Capture back-face printing images for double-faced cards

Add a back_image_uri column to printings, populated during ingest from
a card's second card_faces image (only present for transform/MDFC/
reversible cards — split/adventure cards share one combined image and
correctly get ""). Plumb it through CardRef across every query path
(search, library, filters, deck contents) via the same printing row,
using a shared deterministic ORDER BY so front/back always come from
one printing.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

crates/mtgc-core/src/db.rs

@@ -21,12 +21,16 @@ const LIBRARY_MIGRATIONS: &[&str] = &[
 /// The attached alias under which the reference db is available at runtime.
 pub const REF_DB: &str = "ref";
 
-/// Correlated subquery selecting one image URL for the oracle card aliased `oc`.
+/// Correlated subquery selecting one column from the same printing (the first,
-/// Returns NULL when no printing has an image. Read it as `Option<String>`.
+/// by `rowid`, with a non-empty front image) for the oracle card aliased `oc`.
-pub fn image_subquery() -> String {
+/// Call once per desired column (e.g. `"image_uri"`, `"back_image_uri"`) — the
+/// shared `ORDER BY p.rowid` ensures they all resolve to the *same* printing
+/// row. Returns NULL when no printing has an image; read as `Option<String>`.
+pub fn image_subquery(column: &str) -> String {
     format!(
-        "(SELECT p.image_uri FROM {REF_DB}.printings p
+        "(SELECT p.{column} FROM {REF_DB}.printings p
-          WHERE p.oracle_id = oc.oracle_id AND p.image_uri <> '' LIMIT 1)"
+          WHERE p.oracle_id = oc.oracle_id AND p.image_uri <> ''
+          ORDER BY p.rowid LIMIT 1)"
     )
 }
 

crates/mtgc-core/src/decks.rs

@@ -82,13 +82,14 @@ impl Catalog {
         let mut stmt = self.conn.prepare(&format!(
             "SELECT dc.quantity, dc.is_commander, COALESCE(lc.quantity_owned, 0),
                     oc.oracle_id, oc.name, oc.mana_value, oc.colors, oc.color_identity,
-                    oc.type_line, {image}
+                    oc.type_line, {image}, {back}
              FROM deck_cards dc
              JOIN {REF_DB}.oracle_cards oc ON oc.oracle_id = dc.oracle_id
              LEFT JOIN library_cards lc ON lc.oracle_id = dc.oracle_id
              WHERE dc.deck_id = ?1
              ORDER BY oc.name COLLATE NOCASE",
-            image = crate::db::image_subquery()
+            image = crate::db::image_subquery("image_uri"),
+            back = crate::db::image_subquery("back_image_uri")
         ))?;
         let rows = stmt
             .query_map(params![deck_id], |r| {
@@ -104,6 +105,7 @@ impl Catalog {
                         color_identity: ColorSet(r.get::<_, i64>(7)? as u8),
                         type_line: r.get(8)?,
                         image_uri: r.get::<_, Option<String>>(9)?.unwrap_or_default(),
+                        back_image_uri: r.get::<_, Option<String>>(10)?.unwrap_or_default(),
                     },
                 })
             })?

crates/mtgc-core/src/filters.rs

@@ -18,11 +18,12 @@ impl Catalog {
     pub fn search_library(&self, filter: &LibraryFilter) -> Result<Vec<LibraryCard>> {
         let mut sql = format!(
             "SELECT lc.oracle_id, lc.quantity_owned, lc.location,
-                    oc.name, oc.mana_value, oc.colors, oc.color_identity, oc.type_line, {image}
+                    oc.name, oc.mana_value, oc.colors, oc.color_identity, oc.type_line, {image}, {back}
              FROM library_cards lc
              JOIN {REF_DB}.oracle_cards oc ON oc.oracle_id = lc.oracle_id
              WHERE lc.quantity_owned > 0",
-            image = crate::db::image_subquery()
+            image = crate::db::image_subquery("image_uri"),
+            back = crate::db::image_subquery("back_image_uri")
         );
         let mut vals: Vec<Value> = Vec::new();
 

