Remove Boilerplate Use-case thingy

2021-03-03 16:36:08 +01:00
parent 3e1683dfe5
commit a4bf998c5b
37 changed files with 382 additions and 495 deletions
@@ -0,0 +1,76 @@
+package be.simplenotes.domain
+
+import arrow.core.Either
+import arrow.core.computations.either
+import arrow.core.left
+import arrow.core.right
+import be.simplenotes.domain.validation.NoteValidations
+import be.simplenotes.types.NoteMetadata
+import com.vladsch.flexmark.html.HtmlRenderer
+import com.vladsch.flexmark.parser.Parser
+import io.konform.validation.ValidationErrors
+import org.yaml.snakeyaml.Yaml
+import org.yaml.snakeyaml.parser.ParserException
+import org.yaml.snakeyaml.scanner.ScannerException
+import javax.inject.Singleton
+
+interface MarkdownService {
+    fun renderDocument(input: String): Either<MarkdownParsingError, Document>
+}
+
+private typealias MetaMdPair = Pair<String, String>
+
+@Singleton
+internal class MarkdownServiceImpl(
+    private val parser: Parser,
+    private val renderer: HtmlRenderer,
+) : MarkdownService {
+    private val yamlBoundPattern = "-{3}".toRegex()
+    private fun splitMetaFromDocument(input: String): Either<MarkdownParsingError.MissingMeta, MetaMdPair> {
+        val split = input.split(yamlBoundPattern, 3)
+        if (split.size < 3) return MarkdownParsingError.MissingMeta.left()
+        return (split[1].trim() to split[2].trim()).right()
+    }
+
+    private val yaml = Yaml()
+    private fun parseMeta(input: String): Either<MarkdownParsingError.InvalidMeta, NoteMetadata> {
+        val load: Map<String, Any> = try {
+            yaml.load(input)
+        } catch (e: ParserException) {
+            return MarkdownParsingError.InvalidMeta.left()
+        } catch (e: ScannerException) {
+            return MarkdownParsingError.InvalidMeta.left()
+        }
+
+        val title = when (val titleNode = load["title"]) {
+            is String, is Number -> titleNode.toString()
+            else -> return MarkdownParsingError.InvalidMeta.left()
+        }
+
+        val tagsNode = load["tags"]
+        val tags = if (tagsNode !is List<*>)
+            emptyList()
+        else
+            tagsNode.map { it.toString() }
+
+        return NoteMetadata(title, tags).right()
+    }
+
+    private fun renderMarkdown(markdown: String) = parser.parse(markdown).run(renderer::render)
+
+    override fun renderDocument(input: String) = either.eager<MarkdownParsingError, Document> {
+        val (meta, md) = !splitMetaFromDocument(input)
+        val parsedMeta = !parseMeta(meta)
+        !Either.fromNullable(NoteValidations.validateMetadata(parsedMeta)).swap()
+        val html = renderMarkdown(md)
+        Document(parsedMeta, html)
+    }
+}
+
+sealed class MarkdownParsingError {
+    object MissingMeta : MarkdownParsingError()
+    object InvalidMeta : MarkdownParsingError()
+    class ValidationError(val validationErrors: ValidationErrors) : MarkdownParsingError()
+}
+
+data class Document(val metadata: NoteMetadata, val html: String)