import random
from collections import defaultdict
from concurrent.futures import ThreadPoolExecutor
from typing import Tuple, Type

# from lhotse import CutSet
# from lhotse.dataset.collation import collate_features
# from lhotse.dataset.input_strategies import (
#     ExecutorType,
#     PrecomputedFeatures,
#     _get_executor,
# )
# from lhotse.utils import fastcopy


class PromptedFeatures:
    def __init__(self, prompts, features):
        self.prompts = prompts
        self.features = features

    def to(self, device):
        return PromptedFeatures(
            self.prompts.to(device), self.features.to(device)
        )

    def sum(self):
        return self.features.sum()

    @property
    def ndim(self):
        return self.features.ndim

    @property
    def data(self):
        return (self.prompts, self.features)


# class PromptedPrecomputedFeatures(PrecomputedFeatures):
#     """
#     :class:`InputStrategy` that reads pre-computed features, whose manifests
#     are attached to cuts, from disk.
#
#     It automatically pads the feature matrices with pre or post feature.
#
#     .. automethod:: __call__
#     """
#
#     def __init__(
#         self,
#         dataset: str,
#         cuts: CutSet,
#         num_workers: int = 0,
#         executor_type: Type[ExecutorType] = ThreadPoolExecutor,
#     ) -> None:
#         super(PromptedPrecomputedFeatures, self).__init__(
#             num_workers, executor_type
#         )
#
#         self.utt2neighbors = defaultdict(lambda: [])
#
#         if dataset.lower() == "libritts":
#             # 909_131041_000013_000002
#             # 909_131041_000013_000003
#             speaker2utts = defaultdict(lambda: [])
#
#             utt2cut = {}
#             for cut in cuts:
#                 speaker = cut.supervisions[0].speaker
#                 speaker2utts[speaker].append(cut.id)
#                 utt2cut[cut.id] = cut
#
#             for spk in speaker2utts:
#                 uttids = sorted(speaker2utts[spk])
#                 # Using the property of sorted keys to find previous utterance
#                 # The keys has structure speaker_book_x_y e.g. 1089_134691_000004_000001
#                 if len(uttids) == 1:
#                     self.utt2neighbors[uttids[0]].append(utt2cut[uttids[0]])
#                     continue
#
#                 utt2prevutt = dict(zip(uttids, [uttids[1]] + uttids[:-1]))
#                 utt2postutt = dict(zip(uttids[:-1], uttids[1:]))
#
#                 for utt in utt2prevutt:
#                     self.utt2neighbors[utt].append(utt2cut[utt2prevutt[utt]])
#
#                 for utt in utt2postutt:
#                     self.utt2neighbors[utt].append(utt2cut[utt2postutt[utt]])
#         elif dataset.lower() == "ljspeech":
#             utt2cut = {}
#             uttids = []
#             for cut in cuts:
#                 uttids.append(cut.id)
#                 utt2cut[cut.id] = cut
#
#             if len(uttids) == 1:
#                 self.utt2neighbors[uttids[0]].append(utt2cut[uttids[0]])
#             else:
#                 # Using the property of sorted keys to find previous utterance
#                 # The keys has structure: LJ001-0010
#                 utt2prevutt = dict(zip(uttids, [uttids[1]] + uttids[:-1]))
#                 utt2postutt = dict(zip(uttids[:-1], uttids[1:]))
#
#                 for utt in utt2postutt:
#                     postutt = utt2postutt[utt]
#                     if utt[:5] == postutt[:5]:
#                         self.utt2neighbors[utt].append(utt2cut[postutt])
#
#                 for utt in utt2prevutt:
#                     prevutt = utt2prevutt[utt]
#                     if utt[:5] == prevutt[:5] or not self.utt2neighbors[utt]:
#                         self.utt2neighbors[utt].append(utt2cut[prevutt])
#         else:
#             raise ValueError
#
#     def __call__(
#         self, cuts: CutSet
#     ) -> Tuple[PromptedFeatures, PromptedFeatures]:
#         """
#         Reads the pre-computed features from disk/other storage.
#         The returned shape is``(B, T, F) => (batch_size, num_frames, num_features)``.
#
#         :return: a tensor with collated features, and a tensor of ``num_frames`` of each cut before padding.
#         """
#         features, features_lens = collate_features(
#             cuts,
#             executor=_get_executor(
#                 self.num_workers, executor_type=self._executor_type
#             ),
#         )
#
#         prompts_cuts = []
#         for k, cut in enumerate(cuts):
#             prompts_cut = random.choice(self.utt2neighbors[cut.id])
#             prompts_cuts.append(fastcopy(prompts_cut, id=f"{cut.id}-{str(k)}"))
#
#         mini_duration = min([cut.duration for cut in prompts_cuts] + [3.0])
#         # prompts_cuts = CutSet.from_cuts(prompts_cuts).truncate(
#         #     max_duration=mini_duration,
#         #     offset_type="random",
#         #     preserve_id=True,
#         # )
#         prompts_cuts = CutSet(
#             cuts={k: cut for k, cut in enumerate(prompts_cuts)}
#         ).truncate(
#             max_duration=mini_duration,
#             offset_type="random",
#             preserve_id=False,
#         )
#
#         prompts, prompts_lens = collate_features(
#             prompts_cuts,
#             executor=_get_executor(
#                 self.num_workers, executor_type=self._executor_type
#             ),
#         )
#
#         return PromptedFeatures(prompts, features), PromptedFeatures(
#             prompts_lens, features_lens
#         )