#!/usr/bin/env python
"""
A cgi to warn people before downloading ppmxl; this also should fend 
off robots.

You'll want to have it in your apache config with something like
ScriptAlias /ppmxl /data/gavo/inputs/ppmxl/bin/download.cgi
and a link from
$DOCUMENT_ROOT/textdumps/ppmxl.gz to $GAVO_INPUTS/ppmxl/static/dump-for-web.gz
"""

import cgi
import os

from nevow import tags as T
from nevow import flat

destLink = "http://vo.ari.uni-heidelberg.de/textdumps/ppmxl.gz"

def makeFwdDoc():
	return T.html[
		T.head[
			T.title["PPMXL Download"],
			T.meta(**{"http-equiv": "Refresh", "content": "0;URL="+destLink})],
		T.body[
			T.h1["PPMXL Download"],
			T.p["If you are seeing this, you probably have to click ",
				T.a(href=destLink)["this link"],
				" manually.  It will start a download of more than 42 Gigabytes."]]]


def makeFwdDocIfBroken():
	return T.html[
		T.head[
			T.title["PPMXL Download Not Available"],
		T.body[
			T.h1["PPMXL Download Not Available"],
			T.p["The download of a PPMXL dump is not available at this time."
				"  Please contact gavo@ari.uni-heidelberg.de, and we'll make a"
				" dump again."]]]]



def makeFormDoc():
	return T.html[
		T.head[
			T.title["PPMXL Download"]],
		T.body[
			T.h1["PPMXL Download"],
			T.p["You are about to download PPMXL, a catalog of about 10",
				T.sup["9"],
				" stars.  For details, see ",
				T.a(href="http://dc.zah.uni-heidelberg.de/ppmxl/q/cone/info")[
					"the service info on PPMXL cone search"],
				" in the GAVO data center and the ",
				T.a(href="http://dc.zah.uni-heidelberg.de/__system__/dc_tables/show/tableinfo/ppmxl.main?dbOrder=True")[
					"Column description"],
				"."],
			T.form(action=os.environ.get("SCRIPT_NAME"), method="GET",
					style="border:2pt solid red;padding:0.5cm; width:6cm;"
					"margin-left:auto;margin-right:auto;margin-top:1cm")[
				T.p[
					"I have noticed that I am about to download about ",
					T.strong["43.5 GiB"],
					" and that that would take about ",
					T.strong[
						"80 hours on a line with a constant throughput of 1 Mbit/s."],
					"  I have enough free space on my drive"
					" and will not waste the bandwidth I am going to consume by"
					' clicking "Go ahead" below.'],
				T.div(style="text-align:center")[
					T.input(type="hidden", name="clickedOK", value="True"),
					T.input(type="submit", value="Go ahead")]]]]


def writeDoc(stan):
	print "content-type: text/html"
	print ""
	print flat.flatten(stan)


def main():
	fs = cgi.FieldStorage()
	if fs.getfirst("clickedOK")=="True":
		writeDoc(makeFwdDoc())
	else:
		writeDoc(makeFormDoc())

if __name__=="__main__":
	main()