#!/usr/bin/env python

import string
import os
import sys

log_name = 'config.log'
if os.path.isfile(log_name):
    os.unlink(log_name)

def write_log(msg):
    log_file = open(log_name, 'a')
    log_file.write(msg)
    log_file.write('\n')
    log_file.close()

def exit(code=0):
    sys.exit(code)

def msg_checking(msg):
    print "Checking", msg, "...",

def execute(cmd):
    write_log("Execute: %s" % cmd)
    full_cmd = '%s 1>>%s 2>&1' % (cmd, log_name)
    return os.system(full_cmd)

def run_test(input, flags = ''):
    try:
        f = open('_temp.c', 'w')
        f.write(input)
        f.close()
        compile_cmd = '%s -o _temp _temp.c %s' % (os.environ.get('CC', 'cc'),
                                                  flags)
        write_log("executing test: %s" % compile_cmd)
        if not execute(compile_cmd):
            execute('./_temp')
    finally:
        execute('rm -f _temp.c _temp')
    
ao_test_program = '''
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ao/ao.h>

int main ()
{
  system("touch conf.aotest");
  return 0;
}
'''

def find_ao(ao_prefix = '/usr/local', enable_aotest = 1):
    """A rough translation of ao.m4"""

    ao_cflags = []
    ao_libs = []
    
    ao_include_dir = ao_prefix + '/include'
    ao_lib_dir = ao_prefix + '/lib'
    ao_libs = 'ao'

    msg_checking('for Ao')

    if enable_aotest:
        execute('rm -f conf.aotest')

        try:
            run_test(ao_test_program, "-I" + ao_include_dir)
            if not os.path.isfile('conf.aotest'):
                raise RuntimeError, "Did not produce output"
            execute('rm conf.aotest')
            
        except Exception, e:
            print "test program failed"
            return None

    print "success"

    return {'ao_libs' : ao_libs,
            'ao_lib_dir' : ao_lib_dir,
            'ao_include_dir' : ao_include_dir}

def write_data(data):
    f = open('Setup', 'w')
    for item in data.items():
        f.write('%s = %s\n' % item)
    f.close()
    print "Wrote Setup file"
            
def print_help():
    print '''%s
    --prefix                 Give the prefix in which ao was installed
                               (separated by a space)''' % sys.argv[0]
    exit()

def parse_args():
    def arg_check(data, argv, pos, arg_type, key):
        "Register an command line arg which takes an argument"
        if len(argv) == pos:
            print arg_type, "needs an argument"
            exit(1)
        data[key] = argv[pos]
        
    data = {}
    argv = sys.argv
    for pos in range(len(argv)):
        if argv[pos] == '--help':
            print_help()
        if argv[pos] == '--prefix':
            pos = pos + 1
            arg_check(data, argv, pos, "Ao Prefix", 'prefix')
    return data
    
def main():
    args = parse_args()
    prefix = args.get('prefix', '/usr/local')

    data = find_ao(ao_prefix = prefix)
    if not data:
        print "Config failure"
        exit(1)
    write_data(data)

if __name__ == '__main__':
    main()