crates/mtgc-core/src/ingest.rs

@@ -599,8 +599,8 @@ fn load_printings(conn: &Connection, reader: impl Read, cancel: &CancelToken) ->
     {
         let mut ins = conn.prepare(
             "INSERT OR IGNORE INTO printings
-               (scryfall_id,oracle_id,set_code,collector_number,finishes,rarity,image_uri)
+               (scryfall_id,oracle_id,set_code,collector_number,finishes,rarity,image_uri,back_image_uri)
-             VALUES (?1,?2,?3,?4,?5,?6,?7)",
+             VALUES (?1,?2,?3,?4,?5,?6,?7,?8)",
         )?;
         stream_json_array::<_, ScryPrinting, _>(reader, |p| {
             if cancel.is_cancelled() {
@@ -621,6 +621,16 @@ fn load_printings(conn: &Connection, reader: impl Read, cancel: &CancelToken) ->
                         .and_then(|i| i.normal.clone())
                 })
                 .unwrap_or_default();
+            // Only transform/modal-DFC/reversible cards carry per-face images
+            // with a distinct second face; split/adventure cards share one
+            // combined top-level image and have no per-face `image_uris`.
+            let back_image = p
+                .card_faces
+                .as_ref()
+                .and_then(|f| f.get(1))
+                .and_then(|f| f.image_uris.as_ref())
+                .and_then(|i| i.normal.clone())
+                .unwrap_or_default();
             ins.execute(params![
                 p.id,
                 oracle_id,
@@ -629,6 +639,7 @@ fn load_printings(conn: &Connection, reader: impl Read, cancel: &CancelToken) ->
                 p.finishes.join(","),
                 p.rarity,
                 image,
+                back_image,
             ])?;
             count += 1;
             Ok(())
@@ -785,4 +796,51 @@ mod tests {
             .unwrap();
         assert_eq!(g as u8, crate::model::G);
     }
+
+    #[test]
+    fn captures_back_face_image_for_double_faced_cards() {
+        // Transform/MDFC cards: two `card_faces`, each with its own image.
+        let dfc = r#"[
+          {"id":"p-dfc","oracle_id":"oid-dfc","set":"znr","collector_number":"1",
+           "rarity":"rare",
+           "card_faces":[
+             {"image_uris":{"normal":"http://img/front"}},
+             {"image_uris":{"normal":"http://img/back"}}
+           ]}
+        ]"#;
+        // Split card: two `card_faces` for oracle text, but no per-face images —
+        // the whole card is one combined top-level image.
+        let split = r#"[
+          {"id":"p-split","oracle_id":"oid-split","set":"grn","collector_number":"2",
+           "rarity":"common","image_uris":{"normal":"http://img/split-combined"},
+           "card_faces":[{"image_uris":null},{"image_uris":null}]}
+        ]"#;
+
+        let dir = tempfile::tempdir().unwrap();
+        let dest = dir.path().join("reference.db");
+        let conn = open_reference_for_build(&dest).unwrap();
+
+        load_printings(&conn, dfc.as_bytes(), &CancelToken::new()).unwrap();
+        load_printings(&conn, split.as_bytes(), &CancelToken::new()).unwrap();
+
+        let (front, back): (String, String) = conn
+            .query_row(
+                "SELECT image_uri, back_image_uri FROM printings WHERE scryfall_id='p-dfc'",
+                [],
+                |r| Ok((r.get(0)?, r.get(1)?)),
+            )
+            .unwrap();
+        assert_eq!(front, "http://img/front");
+        assert_eq!(back, "http://img/back");
+
+        let (front, back): (String, String) = conn
+            .query_row(
+                "SELECT image_uri, back_image_uri FROM printings WHERE scryfall_id='p-split'",
+                [],
+                |r| Ok((r.get(0)?, r.get(1)?)),
+            )
+            .unwrap();
+        assert_eq!(front, "http://img/split-combined");
+        assert_eq!(back, "", "split cards have no distinct back face");
+    }
 }

crates/mtgc-core/src/library.rs

@@ -10,8 +10,8 @@ use crate::model::{CardRef, ColorSet, LibraryCard};
 use crate::Catalog;
 
 /// Map a row shaped `(oracle_id, quantity_owned, location, name, mana_value,
-/// colors, color_identity, type_line, image_uri)` into its library parts. Shared
+/// colors, color_identity, type_line, image_uri, back_image_uri)` into its
-/// by [`Catalog::list_library`] and the criteria search.
+/// library parts. Shared by [`Catalog::list_library`] and the criteria search.
 pub(crate) fn row_to_library_parts(
     r: &rusqlite::Row,
 ) -> rusqlite::Result<(String, i64, String, CardRef)> {
@@ -28,6 +28,7 @@ pub(crate) fn row_to_library_parts(
             color_identity: ColorSet(r.get::<_, i64>(6)? as u8),
             type_line: r.get(7)?,
             image_uri: r.get::<_, Option<String>>(8)?.unwrap_or_default(),
+            back_image_uri: r.get::<_, Option<String>>(9)?.unwrap_or_default(),
         },
     ))
 }
@@ -69,12 +70,13 @@ impl Catalog {
 
