import argparse
import os
import re
import shutil
import sys
import time

from voussoirkit import betterhelp
from voussoirkit import bytestring
from voussoirkit import pathclass
from voussoirkit import winglob

RESERVE_SPACE_ON_DRIVE = 30 * bytestring.GIBIBYTE

class RarParException(Exception):
    pass

class NotEnoughSpace(RarParException):
    pass

def RARCOMMAND(
        basename,
        input_pattern,
        workdir,
        password=None,
        rec=None,
        rev=None,
        volume=None,
    ):
    '''
    winrar
        a = make archive
        -ibck = run in the background
        -ma = rar5 mode
        -m0 = compression level: store
        -mt1 = thread count: 1
        -v{x}M = split into x megabyte volumes
        -ri x:y = x priority (lower is less pri) y ms sleep between ops
        -r = include subdirectories
        -ep1 = arcnames will start relative to the main folder,
               instead of having the whole abspath of the input_pattern.
        -rr{x}% = x% recovery record
        -rv{x}% = x% recovery volumes
        -hp{x} = encrypt with password x
        -y = yes on all prompts
        -x = exclude certain filenames
    destination
        workdir/basename.rar
    files to include
        input_pattern
    '''
    command = [
        'winrar',
        'a -ibck -ma -m0 -mt1 -ri1:30 -r -ep1',
        '-y -xthumbs.db -xdesktop.ini',
    ]
    if volume is not None:
        command.append(f'-v{volume}M')

    if rec is not None:
        command.append(f'-rr{rec}%')

    if rev is not None:
        command.append(f'-rv{rev}%')

    if password is not None:
        command.append(f'-hp{password}')

    command.append(f'"{workdir.absolute_path}{os.sep}{basename}.rar"')
    command.append(f'"{input_pattern}"')

    command = ' '.join(command)
    return command

def PARCOMMAND(workdir, basename, par):
    '''
    phpar2
        c = create pars
        -t1 = thread count: 1
        -r{x} = x% recovery
    destination
        workdir/basename.par2
    '''
    command = [
        'phpar2',
        'c -t1',
        f'-r{par}',
        f'"{workdir.absolute_path}{os.sep}{basename}"',
        f'"{workdir.absolute_path}{os.sep}{basename}*.rar"',
    ]
    command = ' '.join(command)
    return command

def assert_enough_space(pathsize, workdir, moveto, rec, rev, par):
    plus_percent = (rec + rev + par) / 100
    needed = pathsize * (1 + plus_percent)
    reserve = RESERVE_SPACE_ON_DRIVE + needed

    workdir_drive = os.path.splitdrive(workdir.absolute_path)[0]
    free_space = shutil.disk_usage(workdir_drive).free

    if moveto is not None:
        moveto_drive = os.path.splitdrive(moveto.absolute_path)[0]
        free_space = min(free_space, shutil.disk_usage(moveto_drive).free)

    message = ' '.join([
        f'For {bytestring.bytestring(pathsize)},',
        f'Reserving {bytestring.bytestring(reserve)} /',
        f'{bytestring.bytestring(free_space)}.',
    ])
    print(message)

    if reserve > free_space:
        raise NotEnoughSpace('Please leave more space')

def move(pattern, directory):
    files = winglob.glob(pattern)
    for file in files:
        print(file)
        shutil.move(file, directory)

def _normalize_percentage(rec):
    if rec is None:
        return None

    if rec == 0:
        return None

    if isinstance(rec, str):
        rec = rec.strip('%')

    rec = int(rec)

    if not (0 <= rec <= 100):
        raise ValueError(f'rec, rev, par {rec} must be 0-100.')

    return rec

def normalize_password(password):
    if password is None:
        return None

    if not isinstance(password, str):
        raise TypeError(f'password must be a {str}, not {type(password)}')

    if password == '':
        return None

    return password

def _normalize_volume(volume, pathsize):
    if volume is None:
        return None

    if isinstance(volume, int):
        return volume

    if isinstance(volume, float):
        return int(volume)

    if isinstance(volume, str):
        volume = volume.strip()

        if volume == '100%':
            return None

        minmax_parts = re.findall(r'(min|max)\((.+?), (.+?)\)', volume)
        if minmax_parts:
            (func, left, right) = minmax_parts[0]
            func = {'min': min, 'max': max}[func]
            left = _normalize_volume(left, pathsize=pathsize)
            right = _normalize_volume(right, pathsize=pathsize)
            return func(left, right)

        if volume.endswith('%'):
            volume = volume[:-1]
            volume = float(volume) / 100
            volume = (pathsize * volume) / bytestring.MIBIBYTE
            volume = max(1, volume)
            return int(volume)

        return int(volume)

    raise TypeError(f'Invalid volume {type(volume)}.')

