#!/usr/bin/env python
#
#===- exploded-graph-rewriter.py - ExplodedGraph dump tool -----*- python -*--#
#
# Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
# See https://llvm.org/LICENSE.txt for license information.
# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
#
#===-----------------------------------------------------------------------===#


from __future__ import print_function

import argparse
import collections
import json
import logging
import re


# A deserialized source location.
class SourceLocation(object):
    def __init__(self, json_loc):
        super(SourceLocation, self).__init__()
        self.line = json_loc['line']
        self.col = json_loc['column']
        self.filename = json_loc['filename'] \
            if 'filename' in json_loc else '(main file)'


# A deserialized program point.
class ProgramPoint(object):
    def __init__(self, json_pp):
        super(ProgramPoint, self).__init__()
        self.kind = json_pp['kind']
        self.tag = json_pp['tag']
        if self.kind == 'Edge':
            self.src_id = json_pp['src_id']
            self.dst_id = json_pp['dst_id']
        elif self.kind == 'Statement':
            self.stmt_kind = json_pp['stmt_kind']
            self.pointer = json_pp['pointer']
            self.pretty = json_pp['pretty']
            self.loc = SourceLocation(json_pp['location']) \
                if json_pp['location'] is not None else None
        elif self.kind == 'BlockEntrance':
            self.block_id = json_pp['block_id']


# A value of a single expression in a deserialized Environment.
class EnvironmentBinding(object):
    def __init__(self, json_eb):
        super(EnvironmentBinding, self).__init__()
        self.stmt_id = json_eb['stmt_id']
        self.pretty = json_eb['pretty']
        self.value = json_eb['value']


# Deserialized description of a location context.
class LocationContext(object):
    def __init__(self, json_frame):
        super(LocationContext, self).__init__()
        self.lctx_id = json_frame['lctx_id']
        self.caption = json_frame['location_context']
        self.decl = json_frame['calling']
        self.line = json_frame['call_line']


# A group of deserialized Environment bindings that correspond to a specific
# location context.
class EnvironmentFrame(object):
    def __init__(self, json_frame):
        super(EnvironmentFrame, self).__init__()
        self.location_context = LocationContext(json_frame)
        self.bindings = [EnvironmentBinding(b) for b in json_frame['items']] \
            if json_frame['items'] is not None else []


# A deserialized Environment.
class Environment(object):
    def __init__(self, json_e):
        super(Environment, self).__init__()
        self.frames = [EnvironmentFrame(f) for f in json_e]


# A single binding in a deserialized RegionStore cluster.
class StoreBinding(object):
    def __init__(self, json_sb):
        super(StoreBinding, self).__init__()
        self.kind = json_sb['kind']
        self.offset = json_sb['offset']
        self.value = json_sb['value']


# A single cluster of the deserialized RegionStore.
class StoreCluster(object):
    def __init__(self, json_sc):
        super(StoreCluster, self).__init__()
        self.base_region = json_sc['cluster']
        self.bindings = [StoreBinding(b) for b in json_sc['items']]


# A deserialized RegionStore.
class Store(object):
    def __init__(self, json_s):
        super(Store, self).__init__()
        self.clusters = [StoreCluster(c) for c in json_s]


# A deserialized program state.
class ProgramState(object):
    def __init__(self, state_id, json_ps):
        super(ProgramState, self).__init__()
        logging.debug('Adding ProgramState ' + str(state_id))

        self.state_id = state_id
        self.store = Store(json_ps['store']) \
            if json_ps['store'] is not None else None
        self.environment = Environment(json_ps['environment']) \
            if json_ps['environment'] is not None else None
        # TODO: Objects under construction.
        # TODO: Constraint ranges.
        # TODO: Dynamic types of objects.
        # TODO: Checker messages.


# A deserialized exploded graph node. Has a default constructor because it
# may be referenced as part of an edge before its contents are deserialized,
# and in this moment we already need a room for predecessors and successors.
class ExplodedNode(object):
    def __init__(self):
        super(ExplodedNode, self).__init__()
        self.predecessors = []
        self.successors = []

    def construct(self, node_id, json_node):
        logging.debug('Adding ' + node_id)
        self.node_id = json_node['node_id']
        self.ptr = json_node['pointer']
        self.points = [ProgramPoint(p) for p in json_node['program_points']]
        self.state = ProgramState(json_node['state_id'],
                                  json_node['program_state']) \
            if json_node['program_state'] is not None else None

        assert self.node_name() == node_id

    def node_name(self):
        return 'Node' + self.ptr


# A deserialized ExplodedGraph. Constructed by consuming a .dot file
# line-by-line.
class ExplodedGraph(object):
    # Parse .dot files with regular expressions.
    node_re = re.compile(
        '^(Node0x[0-9a-f]*) \\[shape=record,.*label="{(.*)\\\\l}"\\];$')
    edge_re = re.compile(
        '^(Node0x[0-9a-f]*) -> (Node0x[0-9a-f]*);$')

    def __init__(self):
        super(ExplodedGraph, self).__init__()
        self.nodes = collections.defaultdict(ExplodedNode)
        self.root_id = None
        self.incomplete_line = ''

    def add_raw_line(self, raw_line):
        if raw_line.startswith('//'):
            return

