Initial commit: snapAna 截图智能整理工具

包含 FastAPI 后端、React 前端、队列/OCR/标签/待办等完整功能。

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/app/services/exif_utils.py

@@ -0,0 +1,107 @@
+"""从图片 EXIF 提取拍摄时间与 GPS 地点标签。"""
+from __future__ import annotations
+
+from datetime import datetime
+from fractions import Fraction
+from pathlib import Path
+from typing import Optional
+
+from PIL import ExifTags, Image
+
+from app.core.logger import get_logger
+
+
+logger = get_logger(__name__)
+
+# EXIF 地点类标签前缀，重分析时保留不被 AI 覆盖
+EXIF_TAG_PREFIX = "地点:"
+
+
+def _ratio_to_float(value) -> float:
+    """EXIF 有理数 → float。"""
+    if isinstance(value, tuple) and len(value) == 2:
+        num, den = value
+        return float(num) / float(den) if den else 0.0
+    if isinstance(value, Fraction):
+        return float(value)
+    return float(value)
+
+
+def _dms_to_decimal(dms: tuple, ref: str) -> Optional[float]:
+    """度分秒 → 十进制度。"""
+    try:
+        deg, minutes, seconds = dms
+        decimal = _ratio_to_float(deg) + _ratio_to_float(minutes) / 60 + _ratio_to_float(seconds) / 3600
+        if ref in ("S", "W"):
+            decimal = -decimal
+        return round(decimal, 6)
+    except (TypeError, ValueError, ZeroDivisionError):
+        return None
+
+
+def extract_image_metadata(path: Path) -> tuple[Optional[datetime], list[str]]:
+    """读取 EXIF，返回 (拍摄时间, 地点标签列表)。"""
+    captured: Optional[datetime] = None
+    location_tags: list[str] = []
+
+    try:
+        with Image.open(path) as img:
+            exif = img.getexif()
+            if not exif:
+                return None, []
+
+            # 拍摄时间：优先 DateTimeOriginal
+            for key in (36867, 36868, 306):  # DateTimeOriginal / DateTimeDigitized / DateTime
+                raw = exif.get(key)
+                if raw:
+                    captured = _parse_exif_datetime(str(raw))
+                    if captured:
+                        break
+
+            # GPS → 地点标签
+            gps_ifd = exif.get_ifd(ExifTags.IFD.GPSInfo) if hasattr(exif, "get_ifd") else None
+            if gps_ifd:
+                lat = _dms_to_decimal(
+                    gps_ifd.get(2),
+                    gps_ifd.get(1, "N"),
+                )
+                lon = _dms_to_decimal(
+                    gps_ifd.get(4),
+                    gps_ifd.get(3, "E"),
+                )
+                if lat is not None and lon is not None:
+                    location_tags.append(f"{EXIF_TAG_PREFIX}{lat},{lon}")
+
+            # 部分设备写入可读地名（XP Keywords / ImageDescription 等）
+            for key, val in exif.items():
+                tag_name = ExifTags.TAGS.get(key, "")
+                if tag_name in ("ImageDescription", "XPComment") and val:
+                    text = str(val).strip()[:64]
+                    if text and _looks_like_place(text):
+                        location_tags.append(f"{EXIF_TAG_PREFIX}{text}")
+
+    except Exception as exc:  # noqa: BLE001
+        logger.debug("读取 EXIF 失败 %s: %s", path.name, exc)
+
+    return captured, location_tags
+
+
+def _parse_exif_datetime(raw: str) -> Optional[datetime]:
+    """解析 EXIF 时间字符串。"""
+    for fmt in ("%Y:%m:%d %H:%M:%S", "%Y-%m-%d %H:%M:%S"):
+        try:
+            return datetime.strptime(raw.strip(), fmt)
+        except ValueError:
+            continue
+    return None
+
+
+def _looks_like_place(text: str) -> bool:
+    """粗判字符串是否像地名（含中文或常见地址关键词）。"""
+    keywords = ("市", "省", "区", "县", "镇", "村", "路", "街", "国", "GPS")
+    return any(k in text for k in keywords) or any("\u4e00" <= c <= "\u9fff" for c in text)
+
+
+def is_exif_location_tag(name: str) -> bool:
+    """是否为 EXIF 自动写入的地点标签。"""
+    return name.startswith(EXIF_TAG_PREFIX)