Wordpress Plugin (api integration)

It is a project without front-end programming, where the programmer who understands well the WP, assembles the functions without difficulty. The demand is a plugin that will interact with Wordpress in 3 situations: Insert, change and delete. The programmer can use the existing API plugin to work, but doing the data processing first. This data will arrive in a single JSON for input, with the following parameters: - - - - STANDARD FIELDS OF WORDPRESS (Default fields of a Wordpress post / custom post) - action (create, change, delete) - date (day, month, year, hour) - enable comment (yes, no) - type of post (post-standard, custom-post-x, custom-post-y, custom-post-z) - category (the title of the categories separated by commas) - tag (the title of tags separated by commas) - title-of-post - url-friend-of-post - resume-text-from-post - long-text-post (may contain url of images) - featured-image (will come with the url of an image) CUSTOMIZED FIELDS (Data that will enter as custom fields) - post-language (EN, PT, ES, IT, etc.) - original ID (of the content in the source system, for future update or delete) - several variable fields (all always stored as custom field, these fields can receive for example a url list of images separated by commas) LIST OF MEDIA (One image per node with all parameters) - source (featured img, img in body of long text, img in custom field) - Url - friendly image - title - alternative text - description - - - - Processing of data before insertion: 1 - Multisite installation: The post must be created in the multisite installation corresponding to the language provided (each language has its own installation in the multisite format as follows: EN = 1, PT = 2, ES = 3, IT = 4). 2 - The MEDIA (LIST OF MEDIA) need to be registered one by one in the media library (all attachments via url, such as images, pdf, etc). 3 - In the long text field (the main content of the post), the images should have the URL replaced with the URL of the imported image in Wordpress. 4 - In the fields custom fields, in case of media, will only store the ID of the media (in the case of a custom fields containing a photo gallery for example). Categories and Tags should check if they already exist (checking the title) before they are created. - - - - Action UPDATE / EXCLUSION: - all custom fields in the post should be deleted and reinserted (tags and categories do not need to be deleted). - All media inserted in the long text field, highlight image and custom fields should be deleted and reinserted (in case of update). * The reference of the post to be modified or deleted will be the custom-field "original ID" (of the content in the source system, for future update or delete) - - - - Final information: After performing the action (INSERT, UPDATE, DELETE) the plugin should return the parameter confirming the action or declining, informing the error (ex: xml with problem, authentication refused). * The plugin should not use a PHP framework to be developed, but the programming can be POO.