from glob import glob
from os import path

import ycm_core


def findCompilationDatabaseFolder(dir='.'):
    dirs = [path.dirname(f) for f in glob(dir + '/**/compile_commands.json',
                                          recursive=True)]
    return dirs


def generateQtFlags():
    flags = []
    for p in glob('/usr/include/qt/*/'):
        flags += ['-isystem', p]
    return flags


def isHeader(filename):
    ext = path.splitext(filename)[1]
    return ext in ['.hpp', '.h']


def GetCompilationInfoForFile(database, filename):
    if isHeader(filename):
        basename = path.splitext(filename)[0]
        for ext in ['.cpp', '.c']:
            cpp_file = basename + ext
            if path.exists(cpp_file):
                compilation_info = database.GetCompilationInfoForFile(
                    cpp_file)
                if compilation_info.compiler_flags_:
                    return compilation_info
        return None
    return database.GetCompilationInfoForFile(filename)


def FlagsForFile(filename, **kwargs):
    client_data = kwargs['client_data']
    cwd = client_data['getcwd()']

    extra_flags = [
        '-Wall',
        '-Wextra',
        # '-Wshadow',
        # '-Werror',
        # '-Wc++98-compat',
        # '-Wno-long-long',
        # '-Wno-variadic-macros',
        # '-fexceptions',
        # '-DNDEBUG',
    ]

    folders = findCompilationDatabaseFolder(cwd)
    if not folders:
        folder = None
    else:
        folder = folders[0]
        if len(folders) > 1:
            print("Multiple compilation databases found!")
            print(folders)
            print("Selecting first: %s" % (folder))

    if folder:
        database = ycm_core.CompilationDatabase(folder)
        compilation_info = GetCompilationInfoForFile(database, filename)
        if not compilation_info:
            return None
        flags = list(compilation_info.compiler_flags_)
    else:
        flags = [
            '-std=c++14',
            '-stdlib=libstdc++',
            '-x', 'c++',
            '-isystem', '/usr/include',
            '-isystem', '/usr/local/include',
            '-I', cwd,
            '-I', cwd + '/include',
        ]
        flags += generateQtFlags()

    return {
        'flags': flags + extra_flags,
        'do_cache': True
    }