#!/usr/bin/env python3

import shutil, sys, subprocess, argparse, pathlib
import platform

parser = argparse.ArgumentParser()

parser.add_argument('--private-dir', required=True)
parser.add_argument('-o', required=True)
parser.add_argument('cmparr', nargs='+')

contents = '''#include<stdio.h>

void flob(void) {
    printf("Now flobbing.\\n");
}
'''

def get_pic_args():
    platname = platform.system().lower()
    if platname in ['windows', 'darwin'] or sys.platform == 'cygwin':
        return []
    return ['-fPIC']

def generate_lib_gnulike(outfile, c_file, private_dir, compiler_array):
    if shutil.which('ar'):
        static_linker = 'ar'
    elif shutil.which('llvm-ar'):
        static_linker = 'llvm-ar'
    elif shutil.which('gcc-ar'):
        static_linker = 'gcc-ar'
    else:
        sys.exit('Could not detect a static linker.')
    o_file = c_file.with_suffix('.o')
    compile_cmd = compiler_array + ['-c', '-g', '-O2', '-o', str(o_file), str(c_file)]
    compile_cmd += get_pic_args()
    subprocess.check_call(compile_cmd)
    out_file = pathlib.Path(outfile)
    if out_file.exists():
        out_file.unlink()
    link_cmd = [static_linker, 'csr', outfile, str(o_file)]
    subprocess.check_call(link_cmd)
    return 0


def generate_lib_msvc(outfile, c_file, private_dir, compiler_array):
    static_linker = 'lib'
    o_file = c_file.with_suffix('.obj')
    compile_cmd = compiler_array + ['/MDd',
                                    '/nologo',
                                    '/ZI',
                                    '/Ob0',
                                    '/Od',
                                    '/c',
                                    '/Fo' + str(o_file),
                                    str(c_file)]
    subprocess.check_call(compile_cmd)
    out_file = pathlib.Path(outfile)
    if out_file.exists():
        out_file.unlink()
    link_cmd = [static_linker,
                '/nologo',
                '/OUT:' + str(outfile),
                str(o_file)]
    subprocess.check_call(link_cmd)
    return 0

def generate_lib(outfile, private_dir, compiler_array):
    private_dir = pathlib.Path(private_dir)
    if not private_dir.exists():
        private_dir.mkdir()
    c_file = private_dir / 'flob.c'
    c_file.write_text(contents)
    for i in compiler_array:
        if (i.endswith('cl') or i.endswith('cl.exe')) and 'clang-cl' not in i:
            return generate_lib_msvc(outfile, c_file, private_dir, compiler_array)
    return generate_lib_gnulike(outfile, c_file, private_dir, compiler_array)

if __name__ == '__main__':
    options = parser.parse_args()
    sys.exit(generate_lib(options.o, options.private_dir, options.cmparr))