support for poetry and epigraphs

shared/src/commonMain/kotlin/net/sergeych/toread/fb2/Fb2Book.kt

@@ -15,6 +15,7 @@ data class Fb2Book(
     val documentInfo: Fb2DocumentInfo = Fb2DocumentInfo(),
     val bodyTitle: List<String> = emptyList(),
     val bodyImages: List<Fb2ImageRef> = emptyList(),
+    val bodyEpigraphs: List<Fb2Epigraph> = emptyList(),
     val sections: List<Fb2Section> = emptyList(),
     val binaries: List<Fb2Binary> = emptyList(),
 ) {
@@ -69,10 +70,50 @@ data class Fb2Binary(
 sealed interface Fb2Block {
     data class Paragraph(val content: Fb2Text) : Fb2Block
     data class Subtitle(val content: Fb2Text) : Fb2Block
+    data class Epigraph(val epigraph: Fb2Epigraph) : Fb2Block
+    data class Cite(val cite: Fb2Cite) : Fb2Block
+    data class Poem(val poem: Fb2Poem) : Fb2Block
     data class Image(val image: Fb2ImageRef) : Fb2Block
     data object EmptyLine : Fb2Block
 }
 
+data class Fb2Epigraph(
+    val blocks: List<Fb2EpigraphBlock> = emptyList(),
+    val textAuthors: List<Fb2Text> = emptyList(),
+)
+
+data class Fb2Cite(
+    val blocks: List<Fb2EpigraphBlock> = emptyList(),
+    val textAuthors: List<Fb2Text> = emptyList(),
+)
+
+sealed interface Fb2EpigraphBlock {
+    data class Paragraph(val content: Fb2Text) : Fb2EpigraphBlock
+    data class Subtitle(val content: Fb2Text) : Fb2EpigraphBlock
+    data class Poem(val poem: Fb2Poem) : Fb2EpigraphBlock
+    data class Cite(val cite: Fb2Cite) : Fb2EpigraphBlock
+    data object EmptyLine : Fb2EpigraphBlock
+}
+
+data class Fb2Poem(
+    val title: List<Fb2Text> = emptyList(),
+    val epigraphs: List<Fb2Epigraph> = emptyList(),
+    val blocks: List<Fb2PoemBlock> = emptyList(),
+    val textAuthors: List<Fb2Text> = emptyList(),
+    val date: String? = null,
+)
+
+sealed interface Fb2PoemBlock {
+    data class Subtitle(val content: Fb2Text) : Fb2PoemBlock
+    data class Stanza(val stanza: Fb2Stanza) : Fb2PoemBlock
+}
+
+data class Fb2Stanza(
+    val title: List<Fb2Text> = emptyList(),
+    val subtitle: Fb2Text? = null,
+    val verses: List<Fb2Text> = emptyList(),
+)
+
 data class Fb2Text(
     val spans: List<Fb2TextSpan>,
 ) {

shared/src/commonMain/kotlin/net/sergeych/toread/fb2/Fb2XmlMapper.kt

@@ -32,6 +32,7 @@ internal object Fb2XmlMapper {
             documentInfo = documentInfoFrom(documentInfo),
             bodyTitle = body?.first("title")?.children("p")?.mapNotNull { it.text().ifBlank { null } }.orEmpty(),
             bodyImages = body?.children("image")?.mapNotNull(::imageRefFrom).orEmpty(),
+            bodyEpigraphs = body?.children("epigraph")?.map(::epigraphFrom).orEmpty(),
             sections = body?.children("section")?.map(::sectionFrom).orEmpty(),
             binaries = root.children("binary").mapNotNull(::binaryFrom),
         )
@@ -124,6 +125,9 @@ internal object Fb2XmlMapper {
             when (child.localName) {
                 "p" -> Fb2Block.Paragraph(textFrom(child))
                 "subtitle" -> Fb2Block.Subtitle(textFrom(child))
+                "epigraph" -> Fb2Block.Epigraph(epigraphFrom(child))
+                "cite" -> Fb2Block.Cite(citeFrom(child))
+                "poem" -> Fb2Block.Poem(poemFrom(child))
                 "image" -> imageRefFrom(child)?.let(Fb2Block::Image)
                 "empty-line" -> Fb2Block.EmptyLine
                 else -> null
@@ -140,8 +144,64 @@ internal object Fb2XmlMapper {
         )
     }
 
