# -*- coding: utf-8 -*-
# Copyright 2016 Christoph Reiter
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.

"""
Deletes unneeded DLLs and checks DLL dependencies.
Execute with the build python, will figure out the rest.
"""

import subprocess
import os
import sys

import gi
gi.require_version("GIRepository", "2.0")
from gi.repository import GIRepository


def get_required_by_typelibs():
    deps = set()
    repo = GIRepository.Repository()
    for tl in os.listdir(repo.get_search_path()[0]):
        namespace, version = os.path.splitext(tl)[0].split("-", 1)
        repo.require(namespace, version, 0)
        lib = repo.get_shared_library(namespace)
        if lib:
            deps.update(lib.split(","))
    return deps


EXTENSIONS = [".exe", ".pyd", ".dll"]
SYSTEM_LIBS = ['advapi32.dll',
    "cabinet.dll", "comctl32.dll", "comdlg32.dll", "crypt32.dll", "d3d9.dll",
    "dnsapi.dll", "dsound.dll", "dwmapi.dll", "gdi32.dll", "imm32.dll",
    "iphlpapi.dll", "kernel32.dll", "ksuser.dll", "msi.dll", "msimg32.dll",
    "msvcr71.dll", "msvcr80.dll", "msvcrt.dll", "ole32.dll", "oleaut32.dll",
    "opengl32.dll", "rpcrt4.dll", "setupapi.dll", "shell32.dll", "user32.dll",
    "usp10.dll", "winmm.dll", "winspool.drv", "wldap32.dll", "ws2_32.dll",
    "wsock32.dll", "shlwapi.dll"
]


def get_dependencies(filename):
    deps = []
    try:
        data = subprocess.getoutput("objdump -p %s" % filename)
    except Exception as error:
        print(error)
        return deps

    for line in data.splitlines():
        line = line.strip()
        if line.startswith("DLL Name:"):
            deps.append(line.split(":", 1)[-1].strip().lower())
    return deps


def find_lib(root, name):
    search_path = os.path.join(root, "bin")
    if os.path.exists(os.path.join(search_path, name)):
        return os.path.join(search_path, name)
    elif name in SYSTEM_LIBS:
        return name


def get_things_to_delete(root):
    all_libs = set()
    needed = set()
    for base, dirs, files in os.walk(root):
        for f in files:
            path = os.path.join(base, f)
            if os.path.splitext(path)[-1].lower() in EXTENSIONS:
                all_libs.add(f.lower())
                for lib in get_dependencies(path):
                    all_libs.add(lib)
                    needed.add(lib)
                    if not find_lib(root, lib):
                        print("MISSING:", path, lib)

    for lib in get_required_by_typelibs():
        needed.add(lib)
        if not find_lib(root, lib):
            print("MISSING:", path, lib)

    # get rid of things not in the search path,
    # maybe loaded through other means?
    not_needed = filter(
        lambda l: find_lib(root, l) and \
            os.path.splitext(l)[-1].lower() != ".exe", all_libs - needed)

    return [find_lib(root, l) for l in not_needed]


def main():
    libs = get_things_to_delete(sys.prefix)
    while libs:
        for l in libs:
            print("DELETE:", l)
            os.unlink(l)
        libs = get_things_to_delete(sys.prefix)


if __name__ == "__main__":
    main()