from .base import BasePrompt

import os

from sqlalchemy.exc import NoResultFound
from textwrap import dedent, wrap

from groove import db
from groove.exceptions import PlaylistValidationError


class _playlist(BasePrompt):
    """
    """

    def __init__(self, parent, manager=None):
        super().__init__(manager=manager, parent=parent)
        self._parent = parent
        self._commands = None

    @property
    def help_text(self):
        synopsis = (
            f"You are currently editing the [b]{self.parent.playlist.name}[/b]"
            f" playlist. From this prompt you can quickly append new tracks "
            f"to the playlist. You can invoke your editor "
            f"([link]{os.environ['EDITOR']}[/link]) to change the playlist "
            f"name and description, or reorder or remove tracks. You can also "
            f"delete the playlist."
        )

        try:
            width = int(os.environ.get('CONSOLE_WIDTH', '80'))
        except ValueError:
            width = 80
        synopsis = '\n        '.join(wrap(synopsis, width=width))

        return dedent(f"""
        [title]WORKING WITH PLAYLISTS[/title]

        {synopsis}

        [title]USAGE[/title]

            [link]playlist> COMMAND [ARG ..][/link]

        [title]COMMANDS[/title]
        [help]
            [b]add[/b]      Add one or more tracks to the playlist
            [b]edit[/b]     Open the playlist in the system editor
            [b]show[/b]     Display the complete playlist
            [b]delete[/b]   Delete the playlist
            [b]help[/b]     This message

            Try 'help command' for command-specific help.[/help]
        """)

    @property
    def prompt(self):
        return [
            "",
            "[help]Available commands: add, edit, show, delete, help. Hit Enter to return.[/help]",
            f"[prompt]{self.parent.playlist.slug}[/prompt]",
        ]

    @property
    def values(self):
        return self.commands.keys()

    @property
    def commands(self):
        if not self._commands:
            self._commands = {
                'delete': self.delete,
                'add': self.add,
                'show': self.show,
                'edit': self.edit,
                'help': self.help
            }
        return self._commands

    def process(self, cmd, *parts):
        if cmd in self.commands:
            return True if self.commands[cmd](parts) else False
        self.parent.console.error(f"Command not understood: {cmd}")
        return True

    def edit(self, *parts):
        try:
            self.parent.playlist.edit()
        except PlaylistValidationError as e:
            self.parent.console.error(f"Changes were not saved: {e}")
        else:
            self.show()
        return True

    def show(self, *parts):
        self.parent.console.print(self.parent.playlist.as_richtext)
        return True

    def add(self, *parts):
        self.parent.console.print(
            "Add tracks one at a time by title. Hit Enter to finish."
        )
        added = False
        while True:
            text = self.parent.console.prompt(
                [' ?'],
                completer=self.manager.fuzzy_table_completer(
                    db.track,
                    db.track.c.relpath,
                    lambda row: row.relpath
                ),
                complete_in_thread=True, complete_while_typing=True
            )
            if not text:
                if added:
                    self.show()
                return True
            self._add_track(text)
            added = True

    def _add_track(self, text):
        sess = self.parent.manager.session
        try:
            track = sess.query(db.track).filter(db.track.c.relpath == text).one()
            self.parent.playlist.create_entries([track])
        except NoResultFound:
            self.parent.console.error("No match for '{text}'")
            return
        return text

    def delete(self, *parts):
        res = self.parent.console.prompt([
            f"[error]Type [b]DELETE[/b] to permanently delete the playlist "
            f'"{self.parent.playlist.record.name}".[/error]',
            f"[prompt]DELETE {self.parent.playlist.slug}[/prompt]",
        ])
        if res != 'DELETE':
            self.parent.console.error("Delete aborted. No changes have been made.")
            return True

        self.parent.playlist.delete()
        self.parent.console.print("Deleted the playlist.")
        self.parent._playlist = None
        return False

    def start(self):
        self.show()
        super().start()