"""
A commandline tool for drawing RDF graphs in Graphviz DOT format

You can draw the graph of an RDF file directly:

.. code-block: bash

   rdf2dot my_rdf_file.rdf | dot -Tpng | display

"""

import rdflib
import rdflib.extras.cmdlineutils

import sys
import cgi
import collections

from rdflib import XSD

LABEL_PROPERTIES = [rdflib.RDFS.label,
                    rdflib.URIRef("http://purl.org/dc/elements/1.1/title"),
                    rdflib.URIRef("http://xmlns.com/foaf/0.1/name"),
                    rdflib.URIRef("http://www.w3.org/2006/vcard/ns#fn"),
                    rdflib.URIRef("http://www.w3.org/2006/vcard/ns#org")
                    ]

XSDTERMS = [
    XSD[x] for x in (
        "anyURI", "base64Binary", "boolean", "byte", "date",
        "dateTime", "decimal", "double", "duration", "float", "gDay", "gMonth",
        "gMonthDay", "gYear", "gYearMonth", "hexBinary", "ID", "IDREF",
        "IDREFS", "int", "integer", "language", "long", "Name", "NCName",
        "negativeInteger", "NMTOKEN", "NMTOKENS", "nonNegativeInteger",
        "nonPositiveInteger", "normalizedString", "positiveInteger", "QName",
        "short", "string", "time", "token", "unsignedByte", "unsignedInt",
        "unsignedLong", "unsignedShort")]

EDGECOLOR = "blue"
NODECOLOR = "black"
ISACOLOR = "black"


def rdf2dot(g, stream, opts={}):
    """
    Convert the RDF graph to DOT
    writes the dot output to the stream
    """

    fields = collections.defaultdict(set)
    nodes = {}

    def node(x):

        if x not in nodes:
            nodes[x] = "node%d" % len(nodes)
        return nodes[x]

    def label(x, g):

        for labelProp in LABEL_PROPERTIES:
            l = g.value(x, labelProp)
            if l:
                return l

        try:
            return g.namespace_manager.compute_qname(x)[2]
        except:
            return x

    def formatliteral(l, g):
        v = cgi.escape(l)
        if l.datatype:
            return '"%s"^^%s' % (v, qname(l.datatype, g))
        elif l.language:
            return '"%s"@%s' % (v, l.language)
        return '"%s"' % v

    def qname(x, g):
        try:
            q = g.compute_qname(x)
            return q[0] + ":" + q[2]
        except:
            return x

    def color(p):
        return "BLACK"

    stream.write("digraph { \n node [ fontname=\"DejaVu Sans\" ] ; \n")

    for s, p, o in g:
        sn = node(s)
        if p == rdflib.RDFS.label:
            continue
        if isinstance(o, (rdflib.URIRef, rdflib.BNode)):
            on = node(o)
            opstr = "\t%s -> %s [ color=%s, label=< <font point-size='10' " + \
                    "color='#336633'>%s</font> > ] ;\n"
            stream.write(opstr % (sn, on, color(p), qname(p, g)))
        else:
            fields[sn].add((qname(p, g), formatliteral(o, g)))

    for u, n in list(nodes.items()):
        stream.write("# %s %s\n" % (u, n))
        f = ["<tr><td align='left'>%s</td><td align='left'>%s</td></tr>" %
             x for x in sorted(fields[n])]
        opstr = "%s [ shape=none, color=%s label=< <table color='#666666'" + \
                " cellborder='0' cellspacing='0' border='1'><tr>" + \
                "<td colspan='2' bgcolor='grey'><B>%s</B></td></tr><tr>" + \
                "<td href='%s' bgcolor='#eeeeee' colspan='2'>" + \
                "<font point-size='10' color='#6666ff'>%s</font></td>" + \
                "</tr>%s</table> > ] \n"
        stream.write(opstr % (n, NODECOLOR, label(u, g), u, u, "".join(f)))

    stream.write("}\n")


def _help():
    sys.stderr.write("""
rdf2dot.py [-f <format>] files...
Read RDF files given on STDOUT, writes a graph of the RDFS schema in DOT
language to stdout
-f specifies parser to use, if not given,

""")


def main():
    rdflib.extras.cmdlineutils.main(rdf2dot, _help)

if __name__ == '__main__':
    main()