Simplify and caption

src/lib/overlay.py

@@ -0,0 +1,106 @@
+"""Text overlay rendering for the e-ink frame.
+
+Paints aliased white-on-black-stroke text into the dithered palette index
+array; black/white survive Atkinson dithering so edges stay crisp on e-ink.
+"""
+
+import os
+from datetime import datetime, timezone
+
+import numpy as np
+from PIL import Image, ImageDraw, ImageFont
+
+FONT_CANDIDATES = (
+    "/usr/share/fonts/truetype/dejavu/DejaVuSans-Bold.ttf",
+    "/usr/share/fonts/truetype/dejavu/DejaVuSans.ttf",
+    "/usr/share/fonts/truetype/freefont/FreeSansBold.ttf",
+    "/System/Library/Fonts/Helvetica.ttc",
+)
+
+PALETTE_BLACK = 0
+PALETTE_WHITE = 1
+
+
+def _load_font(size: int) -> ImageFont.ImageFont:
+    for path in FONT_CANDIDATES:
+        if os.path.exists(path):
+            return ImageFont.truetype(path, size)
+    return ImageFont.load_default()
+
+
+def format_age(asset: dict) -> str | None:
+    """Photo capture age as 'N days/weeks/months/years ago'."""
+    exif = asset.get("exifInfo") or {}
+    date_str = exif.get("dateTimeOriginal") or asset.get("fileCreatedAt")
+    if not date_str:
+        return None
+    try:
+        dt = datetime.fromisoformat(date_str.replace("Z", "+00:00"))
+    except (ValueError, AttributeError):
+        return None
+    if dt.tzinfo is None:
+        dt = dt.replace(tzinfo=timezone.utc)
+    days = (datetime.now(timezone.utc) - dt).days
+    if days < 0:
+        return None
+    if days == 0:
+        return "Today"
+    if days == 1:
+        return "Yesterday"
+    if days < 7:
+        return f"{days} days ago"
+    for n, unit in ((365, "year"), (30, "month"), (7, "week")):
+        if days >= n:
+            count = max(1, days // n)
+            return f"{count} {unit}{'s' if count > 1 else ''} ago"
+
+
+def format_location(asset: dict) -> str | None:
+    """Most specific location available from EXIF."""
+    exif = asset.get("exifInfo") or {}
+    return exif.get("city") or exif.get("state") or exif.get("country") or None
+
+
+def render_text_into_indices(indices: np.ndarray,
+                             left_text: str | None,
+                             right_text: str | None,
+                             orientation: int = 0) -> None:
+    """Paint white-on-black-stroke text into a (height, width) palette-index array.
+
+    Text is laid out viewer-bottom-left/right, then rotated by `orientation`
+    so labels land at the viewer's bottom regardless of frame mounting.
+    """
+    font_size, margin, stroke_width = 20, 18, 2
+    buffer_h, buffer_w = indices.shape
+    if orientation in (90, 270):
+        view_w, view_h = buffer_h, buffer_w
+    else:
+        view_w, view_h = buffer_w, buffer_h
+
+    fill_layer = Image.new("L", (view_w, view_h), 0)
+    full_layer = Image.new("L", (view_w, view_h), 0)
+    fill_draw = ImageDraw.Draw(fill_layer)
+    full_draw = ImageDraw.Draw(full_layer)
+    font = _load_font(font_size)
+    baseline = view_h - margin
+
+    if left_text:
+        pos = (margin, baseline)
+        fill_draw.text(pos, left_text, font=font, fill=255, anchor="lb")
+        full_draw.text(pos, left_text, font=font, fill=255, anchor="lb",
+                       stroke_width=stroke_width, stroke_fill=255)
+
+    if right_text:
+        pos = (view_w - margin, baseline)
+        fill_draw.text(pos, right_text, font=font, fill=255, anchor="rb")
+        full_draw.text(pos, right_text, font=font, fill=255, anchor="rb",
+                       stroke_width=stroke_width, stroke_fill=255)
+
+    if orientation:
+        fill_layer = fill_layer.rotate(orientation, expand=True)
+        full_layer = full_layer.rotate(orientation, expand=True)
+
+    fill_mask = np.asarray(fill_layer) >= 128
+    stroke_mask = (np.asarray(full_layer) >= 128) & ~fill_mask
+    indices[stroke_mask] = PALETTE_BLACK
+    indices[fill_mask] = PALETTE_WHITE