        # Allow line breaks by waiting for ';'. This is not valid in
        # a .dot file, but it is useful for writing tests.
        if len(raw_line) > 0 and raw_line[-1] != ';':
            self.incomplete_line += raw_line
            return
        raw_line = self.incomplete_line + raw_line
        self.incomplete_line = ''

        # Apply regexps one by one to see if it's a node or an edge
        # and extract contents if necessary.
        logging.debug('Line: ' + raw_line)
        result = self.edge_re.match(raw_line)
        if result is not None:
            logging.debug('Classified as edge line.')
            pred = result.group(1)
            succ = result.group(2)
            self.nodes[pred].successors.append(succ)
            self.nodes[succ].predecessors.append(pred)
            return
        result = self.node_re.match(raw_line)
        if result is not None:
            logging.debug('Classified as node line.')
            node_id = result.group(1)
            if len(self.nodes) == 0:
                self.root_id = node_id
            # Note: when writing tests you don't need to escape everything,
            # even though in a valid dot file everything is escaped.
            node_label = result.group(2).replace('\\l', '') \
                                        .replace('&nbsp;', '') \
                                        .replace('\\"', '"') \
                                        .replace('\\{', '{') \
                                        .replace('\\}', '}') \
                                        .replace('\\<', '\\\\<') \
                                        .replace('\\>', '\\\\>') \
                                        .rstrip(',')
            logging.debug(node_label)
            json_node = json.loads(node_label)
            self.nodes[node_id].construct(node_id, json_node)
            return
        logging.debug('Skipping.')


# A visitor that dumps the ExplodedGraph into a DOT file with fancy HTML-based
# syntax highlighing.
class DotDumpVisitor(object):
    def __init__(self):
        super(DotDumpVisitor, self).__init__()

    @staticmethod
    def _dump_raw(s):
        print(s, end='')

    @staticmethod
    def _dump(s):
        print(s.replace('&', '&amp;')
               .replace('{', '\\{')
               .replace('}', '\\}')
               .replace('\\<', '&lt;')
               .replace('\\>', '&gt;')
               .replace('\\l', '<br />')
               .replace('|', ''), end='')

    def visit_begin_graph(self, graph):
        self._graph = graph
        self._dump_raw('digraph "ExplodedGraph" {\n')
        self._dump_raw('label="";\n')

    def visit_program_point(self, p):
        if p.kind in ['Edge', 'BlockEntrance', 'BlockExit']:
            color = 'gold3'
        elif p.kind in ['PreStmtPurgeDeadSymbols',
                        'PostStmtPurgeDeadSymbols']:
            color = 'red'
        elif p.kind in ['CallEnter', 'CallExitBegin', 'CallExitEnd']:
            color = 'blue'
        elif p.kind in ['Statement']:
            color = 'cyan3'
        else:
            color = 'forestgreen'

        if p.kind == 'Statement':
            if p.loc is not None:
                self._dump('<tr><td align="left" width="0">'
                           '%s:<b>%s</b>:<b>%s</b>:</td>'
                           '<td align="left" width="0"><font color="%s">'
                           '%s</font></td><td>%s</td></tr>'
                           % (p.loc.filename, p.loc.line,
                              p.loc.col, color, p.stmt_kind, p.pretty))
            else:
                self._dump('<tr><td align="left" width="0">'
                           '<i>Invalid Source Location</i>:</td>'
                           '<td align="left" width="0">'
                           '<font color="%s">%s</font></td><td>%s</td></tr>'
                           % (color, p.stmt_kind, p.pretty))
        elif p.kind == 'Edge':
            self._dump('<tr><td width="0">-</td>'
                       '<td align="left" width="0">'
                       '<font color="%s">%s</font></td><td align="left">'
                       '[B%d] -\\> [B%d]</td></tr>'
                       % (color, p.kind, p.src_id, p.dst_id))
        else:
            # TODO: Print more stuff for other kinds of points.
            self._dump('<tr><td width="0">-</td>'
                       '<td align="left" width="0" colspan="2">'
                       '<font color="%s">%s</font></td></tr>'
                       % (color, p.kind))

