package com.example.livestreaming;

import android.graphics.Outline;
import android.net.Uri;
import android.text.TextUtils;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewOutlineProvider;
import android.widget.ImageView;
import android.widget.TextView;

import androidx.annotation.NonNull;
import androidx.core.content.FileProvider;
import androidx.recyclerview.widget.DiffUtil;
import androidx.recyclerview.widget.ListAdapter;
import androidx.recyclerview.widget.RecyclerView;

import com.bumptech.glide.Glide;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;

public class ConversationMessagesAdapter extends ListAdapter<ChatMessage, RecyclerView.ViewHolder> {

    public interface OnMessageLongClickListener {
        void onMessageLongClick(ChatMessage message, int position, View view);
    }

    private OnMessageLongClickListener longClickListener;

    private static final int TYPE_INCOMING = 1;
    private static final int TYPE_OUTGOING = 2;

    private static final SimpleDateFormat TIME_FORMAT = new SimpleDateFormat("HH:mm", Locale.getDefault());

    public ConversationMessagesAdapter() {
        super(DIFF);
    }

    public void setOnMessageLongClickListener(OnMessageLongClickListener listener) {
        this.longClickListener = listener;
    }

    @Override
    public int getItemViewType(int position) {
        ChatMessage msg = getItem(position);
        if (msg == null) return TYPE_INCOMING;
        String u = msg.getUsername();
        return "我".equals(u) ? TYPE_OUTGOING : TYPE_INCOMING;
    }

    @NonNull
    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        LayoutInflater inflater = LayoutInflater.from(parent.getContext());
        if (viewType == TYPE_OUTGOING) {
            View v = inflater.inflate(R.layout.item_conversation_message_outgoing, parent, false);
            return new OutgoingVH(v);
        }
        View v = inflater.inflate(R.layout.item_conversation_message_incoming, parent, false);
        return new IncomingVH(v);
    }

    @Override
    public void onBindViewHolder(@NonNull RecyclerView.ViewHolder holder, int position) {
        ChatMessage msg = getItem(position);
        if (holder instanceof IncomingVH) {
            ((IncomingVH) holder).bind(msg, longClickListener);
        } else if (holder instanceof OutgoingVH) {
            ((OutgoingVH) holder).bind(msg, longClickListener);
        }
    }

    static class IncomingVH extends RecyclerView.ViewHolder {
        private final ImageView avatarView;
        private final TextView nameText;
        private final TextView msgText;
        private final TextView timeText;

        IncomingVH(@NonNull View itemView) {
            super(itemView);
            avatarView = itemView.findViewById(R.id.avatarView);
            nameText = itemView.findViewById(R.id.nameText);
            msgText = itemView.findViewById(R.id.messageText);
            timeText = itemView.findViewById(R.id.timeText);
            setupAvatarOutline();
        }

        private void setupAvatarOutline() {
            if (avatarView == null) return;
            // 设置圆形裁剪，确保在模拟器上也能正常工作
            // 使用post确保在View布局完成后再设置outline
            avatarView.post(() -> {
                if (avatarView.getWidth() > 0 && avatarView.getHeight() > 0) {
                    avatarView.setOutlineProvider(new ViewOutlineProvider() {
                        @Override
                        public void getOutline(View view, Outline outline) {
                            outline.setOval(0, 0, view.getWidth(), view.getHeight());
                        }
                    });
                    avatarView.setClipToOutline(true);
                }
            });
        }

        void bind(ChatMessage message, OnMessageLongClickListener listener) {
            if (message == null) return;
            nameText.setText(message.getUsername() != null ? message.getUsername() : "");
            msgText.setText(message.getMessage() != null ? message.getMessage() : "");
            timeText.setText(TIME_FORMAT.format(new Date(message.getTimestamp())));
            
            // 清除之前的监听器，避免重复绑定
            itemView.setOnClickListener(null);
            itemView.setOnLongClickListener(null);
            
            // 设置长按监听
            itemView.setOnLongClickListener(v -> {
                if (listener != null) {
                    int position = getBindingAdapterPosition();
                    if (position != RecyclerView.NO_POSITION) {
                        listener.onMessageLongClick(message, position, v);
                        return true;
                    }
                }
                return false;
            });
            
