""" @package antlr3.dottreegenerator
@brief ANTLR3 runtime package, tree module

This module contains all support classes for AST construction and tree parsers.

"""

# begin[licence]
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# lot's of docstrings are missing, don't complain for now...
# pylint: disable-msg=C0111

from google.appengine._internal.antlr3.tree import CommonTreeAdaptor
import stringtemplate3

class DOTTreeGenerator(object):
    """
    A utility class to generate DOT diagrams (graphviz) from
    arbitrary trees.  You can pass in your own templates and
    can pass in any kind of tree or use Tree interface method.
    """

    _treeST = stringtemplate3.StringTemplate(
        template=(
        "digraph {\n" +
        "  ordering=out;\n" +
        "  ranksep=.4;\n" +
        "  node [shape=plaintext, fixedsize=true, fontsize=11, fontname=\"Courier\",\n" +
        "        width=.25, height=.25];\n" +
        "  edge [arrowsize=.5]\n" +
        "  $nodes$\n" +
        "  $edges$\n" +
        "}\n")
        )

    _nodeST = stringtemplate3.StringTemplate(
        template="$name$ [label=\"$text$\"];\n"
        )

    _edgeST = stringtemplate3.StringTemplate(
        template="$parent$ -> $child$ // \"$parentText$\" -> \"$childText$\"\n"
        )

    def __init__(self):
        ## Track node to number mapping so we can get proper node name back
        self.nodeToNumberMap = {}

        ## Track node number so we can get unique node names
        self.nodeNumber = 0


    def toDOT(self, tree, adaptor=None, treeST=_treeST, edgeST=_edgeST):
        if adaptor is None:
            adaptor = CommonTreeAdaptor()

        treeST = treeST.getInstanceOf()

        self.nodeNumber = 0
        self.toDOTDefineNodes(tree, adaptor, treeST)

        self.nodeNumber = 0
        self.toDOTDefineEdges(tree, adaptor, treeST, edgeST)
        return treeST


    def toDOTDefineNodes(self, tree, adaptor, treeST, knownNodes=None):
        if knownNodes is None:
            knownNodes = set()

        if tree is None:
            return

        n = adaptor.getChildCount(tree)
        if n == 0:
            # must have already dumped as child from previous
            # invocation; do nothing
            return

        # define parent node
        number = self.getNodeNumber(tree)
        if number not in knownNodes:
            parentNodeST = self.getNodeST(adaptor, tree)
            treeST.setAttribute("nodes", parentNodeST)
            knownNodes.add(number)

        # for each child, do a "<unique-name> [label=text]" node def
        for i in range(n):
            child = adaptor.getChild(tree, i)

            number = self.getNodeNumber(child)
            if number not in knownNodes:
                nodeST = self.getNodeST(adaptor, child)
                treeST.setAttribute("nodes", nodeST)
                knownNodes.add(number)

            self.toDOTDefineNodes(child, adaptor, treeST, knownNodes)


    def toDOTDefineEdges(self, tree, adaptor, treeST, edgeST):
        if tree is None:
            return

        n = adaptor.getChildCount(tree)
        if n == 0:
            # must have already dumped as child from previous
            # invocation; do nothing
            return

        parentName = "n%d" % self.getNodeNumber(tree)

        # for each child, do a parent -> child edge using unique node names
        parentText = adaptor.getText(tree)
        for i in range(n):
            child = adaptor.getChild(tree, i)
            childText = adaptor.getText(child)
            childName = "n%d" % self.getNodeNumber(child)
            edgeST = edgeST.getInstanceOf()
            edgeST.setAttribute("parent", parentName)
            edgeST.setAttribute("child", childName)
            edgeST.setAttribute("parentText", parentText)
            edgeST.setAttribute("childText", childText)
            treeST.setAttribute("edges", edgeST)
            self.toDOTDefineEdges(child, adaptor, treeST, edgeST)


    def getNodeST(self, adaptor, t):
        text = adaptor.getText(t)
        nodeST = self._nodeST.getInstanceOf()
        uniqueName = "n%d" % self.getNodeNumber(t)
        nodeST.setAttribute("name", uniqueName)
        if text is not None:
            text = text.replace('"', r'\\"')
        nodeST.setAttribute("text", text)
        return nodeST


    def getNodeNumber(self, t):
        try:
            return self.nodeToNumberMap[t]
        except KeyError:
            self.nodeToNumberMap[t] = self.nodeNumber
            self.nodeNumber += 1
            return self.nodeNumber - 1


def toDOT(tree, adaptor=None, treeST=DOTTreeGenerator._treeST, edgeST=DOTTreeGenerator._edgeST):
    """
    Generate DOT (graphviz) for a whole tree not just a node.
    For example, 3+4*5 should generate:

    digraph {
        node [shape=plaintext, fixedsize=true, fontsize=11, fontname="Courier",
            width=.4, height=.2];
        edge [arrowsize=.7]
        "+"->3
        "+"->"*"
        "*"->4
        "*"->5
    }

    Return the ST not a string in case people want to alter.

    Takes a Tree interface object.

    Example of invokation:

        import antlr3
        import antlr3.extras

        input = antlr3.ANTLRInputStream(sys.stdin)
        lex = TLexer(input)
        tokens = antlr3.CommonTokenStream(lex)
        parser = TParser(tokens)
        tree = parser.e().tree
        print tree.toStringTree()
        st = antlr3.extras.toDOT(t)
        print st

    """

    gen = DOTTreeGenerator()
    return gen.toDOT(tree, adaptor, treeST, edgeST)
