First public commit.

lenser/imginfo.py

@@ -0,0 +1,142 @@
+"""Collect descriptive metadata about a source image for the on-disk BASIC
+info program: name, dimensions, format, colour depth, EXIF dates/comments, the
+file's own date, when the C64 version was made, and the host platform.
+"""
+
+from __future__ import annotations
+
+import datetime
+import os
+import platform
+
+from PIL import Image
+
+_DEPTH = {
+    "1": "1 bit mono", "L": "8 bit gray", "LA": "8 bit gray+a",
+    "P": "8 bit palette", "PA": "8 bit pal+a", "RGB": "24 bit rgb",
+    "RGBA": "32 bit rgba", "RGBX": "32 bit rgb", "CMYK": "32 bit cmyk",
+    "YCbCr": "24 bit ycc", "I": "32 bit int", "F": "32 bit float",
+    "I;16": "16 bit gray",
+}
+
+# EXIF tag ids.
+_DATETIME = 306
+_DATETIME_ORIGINAL = 36867
+_DATETIME_DIGITIZED = 36868
+_IMAGE_DESCRIPTION = 270
+_USER_COMMENT = 37510
+_XP_COMMENT = 40092
+_EXIF_IFD = 0x8769
+
+
+def _fmt_ts(ts) -> str:
+    return datetime.datetime.fromtimestamp(ts).strftime("%Y-%m-%d %H:%M")
+
+
+def _parse_exif_dt(value) -> datetime.datetime | None:
+    if isinstance(value, bytes):
+        value = value.decode("ascii", "ignore")
+    try:
+        return datetime.datetime.strptime(str(value).strip(), "%Y:%m:%d %H:%M:%S")
+    except (ValueError, TypeError):
+        return None
+
+
+def _decode_comment(value) -> str | None:
+    if not value:
+        return None
+    if isinstance(value, bytes):
+        raw = value
+        # EXIF UserComment has an 8-byte charset prefix (ASCII / UNICODE / ...).
+        if raw[:8] in (b"ASCII\x00\x00\x00", b"\x00" * 8):
+            raw = raw[8:]
+        elif raw[:8].rstrip(b"\x00") == b"UNICODE":
+            try:
+                return raw[8:].decode("utf-16-be", "ignore").strip("\x00 ") or None
+            except Exception:
+                pass
+        for enc in ("utf-8", "utf-16-le", "latin-1"):
+            try:
+                text = raw.decode(enc, "ignore").strip("\x00 ")
+                if text:
+                    return text
+            except Exception:
+                continue
+        return None
+    text = str(value).strip()
+    return text or None
+
+
+def gather(path: str) -> list[tuple[str, str]]:
+    """Return an ordered list of (label, value) metadata strings."""
+    fields: list[tuple[str, str]] = []
+    fields.append(("name", os.path.basename(path)))
+
+    img = None
+    try:
+        img = Image.open(path)
+    except Exception:
+        pass
+
+    if img is not None:
+        fields.append(("size", f"{img.width} x {img.height}"))
+        fields.append(("format", img.format or "?"))
+        fields.append(("color", _DEPTH.get(img.mode, img.mode)))
+
+    dates: list[datetime.datetime] = []
+    comment = None
+    if img is not None:
+        try:
+            exif = img.getexif()
+            sub = {}
+            try:
+                sub = exif.get_ifd(_EXIF_IFD)
+            except Exception:
+                sub = {}
+            for tag, src in ((_DATETIME, exif), (_DATETIME_ORIGINAL, sub),
+                             (_DATETIME_DIGITIZED, sub)):
+                dt = _parse_exif_dt(src.get(tag))
+                if dt:
+                    dates.append(dt)
+            comment = (_decode_comment(sub.get(_USER_COMMENT))
+                       or _decode_comment(exif.get(_IMAGE_DESCRIPTION))
+                       or _decode_comment(exif.get(_XP_COMMENT)))
+        except Exception:
+            pass
+
+    if dates:
+        fields.append(("exif date", min(dates).strftime("%Y-%m-%d %H:%M")))
+
+    try:
+        st = os.stat(path)
+        birth = getattr(st, "st_birthtime", None)
+        if birth:
+            fields.append(("file date", _fmt_ts(birth)))
+        else:
+            fields.append(("mod date", _fmt_ts(st.st_mtime)))
+    except OSError:
+        pass
+
+    if comment:
+        fields.append(("comment", comment))
+
+    fields.append(("c64 made", datetime.datetime.now().strftime("%Y-%m-%d %H:%M")))
+    fields.append(("system", f"{platform.system()} {platform.release()}"))
+    distro = _linux_distro()
+    if distro:
+        fields.append(("distro", distro))
+    return fields
+
+
+def _linux_distro() -> str | None:
+    """Linux distribution name + version from /etc/os-release, if available."""
+    try:
+        rel = platform.freedesktop_os_release()      # Python 3.10+
+    except (OSError, AttributeError):
+        return None
+    pretty = rel.get("PRETTY_NAME")
+    if pretty:
+        return pretty
+    name = rel.get("NAME", "")
+    version = rel.get("VERSION", rel.get("VERSION_ID", ""))
+    return (f"{name} {version}".strip() or None)