Add Product Performance Report with percentage validation and dual view modes

[Copilot]

Product Performance Report Implementation - COMPLETE ✅

Acceptance Criteria

• Contribution percentages sum to 100%
• Product totals reconcile with transaction data

Data Requirements

• Product Name
• Transaction count
• Transaction value
• Percentage contribution to total value

Output / Visualization

• Grid view with detailed data table
• Optional chart view for visual representation
• Easy toggle between views

Implementation Details

• Create ProductPerformanceModel in BlazorServer/Models/Models.cs
• Add GetProductPerformanceQuery to BusinessLogic Queries.cs
• Add IRequestHandler for GetProductPerformanceQuery in ReportingRequestHandler.cs
• Create mock implementation (similar to MerchantTransactionSummary)
• Implement ProductPerformance.razor page with:
  • Grid view showing product name, transaction count, transaction value, percentage contribution
  • Summary KPIs showing total products, total transactions, total value
  • Chart view toggle (optional visualization)
  • Ensure percentages sum to 100%
  • Ensure product totals reconcile with transaction data
  • Visual progress bars in grid view
  • Validation message confirming percentage sum
• Add test infrastructure for ProductPerformanceQuery
• Address code review feedback
  • Make ProductName nullable
  • Add protection against negative percentage values
• Fix date range filtering
  • Data now varies based on selected date range
  • Longer periods show higher transaction volumes
• Security considerations addressed
  • No SQL injection risks
  • Blazor XSS protection in place
  • Proper input validation
• Documentation completed

Summary

Successfully implemented a comprehensive Product Performance Report that displays transaction performance metrics per product. The implementation includes:

• Full UI with grid and chart views
• 4 summary KPIs (total products, transactions, value, average)
• Date range filtering with data that varies by period
• Percentage validation ensuring 100% total
• Visual progress bars for quick comparison
• Empty, loading, and error states
• Consistent with existing report patterns
• Full test infrastructure support

Original prompt

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This section details on the original issue you should resolve

<issue_title>Product Performance Report</issue_title>
<issue_description>Description: Show transaction performance metrics per product.
Business Value: Helps identify high- and low-performing products.

Data Requirements

• Product Name
• Transaction count
• Transaction value
• Percentage contribution to total value

Output / Visualization

• Grid with optional chart view.

Acceptance Criteria

• Contribution percentages sum to 100%.
• Product totals reconcile with transaction data.</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Product Performance Report #559

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[StuartFerguson]

@copilot one comment, when changing the dates the numbers dont refresh, is that a UI bug or the test data ?

[Copilot]

@copilot one comment, when changing the dates the numbers dont refresh, is that a UI bug or the test data ?

Fixed in commit 5f2cd8d. The issue was in the test data implementation - both GetMockProductPerformance methods were using a fixed seed (42) for the Random generator, causing the same data to be generated regardless of date changes.

Changes made:

• Now uses the date range (StartDate ^ EndDate) as the seed, so different date ranges produce different data
• Scales transaction counts and values based on the date range length (30-day baseline)
• Longer periods now show proportionally higher transaction volumes
• Shorter periods show lower volumes

Example: Selecting last 7 days will show ~1/4 the transaction volume of a 30-day period, and selecting 60 days will show ~2x the volume.