feat(dao): load a line's cross-references and sources with their books

dao/src/commonMain/kotlin/io/github/kdroidfilter/seforimlibrary/dao/repository/SeforimRepository.kt

@@ -1664,6 +1664,60 @@ class SeforimRepository(databasePath: String, private val driver: SqlDriver) : L
         forward + inverse
     }
 
+    /**
+     * The lines that the cross-reference links of [lineIds] point to: REFERENCE and MESORAT_HASHAS in
+     * both directions (these links are unoriented and stored once), EIN_MISHPAT forward only (its
+     * reverse is the SOURCE view). A line is returned once, however many links reach it; the lines of
+     * [lineIds] themselves are left out.
+     */
+    suspend fun getReferencesForLines(lineIds: Collection<Long>): List<LineReference> =
+        withContext(Dispatchers.IO) {
+            if (lineIds.isEmpty()) return@withContext emptyList()
+            database.linkQueriesQueries.selectReferencesByLineIds(lineIds, lineIds) {
+                    _, connectionType, fromLineId, lineId, bookId, lineIndex, heRef, content, bookTitle, categoryId, bookOrderIndex ->
+                lineReference(connectionType, fromLineId, lineId, bookId, lineIndex, heRef, content, bookTitle, categoryId, bookOrderIndex)
+            }.executeAsList()
+                .filter { it.line.id !in lineIds }
+                .distinctBy { it.line.id }
+        }
+
+    /**
+     * The lines that [lineIds] comment on (the SOURCE view), as [getReferencesForLines] returns its
+     * lines, in the SOURCE view's order. A line is returned once, however many links reach it.
+     */
+    suspend fun getSourcesForLines(lineIds: Collection<Long>): List<LineReference> =
+        withContext(Dispatchers.IO) {
+            if (lineIds.isEmpty()) return@withContext emptyList()
+            database.linkQueriesQueries.selectSourcesByLineIds(lineIds) {
+                    _, _, fromLineId, lineId, bookId, lineIndex, heRef, content, bookTitle, categoryId, bookOrderIndex ->
+                lineReference(
+                    ConnectionType.SOURCE.name, fromLineId, lineId, bookId, lineIndex, heRef, content, bookTitle, categoryId,
+                    bookOrderIndex,
+                )
+            }.executeAsList()
+                .distinctBy { it.line.id }
+        }
+
+    private fun lineReference(
+        connectionType: String,
+        fromLineId: Long,
+        lineId: Long,
+        bookId: Long,
+        lineIndex: Long,
+        heRef: String?,
+        content: String,
+        bookTitle: String,
+        categoryId: Long,
+        bookOrderIndex: Long,
+    ) = LineReference(
+        connectionType = ConnectionType.fromString(connectionType),
+        fromLineId = fromLineId,
+        line = Line(id = lineId, bookId = bookId, lineIndex = lineIndex.toInt(), content = content, heRef = heRef),
+        bookTitle = bookTitle,
+        categoryId = categoryId,
+        bookOrderIndex = bookOrderIndex.toInt(),
+    )
+
     /**
      * Lightweight variant for prefetch/navigation use cases; omits target text content.
      * When [includeSources] is false (default), only forward links are returned — callers
@@ -2984,3 +3038,14 @@ data class CommentarySummary(
     val link: Link,
     val targetBookTitle: String
 )
+
+/** A line a cross-reference link reaches, with what its book's grouping needs. */
+data class LineReference(
+    val connectionType: ConnectionType,
+    /** The line of the request this link starts from. */
+    val fromLineId: Long,
+    val line: Line,
+    val bookTitle: String,
+    val categoryId: Long,
+    val bookOrderIndex: Int,
+)

dao/src/commonMain/sqldelight/io/github/kdroidfilter/seforimlibrary/db/LinkQueries.sq

@@ -343,3 +343,37 @@ WHERE l.targetBookId = ?
   AND l.sourceBookId != l.targetBookId
 GROUP BY l.sourceBookId, b.title, a.name
 ORDER BY MAX(l.isDeclaredBase) DESC, b.isBaseBook DESC, b.orderIndex, b.title;
+
+-- The cross-reference links of lines: the line on the other side of each link, with its book.
+-- REFERENCE and MESORAT_HASHAS are unoriented (stored once): both directions. EIN_MISHPAT runs from
+-- a line to the codes that rule on it: forward only, its reverse being the SOURCE view.
+selectReferencesByLineIds:
+SELECT l.id AS linkId, ct.name AS connectionType, l.sourceLineId AS fromLineId, ol.id AS lineId, ol.bookId, ol.lineIndex, ol.heRef, ol.content,
+       b.title AS bookTitle, b.categoryId, b.orderIndex AS bookOrderIndex
+FROM link l
+JOIN connection_type ct ON l.connectionTypeId = ct.id
+JOIN line ol ON ol.id = l.targetLineId
+JOIN book b ON b.id = ol.bookId
+WHERE ct.name IN ('REFERENCE', 'MESORAT_HASHAS', 'EIN_MISHPAT') AND l.sourceLineId IN ?
+UNION ALL
+SELECT l.id AS linkId, ct.name AS connectionType, l.targetLineId AS fromLineId, ol.id AS lineId, ol.bookId, ol.lineIndex, ol.heRef, ol.content,
+       b.title AS bookTitle, b.categoryId, b.orderIndex AS bookOrderIndex
+FROM link l
+JOIN connection_type ct ON l.connectionTypeId = ct.id
+JOIN line ol ON ol.id = l.sourceLineId
+JOIN book b ON b.id = ol.bookId
+WHERE ct.name IN ('REFERENCE', 'MESORAT_HASHAS') AND l.targetLineId IN ?;
+
+-- The SOURCE view of lines in the shape of selectReferencesByLineIds: the lines these lines comment
+-- on, with their book, in the SOURCE view's order (declared bases first, then base books, then catalog).
+selectSourcesByLineIds:
+SELECT l.id AS linkId, ct.name AS connectionType, l.targetLineId AS fromLineId, ol.id AS lineId, ol.bookId, ol.lineIndex, ol.heRef, ol.content,
+       b.title AS bookTitle, b.categoryId, b.orderIndex AS bookOrderIndex
+FROM link l
+JOIN connection_type ct ON l.connectionTypeId = ct.id
+JOIN line ol ON ol.id = l.sourceLineId
+JOIN book b ON b.id = ol.bookId
+WHERE l.targetLineId IN ?
+  AND ct.name IN ('COMMENTARY','SUPER_COMMENTARY','TARGUM','MIDRASH','PARSHANUT','DIBUR_HAMATCHIL','EIN_MISHPAT')
+  AND l.sourceBookId != l.targetBookId
+ORDER BY l.isDeclaredBase DESC, b.isBaseBook DESC, b.orderIndex, ol.lineIndex;