First commit

metadatamanager.py

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+"""
+Metadata Manager Module for Bagheera.
+
+This module provides a dedicated class for handling various metadata formats
+like EXIF, IPTC, and XMP, using the exiv2 library.
+
+Classes:
+    MetadataManager: A class with static methods to read metadata from files.
+"""
+import os
+from PySide6.QtDBus import QDBusConnection, QDBusMessage, QDBus
+try:
+    import exiv2
+    HAVE_EXIV2 = True
+except ImportError:
+    exiv2 = None
+    HAVE_EXIV2 = False
+from utils import preserve_mtime
+
+
+def notify_baloo(path):
+    """
+    Notifies the Baloo file indexer about a file change using DBus.
+
+    This is an asynchronous, non-blocking call. It's more efficient than
+    calling `balooctl` via subprocess.
+
+    Args:
+        path (str): The absolute path of the file that was modified.
+    """
+    if not path:
+        return
+
+    # Use QDBusMessage directly for robust calling
+    msg = QDBusMessage.createMethodCall(
+        "org.kde.baloo.file", "/org/kde/baloo/file",
+        "org.kde.baloo.file.indexer", "indexFile"
+    )
+    msg.setArguments([path])
+    QDBusConnection.sessionBus().call(msg, QDBus.NoBlock)
+
+
+class MetadataManager:
+    """Manages reading EXIF, IPTC, and XMP metadata."""
+
+    @staticmethod
+    def read_all_metadata(path):
+        """
+        Reads all available EXIF, IPTC, and XMP metadata from a file.
+
+        Args:
+            path (str): The path to the image file.
+
+        Returns:
+            dict: A dictionary containing all found metadata key-value pairs.
+                  Returns an empty dictionary if exiv2 is not available or on error.
+        """
+        if not HAVE_EXIV2:
+            return {}
+
+        all_metadata = {}
+        try:
+            image = exiv2.ImageFactory.open(path)
+            image.readMetadata()
+
+            # EXIF
+            for datum in image.exifData():
+                if datum.toString():
+                    all_metadata[datum.key()] = datum.toString()
+
+            # IPTC
+            for datum in image.iptcData():
+                if datum.toString():
+                    all_metadata[datum.key()] = datum.toString()
+
+            # XMP
+            for datum in image.xmpData():
+                if datum.toString():
+                    all_metadata[datum.key()] = datum.toString()
+
+        except Exception as e:
+            print(f"Error reading metadata for {path}: {e}")
+
+        return all_metadata
+
+
+class XattrManager:
+    """A manager class to handle reading and writing extended attributes (xattrs)."""
+    @staticmethod
+    def get_attribute(path_or_fd, attr_name, default_value=""):
+        """
+        Gets a string value from a file's extended attribute. This is a disk read.
+
+        Args:
+            path_or_fd (str or int): The path to the file or a file descriptor.
+            attr_name (str): The name of the extended attribute.
+            default_value (any): The value to return if the attribute is not found.
+
+        Returns:
+            str: The attribute value or the default value.
+        """
+        if path_or_fd is None or path_or_fd == "":
+            return default_value
+        try:
+            return os.getxattr(path_or_fd, attr_name).decode('utf-8')
+        except (OSError, AttributeError):
+            return default_value
+
+    @staticmethod
+    def set_attribute(file_path, attr_name, value):
+        """
+        Sets a string value for a file's extended attribute.
+
+        If the value is None or an empty string, the attribute is removed.
+
+        Args:
+            file_path (str): The path to the file.
+            attr_name (str): The name of the extended attribute.
+            value (str or None): The value to set.
+
+        Raises:
+            IOError: If the attribute could not be saved.
+        """
+        if not file_path:
+            return
+        try:
+            with preserve_mtime(file_path):
+                if value:
+                    os.setxattr(file_path, attr_name, str(value).encode('utf-8'))
+                else:
+                    try:
+                        os.removexattr(file_path, attr_name)
+                    except OSError:
+                        pass
+            notify_baloo(file_path)
+        except Exception as e:
+            raise IOError(f"Could not save xattr '{attr_name}' "
+                          "for {file_path}: {e}") from e