// post.js
// Copyright (C) 2021 Digital Telepresence, LLC
// License: Apache-2.0

'use strict';

const striptags = require('striptags');
const slug = require('slug');

const { SiteService } = require('../../lib/site-lib');

const mongoose = require('mongoose');
const ObjectId = mongoose.Types.ObjectId;

const Post = mongoose.model('Post');

class PostService extends SiteService {

  constructor (dtp) {
    super(dtp, module.exports);

    this.populatePost = [
      {
        path: 'author',
        select: '_id username username_lc displayName picture',
      },
    ];
  }

  async create (author, postDefinition) {
    const NOW = new Date();

    const post = new Post();
    post.created = NOW;
    post.author = author._id;
    post.title = striptags(postDefinition.title.trim());
    post.slug = this.createPostSlug(post._id, post.title);
    post.summary = striptags(postDefinition.summary.trim());
    post.content = postDefinition.content.trim();
    post.status = postDefinition.status || 'draft';
    post.flags = {
      enableComments: postDefinition.enableComments === 'on',
      isFeatured: postDefinition.isFeatured === 'on',
    };

    await post.save();

    return post.toObject();
  }

  async update (post, postDefinition) {
    const NOW = new Date();
    const updateOp = {
      $set: {
        updated: NOW,
      },
    };

    if (postDefinition.title) {
      updateOp.$set.title = striptags(postDefinition.title.trim());
      updateOp.$set.slug = this.createPostSlug(post._id, updateOp.$set.title);
    }
    if (postDefinition.slug) {
      let postSlug = striptags(slug(postDefinition.slug.trim())).split('-');
      while (ObjectId.isValid(postSlug[postSlug.length - 1])) {
        postSlug.pop();
      }
      postSlug = postSlug.splice(0, 4);
      postSlug.push(post._id.toString());
      updateOp.$set.slug = `${postSlug.join('-')}`;
    }
    if (postDefinition.summary) {
      updateOp.$set.summary = striptags(postDefinition.summary.trim());
    }
    if (postDefinition.content) {
      updateOp.$set.content = postDefinition.content.trim();
    }
    if (postDefinition.status) {
      updateOp.$set.status = striptags(postDefinition.status.trim());
    }

    updateOp.$set['flags.enableComments'] = postDefinition.enableComments === 'on';
    updateOp.$set['flags.isFeatured'] = postDefinition.isFeatured === 'on';

    await Post.updateOne(
      { _id: post._id },
      updateOp,
      { upsert: true },
    );
  }

  async getPosts (pagination, status = ['published']) {
    if (!Array.isArray(status)) {
      status = [status];
    }
    const posts = await Post
      .find({ status: { $in: status } })
      .sort({ created: -1 })
      .skip(pagination.skip)
      .limit(pagination.cpp)
      .lean();
    return posts;
  }

  async getById (postId) {
    const post = await Post
      .findById(postId)
      .select('+content')
      .populate(this.populatePost)
      .lean();
    return post;
  }

  async getBySlug (postSlug) {
    const slugParts = postSlug.split('-');
    const postId = slugParts[slugParts.length - 1];
    return this.getById(postId);
  }

  async deletePost (post) {
    this.log.info('deleting post', { postId: post._id });
    await Post.deleteOne({ _id: post._id });
  }

  createPostSlug (postId, postTitle) {
    if ((typeof postTitle !== 'string') || (postTitle.length < 1)) {
      throw new Error('Invalid input for making a post slug');
    }
    const postSlug = slug(postTitle.trim().toLowerCase()).split('-').slice(0, 4).join('-');
    return `${postSlug}-${postId}`;
  }
}

module.exports = {
  slug: 'post',
  name: 'post',
  create: (dtp) => { return new PostService(dtp); },
};