import sys, os.path
import pickle
import time
import socket
import traceback
from urlparse import urlparse

try:
    import pygraphviz
except:
    print 'Warning, could not import pygraphviz, test mode only'

from optparse import OptionParser

from sfa.client.sfi import Sfi
from sfa.util.sfalogging import logger, DEBUG
from sfa.client.sfaserverproxy import SfaServerProxy

def url_hostname_port (url):
    if url.find("://")<0:
        url="http://"+url
    parsed_url=urlparse(url)
    # 0(scheme) returns protocol
    default_port='80'
    if parsed_url[0]=='https': default_port='443'
    # 1(netloc) returns the hostname+port part
    parts=parsed_url[1].split(":")
    # just a hostname
    if len(parts)==1:
        return (url,parts[0],default_port)
    else:
        return (url,parts[0],parts[1])

### a very simple cache mechanism so that successive runs (see make) 
### will go *much* faster
### assuming everything is sequential, as simple as it gets
### { url -> (timestamp,version)}
class VersionCache:
    def __init__ (self, filename=None, expires=60*60):
        # default is to store cache in the same dir as argv[0]
        if filename is None:
            filename=os.path.join(os.path.dirname(sys.argv[0]),"sfascan-version-cache.pickle")
        self.filename=filename
        self.expires=expires
        self.url2version={}
        self.load()

    def load (self):
        try:
            infile=file(self.filename,'r')
            self.url2version=pickle.load(infile)
            infile.close()
        except:
            logger.debug("Cannot load version cache, restarting from scratch")
            self.url2version = {}
        logger.debug("loaded version cache with %d entries %s"%(len(self.url2version),self.url2version.keys()))

    def save (self):
        try:
            outfile=file(self.filename,'w')
            pickle.dump(self.url2version,outfile)
            outfile.close()
        except:
            logger.log_exc ("Cannot save version cache into %s"%self.filename)
    def clean (self):
        try:
            retcod=os.unlink(self.filename)
            logger.info("Cleaned up version cache %s, retcod=%d"%(self.filename,retcod))
        except:
            logger.info ("Could not unlink version cache %s"%self.filename)

    def show (self):
        entries=len(self.url2version)
        print "version cache from file %s has %d entries"%(self.filename,entries)
        key_values=self.url2version.items()
        def old_first (kv1,kv2): return int(kv1[1][0]-kv2[1][0])
        key_values.sort(old_first)
        for key_value in key_values:
            (url,tuple) = key_value
            (timestamp,version) = tuple
            how_old = time.time()-timestamp
            if how_old<=self.expires:
                print url,"-- %d seconds ago"%how_old
            else:
                print "OUTDATED",url,"(%d seconds ago, expires=%d)"%(how_old,self.expires)
    
    # turns out we might have trailing slashes or not
    def normalize (self, url):
        return url.strip("/")
        
    def set (self,url,version):
        url=self.normalize(url)
        self.url2version[url]=( time.time(), version)
    def get (self,url):
        url=self.normalize(url)
        try:
            (timestamp,version)=self.url2version[url]
            how_old = time.time()-timestamp
            if how_old<=self.expires: return version
            else: return None
        except:
            return None

###
class Interface:

    def __init__ (self,url,verbose=False):
        self._url=url
        self.verbose=verbose
        try:
            (self._url,self.hostname,self.port)=url_hostname_port(url)
            self.ip=socket.gethostbyname(self.hostname)
            self.probed=False
        except:
            self.hostname="unknown"
            self.ip='0.0.0.0'
            self.port="???"
            # don't really try it
            self.probed=True
            self._version={}

    def url(self):
        return self._url

    # this is used as a key for creating graph nodes and to avoid duplicates
    def uid (self):
        return "%s:%s"%(self.ip,self.port)

