import Foundation

struct PageInFeed {

    private let swiperStyleSheetPath = "/assets/swiper/swiper-bundle.min.css"

    private let swiperJsPath = "/assets/swiper/swiper-bundle.min.js"

    let language: ContentLanguage

    let title: String

    let description: String

    let navigationBarData: NavigationBarData

    let pageNumber: Int

    let totalPages: Int

    let posts: [FeedEntryData]

    private var swiperHeader: String {
        "<link rel='stylesheet' href='\(swiperStyleSheetPath)' />"
    }

    private var swiperIsNeeded: Bool {
        posts.contains(where: { $0.images.count > 1 })
    }

    private var headers: String {
        swiperIsNeeded ? swiperHeader : ""
    }

    var content: String {
        GenericPage(language: language, title: title, description: description, data: navigationBarData, additionalHeaders: headers) { content in
            for post in posts {
                FeedEntry(data: post)
                    .addContent(to: &content)
            }
            content += PostFeedPageNavigation(currentPage: pageNumber, numberOfPages: totalPages, language: language).content
            if swiperIsNeeded {
                addSwiperInits(to: &content)
            }
        }.content
    }

    private func addSwiperInits(to result: inout String) {
        result += "<script src='\(swiperJsPath)'></script><script>"
        for post in posts {
            guard post.images.count > 1 else {
                continue
            }
            result += ImageGallery.swiperInit(id: post.entryId)
        }
        result += "</script>"
    }
}