A zero configuration minimal and liteweight ASP.net Core URL shortener

This web app requires ASP.net Core 3 or later.
For ASP.net core under v3 you need to change services.AddRazorPages(); in line 19 and endpoints.MapRazorPages(); in line 34 of startup.cs file.

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Directory Structure:

Directory / File	Explanation
/BLL	Contains a class, that used to read last Database ID from lastRecord.txt file (located in Project's root) and +1 it, then write it back to file and also return it as string
/Static_Assets	Contains css, js, images and fonts [1]
urlData.litedb	This is a liteDB database file which is safe to remove/ It will be recreated in runtime!
lastRecord.txt	This 4B sized file, storing last value of urlShortner.Models.urlData.shortUrl inserted to the database, which is used as ID field for database [2]

Other files are based on ASP.net core's directory structure.

[1]: If you having problem accessing these files (such as background doesn't load or bootstrap.css errors) add following lines to the web.config file located in publish folder:
add <location> tag directly under <configuration> tag.

<location path="Static_assets">
  <system.webServer>
    <directoryBrowse enabled="true" />
  </system.webServer>
</location>

[2]: This file's initial value is aa` because urlShortner.Bll.shortUrlCreator.shortner(string filePath) +1 the value, everytime it reads the file. So this way, first shortUrl will be aaa
This property is located in: /models/urlData.cs

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Short URLs life time:

Any single URL will lives until 999 new URL added!
Reason is that Upsert() function is used to add new URL to database in the DbCollection.Upsert(urlDataObj); code line.

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Current short URLs range:

from aaa to zzz.
No uppercase URLs; No numbers...!

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ToDo:

• Edit source code of /BLL to start from aaa after riched ~~~ value in lastRecord.txt
• Fix issue of longUrls which are not starting with http:// or https://
• Make Domain name prefix before shortUrl that showing to the client, Dynamic!
• Fix issue that client is able to shorten a single URL, multiple times!
• Change /BLL source code to make shortUrl string's length configurable by admin! /(still zero config?)*
• Implement shoert URLs' hit times monitor
• show corresponding errors when requested shortUrl doesn't exist or when clien tries to shorten empty longUrl
• Randomize background image
• Add documentaion comments to source code