Generate tag overview, add file action

CHDataManagement/Generator/Page Generators/TagOverviewGenerator.swift

@@ -1,10 +1,78 @@
 
+private struct TagData {
+
+    let url: String
+
+    let title: String
+
+    let localized: LocalizedTag
+
+    init(tag: Tag, language: ContentLanguage) {
+        let localized = tag.localized(in: language)
+        self.url = tag.absoluteUrl(in: language)
+        self.title = localized.linkPreviewTitle ?? localized.name
+        self.localized = localized
+    }
+}
+
+extension TagData: Comparable {
+
+    static func < (lhs: TagData, rhs: TagData) -> Bool {
+        lhs.title < rhs.title
+    }
+
+    static func == (lhs: TagData, rhs: TagData) -> Bool {
+        lhs.title == rhs.title
+    }
+}
+
+private struct TagHeaderContent {
+
+    let language: ContentLanguage
+
+    let title: String
+
+    let description: String?
+
+    let iconUrl: String
+
+    let links: [NavigationBar.Link]
+
+    let headers: Set<HeaderElement>
+
+    let baseUrl: String
+
+    let localizedBaseUrl: String
+
+    private func url(pageNumber: Int) -> String {
+        baseUrl + "/\(pageNumber)"
+    }
+
+    func fileUrl(pageNumber: Int) -> String {
+        url(pageNumber: pageNumber) + ".html"
+    }
+
+    func pageHeader(pageNumber: Int) -> PageHeader {
+        .init(
+            language: language,
+            title: title,
+            description: description,
+            iconUrl: iconUrl,
+            languageButton: .init(
+                text: language.next.rawValue,
+                url: localizedBaseUrl + "/\(pageNumber)"),
+            links: links,
+            headers: headers,
+            icons: [])
+    }
+}
+
 final class TagOverviewGenerator {
 
     let content: Content
 
     let language: ContentLanguage
-
+    
     let results: PageGenerationResults
 
     init(content: Content, language: ContentLanguage, results: PageGenerationResults) {
@@ -13,49 +81,67 @@ final class TagOverviewGenerator {
         self.results = results
     }
 
-    func generatePage(tags: [Tag], overview: TagOverviewPage) {
-        let iconUrl = content.settings.navigation.localized(in: language).rootUrl
-        let languageUrl = overview.absoluteUrl(in: language.next)
-        let languageButton = NavigationBar.Link(
-            text: language.next.rawValue,
-            url: languageUrl)
-
+    func generatePages(tags: [Tag], overview: TagOverviewPage) {
         let localized = overview.localized(in: language)
-
-        let pageHeader = PageHeader(
+        let header = TagHeaderContent(
             language: language,
             title: localized.linkPreviewTitle ?? localized.title,
             description: localized.linkPreviewDescription,
-            iconUrl: iconUrl,
-            languageButton: languageButton,
+            iconUrl: content.settings.navigation.localized(in: language).rootUrl,
             links: content.navigationBar(in: language),
             headers: content.defaultPageHeaders,
-            icons: [])
+            baseUrl: overview.absoluteUrl(in: language),
+            localizedBaseUrl: overview.absoluteUrl(in: language.next))
+
+        // Sort tags by title
+        let tagData = tags.map {
+            TagData(tag: $0, language: language)
+        }.sorted { $0.title }
+
+        let totalCount = tagData.count
+        guard totalCount > 0 else {
+            // Create one empty page
+            generatePage(tags: [], header: header, page: 1, totalPages: 1)
+            return
+        }
+        let tagsPerPage = content.settings.posts.postsPerPage
+
+        let numberOfPages = (totalCount + tagsPerPage - 1) / tagsPerPage // Round up
+        for pageIndex in 1...numberOfPages {
+            let startIndex = (pageIndex - 1) * tagsPerPage
+            let endIndex = min(pageIndex * tagsPerPage, totalCount)
+            let tagsOnPage = tagData[startIndex..<endIndex]
+            generatePage(tags: tagsOnPage, header: header, page: pageIndex, totalPages: numberOfPages)
+        }
+    }
+
+    private func generatePage(tags: ArraySlice<TagData>, header: TagHeaderContent, page pageNumber: Int, totalPages: Int) {
+        let pageHeader = header.pageHeader(pageNumber: pageNumber)
 
         let page = GenericPage(
             header: pageHeader,
             additionalFooter: "") { content in
-                content += "<h1>\(localized.title)</h1>"
+                content += "<h1>\(header.title)</h1>"
                 for tag in tags {
-                    let localized = tag.localized(in: self.language)
-                    let url = tag.absoluteUrl(in: self.language)
-                    let title = localized.name
-                    let description = localized.description ?? ""
-                    let image = self.makePageImage(item: localized)
+                    let description = tag.localized.description ?? ""
+                    let image = self.makePageImage(item: tag.localized)
 
                     content +=  RelatedPageLink(
-                        title: title,
+                        title: tag.title,
                         description: description,
-                        url: url,
+                        url: tag.url,
                         image: image)
-                        .content
+                    .content
+                }
+                if totalPages > 1 {
+                    content += PostFeedPageNavigation(
+                        linkPrefix: header.baseUrl,
+                        currentPage: pageNumber,
+                        numberOfPages: totalPages).content
                 }
-//                if totalPages > 1 {
-//                    content += PostFeedPageNavigation(currentPage: pageNumber, numberOfPages: totalPages, language: language).content
-//                }
             }
         let fileContent = page.content
-        let url = overview.absoluteUrl(in: language) + ".html"
+        let url = header.fileUrl(pageNumber: pageNumber)
 
         guard content.storage.write(fileContent, to: url) else {
             results.unsavedOutput(url, source: .tagOverview)