using afIoc::Inject
using afIoc::RegistryMeta
using afIocConfig::ConfigSource
using web::WebReq
using web::WebUtil
using concurrent

** (Service) -
** Information about the BedSheet server.  
const mixin BedSheetServer {

    ** The pod that contains the initial 'AppModule'.
    abstract Pod?   appPod()
    ** The 'AppModule'.
    abstract Type?  appModule() 
    ** Returns 'pod.dis' (or ''if not found) from the application's pod meta, or the pod name if neither are defined.
    abstract Str appName()
    ** The port BedSheet is listening to.
    abstract Int port()
    ** The public facing domain (including scheme & port) used to create absolute URLs.
    ** If set, this is taken from the `` config value.
    ** If not, then an attempt is made to get this from the HTTP request via the following (in order):
    **  1. The 'Forwarded' HTTP header - see [RFC 7239]``  
    **  2. The 'X-Forwarded-XXXX' HTTP headers
    **  3. The 'host' HTTP header  
    ** See `` for details. 
    ** If all fails then 'http://localhost:${port}/' is returned.
    ** Example:
    **   syntax: fantom
    ** // --> 
    abstract Uri host()
    ** The Registry options BedSheet was started with.
    abstract [Str:Obj]  options()
    ** Returns a list of modules loaded by this BedSheet's IoC
    abstract Type[] moduleTypes()
    ** Returns a unique list of pods that contain modules loaded by this BedSheet's IoC.
    ** Useful for gaining a list of pods used in an application, should you wish to *scan* for
    ** classes. 
    abstract Pod[] modulePods()
    ** The request path to this BedSheet 'WebMod'. 
    ** Only really relevant should BedSheet be started in a [RouteMod]`webmod::RouteMod`.
    ** Starts and ends with a '/'. Example, '`/pub/`'
    ** Returns '`/`' should BedSheet be the root 'WebMod' (the usual case).
    ** @see `web::WebReq.modBase`
    abstract Uri path()
    ** Prepends any extra 'WebMod' path info to the given URL so it may be used by clients and browsers.
    ** The given 'WebMod' local URL should be relative to the BedSheet 'WebMod' and may, or may not, start with a '/'.
    abstract Uri toClientUrl(Uri localUrl)
    ** Creates an absolute URL for public use; including scheme and authority (host).
    ** The given 'clientUrl' should be relative to the host and start with a '/'.
    ** The scheme and authority in the generated URL are taken from the 'host()' method. 
    abstract Uri toAbsoluteUrl(Uri clientUrl)
    ** Returns a 'ClientAsset' for the given local URL.
    ** Throws an Err if 'checked' and a ClientAsset could not be produced.
    abstract ClientAsset? getClientAsset(Uri localUrl, Bool checked := true)

internal const class BedSheetServerImpl : BedSheetServer {

    // nullable for testing
    @Inject private const RegistryMeta?         regMeta 
    @Inject private const ConfigSource?         configSrc 
    @Inject private const |->ClientAssetCache|? assetCache  // assetCache uses BedSheeetServer!
    new make(|This|in) { in(this) }
    override Pod? appPod() {
    override Type? appModule() {
    override Str appName() {
    override Int port() {
    override [Str:Obj] options() {
    override Type[] moduleTypes() {
    override Pod[] modulePods() {
    override Uri path() {
        // default to root for testing
        webReq?.modBase ?: `/`

    override Uri host() {
        // we get host this way 'cos BedSheetServer is used (in a round about way by Pillow) in a 
        // DependencyProvider, so @Config is not available for injection
        // host is validated on startup, so we know it's okay
        bedSheetHost := (Uri) configSrc.get(, Uri#)
        // if someone has gone to the trouble of setting a config value - then let's use it
        // as it's probably the normalised host of multiple sites
        if ( != "localhost")
            return bedSheetHost
        // otherwise, lets parse the web req
        webReq := webReq
        if (webReq != null) {
            host := HttpRequestImpl.hostViaHeaders(webReq.headers)
            if (host != null) {
                // hostViaHeaders is not guaranteed to return a scheme
                if (host.scheme == null)
                    host = `http:${host}`
                return host

        return bedSheetHost

    override Uri toClientUrl(Uri localUrl) {
        // if we stop throwing an Err here, then we need to update ColdFeet
        if ( != null || !localUrl.isRel)   // can't use Uri.isPathOnly because we allow QueryStrs and Fragments...?
            throw ArgErr(BsErrMsgs.urlMustBePathOnly(localUrl, `/css/myStyles.css`))
        return path + localUrl.relTo(`/`)

    override Uri toAbsoluteUrl(Uri clientUrl) {
        Utils.validateLocalUrl(clientUrl, `/css/myStyles.css`)
        return host + clientUrl.relTo(`/`)
    override ClientAsset? getClientAsset(Uri localUrl, Bool checked := true) {
        assetCache().getAndUpdateOrProduce(localUrl) ?: (checked ? throw Err("Could not produce a ClientAsset for: ${localUrl}") : null)
    private WebReq? webReq() {
        // use Actor.locals (and not reg.serviceById) to avoid Errs being thrown during testing