# This file is part of beets.
# Copyright 2016, François-Xavier Thomas.
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.

"""Use command-line tools to check for audio file corruption.
"""


from subprocess import check_output, CalledProcessError, list2cmdline, STDOUT

import shlex
import os
import errno
import sys
import confuse
from beets.plugins import BeetsPlugin
from beets.ui import Subcommand
from beets.util import displayable_path, par_map
from beets import ui
from beets import importer


class CheckerCommandException(Exception):
    """Raised when running a checker failed.

    Attributes:
        checker: Checker command name.
        path: Path to the file being validated.
        errno: Error number from the checker execution error.
        msg: Message from the checker execution error.
    """

    def __init__(self, cmd, oserror):
        self.checker = cmd[0]
        self.path = cmd[-1]
        self.errno = oserror.errno
        self.msg = str(oserror)


class BadFiles(BeetsPlugin):
    def __init__(self):
        super().__init__()
        self.verbose = False

        self.register_listener('import_task_start',
                               self.on_import_task_start)
        self.register_listener('import_task_before_choice',
                               self.on_import_task_before_choice)

    def run_command(self, cmd):
        self._log.debug("running command: {}",
                        displayable_path(list2cmdline(cmd)))
        try:
            output = check_output(cmd, stderr=STDOUT)
            errors = 0
            status = 0
        except CalledProcessError as e:
            output = e.output
            errors = 1
            status = e.returncode
        except OSError as e:
            raise CheckerCommandException(cmd, e)
        output = output.decode(sys.getdefaultencoding(), 'replace')
        return status, errors, [line for line in output.split("\n") if line]

    def check_mp3val(self, path):
        status, errors, output = self.run_command(["mp3val", path])
        if status == 0:
            output = [line for line in output if line.startswith("WARNING:")]
            errors = len(output)
        return status, errors, output

    def check_flac(self, path):
        return self.run_command(["flac", "-wst", path])

    def check_custom(self, command):
        def checker(path):
            cmd = shlex.split(command)
            cmd.append(path)
            return self.run_command(cmd)
        return checker

    def get_checker(self, ext):
        ext = ext.lower()
        try:
            command = self.config['commands'].get(dict).get(ext)
        except confuse.NotFoundError:
            command = None
        if command:
            return self.check_custom(command)
        if ext == "mp3":
            return self.check_mp3val
        if ext == "flac":
            return self.check_flac

    def check_item(self, item):
        # First, check whether the path exists. If not, the user
        # should probably run `beet update` to cleanup your library.
        dpath = displayable_path(item.path)
        self._log.debug("checking path: {}", dpath)
        if not os.path.exists(item.path):
            ui.print_("{}: file does not exist".format(
                ui.colorize('text_error', dpath)))

        # Run the checker against the file if one is found
        ext = os.path.splitext(item.path)[1][1:].decode('utf8', 'ignore')
        checker = self.get_checker(ext)
        if not checker:
            self._log.error("no checker specified in the config for {}",
                            ext)
            return []
        path = item.path
        if not isinstance(path, str):
            path = item.path.decode(sys.getfilesystemencoding())
        try:
            status, errors, output = checker(path)
        except CheckerCommandException as e:
            if e.errno == errno.ENOENT:
                self._log.error(
                    "command not found: {} when validating file: {}",
                    e.checker,
                    e.path
                )
            else:
                self._log.error("error invoking {}: {}", e.checker, e.msg)
            return []

        error_lines = []

        if status > 0:
            error_lines.append(
                "{}: checker exited with status {}"
                .format(ui.colorize('text_error', dpath), status))
            for line in output:
                error_lines.append(f"  {line}")

        elif errors > 0:
            error_lines.append(
                    "{}: checker found {} errors or warnings"
                    .format(ui.colorize('text_warning', dpath), errors))
            for line in output:
                error_lines.append(f"  {line}")
        elif self.verbose:
            error_lines.append(
                "{}: ok".format(ui.colorize('text_success', dpath)))

        return error_lines

    def on_import_task_start(self, task, session):
        if not self.config['check_on_import'].get(False):
            return

        checks_failed = []

        for item in task.items:
            error_lines = self.check_item(item)
            if error_lines:
                checks_failed.append(error_lines)

        if checks_failed:
            task._badfiles_checks_failed = checks_failed

    def on_import_task_before_choice(self, task, session):
        if hasattr(task, '_badfiles_checks_failed'):
            ui.print_('{} one or more files failed checks:'
                      .format(ui.colorize('text_warning', 'BAD')))
            for error in task._badfiles_checks_failed:
                for error_line in error:
                    ui.print_(error_line)

            ui.print_()
            ui.print_('What would you like to do?')

            sel = ui.input_options(['aBort', 'skip', 'continue'])

            if sel == 's':
                return importer.action.SKIP
            elif sel == 'c':
                return None
            elif sel == 'b':
                raise importer.ImportAbort()
            else:
                raise Exception(f'Unexpected selection: {sel}')

    def command(self, lib, opts, args):
        # Get items from arguments
        items = lib.items(ui.decargs(args))
        self.verbose = opts.verbose

        def check_and_print(item):
            for error_line in self.check_item(item):
                ui.print_(error_line)

        par_map(check_and_print, items)

    def commands(self):
        bad_command = Subcommand('bad',
                                 help='check for corrupt or missing files')
        bad_command.parser.add_option(
            '-v', '--verbose',
            action='store_true', default=False, dest='verbose',
            help='view results for both the bad and uncorrupted files'
        )
        bad_command.func = self.command
        return [bad_command]