#!/usr/bin/env python3

"""

Utility for inspecting files in various ways.

This tool is like the collection of tools found in a unix environment but are

cross platform and stable and suitable for our needs in the test suite.

This can be used instead of tools like:

  [

  dd

  find

  head

  hexdump

  ls

  md5sum

  readlink

  sha1sum

  stat

  tail

  test

  readlink.py

  md5sum.py

"""

import binascii

import glob

import hashlib

import optparse

import os

import re

import sys

def iterbytes(s):

    for i in range(len(s)):

        yield s[i : i + 1]

def visit(opts, filenames, outfile):

    """Process filenames in the way specified in opts, writing output to

    outfile."""

    for f in sorted(filenames):

        isstdin = f == '-'

        if not isstdin and not os.path.lexists(f):

            outfile.write(b'%s: file not found\n' % f.encode('utf-8'))

            continue

        quiet = opts.quiet and not opts.recurse or isstdin

        isdir = os.path.isdir(f)

        islink = os.path.islink(f)

        isfile = os.path.isfile(f) and not islink

        dirfiles = None

        content = None

        facts = []

        if isfile:

            if opts.type:

                facts.append(b'file')

            needs_reading = (

                opts.hexdump,

                opts.dump,

                opts.md5,

                opts.sha1,

                opts.raw_sha1,

                opts.sha256,

            )

            if any(needs_reading):

                with open(f, 'rb') as fobj:

                    content = fobj.read()

        elif islink:

            if opts.type:

                facts.append(b'link')

            content = os.readlink(f).encode('utf8')

        elif isstdin:

            content = getattr(sys.stdin, 'buffer', sys.stdin).read()

            if opts.size:

                facts.append(b'size=%d' % len(content))

        elif isdir:

            if opts.recurse or opts.type:

                dirfiles = glob.glob(f + '/*')

                facts.append(b'directory with %d files' % len(dirfiles))

        elif opts.type:

            facts.append(b'type unknown')

        if not isstdin:

            stat = os.lstat(f)

            if opts.size and not isdir:

                facts.append(b'size=%d' % stat.st_size)

            if opts.mode and not islink:

                facts.append(b'mode=%o' % (stat.st_mode & 0o777))

            if opts.links:

                facts.append(b'links=%d' % stat.st_nlink)

            if opts.newer:

                # mtime might be in whole seconds so newer file might be same

                if stat.st_mtime >= os.stat(opts.newer).st_mtime:

                    facts.append(

                        b'newer than %s' % opts.newer.encode('utf8', 'replace')

                    )

                else:

                    facts.append(

                        b'older than %s' % opts.newer.encode('utf8', 'replace')

                    )

        if opts.md5 and content is not None:

            h = hashlib.md5(content)

            facts.append(b'md5=%s' % binascii.hexlify(h.digest())[: opts.bytes])

        if opts.raw_sha1 and content is not None:

            h = hashlib.sha1(content)

            facts.append(b'raw-sha1=%s' % h.digest()[: opts.bytes])

        if opts.sha1 and content is not None:

            h = hashlib.sha1(content)

            facts.append(

                b'sha1=%s' % binascii.hexlify(h.digest())[: opts.bytes]

            )

        if opts.sha256 and content is not None:

            h = hashlib.sha256(content)

            facts.append(

                b'sha256=%s' % binascii.hexlify(h.digest())[: opts.bytes]

            )

        if isstdin:

            outfile.write(b', '.join(facts) + b'\n')

        elif facts:

            outfile.write(b'%s: %s\n' % (f.encode('utf-8'), b', '.join(facts)))

        elif not quiet:

            outfile.write(b'%s:\n' % f.encode('utf-8'))

        if content is not None:

            chunk = content

            if not islink:

                if opts.lines:

                    if opts.lines >= 0:

                        chunk = b''.join(chunk.splitlines(True)[: opts.lines])

                    else:

                        chunk = b''.join(chunk.splitlines(True)[opts.lines :])

                if opts.bytes:

                    if opts.bytes >= 0:

                        chunk = chunk[: opts.bytes]

                    else:

                        chunk = chunk[opts.bytes :]

            if opts.hexdump:

                for i in range(0, len(chunk), 16):

                    s = chunk[i : i + 16]

                    outfile.write(

                        b'%04x: %-47s |%s|\n'

                        % (

                            i,

                            b' '.join(b'%02x' % ord(c) for c in iterbytes(s)),

                            re.sub(b'[^ -~]', b'.', s),

                        )

                    )

            if opts.dump:

                if not quiet:

                    outfile.write(b'>>>\n')

                outfile.write(chunk)

                if not quiet:

                    if chunk.endswith(b'\n'):

                        outfile.write(b'<<<\n')

                    else:

                        outfile.write(b'\n<<< no trailing newline\n')

        if opts.recurse and dirfiles:

            assert not isstdin

            visit(opts, dirfiles, outfile)

if __name__ == "__main__":

    parser = optparse.OptionParser("%prog [options] [filenames]")

    parser.add_option(

        "-t",

        "--type",

        action="store_true",

        help="show file type (file or directory)",

    )

    parser.add_option(

        "-m", "--mode", action="store_true", help="show file mode"

    )

    parser.add_option(

        "-l", "--links", action="store_true", help="show number of links"

    )

    parser.add_option(

        "-s", "--size", action="store_true", help="show size of file"

    )

    parser.add_option(

        "-n", "--newer", action="store", help="check if file is newer (or same)"

    )

    parser.add_option(

        "-r", "--recurse", action="store_true", help="recurse into directories"

    )

    parser.add_option(

        "-S",

        "--sha1",

        action="store_true",

        help="show sha1 hash of the content",

    )

    parser.add_option(

        "",

        "--raw-sha1",

        action="store_true",

        help="show raw bytes of the sha1 hash of the content",

    )

    parser.add_option(

        "",

        "--sha256",

        action="store_true",

        help="show sha256 hash of the content",

    )

    parser.add_option(

        "-M", "--md5", action="store_true", help="show md5 hash of the content"

    )

    parser.add_option(

        "-D", "--dump", action="store_true", help="dump file content"

    )

    parser.add_option(

        "-H", "--hexdump", action="store_true", help="hexdump file content"

    )

    parser.add_option(

        "-B", "--bytes", type="int", help="number of characters to dump"

    )

    parser.add_option(

        "-L", "--lines", type="int", help="number of lines to dump"

    )

    parser.add_option(

        "-q", "--quiet", action="store_true", help="no default output"

    )

    (opts, filenames) = parser.parse_args(sys.argv[1:])

    if not filenames:

        filenames = ['-']

    visit(opts, filenames, getattr(sys.stdout, 'buffer', sys.stdout))