    # connect to server and trigger GetVersion
    def get_version(self):
        ### if we already know the answer:
        if self.probed:
            return self._version
        ### otherwise let's look in the cache file
        logger.debug("searching in version cache %s"%self.url())
        cached_version = VersionCache().get(self.url())
        if cached_version is not None:
            logger.info("Retrieved version info from cache")
            return cached_version
        ### otherwise let's do the hard work
        # dummy to meet Sfi's expectations for its 'options' field
        class DummyOptions:
            pass
        options=DummyOptions()
        options.verbose=self.verbose
        options.timeout=10
        try:
            client=Sfi(options)
            client.read_config()
            key_file = client.get_key_file()
            cert_file = client.get_cert_file(key_file)
            logger.debug("using key %s & cert %s"%(key_file,cert_file))
            url=self.url()
            logger.info('issuing GetVersion at %s'%url)
            # setting timeout here seems to get the call to fail - even though the response time is fast
            #server=SfaServerProxy(url, key_file, cert_file, verbose=self.verbose, timeout=options.timeout)
            server=SfaServerProxy(url, key_file, cert_file, verbose=self.verbose)
            self._version=server.GetVersion()
        except:
            logger.log_exc("failed to get version")
            self._version={}
        # so that next run from this process will find out
        self.probed=True
        # store in version cache so next processes will remember for an hour
        cache=VersionCache()
        cache.set(self.url(),self._version)
        cache.save()
        logger.debug("Saved version for url=%s in version cache"%self.url())
        # that's our result
        return self._version

    @staticmethod
    def multi_lines_label(*lines):
        result='<<TABLE BORDER="0" CELLBORDER="0"><TR><TD>' + \
            '</TD></TR><TR><TD>'.join(lines) + \
            '</TD></TR></TABLE>>'
        return result

    # default is for when we can't determine the type of the service
    # typically the server is down, or we can't authenticate, or it's too old code
    shapes = {"registry": "diamond", "slicemgr":"ellipse", "aggregate":"box", 'default':'plaintext'}
    abbrevs = {"registry": "REG", "slicemgr":"SA", "aggregate":"AM", 'default':'[unknown interface]'}

    # return a dictionary that translates into the node's attr
    def get_layout (self):
        layout={}
        ### retrieve cached GetVersion
        version=self.get_version()
        # set the href; xxx would make sense to try and 'guess' the web URL, not the API's one...
        layout['href']=self.url()
        ### set html-style label
        ### see http://www.graphviz.org/doc/info/shapes.html#html
        # if empty the service is unreachable
        if not version:
            label="offline"
        else:
            label=''
            try: abbrev=Interface.abbrevs[version['interface']]
            except: abbrev=Interface.abbrevs['default']
            label += abbrev
            if 'hrn' in version: label += " %s"%version['hrn']
            else:                label += "[no hrn]"
            if 'code_tag' in version: 
                label += " %s"%version['code_tag']
            if 'testbed' in version:
                label += " (%s)"%version['testbed']
        layout['label']=Interface.multi_lines_label(self.url(),label)
        ### set shape
        try: shape=Interface.shapes[version['interface']]
        except: shape=Interface.shapes['default']
        layout['shape']=shape
        ### fill color to outline wrongly configured bodies
        if 'geni_api' not in version and 'sfa' not in version:
            layout['style']='filled'
            layout['fillcolor']='gray'
        return layout

class Scanner:

    # provide the entry points (a list of interfaces)
    def __init__ (self, left_to_right=False, verbose=False):
        self.verbose=verbose
        self.left_to_right=left_to_right

    def graph (self,entry_points):
        graph=pygraphviz.AGraph(directed=True)
        if self.left_to_right: 
            graph.graph_attr['rankdir']='LR'
        self.scan(entry_points,graph)
        return graph
    
    # scan from the given interfaces as entry points
    def scan(self,interfaces,graph):
        if not isinstance(interfaces,list):
            interfaces=[interfaces]

        # remember node to interface mapping
        node2interface={}
        # add entry points right away using the interface uid's as a key
        to_scan=interfaces
        for i in interfaces: 
            graph.add_node(i.uid())
            node2interface[graph.get_node(i.uid())]=i
        scanned=[]
        # keep on looping until we reach a fixed point
        # don't worry about abels and shapes that will get fixed later on
        while to_scan:
            for interface in to_scan:
                # performing xmlrpc call
                logger.info("retrieving/fetching version at interface %s"%interface.url())
                version=interface.get_version()
                if not version:
                    logger.info("<EMPTY GetVersion(); offline or cannot authenticate>")
                else: 
                    for (k,v) in version.iteritems(): 
                        if not isinstance(v,dict):
                            logger.debug("\r\t%s:%s"%(k,v))
                        else:
                            logger.debug(k)
                            for (k1,v1) in v.iteritems():
                                logger.debug("\r\t\t%s:%s"%(k1,v1))
                # 'geni_api' is expected if the call succeeded at all
                # 'peers' is needed as well as AMs typically don't have peers
                if 'geni_api' in version and 'peers' in version: 
                    # proceed with neighbours
                    for (next_name,next_url) in version['peers'].iteritems():
                        next_interface=Interface(next_url)
                        # locate or create node in graph
                        try:
                            # if found, we're good with this one
                            next_node=graph.get_node(next_interface.uid())
                        except:
                            # otherwise, let's move on with it
                            graph.add_node(next_interface.uid())
                            next_node=graph.get_node(next_interface.uid())
                            node2interface[next_node]=next_interface
                            to_scan.append(next_interface)
                        graph.add_edge(interface.uid(),next_interface.uid())
                scanned.append(interface)
                to_scan.remove(interface)
            # we've scanned the whole graph, let's get the labels and shapes right
            for node in graph.nodes():
                interface=node2interface.get(node,None)
                if interface:
                    for (k,v) in interface.get_layout().iteritems():
                        node.attr[k]=v
                else:
                    logger.error("MISSED interface with node %s"%node)
    

class SfaScan:

    default_outfiles=['sfa.png','sfa.svg','sfa.dot']

    def main(self):
        usage="%prog [options] url-entry-point(s)"
        parser=OptionParser(usage=usage)
        parser.add_option("-d", "--dir", dest="sfi_dir",
                          help="config & working directory - default is " + Sfi.default_sfi_dir(),
                          metavar="PATH", default=Sfi.default_sfi_dir())
        parser.add_option("-o","--output",action='append',dest='outfiles',default=[],
                          help="output filenames (cumulative) - defaults are %r"%SfaScan.default_outfiles)
        parser.add_option("-l","--left-to-right",action="store_true",dest="left_to_right",default=False,
                          help="instead of top-to-bottom")
        parser.add_option("-v", "--verbose", action="count", dest="verbose", default=0,
                          help="verbose - can be repeated for more verbosity")
        parser.add_option("-c", "--clean-cache",action='store_true',
                          dest='clean_cache',default=False,
                          help='clean/trash version cache and exit')
        parser.add_option("-s","--show-cache",action='store_true',
                          dest='show_cache',default=False,
                          help='show/display version cache')
        
        (options,args)=parser.parse_args()
        logger.enable_console()
        # apply current verbosity to logger
        logger.setLevelFromOptVerbose(options.verbose)
        # figure if we need to be verbose for these local classes that only have a bool flag
        bool_verbose=logger.getBoolVerboseFromOpt(options.verbose)
    
        if options.show_cache: 
            VersionCache().show()
            sys.exit(0)
        if options.clean_cache:
            VersionCache().clean()
            sys.exit(0)
        if not args:
            parser.print_help()
            sys.exit(1)
            
        if not options.outfiles:
            options.outfiles=SfaScan.default_outfiles
        scanner=Scanner(left_to_right=options.left_to_right, verbose=bool_verbose)
        entries = [ Interface(entry) for entry in args ]
        try:
            g=scanner.graph(entries)
            logger.info("creating layout")
            g.layout(prog='dot')
            for outfile in options.outfiles:
                logger.info("drawing in %s"%outfile)
                g.draw(outfile)
            logger.info("done")
        # test mode when pygraphviz is not available
        except:
            entry=entries[0]
            print "GetVersion at %s returned %s"%(entry.url(),entry.get_version())