From 84e82252dfe46f6d205143c19f9cc86c9346c1fe Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E2=80=9DNyymix=E2=80=9D?= <nyymix@gmail.com>
Date: Sun, 5 Jan 2025 17:23:30 +0200
Subject: [PATCH] Add exif.py

---
 gallery/exif.py | 122 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 122 insertions(+)
 create mode 100644 gallery/exif.py

diff --git a/gallery/exif.py b/gallery/exif.py
new file mode 100644
index 0000000..10706bc
--- /dev/null
+++ b/gallery/exif.py
@@ -0,0 +1,122 @@
+import json
+import logging
+import os
+from datetime import datetime
+
+import pytz
+from PIL import Image, IptcImagePlugin, TiffImagePlugin
+
+logger = logging.getLogger(__name__)
+
+""" Required exif values """
+TAGS_EXIF = {
+    0x9003: "DateTimeOriginal",
+    0x829D: "FNumber",
+    0x829A: "ExposureTime",
+    0x8827: "ISOSpeedRatings",
+    0x9204: "ExposureBiasValue",
+    0x8822: "ExposureProgram",
+    0x9207: "MeteringMode",
+    0x920A: "FocalLength",
+    0xA405: "FocalLengthIn35mmFilm",
+    0x0110: "Model",
+    0xA434: "LensModel",
+}
+
+""" Required iptc values """
+TAGS_IPTC = {
+    (2, 25): "Keywords",
+    (2, 55): "DateCreated",
+    (2, 60): "TimeCreated",
+}
+
+
+class Exif:
+
+    def __init__(self, filename: str):
+        self.filename = filename
+        self._exif = {}
+        self._iptc = {}
+        self.data = {}
+
+        self._process_image()
+        self._read_exif()
+        self._read_iptc()
+
+    def _process_image(self):
+        """ Open and verify image file """
+        try:
+            with Image.open(self.filename) as self.img:
+                self.img.verify()
+        except (OSError, IOError) as e:
+            logger.exception('Could not open or verify image: %s', self.filename)
+            raise e
+
+    def _read_exif(self):
+        """ Read and process EXIF metadata """
+        try:
+            exif_data = self.img._getexif()
+            if exif_data is not None:
+                self._exif = {
+                    TAGS_EXIF[k]: v
+                    for k, v in exif_data.items()
+                    if k in TAGS_EXIF
+                }
+                for key, value in self._exif.items():
+                    if isinstance(value, TiffImagePlugin.IFDRational):
+                        self.data[key] = float(value)
+                    elif isinstance(value, tuple):
+                        self.data[key] = tuple(float(t) if isinstance(t, TiffImagePlugin.IFDRational) else t for t in value)
+                    elif isinstance(value, bytes):
+                        self.data[key] = value.decode('utf-8')
+                    else:
+                        self.data[key] = value
+        except AttributeError:
+            logger.warning('No EXIF metadata found for: %s', self.filename)
+        except Exception as e:
+            logger.warning('Could not read EXIF metadata from: %s, Error: %s', self.filename, e)
+
+    def _read_iptc(self):
+        """ Read and process IPTC metadata """
+        try:
+            iptc_data = IptcImagePlugin.getiptcinfo(self.img)
+            if iptc_data is not None:
+                self._iptc = {
+                    TAGS_IPTC[k]: v
+                    for k, v in iptc_data.items()
+                    if k in TAGS_IPTC
+                }
+                for key, value in self._iptc.items():
+                    if isinstance(value, list):
+                        self.data[key] = [x.decode('utf-8') for x in value]
+                    else:
+                        self.data[key] = value.decode('utf-8')
+        except Exception as e:
+            logger.warning('Could not read IPTC metadata from: %s, Error: %s', self.filename, e)
+
+    def datetimeoriginal(self, timezone='UTC'):
+        """ Return DateTimeOriginal with timezone, or fallback to file creation date if not available. """
+        if 'DateTimeOriginal' in self.data:
+            try:
+                return datetime.strptime(self.data['DateTimeOriginal'], "%Y:%m:%d %H:%M:%S").astimezone(pytz.timezone(timezone))
+            except ValueError:
+                logger.warning('Invalid EXIF DateTimeOriginal format in: %s', self.filename)
+
+        # If EXIF DateTimeOriginal is not available, fallback to file creation date
+        try:
+            creation_time = os.path.getctime(self.filename)
+            return datetime.fromtimestamp(creation_time).astimezone(pytz.timezone(timezone))
+        except Exception as e:
+            logger.warning('Could not retrieve file creation date for: %s, Error: %s', self.filename, e)
+            return datetime.now(pytz.timezone(timezone))  # Fallback to current time if all else fails
+
+    def json(self):
+        """ Return exif data in json format """
+        return json.dumps(self.data)
+
+    def keywords(self):
+        """ Return Keywords list """
+        return self.data.get('Keywords', [])
+
+    def __str__(self):
+        return self.filename