#!/usr/bin/env python3
# pylint: disable=C0103,C0114,C0116
######################################################################

import argparse
import collections
import glob
import os.path
import re
import sys


def diff(a, b):

    if not os.path.exists(a):
        sys.exit("%Error: No old diff filename found: " + a)
    if not os.path.exists(b):
        sys.exit("%Error: No new diff filename found: " + b)

    if os.path.isdir(a) and os.path.isdir(b):
        diff_dir(a, b)
    elif os.path.isfile(a) and os.path.isfile(b):
        diff_file(a, b)
    else:
        sys.exit("%Error: Mix of files and dirs")


def diff_dir(a, b):
    # Diff all files under two directories
    files = collections.defaultdict(lambda: {})

    for fn in glob.glob(a + "/*.tree"):
        base = re.sub(r'.*/', '', fn)
        files[base]['a'] = fn
    for fn in glob.glob(b + "/*.tree"):
        base = re.sub(r'.*/', '', fn)
        files[base]['b'] = fn

    anyfile = False
    for base in sorted(files.keys()):
        if (not 'a' in files[base]) or (not 'b' in files[base]):
            continue
        a = files[base]['a']
        b = files[base]['b']
        print("=" * 70)
        print("= %s <-> %s" % (a, b))
        diff_file(a, b)
        anyfile = True
    if not anyfile:
        sys.stderr.write(
            "%Warning: No .tree files found that have similar base names\n")


def diff_file(a, b):
    # Compare the two tree files
    short_a = re.sub(r'[^a-zA-Z0-9.]+', '_', a)
    short_b = re.sub(r'[^a-zA-Z0-9.]+', '_', b)
    tmp_a = "/tmp/%s_%s.a" % (os.getpid(), short_a)
    tmp_b = "/tmp/%s_%s.b" % (os.getpid(), short_b)

    # Version conversion deprecated, but for future...
    # vera = version_from(a)
    # verb = version_from(b)
    # verCvt = ((vera < 0x3900 and verb >= 0x3900)
    #            or (vera >= 0x3900 and verb < 0x3900))

    filterf(a, tmp_a)
    filterf(b, tmp_b)
    os.system("diff -u " + tmp_a + " " + tmp_b)
    os.unlink(tmp_a)
    os.unlink(tmp_b)


def version_from(filename):
    # Return dump format
    with open(filename) as fh:
        lineno = 0
        for line in fh:
            if lineno > 10:
                break
            match = re.search(r'format (0x[0-9.]+)', line)
            if match:
                return hex(match.group(1))
    return 1.0


def filterf(fn1, fn2):
    # Remove hex numbers before diffing
    with open(fn1) as fh1:
        with open(fn2, "w") as fh2:
            for line in fh1:
                if re.search(r' This=', line):
                    continue
                line = re.sub(r'0x[a-f0-9]+', '0x', line)
                line = re.sub(r'<e[0-9]+\#?>', '<e>', line)
                if not Args.no_lineno:
                    line = re.sub(r'{[a-z]*\d+}', '{}', line)
                fh2.write(line)


######################################################################
######################################################################

parser = argparse.ArgumentParser(
    allow_abbrev=False,
    formatter_class=argparse.RawDescriptionHelpFormatter,
    description="""Compare two Verilator debugging trees""",
    epilog=
    """Verilator_difftree is used for debugging Verilator tree output files.
It performs a diff between two files, or all files common between two
directories, ignoring irrelevant pointer differences.

For documentation see
https://verilator.org/guide/latest/exe_verilator_difftree.html

Copyright 2005-2022 by Wilson Snyder. This program is free software; you
can redistribute it and/or modify it under the terms of either the GNU
Lesser General Public License Version 3 or the Perl Artistic License
Version 2.0.

SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0""")

parser.add_argument('--debug',
                    action='store_const',
                    const=9,
                    help='enable debug')
parser.add_argument('--no-lineno',
                    action='store_false',
                    help='do not show differences in line numbering')
parser.add_argument('filea', help='input file a to diff')
parser.add_argument('fileb', help='input file b to diff')

Args = parser.parse_args()
diff(Args.filea, Args.fileb)

######################################################################
# Local Variables:
# compile-command: "./verilator_difftree ../test_regress/t/t_difftree.{a,b}.tree"
# End:
