package exh.source

import eu.kanade.tachiyomi.source.model.*
import eu.kanade.tachiyomi.source.online.HttpSource
import okhttp3.Request
import okhttp3.Response
import rx.Observable
import java.lang.RuntimeException

abstract class DelegatedHttpSource(val delegate: HttpSource): HttpSource() {
    /**
     * Returns the request for the popular manga given the page.
     *
     * @param page the page number to retrieve.
     */
    override fun popularMangaRequest(page: Int)
            = throw UnsupportedOperationException("Should never be called!")

    /**
     * Parses the response from the site and returns a [MangasPage] object.
     *
     * @param response the response from the site.
     */
    override fun popularMangaParse(response: Response)
            = throw UnsupportedOperationException("Should never be called!")

    /**
     * Returns the request for the search manga given the page.
     *
     * @param page the page number to retrieve.
     * @param query the search query.
     * @param filters the list of filters to apply.
     */
    override fun searchMangaRequest(page: Int, query: String, filters: FilterList)
            = throw UnsupportedOperationException("Should never be called!")

    /**
     * Parses the response from the site and returns a [MangasPage] object.
     *
     * @param response the response from the site.
     */
    override fun searchMangaParse(response: Response)
            = throw UnsupportedOperationException("Should never be called!")

    /**
     * Returns the request for latest manga given the page.
     *
     * @param page the page number to retrieve.
     */
    override fun latestUpdatesRequest(page: Int)
            = throw UnsupportedOperationException("Should never be called!")

    /**
     * Parses the response from the site and returns a [MangasPage] object.
     *
     * @param response the response from the site.
     */
    override fun latestUpdatesParse(response: Response)
            = throw UnsupportedOperationException("Should never be called!")

    /**
     * Parses the response from the site and returns the details of a manga.
     *
     * @param response the response from the site.
     */
    override fun mangaDetailsParse(response: Response)
            = throw UnsupportedOperationException("Should never be called!")

    /**
     * Parses the response from the site and returns a list of chapters.
     *
     * @param response the response from the site.
     */
    override fun chapterListParse(response: Response)
            = throw UnsupportedOperationException("Should never be called!")

    /**
     * Parses the response from the site and returns a list of pages.
     *
     * @param response the response from the site.
     */
    override fun pageListParse(response: Response)
            = throw UnsupportedOperationException("Should never be called!")

    /**
     * Parses the response from the site and returns the absolute url to the source image.
     *
     * @param response the response from the site.
     */
    override fun imageUrlParse(response: Response)
            = throw UnsupportedOperationException("Should never be called!")

    /**
     * Base url of the website without the trailing slash, like: http://mysite.com
     */
    override val baseUrl = delegate.baseUrl

    /**
     * Whether the source has support for latest updates.
     */
    override val supportsLatest = delegate.supportsLatest
    /**
     * Name of the source.
     */
    final override val name = delegate.name

    // ===> OPTIONAL FIELDS

    /**
     * Id of the source. By default it uses a generated id using the first 16 characters (64 bits)
     * of the MD5 of the string: sourcename/language/versionId
     * Note the generated id sets the sign bit to 0.
     */
    override val id = delegate.id
    /**
     * Default network client for doing requests.
     */
    override val client = delegate.client

    /**
     * Visible name of the source.
     */
    override fun toString() = delegate.toString()

    /**
     * Returns an observable containing a page with a list of manga. Normally it's not needed to
     * override this method.
     *
     * @param page the page number to retrieve.
     */
    override fun fetchPopularManga(page: Int): Observable<MangasPage> {
        ensureDelegateCompatible()
        return delegate.fetchPopularManga(page)
    }

    /**
     * Returns an observable containing a page with a list of manga. Normally it's not needed to
     * override this method.
     *
     * @param page the page number to retrieve.
     * @param query the search query.
     * @param filters the list of filters to apply.
     */
    override fun fetchSearchManga(page: Int, query: String, filters: FilterList): Observable<MangasPage> {
        ensureDelegateCompatible()
        return delegate.fetchSearchManga(page, query, filters)
    }

    /**
     * Returns an observable containing a page with a list of latest manga updates.
     *
     * @param page the page number to retrieve.
     */
    override fun fetchLatestUpdates(page: Int): Observable<MangasPage> {
        ensureDelegateCompatible()
        return delegate.fetchLatestUpdates(page)
    }

    /**
     * Returns an observable with the updated details for a manga. Normally it's not needed to
     * override this method.
     *
     * @param manga the manga to be updated.
     */
    override fun fetchMangaDetails(manga: SManga): Observable<SManga> {
        ensureDelegateCompatible()
        return delegate.fetchMangaDetails(manga)
    }

    /**
     * Returns the request for the details of a manga. Override only if it's needed to change the
     * url, send different headers or request method like POST.
     *
     * @param manga the manga to be updated.
     */
    override fun mangaDetailsRequest(manga: SManga): Request {
        ensureDelegateCompatible()
        return delegate.mangaDetailsRequest(manga)
    }

    /**
     * Returns an observable with the updated chapter list for a manga. Normally it's not needed to
     * override this method.  If a manga is licensed an empty chapter list observable is returned
     *
     * @param manga the manga to look for chapters.
     */
    override fun fetchChapterList(manga: SManga): Observable<List<SChapter>> {
        ensureDelegateCompatible()
        return delegate.fetchChapterList(manga)
    }

    /**
     * Returns an observable with the page list for a chapter.
     *
     * @param chapter the chapter whose page list has to be fetched.
     */
    override fun fetchPageList(chapter: SChapter): Observable<List<Page>> {
        ensureDelegateCompatible()
        return delegate.fetchPageList(chapter)
    }

    /**
     * Returns an observable with the page containing the source url of the image. If there's any
     * error, it will return null instead of throwing an exception.
     *
     * @param page the page whose source image has to be fetched.
     */
    override fun fetchImageUrl(page: Page): Observable<String> {
        ensureDelegateCompatible()
        return delegate.fetchImageUrl(page)
    }

    /**
     * Called before inserting a new chapter into database. Use it if you need to override chapter
     * fields, like the title or the chapter number. Do not change anything to [manga].
     *
     * @param chapter the chapter to be added.
     * @param manga the manga of the chapter.
     */
    override fun prepareNewChapter(chapter: SChapter, manga: SManga) {
        ensureDelegateCompatible()
        return delegate.prepareNewChapter(chapter, manga)
    }

    /**
     * Returns the list of filters for the source.
     */
    override fun getFilterList() = delegate.getFilterList()

    private fun ensureDelegateCompatible() {
        if(versionId != delegate.versionId
                || lang != delegate.lang) {
            throw IncompatibleDelegateException("Delegate source is not compatible (versionId: $versionId <=> ${delegate.versionId}, lang: $lang <=> ${delegate.lang})!")
        }
    }

    class IncompatibleDelegateException(message: String) : RuntimeException(message)
}