#!/usr/bin/env python3
"""
# OpenWrt download directory cleanup utility.
# Delete all but the very last version of the program tarballs.
#
# Copyright (C) 2010-2015 Michael Buesch <m@bues.ch>
# Copyright (C) 2013-2015 OpenWrt.org
"""

from __future__ import print_function

import sys
import os
import re
import getopt

# Commandline options
opt_dryrun = False


def parseVer_1234(match, filepath):
    progname = match.group(1)
    progversion = (
        (int(match.group(2)) << 64)
        | (int(match.group(3)) << 48)
        | (int(match.group(4)) << 32)
        | (int(match.group(5)) << 16)
    )
    return (progname, progversion)


def parseVer_123(match, filepath):
    progname = match.group(1)
    try:
        patchlevel = match.group(5)
    except IndexError as e:
        patchlevel = None
    if patchlevel:
        patchlevel = ord(patchlevel[0])
    else:
        patchlevel = 0
    progversion = (
        (int(match.group(2)) << 64)
        | (int(match.group(3)) << 48)
        | (int(match.group(4)) << 32)
        | patchlevel
    )
    return (progname, progversion)


def parseVer_12(match, filepath):
    progname = match.group(1)
    try:
        patchlevel = match.group(4)
    except IndexError as e:
        patchlevel = None
    if patchlevel:
        patchlevel = ord(patchlevel[0])
    else:
        patchlevel = 0
    progversion = (int(match.group(2)) << 64) | (int(match.group(3)) << 48) | patchlevel
    return (progname, progversion)


def parseVer_r(match, filepath):
    progname = match.group(1)
    progversion = int(match.group(2)) << 64
    return (progname, progversion)


def parseVer_ymd_GIT_SHASUM(match, filepath):
    progname = match.group(1)
    progversion = (
        (int(match.group(2)) << 64)
        | (int(match.group(3)) << 48)
        | (int(match.group(4)) << 32)
    )
    return (progname, progversion)


def parseVer_ymd(match, filepath):
    progname = match.group(1)
    progversion = (
        (int(match.group(2)) << 64)
        | (int(match.group(3)) << 48)
        | (int(match.group(4)) << 32)
    )
    return (progname, progversion)


def parseVer_GIT(match, filepath):
    progname = match.group(1)
    st = os.stat(filepath)
    progversion = int(st.st_mtime) << 64
    return (progname, progversion)


extensions = (
    ".tar.gz",
    ".tar.bz2",
    ".tar.xz",
    ".orig.tar.gz",
    ".orig.tar.bz2",
    ".orig.tar.xz",
    ".zip",
    ".tgz",
    ".tbz",
    ".txz",
)

versionRegex = (
    (re.compile(r"(gcc[-_]\d+)\.(\d+)\.(\d+)"), parseVer_12),  # gcc.1.2
    (re.compile(r"(linux[-_]\d+\.\d+)\.(\d+)"), parseVer_r),  # linux.1
    (re.compile(r"(.+)[-_](\d+)\.(\d+)\.(\d+)\.(\d+)"), parseVer_1234),  # xxx-1.2.3.4
    (
        re.compile(r"(.+)[-_](\d\d\d\d)-?(\d\d)-?(\d\d)-"),
        parseVer_ymd_GIT_SHASUM,
    ),  # xxx-YYYY-MM-DD-GIT_SHASUM
    (re.compile(r"(.+)[-_](\d\d\d\d)-?(\d\d)-?(\d\d)"), parseVer_ymd),  # xxx-YYYY-MM-DD
    (re.compile(r"(.+)[-_]([0-9a-fA-F]{40,40})"), parseVer_GIT),  # xxx-GIT_SHASUM
    (re.compile(r"(.+)[-_](\d+)\.(\d+)\.(\d+)(\w?)"), parseVer_123),  # xxx-1.2.3a
    (re.compile(r"(.+)[-_](\d+)_(\d+)_(\d+)"), parseVer_123),  # xxx-1_2_3
    (re.compile(r"(.+)[-_](\d+)\.(\d+)(\w?)"), parseVer_12),  # xxx-1.2a
    (re.compile(r"(.+)[-_]r?(\d+)"), parseVer_r),  # xxx-r1111
)

