import os
import sys
from argparse import ArgumentParser, Action
from datetime import datetime
import logging

logging.basicConfig(stream=sys.stdout)
logger = logging.getLogger("cli")


CWD = os.getcwd()

from . import forge
from . import maint
from .config_manager import get_config
from . import server


def pre_check_permissions():
    def is_writable(d):
        return os.access(d, os.W_OK)

    if is_writable(get_config()["AUDIO_INPUT"]):
        yield "Audio input '%s' writable" % get_config()["AUDIO_INPUT"]
    if not os.access(get_config()["AUDIO_INPUT"], os.R_OK):
        yield "Audio input '%s' unreadable" % get_config()["AUDIO_INPUT"]
        sys.exit(10)
    if is_writable(os.getcwd()):
        yield "Code writable"
    if not is_writable(get_config()["AUDIO_OUTPUT"]):
        yield "Audio output '%s' not writable" % get_config()["AUDIO_OUTPUT"]
        logger.critical("Aborting")
        sys.exit(10)


def pre_check_user():
    if os.geteuid() == 0:
        yield "You're running as root; this is dangerous"


def pre_check_ffmpeg():
    path = get_config()["FFMPEG_PATH"]
    if not path.startswith("/"):
        yield "FFMPEG_PATH is not absolute: %s" % path
        from subprocess import check_output

        try:
            check_output([path, "-version"])
        except OSError:
            yield "FFMPEG not found as " + path
    else:
        if not os.path.exists(path):
            yield "FFMPEG not found in " + path


class DateTimeAction(Action):
    def __call__(self, parser, namespace, values, option_string=None):
        if len(values) == 15 or len(values) == 13:
            parsed_val = datetime.strptime(values, "%Y%m%d-%H%M%S")
        else:
            raise ValueError("'%s' is not a valid datetime" % values)
        setattr(namespace, self.dest, parsed_val)


def common_pre():
    prechecks = [pre_check_user, pre_check_permissions, pre_check_ffmpeg]
    configs = ["default_config.py"]
    if "TECHREC_CONFIG" in os.environ:
        for conf in os.environ["TECHREC_CONFIG"].split(":"):
            if not conf:
                continue
            path = os.path.realpath(conf)
            if not os.path.exists(path):
                logger.warn("Configuration file '%s' does not exist; skipping" % path)
                continue
            configs.append(path)
    os.chdir(os.path.dirname(os.path.realpath(__file__)))
    for conf in configs:
        get_config().from_pyfile(conf)

    for check in prechecks:
        for warn in check():
            logger.warn(warn)


def main():
    parser = ArgumentParser(description="creates mp3 from live recordings")
    parser.add_argument(
        "--verbose",
        "-v",
        action="count",
        default=0,
        help="Increase verbosity; can be used multiple times",
    )
    parser.add_argument(
        "--pretend",
        "-p",
        action="store_true",
        default=False,
        help="Only pretend; no real action will be done",
    )
    sub = parser.add_subparsers(
        title="main subcommands", description="valid subcommands"
    )
    serve_p = sub.add_parser("serve", help="Start an HTTP server")
    serve_p.set_defaults(func=server.main_cmd)
    forge_p = sub.add_parser("forge", help="Create an audio file")
    forge_p.add_argument(
        "starttime",
        metavar="START",
        help="Start time, espressed as 19450425_1200 (%%Y%%m%%d-%%H%%M%%S)",
        action=DateTimeAction,
    )
    forge_p.add_argument(
        "endtime",
        metavar="END",
        help="End time, espressed as 19450425_1200 (%%Y%%m%%d-%%H%%M%%S)",
        action=DateTimeAction,
    )
    forge_p.add_argument(
        "-o",
        metavar="OUTFILE",
        dest="outfile",
        default="out.mp3",
        help="Path of the output mp3",
    )
    forge_p.set_defaults(func=forge.main_cmd)

    cleanold_p = sub.add_parser(
        "cleanold",
        help="Remove old files from DB",
        description="Will remove oldfiles with no filename from DB",
    )
    cleanold_p.add_argument(
        "-t",
        metavar="MINAGE",
        dest="minage",
        default="14",
        type=int,
        help="Minimum age (in days) for removal",
    )
    cleanold_p.set_defaults(func=maint.cleanold_cmd)

    options = parser.parse_args()
    options.cwd = CWD
    if options.verbose < 1:
        logging.basicConfig(level=logging.WARNING)
    elif options.verbose == 1:
        logging.basicConfig(level=logging.INFO)
    elif options.verbose >= 2:
        logging.basicConfig(level=logging.DEBUG)
        if options.verbose > 2:
            logging.info("giving verbose flag >2 times is useless")
    common_pre()
    options.func(options)


if __name__ == "__main__":
    main()