package org.thoughtcrime.securesms.stickers;

import android.support.annotation.NonNull;
import android.support.annotation.StringRes;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;

import com.annimon.stream.Stream;
import com.bumptech.glide.load.resource.drawable.DrawableTransitionOptions;

import org.thoughtcrime.securesms.database.model.StickerPackRecord;
import org.thoughtcrime.securesms.mms.DecryptableStreamUriLoader.DecryptableUri;
import org.thoughtcrime.securesms.mms.GlideRequests;
import org.thoughtcrime.securesms.util.StableIdGenerator;

import java.util.ArrayList;
import java.util.List;

import network.loki.messenger.R;

final class StickerManagementAdapter extends RecyclerView.Adapter {

  private static final int TYPE_HEADER = 1;
  private static final int TYPE_EMPTY  = 2;
  private static final int TYPE_PACK   = 3;

  private static final String TAG_YOUR_STICKERS    = "YourStickers";
  private static final String TAG_MESSAGE_STICKERS = "MessageStickers";
  private static final String TAG_BLESSED_STICKERS = "BlessedStickers";

  private final GlideRequests             glideRequests;
  private final EventListener             eventListener;
  private final StableIdGenerator<String> stableIdGenerator;

  private final List<Section> sections = new ArrayList<Section>(3) {{
    Section yourStickers    = new Section(TAG_YOUR_STICKERS,
                                          R.string.StickerManagementAdapter_installed_stickers,
                                          R.string.StickerManagementAdapter_no_stickers_installed,
                                          new ArrayList<>(),
                                          0);
    Section messageStickers = new Section(TAG_MESSAGE_STICKERS,
                                          R.string.StickerManagementAdapter_stickers_you_received,
                                          R.string.StickerManagementAdapter_stickers_from_incoming_messages_will_appear_here,
                                          new ArrayList<>(),
                                          yourStickers.size());

    add(yourStickers);
    add(messageStickers);
  }};

  StickerManagementAdapter(@NonNull GlideRequests glideRequests, @NonNull EventListener eventListener) {
    this.glideRequests     = glideRequests;
    this.eventListener     = eventListener;
    this.stableIdGenerator = new StableIdGenerator<>();

    setHasStableIds(true);
  }

  @Override
  public long getItemId(int position) {
    for (Section section : sections) {
      if (section.handles(position)) {
        return section.getItemId(stableIdGenerator, position);
      }
    }
    throw new NoSectionException();
  }

  @Override
  public int getItemViewType(int position) {
    for (Section section : sections) {
      if (section.handles(position)) {
        return section.getViewType(position);
      }
    }
    throw new NoSectionException();
  }

  @Override
  public @NonNull RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int viewType) {
    switch (viewType) {
      case TYPE_HEADER:
        return new HeaderViewHolder(LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.sticker_management_header_item, viewGroup, false));
      case TYPE_EMPTY:
        return new EmptyViewHolder(LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.sticker_management_empty_item, viewGroup, false));
      case TYPE_PACK:
        return new StickerViewHolder(LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.sticker_management_sticker_item, viewGroup, false));
      default:
        throw new AssertionError("Unexpected viewType! " + viewType);
    }
  }

  @Override
  public void onBindViewHolder(@NonNull RecyclerView.ViewHolder viewHolder, int position) {
    for (Section section : sections) {
      if (section.handles(position)) {
        section.bindViewHolder(viewHolder, position, glideRequests, eventListener);
        return;
      }
    }
    throw new NoSectionException();
  }

  @Override
  public void onViewRecycled(@NonNull RecyclerView.ViewHolder holder) {
    if (holder instanceof StickerViewHolder) {
      ((StickerViewHolder) holder).recycle();
    }
  }