    def visit_environment(self, e):
        self._dump('<table border="0">')

        for f in e.frames:
            self._dump('<tr><td align="left"><b>%s</b></td>'
                       '<td align="left"><font color="grey60">%s </font>'
                       '%s</td></tr>'
                       % (f.location_context.caption,
                          f.location_context.decl,
                          ('(line %s)' % f.location_context.line)
                          if f.location_context.line is not None else ''))
            for b in f.bindings:
                self._dump('<tr><td align="left"><i>S%s</i></td>'
                           '<td align="left">%s</td>'
                           '<td align="left">%s</td></tr>'
                           % (b.stmt_id, b.pretty, b.value))

        self._dump('</table>')

    def visit_store(self, s):
        self._dump('<table border="0">')

        for c in s.clusters:
            for b in c.bindings:
                self._dump('<tr><td align="left">%s</td>'
                           '<td align="left">%s</td>'
                           '<td align="left">%s</td>'
                           '<td align="left">%s</td></tr>'
                           % (c.base_region, b.offset,
                              '(<i>Default</i>)' if b.kind == 'Default'
                              else '',
                              b.value))

        self._dump('</table>')

    def visit_state(self, s):
        self._dump('<tr><td align="left">'
                   '<b>Store: </b>')
        if s.store is None:
            self._dump('<i> Nothing!</i>')
        else:
            self._dump('</td></tr>'
                       '<tr><td align="left">')
            self.visit_store(s.store)

        self._dump('</td></tr><hr />'
                   '<tr><td align="left">'
                   '<b>Environment: </b>')
        if s.environment is None:
            self._dump('<i> Nothing!</i>')
        else:
            self._dump('</td></tr>'
                       '<tr><td align="left">')
            self.visit_environment(s.environment)

        self._dump('</td></tr>')

    def visit_node(self, node):
        self._dump('%s [shape=record,label=<<table border="0">'
                   % (node.node_name()))

        self._dump('<tr><td bgcolor="grey"><b>Node %d (%s) - '
                   'State %s</b></td></tr>'
                   % (node.node_id, node.ptr, node.state.state_id
                      if node.state is not None else 'Unspecified'))
        self._dump('<tr><td align="left" width="0">')
        if len(node.points) > 1:
            self._dump('<b>Program points:</b></td></tr>')
        else:
            self._dump('<b>Program point:</b></td></tr>')
        self._dump('<tr><td align="left" width="0">'
                   '<table border="0" align="left" width="0">')
        for p in node.points:
            self.visit_program_point(p)
        self._dump('</table></td></tr>')

        if node.state is not None:
            self._dump('<hr />')
            self.visit_state(node.state)
        self._dump_raw('</table>>];\n')

    def visit_edge(self, pred, succ):
        self._dump_raw('%s -> %s;\n' % (pred.node_name(), succ.node_name()))

    def visit_end_of_graph(self):
        self._dump_raw('}\n')


# A class that encapsulates traversal of the ExplodedGraph. Different explorer
# kinds could potentially traverse specific sub-graphs.
class Explorer(object):
    def __init__(self):
        super(Explorer, self).__init__()

    def explore(self, graph, visitor):
        visitor.visit_begin_graph(graph)
        for node in sorted(graph.nodes):
            logging.debug('Visiting ' + node)
            visitor.visit_node(graph.nodes[node])
            for succ in sorted(graph.nodes[node].successors):
                logging.debug('Visiting edge: %s -> %s ' % (node, succ))
                visitor.visit_edge(graph.nodes[node], graph.nodes[succ])
        visitor.visit_end_of_graph()


def main():
    parser = argparse.ArgumentParser()
    parser.add_argument('filename', type=str)
    parser.add_argument('-d', '--debug', action='store_const', dest='loglevel',
                        const=logging.DEBUG, default=logging.WARNING,
                        help='enable debug prints')
    parser.add_argument('-v', '--verbose', action='store_const',
                        dest='loglevel', const=logging.INFO,
                        default=logging.WARNING,
                        help='enable info prints')
    args = parser.parse_args()
    logging.basicConfig(level=args.loglevel)

    graph = ExplodedGraph()
    with open(args.filename) as fd:
        for raw_line in fd:
            raw_line = raw_line.strip()
            graph.add_raw_line(raw_line)

    explorer = Explorer()
    visitor = DotDumpVisitor()
    explorer.explore(graph, visitor)


if __name__ == '__main__':
    main()