from beets import ui
from beets.plugins import BeetsPlugin
from beets.ui import Subcommand, print_
from beets.ui.commands import print_and_modify

from beets.dbcore import types
from beets.dbcore import FieldQuery

import optparse

import json

def do_modify_labels(lib, objs, label, action):
    changed = []

    for obj in objs:
        labels = {}
        if action != 2:
            if "mylabels" in obj:
                labels = json.loads(obj["mylabels"])

            split = label.split(":")

            if action == 0:
                if len(split) == 1:
                    labels[label] = 0
                else:
                    labels[split[0]] = int(split[1])
            elif label in labels:
                del labels[label]

        obj_mods = {
            "mylabels": json.dumps(labels)
        }
        if print_and_modify(obj, obj_mods, []) and obj not in changed:
            changed.append(obj)

    # Still something to do?
    if not changed:
        print_("No changes to make.")
        return

    # Confirm action.
    changed = ui.input_select_objects(
        "Really modify",
        changed,
        lambda o: print_and_modify(o, mods, dels),
    )

    # Apply changes to database and files
    with lib.transaction():
        for obj in changed:
            obj.try_sync(True, False, False)

action_map = {
    "add": 0,
    "remove": 1,
    "removeall": 2,
    "show": 3
}

def modify_labels(lib, opts, args):
    action = args[0]

    if action not in action_map:
        print_("%s is not a valid action. " % action)
        print_("Valid actions are: add, remove, removeall, show")
        return

    actnum = action_map[action]

    if actnum >= 2:
        label = None
        query = args[1:]
    else:
        label = args[1]
        query = args[2:]

    items = lib.items(query=query)

    if actnum == 3:
        for obj in items:
            print_(obj.title)
            if "mylabels" in obj:
                print_("  " + "; ".join(obj["mylabels"]))
    else:
        do_modify_labels(lib, items, label, actnum)

labels_command = Subcommand('labels', help='Add or remove labels')
labels_command.func = modify_labels

class JSONHas(FieldQuery):
    @classmethod
    def value_match(self, pattern, val):
        if val is not None:
            labels = json.loads(val)
            return pattern in labels
        return False

class BeetsLabelsPlugin(BeetsPlugin):
    # item_queries = { 'has_label': DelimitedHasExact }
    # item_types = {'mylabels': types.SEMICOLON_SPACE_DSV}

    def queries(self):
        return {
            "JSON@" : JSONHas
        }

    def commands(self):
        return [labels_command]