def normalize_volume(volume, pathsize):
    volume = _normalize_volume(volume, pathsize)
    if volume is not None and volume < 1:
        raise ValueError('Volume must be >= 1.')
    return volume

def run_script(script, dry=False):
    '''
    `script` can be a list of strings, which are command line commands, or
    callable Python functions. They will be run in order, and the sequence
    will terminate if any step returns a bad status code. Your Python functions
    must return either 0 or None to be considered successful, all other return
    values will be considered failures.
    '''
    status = 0

    if dry:
        for command in script:
            print(command)
        return status

    for command in script:
        print(command)
        if isinstance(command, str):
            status = os.system(command)
        else:
            status = command()
        if status not in [0, None]:
            break

    return status

def rarpar(
        path,
        *,
        basename=None,
        dry=False,
        moveto=None,
        par=None,
        password=None,
        rec=None,
        rev=None,
        volume=None,
        workdir='.',
    ):
    path = pathclass.Path(path)

    path.assert_exists()

    if path.is_dir:
        input_pattern = path.absolute_path + '\\*'
    else:
        input_pattern = path.absolute_path

    workdir = pathclass.Path(workdir)
    workdir.assert_is_directory()

    if moveto:
        moveto = pathclass.Path(moveto)
        moveto.assert_is_directory()

    pathsize = path.size

    volume = normalize_volume(volume, pathsize)
    rec = _normalize_percentage(rec)
    rev = _normalize_percentage(rev)
    par = _normalize_percentage(par)

    if RESERVE_SPACE_ON_DRIVE:
        assert_enough_space(
            pathsize,
            workdir=workdir,
            moveto=moveto,
            rec=rec or 0,
            rev=rev or 0,
            par=par or 0,
        )

    timestamp = time.strftime('%Y-%m-%d')
    if not basename:
        basename = f'{path.basename} ({timestamp})'
    else:
        basename = basename.format(timestamp=timestamp)

    existing = winglob.glob(f'{basename}*.rar')
    if existing:
        raise Exception(f'{existing[0]} already exists.')

    #### ####

    script = []

    rarcommand = RARCOMMAND(
        basename=basename,
        input_pattern=input_pattern,
        password=password,
        rec=rec,
        rev=rev,
        volume=volume,
        workdir=workdir,
    )
    script.append(rarcommand)

    if par:
        parcommand = PARCOMMAND(
            basename=basename,
            par=par,
            workdir=workdir,
        )
        script.append(parcommand)

    def move_rars():
        move(f'{workdir.absolute_path}\\{basename}*.rar', f'{moveto.absolute_path}')
    def move_revs():
        move(f'{workdir.absolute_path}\\{basename}*.rev', f'{moveto.absolute_path}')
    def move_pars():
        move(f'{workdir.absolute_path}\\{basename}*.par2', f'{moveto.absolute_path}')

    if moveto:
        if True:
            script.append(move_rars)
        if rev:
            script.append(move_revs)
        if par:
            script.append(move_pars)

    #### ####

    status = run_script(script, dry)

    return status

def rarpar_argparse(args):
    return rarpar(
        path=args.path,
        volume=args.volume,
        basename=args.basename,
        dry=args.dry,
        moveto=args.moveto,
        par=args.par,
        password=args.password,
        rec=args.rec,
        rev=args.rev,
        workdir=args.workdir,
    )

DOCSTRING = '''
path:
    The input file or directory to rarpar.

--volume X | X% | min(A, B) | max(A, B)
    Split rars into volumes of this many megabytes. Should be
    An integer number of megabytes, or;
    A percentage "X%" to calculate volumes as X% of the file size, down to
    a 1 MB minimum, or;
    A string "min(A, B)" or "max(A, B)" where A and B follow the above rules.

--rec X
    A integer to generate X% recovery record in the rars.
    See winrar documentation for information about recovery records.

--rev X
    A integer to generate X% recovery volumes.
    Note that winrar's behavior is the number of revs will always be less than
    the number of rars. If you don't split volumes, you will have 1 rar and
    thus 0 revs even if you ask for 100% rev.
    See winrar documentation for information about recovery volumes.

--par X
    A number to generate X% recovery with par2.

--basename
    A basename for the rar and par files. You will end up with
    basename.partXX.rar and basename.par2.
    Without this argument, the default basename is "basename ({timestamp})".
    Your string may include {timestamp} including the braces to get the
    timestamp there.

--password
    A password with which to encrypt the rar files.

--workdir:
    The directory in which the rars and pars will be generated while the
    program is working.

--moveto:
    The directory to which the rars and pars will be moved after the program
    has finished working.

--dry:
    Print the commands that will be run, but don't actually run them.
'''

def main(argv):
    parser = argparse.ArgumentParser(description=__doc__)

    parser.add_argument('path')
    parser.add_argument('--volume', dest='volume')
    parser.add_argument('--rec', dest='rec')
    parser.add_argument('--rev', dest='rev')
    parser.add_argument('--par', dest='par')
    parser.add_argument('--basename', dest='basename')
    parser.add_argument('--password', dest='password')
    parser.add_argument('--workdir', dest='workdir', default='.')
    parser.add_argument('--moveto', dest='moveto')
    parser.add_argument('--dry', dest='dry', action='store_true')
    parser.set_defaults(func=rarpar_argparse)

    return betterhelp.single_main(argv, parser, DOCSTRING)

if __name__ == '__main__':
    raise SystemExit(main(sys.argv[1:]))