final class PageGenerator {

    private let content: Content

    private let imageGenerator: ImageGenerator

    init(content: Content, imageGenerator: ImageGenerator) {
        self.content = content
        self.imageGenerator = imageGenerator
    }

    func makeHeaders(requiredItems: [HeaderFile]) -> [HeaderElement] {
        var result = [HeaderElement]()
        for item in requiredItems {
            guard let header = item.header(content: content) else {
                #warning("Add warning on missing file assignment")
                continue
            }
            result.append(header)
        }
        return result
    }

    func generate(page: Page, language: ContentLanguage) throws -> (page: String, results: PageGenerationResults) {
        let contentGenerator = PageContentParser(
            content: content,
            language: language)

        let rawPageContent = try content.storage.pageContent(for: page.id, language: language)

        let pageContent = contentGenerator.generatePage(from: rawPageContent)

        contentGenerator.requestImages(imageGenerator)

        let localized = page.localized(in: language)

        let tags: [FeedEntryData.Tag] = page.tags.map { tag in
            .init(name: tag.localized(in: language).name,
                  url: content.absoluteUrlToTag(tag, language: language))
        }

        let headers = makeHeaders(requiredItems: contentGenerator.results.requiredHeaders.sorted())

        let fullPage = ContentPage(
            language: language,
            dateString: page.dateText(in: language),
            title: localized.title,
            tags: tags,
            linkTitle: localized.linkPreviewTitle ?? localized.title,
            description: localized.linkPreviewDescription ?? "",
            navigationBarLinks: content.navigationBar(in: language),
            pageContent: pageContent,
            headers: headers,
            footers: contentGenerator.results.requiredFooters.sorted(),
            icons: contentGenerator.results.requiredIcons)
            .content

        return (fullPage, contentGenerator.results)
    }
}