOWED_EXTENSIONS:
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allowed = ", ".join(ATTACHMENT_ALLOWED_EXTENSIONS)
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raise ValueError(f"不支持的文件类型: {suffix or '未知'}，当前仅支持 {allowed}")
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temp_dir = _ensure_workdir()
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temp_path = temp_dir / f"{uuid.uuid4().hex}{suffix}"
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try:
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file_size = await _write_upload_to_disk(upload, temp_path)
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markdown = await Parser.aparse(str(temp_path))
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markdown, truncated = _truncate_markdown(markdown)
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return ConversionResult(
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file_id=uuid.uuid4().hex,
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file_name=file_name,
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file_type=upload.content_type,
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file_size=file_size,
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markdown=markdown,
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truncated=truncated,
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)
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except Exception as exc: # noqa: BLE001
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logger.error("Attachment conversion failed: %s", exc)
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raise
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