diora-web/docs/library.md

Folders and the library (redesign)

Folders everywhere: tags shown as filter chips

One idea of a folder for every area — Bücher, Zeitschriften, Hörbücher, Podcasts, Blogs (and the news' Ressorts, which already work this way):

• A thing can be in several folders (they work like tags); none is fine.
• Folders are filters, not rooms: a row of chips on top — Alle · <folder> n · … · Ohne Ordner — tapping one filters in place; no "inside a folder" view, no back button. On a wide window the row wraps.
• Assigning: mark one or more things (long press / ☐ select mode, or ⋮ on one), then "In Ordner …": a sheet with every folder of the area as checkboxes and "Neuer Ordner". No typing a name that must match.
• Managing (⋮ on the chip row → "Ordner verwalten"): rename, merge (rename onto an existing name), delete (the things stay, only the folder goes), reorder by dragging. The order is the chip order.
• Automatic groups stay automatic and look different from folders (no chip; a stack/group heading): audiobook series, magazine periodicals.

Where folders are kept

Area	Field	Notes
E-books, magazines	encrypted meta folders: [names]	folder (the first) kept for older clients; read folders or else [folder]
Audiobooks, podcasts	PodcastFeed.folders (JSON list)	feed setting folders; folder (string) still accepted
Blogs	Source.folders (exists)
News	Source.category (one Ressort)	already chips in Nachrichten

The folder order per area: e-books in the encrypted user settings blob (names are private), the others on the server (/podcasts/folders/, /feeds/folders/, {order: [names]}).

Shared code: static/js/folders.js (diora-web, every platform)

DioraFolders.chips(el, {folders: [{name, count}], active, none: count|0, onPick(name|''|null), onManage()})
DioraFolders.assign({title, folders: [names], selected: [names], onDone(names)})     // the sheet
DioraFolders.manage({folders: [names], onRename(old, new), onDelete(name), onOrder(names)})

Each area keeps its own storage and calls these for the look and the dialogs.

The library (Bücher, Zeitschriften)

• Header: title, search (title, author), sort (zuletzt gelesen · Titel · Autor · hinzugefügt), ⊞/☰ grid or list, + (Buch hinzufügen, Aus Cloud).
• Filter chips: Alle · Angefangen · Ungelesen · Gelesen — then the folders.
• Weiterlesen: one card on top (cover, title, "Seite 132 von 186 · gestern", ▶), not repeated in the list below.
• Grid (default on phone and desktop): covers with a progress line, title. List (default on e-ink / diora Reader): one row per book, small cover, title, author, % / ✓.

Covers, end-to-end encrypted

A client that has a book's file extracts its cover (EPUB: the OPF cover image; PDF: page 1), scales it to 240 px wide JPEG, encrypts it with the user's key (AES-GCM like the meta) and uploads it once: POST /books/<id>/cover/ {cover_ct, cover_iv}. GET /books/ lists has_cover; GET /books/<id>/cover/ returns {cover_ct, cover_iv}. Clients cache the decrypted image locally. The server never sees a cover.

Generated covers

A book without a cover (or one set to cover: 'generated' in its meta) gets one drawn by static/js/gencover.js: an SVG, the same on every device, never stored. A concept (motif, palettes, typeface) is chosen by score:

• words in the title (3), the shelf category (2) and the author (2, only at a name's start). A stem of five letters or more counts anywhere (German compounds), a shorter one at a word's start, one of three letters as a whole word; ^ / $ in the list force a word's start / end.
• the folders, by name (FOLDER_THEMES): the first counts 2.5 — more than an author or shelf word, less than a title word — further ones 1.

Concepts: konstruktiv (Marx), geometrie (Philosophie: rings, turning squares, triangle/circle/square), psyche (Psychoanalyse: two ellipses, the Borromean knot, a spiral), karte (Geschichte), kosmos (Science-Fiction), ornament (Fantasy), raster (Politik, Soziologie), schatten (Krimi: a red line, a lit doorway), grusel (Horror), klassiker (patterned paper with a title plate), sakral (Religion & Mythologie), spiel (Kinder & Jugend), code (Informatik), typo, wellen, botanik, berge, zellen — and bauhaus when nothing matches. A hash of title and author picks palette, layout and every detail.