            // 确保头像圆形裁剪设置正确
            setupAvatarOutline();
            // 加载对方头像（优先使用消息中的头像 URL，如果没有则使用默认头像）
            loadAvatar(message);
        }

        private void loadAvatar(ChatMessage message) {
            // TODO: 接入后端接口 - 加载消息发送者头像
            // 接口路径: GET /api/users/{userId}/avatar 或直接从ChatMessage的avatarUrl字段获取
            // ChatMessage对象应包含avatarUrl字段，如果为空，则根据userId调用接口获取
            // 建议后端在返回消息列表时，每条消息都包含发送者的avatarUrl，避免额外请求
            if (avatarView == null) return;
            
            try {
                // 优先使用消息中的头像 URL（从后端获取）
                String avatarUrl = message != null ? message.getAvatarUrl() : null;
                if (!TextUtils.isEmpty(avatarUrl)) {
                    Glide.with(avatarView)
                            .load(avatarUrl)
                            .circleCrop()
                            .error(R.drawable.ic_account_circle_24)
                            .placeholder(R.drawable.ic_account_circle_24)
                            .into(avatarView);
                    return;
                }
                
                // 如果没有头像 URL，暂时根据用户名生成不同的默认头像
                // 这样不同发送者至少能通过不同的默认头像区分开
                String username = message != null ? message.getUsername() : null;
                int defaultAvatarRes = getDefaultAvatarForUsername(username);
                Glide.with(avatarView)
                        .load(defaultAvatarRes)
                        .circleCrop()
                        .into(avatarView);
            } catch (Exception e) {
                // 如果加载失败，使用默认头像
                Glide.with(avatarView)
                        .load(R.drawable.ic_account_circle_24)
                        .circleCrop()
                        .into(avatarView);
            }
        }
        
        /**
         * 根据用户名生成一个稳定的默认头像资源
         * 这样同一个用户名的消息会显示相同的默认头像
         * TODO: 后续接入后端接口后，这个方法可以改为从后端获取头像 URL
         */
        private int getDefaultAvatarForUsername(String username) {
            if (TextUtils.isEmpty(username)) {
                return R.drawable.ic_account_circle_24;
            }
            
            // 使用用户名的哈希值来选择不同的默认头像
            // 这样不同的发送者至少能通过不同的默认头像区分开
            int hash = Math.abs(username.hashCode());
            int[] defaultAvatars = {
                R.drawable.ic_account_circle_24,
                // 如果有其他默认头像资源，可以在这里添加
                // R.drawable.default_avatar_1,
                // R.drawable.default_avatar_2,
            };
            
            return defaultAvatars[hash % defaultAvatars.length];
        }
    }

    static class OutgoingVH extends RecyclerView.ViewHolder {
        private final ImageView avatarView;
        private final TextView msgText;
        private final TextView timeText;
        private final ImageView statusIcon;

        OutgoingVH(@NonNull View itemView) {
            super(itemView);
            avatarView = itemView.findViewById(R.id.avatarView);
            msgText = itemView.findViewById(R.id.messageText);
            timeText = itemView.findViewById(R.id.timeText);
            statusIcon = itemView.findViewById(R.id.statusIcon);
            setupAvatarOutline();
        }

        private void setupAvatarOutline() {
            if (avatarView == null) return;
            // 设置圆形裁剪，确保在模拟器上也能正常工作
            // 使用post确保在View布局完成后再设置outline
            avatarView.post(() -> {
                if (avatarView.getWidth() > 0 && avatarView.getHeight() > 0) {
                    avatarView.setOutlineProvider(new ViewOutlineProvider() {
                        @Override
                        public void getOutline(View view, Outline outline) {
                            outline.setOval(0, 0, view.getWidth(), view.getHeight());
                        }
                    });
                    avatarView.setClipToOutline(true);
                }
            });
        }

        void bind(ChatMessage message, OnMessageLongClickListener listener) {
            if (message == null) return;
            msgText.setText(message.getMessage() != null ? message.getMessage() : "");
            timeText.setText(TIME_FORMAT.format(new Date(message.getTimestamp())));
            
