Form and process list of string with Lua plugin on very old Lua 2.5 - arraylist

Question

I'm trying to write lua plugin to extract and place some metadata from HTML page. It's a plugin for soupault static site generator and it requires lua version 2.5 for work. So no closures and no for loops in particular.
It is no sense to load you how this generator works because plugin exists as a small standalone file .lua and plugs in during the running of generator.
What is significant are the methods used by the plugin. These are used at the input and output of the plugin.
And more importantly, it is how to form and process the list of extracted tags with lua language.
Input data in the body of html page:
<site-meta-data>
#+title: post 1 title
#+subtitle: Post 1 subtitle
#+description: Post 1 decription
#+author: Billy
#+date: 2021-11-03
#+datepublished: 2021-06-02
#+usertags: inventory,errand
#+summary: Post 1 summary
#+id: 1-test1com
</site-meta-data>
And these are steps that plugin should take:
get strings between <site-meta-data></site-meta-data> tags into the
list get string from the list & split by first colon eg.
string.match(destination_number, "(.-):"))
create variable name as first word before colon and without #+ (eg. title)
create conditions for the next operation on this variable. If variable name which is
created from the string = current name, eg. meta_tag = title, insert
metatag with value or insert new tag with extracted value after
parent tag. I'll write by myself which tags should be inserted.
after processing of the list remove all between <site-meta-data></site-meta-data> including
itself.
As being near zero in lua scripting I just wrote the scratch of the script.
all_meta_tags = HTML.select_one(page, "site-meta-data")
all_meta_tags = HTML.parse(page, "site-meta-data")
print(all_meta_tags)
local index = 1
while all_meta_tags[index] do
meta_tag_line = all_meta_tags[index]
meta_tag = string.match(meta_tag_line, "(.-):")
meta_tag_content = string.match(meta_tag_line, ":(.*)")
meta_tag_content = strlower(String.trim(meta_tag_content))
meta_tag = Regex.replace(meta_tag, "#+", "")
if (meta_tag == "title") then
HTML.append_child(page, HTML.create_string('<meta name="title" content="value..">'))
elseif (meta_tag == 'subtitle') then
HTML.append_child(page, HTML.create_string('...'))
elseif (meta_tag == 'description') then
HTML.append_child(page, HTML.create_string('<meta name="description" content="meta_tag_value">'))
elseif (meta_tag == 'author') then
HTML.append_child(page, HTML.create_string('author...'))
elseif (meta_tag == 'date') then
HTML.append_child(page, HTML.create_string('<meta name="date" content="meta_tag_content">'))
end
index = index + 1
end
HTML.delete(HTML.select_one(page, "site-meta-data"))
Please, help me to modify the script to accomplish the above task. I'll correct what tags it should place.

Answer 1

Since version 4.0 soupault supports a pre-parse hook. So it's now possible to reimplement various types of front matter with that hook. The plugin should always put the rendered HTML before the page body. Plugin can be written as this example.
[hooks.pre-parse]
file = "hooks/org-mode-metadata.lua"
template = """
<h1 id="post-title">{{title}}</h1>
...