Plugin for wordpress - autoposting

You need to develop a WordPress plugin that can create a post in two modes.
draft and publication immediately.

The data for the post is on the same host, in the mysql database.
The procedure is already written, you only need a php code.

Requirements

1. The ability to work on a schedule.
In the schedule settings:
weekday
The mode is a draft or immediately post.
User/password to call procedures
name of the procedure to be called
its parameters and their type
commentary

store settings locally, in an ini file, the password is desirable not to be stored in an open form.

1. Call the p_get_template procedure – get a template. Some text
For example, “Hello, today we publish the text of %tag%”
Varchar (300)
2. Calling the p_get_tag procedure – we get an arbitrary type of text that
We'll publish. For example, “wonderful metalworking machines.” Varchar (100)
3. Change %tag% to p_get_tag, which is the introduction.
4. Call p_get_setting procedure – we get the settings:

row_before_text tinyint - the number of empty lines between the intro and the intro
textually

delimeter – varchar (10) symbols that divide information, for example:

delimeterposition varchar (6), position of the separators, meanings: left, right, center

row_before_delimeter - number of empty lines in front of the separator

row_after_delimeter - number of empty lines after the separator

row_before_sign - number of lines before signing

Sign - the signature is varchar (200). It will contain hyperlinks.

5. Calling the procedure specified in the settings with the specified parameters - we get a record set.

Id_Text int unsigned, TextValue varchar (700)

Add text from the recordset using previously received settings

text + row_before_delimeter + delimeter and its position according to
delimeterposition + row_after_delimeter + next_text - and so on until the end
record set.

Then row_before_sign + sign, and actually create the post. In the case of
successful creation - in the form of a draft or successful posting -
We run again on the record set and call the procedure:
p_set_used (iId_Text unsigned) - send Id_Text to it. In case of error
It's going to come back negative. We're writing it in the log.

If the post failed to create - write in the log time and reason.
In case of an error in any operation, write to the log. Have the ability to delete the log.

It would be nice to be able to add a picture to the post. However, there is no clear vision of how to do this and how to store it in the database (?) yet.