"""Command line tool to compile songbooks using the songbook library."""

import argparse
import locale
import logging
import os.path
import textwrap
import sys
import yaml

from patacrep.build import SongbookBuilder, DEFAULT_STEPS, config_model
from patacrep.utils import yesno, DictOfDict
from patacrep import __version__
from patacrep import errors
import patacrep.encoding

# Logging configuration
logging.basicConfig(level=logging.INFO)
LOGGER = logging.getLogger()

# pylint: disable=too-few-public-methods
class ParseStepsAction(argparse.Action):
    """Argparse action to split a string into a list."""
    def __call__(self, __parser, namespace, values, __option_string=None):
        if not getattr(namespace, self.dest):
            setattr(namespace, self.dest, [])
        setattr(
            namespace,
            self.dest,
            (
                getattr(namespace, self.dest)
                + [value.strip() for value in values[0].split(',')]
                ),
            )

class VerboseAction(argparse.Action):
    """Set verbosity level with option --verbose."""
    def __call__(self, *_args, **_kwargs):
        LOGGER.setLevel(logging.DEBUG)

def yesno_type(string):
    """Interpret argument as a "yes" or a "no".

    Raise `argparse.ArgumentTypeError` if string cannot be analysed.
    """
    try:
        return yesno(string)
    except ValueError as error:
        raise argparse.ArgumentTypeError(str(error))

def argument_parser(args):
    """Parse arguments"""
    parser = argparse.ArgumentParser(
        prog="songbook",
        description="A song book compiler",
        )

    parser.add_argument(
        '--version', help='Show version', action='version',
        version='%(prog)s ' + __version__,
        )

    parser.add_argument(
        'book', nargs=1, help=textwrap.dedent("Book to compile.")
        )

    parser.add_argument(
        '--datadir', '-d', nargs='+', type=str, action='append',
        help=textwrap.dedent("""\
                Data location. Expected (not necessarily required)
                subdirectories are 'songs', 'img', 'latex', 'templates'.
        """)
        )

    parser.add_argument(
        '--verbose', '-v', nargs=0, action=VerboseAction,
        help=textwrap.dedent("""\
                Show details about the compilation process.
        """)
        )

    parser.add_argument(
        '--cache', '-c', nargs=1,
        help=textwrap.dedent("""\
                Enable song cache.
        """),
        type=yesno_type,
        default=[True],
        )

    parser.add_argument(
        '--steps', '-s', nargs=1, type=str,
        action=ParseStepsAction,
        help=textwrap.dedent("""\
                Steps to run. Default is "{steps}".
                Available steps are:
                "tex" produce .tex file from templates;
                "pdf" compile .tex file;
                "sbx" compile index files;
                "clean" remove temporary files;
                any string beginning with '#' (in this case, it will be run
                in a shell). Several steps (excepted the custom shell
                command) can be combinend in one --steps argument, as a
                comma separated string.

                Substring {{basename}} is replaced by the basename of the song
                book, and substrings {{aux}}, {{log}}, {{out}}, {{pdf}}, {{sxc}}, {{tex}}
                are replaced by "<BASENAME>.aux", "<BASENAME>.log", and so on.
        """.format(steps=','.join(DEFAULT_STEPS))),
        default=None,
        )

    options = parser.parse_args(args)

    return options


def main():
    """Main function:"""

    # set script locale to match user's
    try:
        locale.setlocale(locale.LC_ALL, '')
    except locale.Error as error:
        # Locale is not installed on user's system, or wrongly configured.
        LOGGER.error("Locale error: {}\n".format(str(error)))

    options = argument_parser(sys.argv[1:])

    songbook_path = options.book[-1]
    if os.path.exists(songbook_path + ".yaml") and not os.path.exists(songbook_path):
        songbook_path += ".yaml"

    basename = os.path.basename(songbook_path)[:-len(".yaml")]

    # Load the user songbook config
    try:
        with patacrep.encoding.open_read(songbook_path) as songbook_file:
            user_songbook = yaml.load(songbook_file)
        if 'encoding' in user_songbook:
            with patacrep.encoding.open_read(
                songbook_path,
                encoding=user_songbook['encoding']
                ) as songbook_file:
                user_songbook = yaml.load(songbook_file)
    except Exception as error: # pylint: disable=broad-except
        LOGGER.error(error)
        LOGGER.error("Error while loading file '{}'.".format(songbook_path))
        sys.exit(1)

    # Merge the default and user configs
    default_songbook = DictOfDict(config_model('default'))
    default_songbook.update(user_songbook)
    songbook = dict(default_songbook)

    songbook['_filepath'] = os.path.abspath(songbook_path)
    sbdir = os.path.dirname(songbook['_filepath'])

    # Gathering datadirs
    datadirs = []
    if options.datadir:
        # Command line options
        datadirs += [item[0] for item in options.datadir]
    if 'book' in songbook and 'datadir' in songbook['book']:
        if isinstance(songbook['book']['datadir'], str):
            songbook['book']['datadir'] = [songbook['book']['datadir']]
        datadirs += [
            os.path.join(sbdir, path)
            for path in songbook['book']['datadir']
            ]
        del songbook['book']['datadir']

    # Default value
    datadirs.append(sbdir)
    songbook['_datadir'] = datadirs
    songbook['_cache'] = options.cache[0]

    try:
        sb_builder = SongbookBuilder(songbook, basename)
        sb_builder.unsafe = True

        sb_builder.build_steps(options.steps)
    except errors.SongbookError as error:
        LOGGER.error(error)
        if LOGGER.level >= logging.INFO:
            LOGGER.error(
                "Running again with option '-v' may give more information."
                )
        sys.exit(1)
    except KeyboardInterrupt:
        LOGGER.warning("Aborted by user.")
        sys.exit(1)

    sys.exit(0)

if __name__ == '__main__':
    main()