+    private fun poemFrom(element: XmlElement): Fb2Poem =
+        Fb2Poem(
+            title = titleFrom(element.first("title")),
+            epigraphs = element.children("epigraph").map(::epigraphFrom),
+            blocks = element.nodes.mapNotNull { node ->
+                val child = (node as? XmlNode.ElementNode)?.element ?: return@mapNotNull null
+                when (child.localName) {
+                    "subtitle" -> Fb2PoemBlock.Subtitle(textFrom(child))
+                    "stanza" -> Fb2PoemBlock.Stanza(stanzaFrom(child))
+                    else -> null
+                }
+            },
+            textAuthors = element.children("text-author").map(::textFrom),
+            date = element.first("date")?.text()?.ifBlank { null },
+        )
+
+    private fun epigraphFrom(element: XmlElement): Fb2Epigraph =
+        Fb2Epigraph(
+            blocks = element.nodes.mapNotNull { node ->
+                val child = (node as? XmlNode.ElementNode)?.element ?: return@mapNotNull null
+                when (child.localName) {
+                    "p" -> Fb2EpigraphBlock.Paragraph(textFrom(child))
+                    "poem" -> Fb2EpigraphBlock.Poem(poemFrom(child))
+                    "cite" -> Fb2EpigraphBlock.Cite(citeFrom(child))
+                    "empty-line" -> Fb2EpigraphBlock.EmptyLine
+                    else -> null
+                }
+            },
+            textAuthors = element.children("text-author").map(::textFrom),
+        )
+
+    private fun citeFrom(element: XmlElement): Fb2Cite =
+        Fb2Cite(
+            blocks = element.nodes.mapNotNull { node ->
+                val child = (node as? XmlNode.ElementNode)?.element ?: return@mapNotNull null
+                when (child.localName) {
+                    "p" -> Fb2EpigraphBlock.Paragraph(textFrom(child))
+                    "subtitle" -> Fb2EpigraphBlock.Subtitle(textFrom(child))
+                    "poem" -> Fb2EpigraphBlock.Poem(poemFrom(child))
+                    "empty-line" -> Fb2EpigraphBlock.EmptyLine
+                    else -> null
+                }
+            },
+            textAuthors = element.children("text-author").map(::textFrom),
+        )
+
+    private fun stanzaFrom(element: XmlElement): Fb2Stanza =
+        Fb2Stanza(
+            title = titleFrom(element.first("title")),
+            subtitle = element.first("subtitle")?.let(::textFrom),
+            verses = element.children("v").map(::textFrom),
+        )
+
+    private fun titleFrom(element: XmlElement?): List<Fb2Text> =
+        element?.children("p")?.map(::textFrom).orEmpty()
+
     private fun textFrom(element: XmlElement): Fb2Text =
-        Fb2Text(spansFrom(element.nodes).mergeAdjacent())
+        Fb2Text(spansFrom(element.nodes).mergeAdjacent().trimBoundaryWhitespace())
 
     private fun spansFrom(nodes: List<XmlNode>, styles: Set<Fb2TextStyle> = emptySet()): List<Fb2TextSpan> =
         nodes.flatMap { node ->
@@ -179,6 +239,14 @@ internal object Fb2XmlMapper {
         return merged
     }
 
+    private fun List<Fb2TextSpan>.trimBoundaryWhitespace(): List<Fb2TextSpan> {
+        if (isEmpty()) return emptyList()
+        val trimmed = toMutableList()
+        trimmed[0] = trimmed[0].copy(text = trimmed[0].text.trimStart())
+        trimmed[trimmed.lastIndex] = trimmed.last().copy(text = trimmed.last().text.trimEnd())
+        return trimmed.filter { it.text.isNotEmpty() }
+    }
+
     private fun StringBuilder.appendSection(section: Fb2Section) {
         append("<section>")
         section.title?.takeIf { it.isNotBlank() }?.let {