Refactor HTML generation into shared base handler.

[supermartzin]

Extracted common HTML template and post rendering logic into a new HtmlBasedAdPostsHandlerBase class and project. Updated Email and File handlers to inherit from this base, removing duplicated code. Adjusted project references and solution structure accordingly.

[gemini-code-assist]

Summary of Changes

Hello @supermartzin, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request significantly improves the maintainability and organization of the application's HTML generation capabilities. By extracting the common HTML templating and post-rendering logic into a new HtmlBasedAdPostsHandlerBase class, the PR eliminates duplicated code from the Email and File handlers. This refactoring centralizes the responsibility for HTML creation, making future modifications and extensions to the HTML output much simpler and less error-prone.

Highlights

• New Base Handler: A new abstract base class, HtmlBasedAdPostsHandlerBase, has been introduced to centralize common HTML generation logic.
• Common HTML Templates: All shared HTML template elements (full page, titles, and individual post structures) have been moved into a new static class, CommonHtmlTemplateElements.
• Code Duplication Reduction: The EmailNotifyingAdPostsHandler and LocalFileAdPostsHandler now inherit from the new base class, eliminating significant code duplication related to HTML rendering.
• Project Structure Update: A new project (RealEstatesWatcher.AdPostsHandlers.Base.Html) was added, and existing projects were updated to reference it, while the old RealEstatesWatcher.AdPostsHandlers.Templates project was removed.

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[gemini-code-assist]

Code Review

This pull request successfully refactors the HTML generation logic into a shared base class, HtmlBasedAdPostsHandlerBase, which is a great improvement for code reuse and maintainability. The Email and File handlers are updated to use this new base class, removing significant code duplication.

My review includes a few suggestions to improve the implementation:

• A critical fix for an invalid Target Framework in the project files.
• Two high-severity bug fixes related to incorrect logic in the email and file handlers.
• Some medium-severity suggestions for performance, correctness, and code style in the new base class.

Overall, this is a solid refactoring. Addressing the identified issues will make it even better.

[gemini-code-assist]

For a single new ad post notification, you are using TitleInitialPosts which has the text 'Current Real estate offer'. You should use TitleNewPosts which has the text 'NEW Real estate offer' to be consistent with the email subject and the event.

        await SendEmailAsync("🆕 New Real Estate Advert published!", CreateFullHtmlPage([adPost], CommonHtmlTemplateElements.TitleNewPosts), cancellationToken).ConfigureAwait(false);

[gemini-code-assist]

The comment indicates you intend to keep the <posts/> element for future appends, but the insertion logic is incorrect. pageContent.Insert(index + 8, ...) inserts the new posts after the <posts/> tag. To prepend the new posts and keep the tag for the next run, you should insert at index.

        pageContent = pageContent.Insert(index, htmlPostsElements + Environment.NewLine);

[gemini-code-assist]

The assignment postHtmlBuilder = postHtmlBuilder.Replace(...) is redundant because StringBuilder.Replace modifies the instance in-place and returns this. You can simply chain the calls without the assignment. This applies to the entire method where this pattern is used.

            postHtmlBuilder.Replace("{$address-links-display}", "inline-block")
                               .Replace("{$address-encoded}", HttpUtility.UrlEncode(post.Address));

[gemini-code-assist]

Creating new NumberFormatInfo on each call is inefficient. This object should be created once as a static readonly field and reused. This will improve performance, especially when processing a large number of ad posts. This also applies to formatting AdditionalFees on line 69.

You can add a field to the class:

private static readonly NumberFormatInfo SpaceSeparatedNumberFormat = new() { NumberGroupSeparator = " " };

And then use it here: post.Price.ToString("N", SpaceSeparatedNumberFormat)

[gemini-code-assist]

Using display: table for a <p> element is unconventional and can lead to unexpected layout behavior. The standard and more predictable value for a paragraph is display: block. Unless there's a specific reason for using table, it's better to change it.

            postHtmlBuilder = postHtmlBuilder.Replace("{$text}", post.Text)
                               .Replace("{$text-display}", "block");

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[supermartzin]

/gemini review

[gemini-code-assist]

Code Review

This pull request effectively refactors the HTML generation logic into a shared base class, HtmlBasedAdPostsHandlerBase, which significantly reduces code duplication in EmailNotifyingAdPostsHandler and LocalFileAdPostsHandler. The introduction of the RealEstatesWatcher.AdPostsHandlers.Base.Html project is a good structural improvement.

My review includes a few points:

• A critical issue with an invalid TargetFramework in the project files.
• A high-severity bug where a template placeholder is not replaced, leading to broken links.
• A medium-severity suggestion to improve the generated HTML's CSS for better predictability.

Overall, this is a solid refactoring. Once the identified issues are addressed, the code will be much cleaner and more maintainable.