         let mut stmt = self.conn.prepare(&format!(
             "SELECT lc.oracle_id, lc.quantity_owned, lc.location,
-                    oc.name, oc.mana_value, oc.colors, oc.color_identity, oc.type_line, {image}
+                    oc.name, oc.mana_value, oc.colors, oc.color_identity, oc.type_line, {image}, {back}
              FROM library_cards lc
              JOIN {REF_DB}.oracle_cards oc ON oc.oracle_id = lc.oracle_id
              WHERE lc.quantity_owned > 0
              ORDER BY oc.name COLLATE NOCASE",
-            image = crate::db::image_subquery()
+            image = crate::db::image_subquery("image_uri"),
+            back = crate::db::image_subquery("back_image_uri")
         ))?;
         let rows = stmt
             .query_map([], row_to_library_parts)?
@@ -155,6 +157,29 @@ mod tests {
         assert_eq!(sol.card.image_uri, "http://img/sol-ring");
     }
 
+    #[test]
+    fn back_image_uri_is_plumbed_through() {
+        let fx = test_support::make();
+        let cat = &fx.catalog;
+        cat.connection()
+            .execute(
+                "UPDATE ref.printings SET back_image_uri = 'http://img/back' \
+                 WHERE oracle_id = 'sol-ring'",
+                [],
+            )
+            .unwrap();
+        cat.add_owned("sol-ring", 1).unwrap();
+
+        cat.add_owned("llanowar-elves", 1).unwrap();
+        let lib = cat.list_library().unwrap();
+        let sol = lib.iter().find(|c| c.card.oracle_id == "sol-ring").unwrap();
+        assert_eq!(sol.card.back_image_uri, "http://img/back");
+
+        // Single-faced cards have no back image.
+        let elves = lib.iter().find(|c| c.card.oracle_id == "llanowar-elves").unwrap();
+        assert_eq!(elves.card.back_image_uri, "");
+    }
+
     #[test]
     fn location_is_stored_and_listed() {
         let fx = test_support::make();

crates/mtgc-core/src/model.rs

@@ -88,6 +88,9 @@ pub struct CardRef {
     /// URL of a card image (Scryfall "normal" size) for one of its printings,
     /// or empty if none is available.
     pub image_uri: String,
+    /// URL of the *back face* image for the same printing (transform / modal
+    /// double-faced / reversible cards), or empty for single-faced cards.
+    pub back_image_uri: String,
 }
 
 /// A library row: a card the user owns, with quantity and its deck memberships.

crates/mtgc-core/src/search.rs

@@ -34,9 +34,10 @@ impl NameIndex {
     pub fn build(conn: &Connection) -> Result<Self> {
         let mut stmt = conn.prepare(&format!(
             "SELECT oc.oracle_id, oc.name, oc.mana_value, oc.colors, oc.color_identity,
-                    oc.type_line, {image}
+                    oc.type_line, {image}, {back}
              FROM {REF_DB}.oracle_cards oc",
-            image = crate::db::image_subquery()
+            image = crate::db::image_subquery("image_uri"),
+            back = crate::db::image_subquery("back_image_uri")
         ))?;
         let entries = stmt
             .query_map([], |r| {
@@ -49,6 +50,7 @@ impl NameIndex {
                         color_identity: ColorSet(r.get::<_, i64>(4)? as u8),
                         type_line: r.get(5)?,
                         image_uri: r.get::<_, Option<String>>(6)?.unwrap_or_default(),
+                        back_image_uri: r.get::<_, Option<String>>(7)?.unwrap_or_default(),
                     },
                 })
             })?

crates/mtgc-core/src/sql/reference_schema.sql

@@ -46,7 +46,8 @@ CREATE TABLE IF NOT EXISTS printings (
     collector_number TEXT NOT NULL DEFAULT '',
     finishes         TEXT NOT NULL DEFAULT '',   -- comma-joined, e.g. "nonfoil,foil"
     rarity           TEXT NOT NULL DEFAULT '',
-    image_uri        TEXT NOT NULL DEFAULT ''
+    image_uri        TEXT NOT NULL DEFAULT '',
+    back_image_uri   TEXT NOT NULL DEFAULT ''   -- transform/MDFC/reversible back face
 );
 CREATE INDEX IF NOT EXISTS idx_printings_oid ON printings(oracle_id);