blacklist = [
    ("wl_apsta", re.compile(r"wl_apsta.*")),
    (".fw", re.compile(r".*\.fw")),
    (".arm", re.compile(r".*\.arm")),
    (".bin", re.compile(r".*\.bin")),
    ("rt-firmware", re.compile(r"RT[\d\w]+_Firmware.*")),
]


class EntryParseError(Exception):
    pass


class Entry:
    def __init__(self, directory, filename):
        self.directory = directory
        self.filename = filename
        self.progname = ""
        self.fileext = ""

        for ext in extensions:
            if filename.endswith(ext):
                filename = filename[0 : 0 - len(ext)]
                self.fileext = ext
                break
        else:
            print(self.filename, "has an unknown file-extension")
            raise EntryParseError("ext")
        for (regex, parseVersion) in versionRegex:
            match = regex.match(filename)
            if match:
                (self.progname, self.version) = parseVersion(
                    match, directory + "/" + filename + self.fileext
                )
                break
        else:
            print(self.filename, "has an unknown version pattern")
            raise EntryParseError("ver")

    def getPath(self):
        return (self.directory + "/" + self.filename).replace("//", "/")

    def deleteFile(self):
        path = self.getPath()
        print("Deleting", path)
        if not opt_dryrun:
            os.unlink(path)

    def __ge__(self, y):
        return self.version >= y.version


def usage():
    print("OpenWrt download directory cleanup utility")
    print("Usage: " + sys.argv[0] + " [OPTIONS] <path/to/dl>")
    print("")
    print(" -d|--dry-run            Do a dry-run. Don't delete any files")
    print(" -B|--show-blacklist     Show the blacklist and exit")
    print(" -w|--whitelist ITEM     Remove ITEM from blacklist")


def main(argv):
    global opt_dryrun

    try:
        (opts, args) = getopt.getopt(
            argv[1:],
            "hdBw:",
            [
                "help",
                "dry-run",
                "show-blacklist",
                "whitelist=",
            ],
        )
        if len(args) != 1:
            usage()
            return 1
    except getopt.GetoptError as e:
        usage()
        return 1
    directory = args[0]

    if not os.path.exists(directory):
        print("Can't find dl path", directory)
        return 1

    for (o, v) in opts:
        if o in ("-h", "--help"):
            usage()
            return 0
        if o in ("-d", "--dry-run"):
            opt_dryrun = True
        if o in ("-w", "--whitelist"):
            for i in range(0, len(blacklist)):
                (name, regex) = blacklist[i]
                if name == v:
                    del blacklist[i]
                    break
            else:
                print("Whitelist error: Item", v, "is not in blacklist")
                return 1
        if o in ("-B", "--show-blacklist"):
            for (name, regex) in blacklist:
                sep = "\t\t"
                if len(name) >= 8:
                    sep = "\t"
                print("%s%s(%s)" % (name, sep, regex.pattern))
            return 0

    # Create a directory listing and parse the file names.
    entries = []
    for filename in os.listdir(directory):
        if filename == "." or filename == "..":
            continue
        for (name, regex) in blacklist:
            if regex.match(filename):
                if opt_dryrun:
                    print(filename, "is blacklisted")
                break
        else:
            try:
                entries.append(Entry(directory, filename))
            except EntryParseError as e:
                pass

    # Create a map of programs
    progmap = {}
    for entry in entries:
        if entry.progname in progmap.keys():
            progmap[entry.progname].append(entry)
        else:
            progmap[entry.progname] = [
                entry,
            ]

    # Traverse the program map and delete everything but the last version
    for prog in progmap:
        lastVersion = None
        versions = progmap[prog]
        for version in versions:
            if lastVersion is None or version >= lastVersion:
                lastVersion = version
        if lastVersion:
            for version in versions:
                if version is not lastVersion:
                    version.deleteFile()
            if opt_dryrun:
                print("Keeping", lastVersion.getPath())

    return 0


if __name__ == "__main__":
    sys.exit(main(sys.argv))
