import os
import os.path
import sys
import types
import subprocess

def _make_val(val):
    if isinstance(val, types.StringType):
	return val
    if isinstance(val, types.ListType):
	return ",".join(map(_make_val, val))
    if isinstance(val, types.TupleType):
	return _make_val(list(val))
    return str(val)

def make_command(prog, options = [], flags = "", overwrite = False, quiet = False, verbose = False):
    args = [prog]
    if overwrite:
	args.append("--o")
    if quiet:
	args.append("--q")
    if verbose:
	args.append("--v")
    if flags:
	args.append("-%s" % flags)
    for opt, val in options.iteritems():
	args.append("%s=%s" % (opt, _make_val(val)))
    return args

def start_command(prog, options = [], flags = "", overwrite = False, quiet = False, verbose = False, **kwargs):
    args = make_command(prog, options, flags, overwrite, quiet, verbose)
    return subprocess.Popen(args, **kwargs)

def run_command(*args, **kwargs):
    ps = start_command(*args, **kwargs)
    return ps.wait()

def _parse_env():
    options = {}
    flags = {}
    for var, val in os.environ.iteritems():
	if var.startswith("GIS_OPT_"):
	    opt = var.replace("GIS_OPT_", "", 1).lower()
	    options[opt] = val;
	if var.startswith("GIS_FLAG_"):
	    flg = var.replace("GIS_FLAG_", "", 1).lower()
	    flags[flg] = bool(int(val));
    return (options, flags)

def parser():
    if not os.getenv("GISBASE"):
        print >> sys.stderr, "You must be in GRASS GIS to run this program."
        sys.exit(1)

    if len(sys.argv) > 1 and sys.argv[1] == "@ARGS_PARSED@":
	return _parse_env()

    argv = sys.argv[:]
    name = argv[0]
    if not os.path.isabs(name):
	argv[0] = os.path.normpath(os.path.join(sys.path[0], name))

    os.execvp("g.parser", [name] + argv)
    raise OSError("error executing g.parser")