Rework storage structs, link preview

CHDataManagement/Model/Page.swift

@@ -1,6 +1,8 @@
 import Foundation
 
-final class Page: Item {
+final class Page: Item, DateItem, LocalizedItem {
+
+    override var itemType: ItemType { .page }
 
     /**
      The external link this page points to.
@@ -38,9 +40,7 @@ final class Page: Item {
     @Published
     var tags: [Tag]
 
-    /**
-     Additional files to copy, because the page content references them
-     */
+    /// Additional files to copy, because the page content references them
     @Published
     var requiredFiles: [FileResource]
 
@@ -141,7 +141,7 @@ final class Page: Item {
         content.settings.paths.pagesOutputFolderPath + "/" + localized(in: language).urlString
     }
 
-    override var itemType: ItemType {
+    override var itemReference: ItemReference {
         .page(self)
     }
 
@@ -161,15 +161,57 @@ final class Page: Item {
         if requiredFiles.contains(file) {
             requiredFiles.remove(file)
         }
-        english.remove(linkPreviewImage: file)
-        german.remove(linkPreviewImage: file)
+        english.linkPreview.remove(file)
+        german.linkPreview.remove(file)
     }
 }
 
-extension Page: DateItem {
+// MARK: Storage
 
-}
+extension Page {
 
-extension Page: LocalizedItem {
-    
+    convenience init(context: LoadingContext, id: String, data: Data) {
+        self.init(
+            content: context.content,
+            id: id,
+            externalLink: data.externalLink,
+            isDraft: data.isDraft,
+            createdDate: data.createdDate,
+            hideDate: data.hideDate ?? false,
+            startDate: data.startDate,
+            endDate: data.endDate,
+            german: .init(context: context, data: data.german),
+            english: .init(context: context, data: data.english),
+            tags: data.tags.compactMap(context.tag),
+            requiredFiles: data.requiredFiles?.compactMap(context.file) ?? [])
+    }
+
+    /// The structure to store the metadata of a page on disk
+    struct Data: Codable {
+        let isDraft: Bool
+        let externalLink: String?
+        let tags: [String]
+        let hideDate: Bool?
+        let createdDate: Date
+        let startDate: Date
+        let endDate: Date?
+        let german: LocalizedPage.Data
+        let english: LocalizedPage.Data
+        let requiredFiles: [String]?
+    }
+
+
+    var data: Data {
+        .init(
+            isDraft: isDraft,
+            externalLink: externalLink,
+            tags: tags.map { $0.id },
+            hideDate: hideDate ? true : nil,
+            createdDate: createdDate,
+            startDate: startDate,
+            endDate: hasEndDate ? endDate : nil,
+            german: german.data,
+            english: english.data,
+            requiredFiles: requiredFiles.nonEmpty?.map { $0.id }.sorted())
+    }
 }