import glob
import itertools
import logging
import os
import tempfile

from borgmatic.execute import (
    execute_command,
    execute_command_with_processes,
    execute_command_without_capture,
)

logger = logging.getLogger(__name__)


def _expand_directory(directory):
    '''
    Given a directory path, expand any tilde (representing a user's home directory) and any globs
    therein. Return a list of one or more resulting paths.
    '''
    expanded_directory = os.path.expanduser(directory)

    return glob.glob(expanded_directory) or [expanded_directory]


def _expand_directories(directories):
    '''
    Given a sequence of directory paths, expand tildes and globs in each one. Return all the
    resulting directories as a single flattened tuple.
    '''
    if directories is None:
        return ()

    return tuple(
        itertools.chain.from_iterable(_expand_directory(directory) for directory in directories)
    )


def _expand_home_directories(directories):
    '''
    Given a sequence of directory paths, expand tildes in each one. Do not perform any globbing.
    Return the results as a tuple.
    '''
    if directories is None:
        return ()

    return tuple(os.path.expanduser(directory) for directory in directories)


def _write_pattern_file(patterns=None):
    '''
    Given a sequence of patterns, write them to a named temporary file and return it. Return None
    if no patterns are provided.
    '''
    if not patterns:
        return None

    pattern_file = tempfile.NamedTemporaryFile('w')
    pattern_file.write('\n'.join(patterns))
    pattern_file.flush()

    return pattern_file


def _make_pattern_flags(location_config, pattern_filename=None):
    '''
    Given a location config dict with a potential patterns_from option, and a filename containing
    any additional patterns, return the corresponding Borg flags for those files as a tuple.
    '''
    pattern_filenames = tuple(location_config.get('patterns_from') or ()) + (
        (pattern_filename,) if pattern_filename else ()
    )

    return tuple(
        itertools.chain.from_iterable(
            ('--patterns-from', pattern_filename) for pattern_filename in pattern_filenames
        )
    )


def _make_exclude_flags(location_config, exclude_filename=None):
    '''
    Given a location config dict with various exclude options, and a filename containing any exclude
    patterns, return the corresponding Borg flags as a tuple.
    '''
    exclude_filenames = tuple(location_config.get('exclude_from') or ()) + (
        (exclude_filename,) if exclude_filename else ()
    )
    exclude_from_flags = tuple(
        itertools.chain.from_iterable(
            ('--exclude-from', exclude_filename) for exclude_filename in exclude_filenames
        )
    )
    caches_flag = ('--exclude-caches',) if location_config.get('exclude_caches') else ()
    if_present_flags = tuple(
        itertools.chain.from_iterable(
            ('--exclude-if-present', if_present)
            for if_present in location_config.get('exclude_if_present', ())
        )
    )
    keep_exclude_tags_flags = (
        ('--keep-exclude-tags',) if location_config.get('keep_exclude_tags') else ()
    )
    exclude_nodump_flags = ('--exclude-nodump',) if location_config.get('exclude_nodump') else ()

    return (
        exclude_from_flags
        + caches_flag
        + if_present_flags
        + keep_exclude_tags_flags
        + exclude_nodump_flags
    )


DEFAULT_BORGMATIC_SOURCE_DIRECTORY = '~/.borgmatic'


def borgmatic_source_directories(borgmatic_source_directory):
    '''
    Return a list of borgmatic-specific source directories used for state like database backups.
    '''
    if not borgmatic_source_directory:
        borgmatic_source_directory = DEFAULT_BORGMATIC_SOURCE_DIRECTORY

    return (
        [borgmatic_source_directory]
        if os.path.exists(os.path.expanduser(borgmatic_source_directory))
        else []
    )


DEFAULT_ARCHIVE_NAME_FORMAT = '{hostname}-{now:%Y-%m-%dT%H:%M:%S.%f}'


def create_archive(
    dry_run,
    repository,
    location_config,
    storage_config,
    local_path='borg',
    remote_path=None,
    progress=False,
    stats=False,
    json=False,
    files=False,
    stream_processes=None,
):
    '''
    Given vebosity/dry-run flags, a local or remote repository path, a location config dict, and a
    storage config dict, create a Borg archive and return Borg's JSON output (if any).

