/**
 * Model Chat - Representa uma conversa entre comprador e vendedor
 */

import { model, models, Schema } from "mongoose";

export interface IChat {
  chat_id: string; // ID único: `${listing_id}_${buyer_id}_${seller_id}`
  listing_id: number; // ID do anúncio (PostgreSQL)
  buyer_id: number; // ID do comprador (PostgreSQL)
  seller_id: number; // ID do vendedor (PostgreSQL)
  created_at: Date;
  updated_at: Date;
  last_message_at: Date | null;
  last_message_preview: string | null;
  buyer_unread_count: number;
  seller_unread_count: number;
  is_active: boolean; // Chat ativo (anúncio ainda disponível)

  // Dados cached do anúncio (para performance)
  listing_cache: {
    item_name: string;
    item_image_url?: string;
    price_pix?: number;
    price_tibia_coins?: number;
    price_gold_coins?: number;
    server_name: string;
    listing_status: string;
  };

  // Dados cached dos usuários
  buyer_cache: {
    user_id: number;
    username: string;
    character_name?: string;
  };

  seller_cache: {
    user_id: number;
    username: string;
    character_name?: string;
  };
}

const ChatSchema = new Schema<IChat>(
  {
    chat_id: {
      type: String,
      required: true,
      unique: true,
      index: true,
    },
    listing_id: {
      type: Number,
      required: true,
      index: true,
    },
    buyer_id: {
      type: Number,
      required: true,
      index: true,
    },
    seller_id: {
      type: Number,
      required: true,
      index: true,
    },
    created_at: {
      type: Date,
      default: Date.now,
      index: true,
    },
    updated_at: {
      type: Date,
      default: Date.now,
    },
    last_message_at: {
      type: Date,
      default: null,
      index: true,
    },
    last_message_preview: {
      type: String,
      default: null,
      maxlength: 100,
    },
    buyer_unread_count: {
      type: Number,
      default: 0,
    },
    seller_unread_count: {
      type: Number,
      default: 0,
    },
    is_active: {
      type: Boolean,
      default: true,
      index: true,
    },
    listing_cache: {
      item_name: { type: String, required: true },
      item_image_url: { type: String, default: null },
      price_pix: { type: Number, default: null },
      price_tibia_coins: { type: Number, default: null },
      price_gold_coins: { type: Number, default: null },
      server_name: { type: String, required: true },
      listing_status: { type: String, required: true },
    },
    buyer_cache: {
      user_id: { type: Number, required: true },
      username: { type: String, required: true },
      character_name: { type: String, default: null },
    },
    seller_cache: {
      user_id: { type: Number, required: true },
      username: { type: String, required: true },
      character_name: { type: String, default: null },
    },
  },
  {
    timestamps: false, // Usamos campos manuais
    collection: "chats",
  },
);

// Índices compostos para queries eficientes
ChatSchema.index({ buyer_id: 1, updated_at: -1 });
ChatSchema.index({ seller_id: 1, updated_at: -1 });
ChatSchema.index({ listing_id: 1, buyer_id: 1, seller_id: 1 });

// Atualizar updated_at antes de salvar
ChatSchema.pre("save", function (next) {
  this.updated_at = new Date();
  next();
});

export const Chat = models.Chat || model<IChat>("Chat", ChatSchema);