# A basic setup for the edge
# Strips cookies and un-needed params
# Does a few redirects
# Sets forwarded proxy headers
# Custom error page
vcl 4.0;
import std;

# Backend setup
backend default {
    .host = "brilliantcoding.us";
    .port = "80";
}

sub vcl_recv {

# Only a single backend
      set req.backend_hint= default;

# Setting http headers for backend
      set req.http.X-Forwarded-For = client.ip;
    	set req.http.X-Forwarded-Proto = "https";

# Unset headers that might cause us to cache duplicate infos
    	unset req.http.Accept-Language;
    	unset req.http.User-Agent;

# Redirect www to non-www
    if (req.http.host ~ "^www\.") {
      set req.http.x-redir = regsub(req.http.host, "^www\.(.*)", "https://\1") + req.url;
      return (synth(750, "Moved permanently"));
    }

# Redirect http to https
	  	if ( std.port(server.ip) == 80) {
		    set req.http.x-redir = "https://" + req.http.host + req.url;
        return (synth(750, "Moved permanently"));
      }

 # drop params from static assets
	  	if (req.url ~ "\.(gif|jpg|jpeg|swf|ttf|css|js|flv|mp3|mp4|pdf|ico|png)(\?.*|)$") {
	    	set req.url = regsub(req.url, "\?.*$", "");
	  	}

# drop tracking params
	  	if (req.url ~ "\?(utm_(campaign|medium|source|term)|adParams|client|cx|eid|fbid|feed|ref(id|src)?|v(er|iew))=") {
	    	set req.url = regsub(req.url, "\?.*$", "");
	  	}
 }

sub vcl_backend_response {
    # retry a few times if backend is down
    if (beresp.status == 503 && bereq.retries < 3 ) {
       return(retry);
 }

# if we get a session cookie...caching is a no-go
    if (bereq.http.Cookie ~ "(UserID|_session)") {
        set beresp.http.X-Cacheable = "NO:Got Session";
        set beresp.uncacheable = true;
        return (deliver);

    } elsif (beresp.ttl <= 0s) {
# Varnish determined the object was not cacheable
        set beresp.http.X-Cacheable = "NO:Not Cacheable";

    } elsif (beresp.http.set-cookie) {
# Don't cache content for logged in users
        set beresp.http.X-Cacheable = "NO:Set-Cookie";
        set beresp.uncacheable = true;
        return (deliver);

    } elsif (beresp.http.Cache-Control ~ "private") {
# Respect the Cache-Control=private header from the backend
        set beresp.http.X-Cacheable = "NO:Cache-Control=private";
        set beresp.uncacheable = true;
        return (deliver);

    } else {
# Object is cacheable
        set beresp.http.X-Cacheable = "YES";
    }

# unset cookies from backendresponse
    unset beresp.http.set-cookie;
# remove extra headers
   unset beresp.http.X-Powered-By;
   unset beresp.http.Server;
   unset beresp.http.Via;
   unset beresp.http.X-Pingback;
   unset beresp.http.X-Varnish;

}

sub vcl_hash {
   if ( req.http.X-Forwarded-Proto ) {
    hash_data( req.http.X-Forwarded-Proto );
  }
}


sub vcl_synth {
    # redirect for http
    if (resp.status == 750) {
        set resp.status = 301;
        set resp.http.Location = req.http.x-redir;
        return(deliver);
    }
# display custom error page if backend down
    if (resp.status == 503) {
        set resp.status = 404;
        synthetic(std.fileread("/etc/varnish/error.html"));
        return(deliver);
     }
}


sub vcl_deliver {
    # oh noes backend is down
    if (resp.status == 503) {
        return(restart);
    }
   if (obj.hits > 0) {
     set resp.http.X-Cache = "HIT";
   } else {
     set resp.http.X-Cache = "MISS";
   }
   set resp.http.Access-Control-Allow-Origin = "*";
}
sub vcl_hit {
}

sub vcl_miss {
}