  @Override
  public int getItemCount() {
    return Stream.of(sections).reduce(0, (sum, section) -> sum + section.size());
  }

  void setPackLists(@NonNull List<StickerPackRecord> installedPacks,
                    @NonNull List<StickerPackRecord> availablePacks,
                    @NonNull List<StickerPackRecord> blessedPacks)
  {
    Section yourStickers    = new Section(TAG_YOUR_STICKERS,
                                          R.string.StickerManagementAdapter_installed_stickers,
                                          R.string.StickerManagementAdapter_no_stickers_installed,
                                          installedPacks,
                                          0);
    Section blessedStickers = new Section(TAG_BLESSED_STICKERS,
                                          R.string.StickerManagementAdapter_signal_artist_series,
                                          0,
                                          blessedPacks,
                                          yourStickers.size());
    Section messageStickers = new Section(TAG_MESSAGE_STICKERS,
                                          R.string.StickerManagementAdapter_stickers_you_received,
                                          R.string.StickerManagementAdapter_stickers_from_incoming_messages_will_appear_here,
                                          availablePacks,
                                          yourStickers.size() + (blessedPacks.isEmpty() ? 0 : blessedStickers.size()));

    sections.clear();
    sections.add(yourStickers);

    if (!blessedPacks.isEmpty()) {
      sections.add(blessedStickers);
    }

    sections.add(messageStickers);

    notifyDataSetChanged();
  }

  private static class Section {
    private static final String STABLE_ID_HEADER = "header";
    private static final String STABLE_ID_TEXT   = "text";

    private final String                  tag;
    private final int                     titleResId;
    private final int                     emptyResId;
    private final List<StickerPackRecord> records;
    private final int                     offset;

    Section(@NonNull String tag,
            @StringRes int titleResId,
            @StringRes int emptyResId,
            @NonNull List<StickerPackRecord> records,
            int offset)
    {
      this.tag        = tag;
      this.titleResId = titleResId;
      this.emptyResId = emptyResId;
      this.records    = records;
      this.offset     = offset;
    }

    int getViewType(int globalPosition) {
      int localPosition = globalPosition - offset;

      if (localPosition == 0) {
        return TYPE_HEADER;
      } else if (records.isEmpty()) {
        return TYPE_EMPTY;
      } else {
        return TYPE_PACK;
      }
    }

    long getItemId(@NonNull StableIdGenerator<String> idGenerator, int globalPosition) {
      int localPosition = globalPosition - offset;

      if (localPosition == 0) {
        return idGenerator.getId(tag + "_" + STABLE_ID_HEADER);
      } else if (records.isEmpty()) {
        return idGenerator.getId(tag + "_" + STABLE_ID_TEXT);
      } else {
        return idGenerator.getId(records.get(localPosition - 1).getPackId());
      }
    }

    void bindViewHolder(@NonNull RecyclerView.ViewHolder viewHolder,
                        int globalPosition,
                        @NonNull GlideRequests glideRequests,
                        @NonNull EventListener eventListener)
    {
      int localPosition = globalPosition - offset;

      if (localPosition == 0) {
        ((HeaderViewHolder) viewHolder).bind(titleResId);
      } else if (records.isEmpty()) {
        ((EmptyViewHolder) viewHolder).bind(emptyResId);
      } else {
        ((StickerViewHolder) viewHolder).bind(glideRequests, eventListener, records.get(localPosition - 1), localPosition == records.size());
      }
    }

    boolean handles(int globalPosition) {
      int localPosition = globalPosition - offset;
      return localPosition >= 0 && localPosition < size();
    }

    int size() {
      return records.isEmpty() ? 2 : records.size() + 1;
    }
  }

  static class StickerViewHolder extends RecyclerView.ViewHolder {

    private final ImageView cover;
    private final TextView  title;
    private final TextView  author;
    private final View      badge;
    private final View      divider;
    private final View      actionButton;
    private final ImageView actionButtonImage;
    private final View      shareButton;
    private final ImageView shareButtonImage;