    If a sequence of stream processes is given (instances of subprocess.Popen), then execute the
    create command while also triggering the given processes to produce output.
    '''
    sources = _expand_directories(
        location_config['source_directories']
        + borgmatic_source_directories(location_config.get('borgmatic_source_directory'))
    )

    pattern_file = _write_pattern_file(location_config.get('patterns'))
    exclude_file = _write_pattern_file(
        _expand_home_directories(location_config.get('exclude_patterns'))
    )
    checkpoint_interval = storage_config.get('checkpoint_interval', None)
    chunker_params = storage_config.get('chunker_params', None)
    compression = storage_config.get('compression', None)
    remote_rate_limit = storage_config.get('remote_rate_limit', None)
    umask = storage_config.get('umask', None)
    lock_wait = storage_config.get('lock_wait', None)
    files_cache = location_config.get('files_cache')
    archive_name_format = storage_config.get('archive_name_format', DEFAULT_ARCHIVE_NAME_FORMAT)
    extra_borg_options = storage_config.get('extra_borg_options', {}).get('create', '')

    full_command = (
        (local_path, 'create')
        + _make_pattern_flags(location_config, pattern_file.name if pattern_file else None)
        + _make_exclude_flags(location_config, exclude_file.name if exclude_file else None)
        + (('--checkpoint-interval', str(checkpoint_interval)) if checkpoint_interval else ())
        + (('--chunker-params', chunker_params) if chunker_params else ())
        + (('--compression', compression) if compression else ())
        + (('--remote-ratelimit', str(remote_rate_limit)) if remote_rate_limit else ())
        + (('--one-file-system',) if location_config.get('one_file_system') else ())
        + (('--numeric-owner',) if location_config.get('numeric_owner') else ())
        + (('--noatime',) if location_config.get('atime') is False else ())
        + (('--noctime',) if location_config.get('ctime') is False else ())
        + (('--nobirthtime',) if location_config.get('birthtime') is False else ())
        + (('--read-special',) if (location_config.get('read_special') or stream_processes) else ())
        + (('--nobsdflags',) if location_config.get('bsd_flags') is False else ())
        + (('--files-cache', files_cache) if files_cache else ())
        + (('--remote-path', remote_path) if remote_path else ())
        + (('--umask', str(umask)) if umask else ())
        + (('--lock-wait', str(lock_wait)) if lock_wait else ())
        + (('--list', '--filter', 'AME-') if files and not json and not progress else ())
        + (('--info',) if logger.getEffectiveLevel() == logging.INFO and not json else ())
        + (('--stats',) if stats and not json and not dry_run else ())
        + (('--debug', '--show-rc') if logger.isEnabledFor(logging.DEBUG) and not json else ())
        + (('--dry-run',) if dry_run else ())
        + (('--progress',) if progress else ())
        + (('--json',) if json else ())
        + (tuple(extra_borg_options.split(' ')) if extra_borg_options else ())
        + (
            '{repository}::{archive_name_format}'.format(
                repository=repository, archive_name_format=archive_name_format
            ),
        )
        + sources
    )

    # The progress output isn't compatible with captured and logged output, as progress messes with
    # the terminal directly.
    # FIXME: "--progress" and stream_processes can't be used together.
    if progress:
        execute_command_without_capture(full_command, error_on_warnings=False)
        return

    if json:
        output_log_level = None
    elif (stats or files) and logger.getEffectiveLevel() == logging.WARNING:
        output_log_level = logging.WARNING
    else:
        output_log_level = logging.INFO

    if stream_processes:
        return execute_command_with_processes(
            full_command, stream_processes, output_log_level, error_on_warnings=False
        )

    return execute_command(full_command, output_log_level, error_on_warnings=False)