            // 显示消息状态图标（仅对发送的消息显示）
            if (statusIcon != null && message.getStatus() != null) {
                switch (message.getStatus()) {
                    case SENDING:
                        statusIcon.setImageResource(R.drawable.ic_clock_24);
                        statusIcon.setColorFilter(itemView.getContext().getColor(android.R.color.darker_gray));
                        statusIcon.setVisibility(View.VISIBLE);
                        break;
                    case SENT:
                        statusIcon.setImageResource(R.drawable.ic_check_24);
                        statusIcon.setColorFilter(itemView.getContext().getColor(android.R.color.darker_gray));
                        statusIcon.setVisibility(View.VISIBLE);
                        break;
                    case READ:
                        statusIcon.setImageResource(R.drawable.ic_check_double_24);
                        statusIcon.setColorFilter(0xFF4CAF50);
                        statusIcon.setVisibility(View.VISIBLE);
                        break;
                    default:
                        statusIcon.setVisibility(View.GONE);
                        break;
                }
            }
            
            // 清除之前的监听器，避免重复绑定
            itemView.setOnClickListener(null);
            itemView.setOnLongClickListener(null);
            
            // 设置长按监听
            itemView.setOnLongClickListener(v -> {
                if (listener != null) {
                    int position = getBindingAdapterPosition();
                    if (position != RecyclerView.NO_POSITION) {
                        listener.onMessageLongClick(message, position, v);
                        return true;
                    }
                }
                return false;
            });
            
            // 确保头像圆形裁剪设置正确
            setupAvatarOutline();
            // 加载用户头像
            loadAvatar();
        }

        private void loadAvatar() {
            if (avatarView == null) return;
            
            try {
                String avatarUri = avatarView.getContext()
                        .getSharedPreferences("profile_prefs", android.content.Context.MODE_PRIVATE)
                        .getString("profile_avatar_uri", null);
                
                if (!TextUtils.isEmpty(avatarUri)) {
                    Uri uri = Uri.parse(avatarUri);
                    // 如果是 file:// 协议，尝试转换为 FileProvider URI
                    if ("file".equals(uri.getScheme())) {
                        try {
                            java.io.File file = new java.io.File(uri.getPath());
                            if (file.exists()) {
                                uri = FileProvider.getUriForFile(
                                    avatarView.getContext(),
                                    avatarView.getContext().getPackageName() + ".fileprovider",
                                    file
                                );
                            }
                        } catch (Exception e) {
                            // 如果转换失败，使用原始 URI
                        }
                    }
                    Glide.with(avatarView)
                            .load(uri)
                            .circleCrop()
                            .error(R.drawable.ic_account_circle_24)
                            .placeholder(R.drawable.ic_account_circle_24)
                            .into(avatarView);
                    return;
                }

                int avatarRes = avatarView.getContext()
                        .getSharedPreferences("profile_prefs", android.content.Context.MODE_PRIVATE)
                        .getInt("profile_avatar_res", 0);
                
                if (avatarRes != 0) {
                    Glide.with(avatarView)
                            .load(avatarRes)
                            .circleCrop()
                            .error(R.drawable.ic_account_circle_24)
                            .into(avatarView);
                } else {
                    Glide.with(avatarView)
                            .load(R.drawable.ic_account_circle_24)
                            .circleCrop()
                            .into(avatarView);
                }
            } catch (Exception e) {
                Glide.with(avatarView)
                        .load(R.drawable.ic_account_circle_24)
                        .circleCrop()
                        .into(avatarView);
            }
        }
    }

    private static final DiffUtil.ItemCallback<ChatMessage> DIFF = new DiffUtil.ItemCallback<ChatMessage>() {
        @Override
        public boolean areItemsTheSame(@NonNull ChatMessage oldItem, @NonNull ChatMessage newItem) {
            // 使用messageId作为唯一标识
            return oldItem.getMessageId() != null && oldItem.getMessageId().equals(newItem.getMessageId());
        }

        @Override
        public boolean areContentsTheSame(@NonNull ChatMessage oldItem, @NonNull ChatMessage newItem) {
            // 比较消息内容、状态等是否相同
            return oldItem.getMessageId() != null && oldItem.getMessageId().equals(newItem.getMessageId()) &&
                   oldItem.getStatus() == newItem.getStatus() &&
                   oldItem.getMessage() != null && oldItem.getMessage().equals(newItem.getMessage());
        }
    };
}