Initial commit

site/social/media.py

@@ -0,0 +1,91 @@
+"""Helpers for social post media (StoredFile-backed)."""
+
+from __future__ import annotations
+
+import json
+from typing import Any
+
+from django.conf import settings
+from django.urls import reverse
+
+from core.models import StoredFile
+
+ALLOWED_IMAGE_TYPES = frozenset(
+    {"image/jpeg", "image/jpg", "image/png", "image/gif", "image/webp"}
+)
+ALLOWED_VIDEO_TYPES = frozenset(
+    {"video/mp4", "video/quicktime", "video/webm"}
+)
+MAX_IMAGE_BYTES = 8 * 1024 * 1024  # 8 MB
+MAX_VIDEO_BYTES = 100 * 1024 * 1024  # 100 MB
+MAX_IMAGES = 10
+
+
+def public_file_url(file_id: str) -> str:
+    """Absolute URL Meta/LinkedIn can fetch (UUID = capability token)."""
+    base = (settings.PUBLIC_SITE_URL or "").rstrip("/")
+    path = reverse("core:stored_file", kwargs={"pk": file_id})
+    if not base:
+        return path
+    return f"{base}{path}"
+
+
+def media_item_from_stored(stored: StoredFile) -> dict[str, Any]:
+    kind = stored.kind
+    media_type = "video" if kind == StoredFile.Kind.SOCIAL_VIDEO else "image"
+    return {
+        "id": str(stored.pk),
+        "type": media_type,
+        "url": public_file_url(str(stored.pk)),
+        "content_type": stored.content_type,
+        "filename": stored.filename or "",
+        "size": stored.size,
+    }
+
+
+def parse_media_json(raw: str) -> list[dict[str, Any]]:
+    """Parse composer hidden media JSON into a cleaned list."""
+    raw = (raw or "").strip()
+    if not raw:
+        return []
+    try:
+        data = json.loads(raw)
+    except json.JSONDecodeError as exc:
+        raise ValueError("Invalid media payload.") from exc
+    if not isinstance(data, list):
+        raise ValueError("Media payload must be a list.")
+
+    items: list[dict[str, Any]] = []
+    for entry in data:
+        if not isinstance(entry, dict):
+            continue
+        file_id = str(entry.get("id") or "").strip()
+        if not file_id:
+            continue
+        try:
+            stored = StoredFile.objects.get(pk=file_id)
+        except (StoredFile.DoesNotExist, ValueError) as exc:
+            raise ValueError(f"Unknown media file: {file_id}") from exc
+        if stored.kind not in {
+            StoredFile.Kind.SOCIAL_IMAGE,
+            StoredFile.Kind.SOCIAL_VIDEO,
+            StoredFile.Kind.CAMPAIGN_IMAGE,
+        }:
+            raise ValueError("File is not a social media attachment.")
+        items.append(media_item_from_stored(stored))
+
+    videos = [m for m in items if m["type"] == "video"]
+    images = [m for m in items if m["type"] == "image"]
+    if len(videos) > 1:
+        raise ValueError("Attach at most one video per post.")
+    if videos and images:
+        raise ValueError("Use either images or one video — not both.")
+    if len(images) > MAX_IMAGES:
+        raise ValueError(f"Attach at most {MAX_IMAGES} images.")
+    return items
+
+
+def split_media(media: list[dict[str, Any]]) -> tuple[list[dict], list[dict]]:
+    images = [m for m in media if m.get("type") == "image"]
+    videos = [m for m in media if m.get("type") == "video"]
+    return images, videos