# Copyright (c) 2015-2018 Claudiu Popa <pcmanticore@gmail.com>
# Copyright (c) 2015 Florian Bruhin <me@the-compiler.org>
# Copyright (c) 2018 ssolanki <sushobhitsolanki@gmail.com>
# Copyright (c) 2020 Anthony Sottile <asottile@umich.edu>

# Licensed under the GPL: https://www.gnu.org/licenses/old-licenses/gpl-2.0.html
# For details: https://github.com/PyCQA/pylint/blob/master/COPYING

"""Functions to generate files readable with Georg Sander's vcg
(Visualization of Compiler Graphs).

You can download vcg at http://rw4.cs.uni-sb.de/~sander/html/gshome.html
Note that vcg exists as a debian package.

See vcg's documentation for explanation about the different values that
maybe used for the functions parameters.
"""

ATTRS_VAL = {
    "algos": (
        "dfs",
        "tree",
        "minbackward",
        "left_to_right",
        "right_to_left",
        "top_to_bottom",
        "bottom_to_top",
        "maxdepth",
        "maxdepthslow",
        "mindepth",
        "mindepthslow",
        "mindegree",
        "minindegree",
        "minoutdegree",
        "maxdegree",
        "maxindegree",
        "maxoutdegree",
    ),
    "booleans": ("yes", "no"),
    "colors": (
        "black",
        "white",
        "blue",
        "red",
        "green",
        "yellow",
        "magenta",
        "lightgrey",
        "cyan",
        "darkgrey",
        "darkblue",
        "darkred",
        "darkgreen",
        "darkyellow",
        "darkmagenta",
        "darkcyan",
        "gold",
        "lightblue",
        "lightred",
        "lightgreen",
        "lightyellow",
        "lightmagenta",
        "lightcyan",
        "lilac",
        "turquoise",
        "aquamarine",
        "khaki",
        "purple",
        "yellowgreen",
        "pink",
        "orange",
        "orchid",
    ),
    "shapes": ("box", "ellipse", "rhomb", "triangle"),
    "textmodes": ("center", "left_justify", "right_justify"),
    "arrowstyles": ("solid", "line", "none"),
    "linestyles": ("continuous", "dashed", "dotted", "invisible"),
}

# meaning of possible values:
#   O    -> string
#   1    -> int
#   list -> value in list
GRAPH_ATTRS = {
    "title": 0,
    "label": 0,
    "color": ATTRS_VAL["colors"],
    "textcolor": ATTRS_VAL["colors"],
    "bordercolor": ATTRS_VAL["colors"],
    "width": 1,
    "height": 1,
    "borderwidth": 1,
    "textmode": ATTRS_VAL["textmodes"],
    "shape": ATTRS_VAL["shapes"],
    "shrink": 1,
    "stretch": 1,
    "orientation": ATTRS_VAL["algos"],
    "vertical_order": 1,
    "horizontal_order": 1,
    "xspace": 1,
    "yspace": 1,
    "layoutalgorithm": ATTRS_VAL["algos"],
    "late_edge_labels": ATTRS_VAL["booleans"],
    "display_edge_labels": ATTRS_VAL["booleans"],
    "dirty_edge_labels": ATTRS_VAL["booleans"],
    "finetuning": ATTRS_VAL["booleans"],
    "manhattan_edges": ATTRS_VAL["booleans"],
    "smanhattan_edges": ATTRS_VAL["booleans"],
    "port_sharing": ATTRS_VAL["booleans"],
    "edges": ATTRS_VAL["booleans"],
    "nodes": ATTRS_VAL["booleans"],
    "splines": ATTRS_VAL["booleans"],
}
NODE_ATTRS = {
    "title": 0,
    "label": 0,
    "color": ATTRS_VAL["colors"],
    "textcolor": ATTRS_VAL["colors"],
    "bordercolor": ATTRS_VAL["colors"],
    "width": 1,
    "height": 1,
    "borderwidth": 1,
    "textmode": ATTRS_VAL["textmodes"],
    "shape": ATTRS_VAL["shapes"],
    "shrink": 1,
    "stretch": 1,
    "vertical_order": 1,
    "horizontal_order": 1,
}
EDGE_ATTRS = {
    "sourcename": 0,
    "targetname": 0,
    "label": 0,
    "linestyle": ATTRS_VAL["linestyles"],
    "class": 1,
    "thickness": 0,
    "color": ATTRS_VAL["colors"],
    "textcolor": ATTRS_VAL["colors"],
    "arrowcolor": ATTRS_VAL["colors"],
    "backarrowcolor": ATTRS_VAL["colors"],
    "arrowsize": 1,
    "backarrowsize": 1,
    "arrowstyle": ATTRS_VAL["arrowstyles"],
    "backarrowstyle": ATTRS_VAL["arrowstyles"],
    "textmode": ATTRS_VAL["textmodes"],
    "priority": 1,
    "anchor": 1,
    "horizontal_order": 1,
}


# Misc utilities ###############################################################


class VCGPrinter:
    """A vcg graph writer.
    """

    def __init__(self, output_stream):
        self._stream = output_stream
        self._indent = ""

    def open_graph(self, **args):
        """open a vcg graph
        """
        self._stream.write("%sgraph:{\n" % self._indent)
        self._inc_indent()
        self._write_attributes(GRAPH_ATTRS, **args)

    def close_graph(self):
        """close a vcg graph
        """
        self._dec_indent()
        self._stream.write("%s}\n" % self._indent)

    def node(self, title, **args):
        """draw a node
        """
        self._stream.write('%snode: {title:"%s"' % (self._indent, title))
        self._write_attributes(NODE_ATTRS, **args)
        self._stream.write("}\n")

    def edge(self, from_node, to_node, edge_type="", **args):
        """draw an edge from a node to another.
        """
        self._stream.write(
            '%s%sedge: {sourcename:"%s" targetname:"%s"'
            % (self._indent, edge_type, from_node, to_node)
        )
        self._write_attributes(EDGE_ATTRS, **args)
        self._stream.write("}\n")

    # private ##################################################################

    def _write_attributes(self, attributes_dict, **args):
        """write graph, node or edge attributes
        """
        for key, value in args.items():
            try:
                _type = attributes_dict[key]
            except KeyError:
                raise Exception(
                    """no such attribute %s
possible attributes are %s"""
                    % (key, attributes_dict.keys())
                )

            if not _type:
                self._stream.write('%s%s:"%s"\n' % (self._indent, key, value))
            elif _type == 1:
                self._stream.write("%s%s:%s\n" % (self._indent, key, int(value)))
            elif value in _type:
                self._stream.write("%s%s:%s\n" % (self._indent, key, value))
            else:
                raise Exception(
                    """value %s isn\'t correct for attribute %s
correct values are %s"""
                    % (value, key, _type)
                )

    def _inc_indent(self):
        """increment indentation
        """
        self._indent = "  %s" % self._indent

    def _dec_indent(self):
        """decrement indentation
        """
        self._indent = self._indent[:-2]
