const mongoose = require("mongoose");

const PostSchema = new mongoose.Schema(
  {
    user: {
      type: mongoose.Schema.Types.ObjectId,
      ref: "User",
      required: true,
      index: true,
    },
    content: {
      type: String,
      required: true,
    },
    imageUrl: {
      type: String,
    },
    cloudinaryPublicId: {
      type: String,
    },
    likes: [
      {
        type: mongoose.Schema.Types.ObjectId,
        ref: "User",
      },
    ],
    commentsCount: {
      type: Number,
      default: 0,
    },
  },
  {
    timestamps: true,
  },
);

// Index for querying posts by creation date
PostSchema.index({ createdAt: -1 });

// Update user relationship when post is created
PostSchema.post("save", async function (doc) {
  const User = mongoose.model("User");

  // Add post to user's posts if not already there
  await User.updateOne(
    { _id: doc.user },
    { $addToSet: { posts: doc._id } }
  );
});

// Cascade cleanup when a post is deleted
PostSchema.pre("deleteOne", { document: true, query: false }, async function () {
  const User = mongoose.model("User");

  // Remove post from user's posts
  await User.updateOne(
    { _id: this.user },
    { $pull: { posts: this._id } }
  );
});

module.exports = mongoose.model("Post", PostSchema);