    StickerViewHolder(@NonNull View itemView) {
      super(itemView);

      this.cover             = itemView.findViewById(R.id.sticker_management_cover);
      this.title             = itemView.findViewById(R.id.sticker_management_title);
      this.author            = itemView.findViewById(R.id.sticker_management_author);
      this.badge             = itemView.findViewById(R.id.sticker_management_blessed_badge);
      this.divider           = itemView.findViewById(R.id.sticker_management_divider);
      this.actionButton      = itemView.findViewById(R.id.sticker_management_action_button);
      this.actionButtonImage = itemView.findViewById(R.id.sticker_management_action_button_image);
      this.shareButton       = itemView.findViewById(R.id.sticker_management_share_button);
      this.shareButtonImage  = itemView.findViewById(R.id.sticker_management_share_button_image);
    }

    void bind(@NonNull GlideRequests glideRequests,
              @NonNull EventListener eventListener,
              @NonNull StickerPackRecord stickerPack,
              boolean lastInList)
    {
      title.setText(stickerPack.getTitle().or(itemView.getResources().getString(R.string.StickerManagementAdapter_untitled)));
      author.setText(stickerPack.getAuthor().or(itemView.getResources().getString(R.string.StickerManagementAdapter_unknown)));
      divider.setVisibility(lastInList ? View.GONE : View.VISIBLE);
      badge.setVisibility(BlessedPacks.contains(stickerPack.getPackId()) ? View.VISIBLE : View.GONE);

      glideRequests.load(new DecryptableUri(stickerPack.getCover().getUri()))
                   .transition(DrawableTransitionOptions.withCrossFade())
                   .into(cover);

      if (stickerPack.isInstalled()) {
        actionButtonImage.setImageResource(R.drawable.ic_x);
        actionButton.setOnClickListener(v -> eventListener.onStickerPackUninstallClicked(stickerPack.getPackId(), stickerPack.getPackKey()));

        shareButton.setVisibility(View.VISIBLE);
        shareButtonImage.setVisibility(View.VISIBLE);
        shareButton.setOnClickListener(v -> eventListener.onStickerPackShareClicked(stickerPack.getPackId(), stickerPack.getPackKey()));
      } else {
        actionButtonImage.setImageResource(R.drawable.ic_arrow_down);
        actionButton.setOnClickListener(v -> eventListener.onStickerPackInstallClicked(stickerPack.getPackId(), stickerPack.getPackKey()));

        shareButton.setVisibility(View.GONE);
        shareButtonImage.setVisibility(View.GONE);
        shareButton.setOnClickListener(null);
      }

      itemView.setOnClickListener(v -> eventListener.onStickerPackClicked(stickerPack.getPackId(), stickerPack.getPackKey()));
    }

    void recycle() {
      actionButton.setOnClickListener(null);
      shareButton.setOnClickListener(null);
      itemView.setOnClickListener(null);
    }
  }

  static class HeaderViewHolder extends RecyclerView.ViewHolder {

    private final TextView titleView;

    HeaderViewHolder(@NonNull View itemView) {
      super(itemView);

      this.titleView = itemView.findViewById(R.id.sticker_management_header);
    }

    void bind(@StringRes int title) {
      titleView.setText(title);
    }
  }

  static class EmptyViewHolder extends RecyclerView.ViewHolder {

    private final TextView text;

    EmptyViewHolder(@NonNull View itemView) {
      super(itemView);

      this.text = itemView.findViewById(R.id.sticker_management_empty_text);
    }

    void bind(@StringRes int title) {
      text.setText(title);
    }
  }

  interface EventListener {
    void onStickerPackClicked(@NonNull String packId, @NonNull String packKey);
    void onStickerPackUninstallClicked(@NonNull String packId, @NonNull String packKey);
    void onStickerPackInstallClicked(@NonNull String packId, @NonNull String packKey);
    void onStickerPackShareClicked(@NonNull String packId, @NonNull String packKey);
  }

  private static class NoSectionException extends IllegalStateException {}
}