# 🛠️ Fix Data Fetching and Conditional Logic in History Charts

## **Overview**

This PR addresses critical issues in the `AbstractHistoryChart` component related to data fetching and conditional logic, ensuring that historical timeseries data is correctly retrieved and processed for accurate chart rendering.

## **Issues Addressed**

1. **Incorrect Data Fetching Logic**
   - **Problem:** The `queryHistoricTimeseriesData` method was improperly returning empty data regardless of the API response, leading to charts displaying undefined or empty datasets.
   - **Solution:** Refactored the method to properly handle asynchronous API responses, ensuring that actual data is returned and errors are handled gracefully.

2. **Faulty Conditional Statement**
   - **Problem:** The condition
     ```typescript
     if ("_sum/EssActivePowerL1" && "_sum/EssActivePowerL2" && "_sum/EssActivePowerL3" in result.data && this.showPhases == true) {
     ```
     was always evaluating to `true` due to operator precedence, causing logical errors.
   - **Solution:** Updated the condition to explicitly check each channel using the `in` operator:
     ```typescript
     if ("_sum/EssActivePowerL1" in result.data && "_sum/EssActivePowerL2" in result.data && "_sum/EssActivePowerL3" in result.data && this.showPhases === true) {
     ```

## **Changes Made**

- **Refactored `queryHistoricTimeseriesData` Method:**
  - Removed the immediate return of empty data.
  - Ensured the method resolves with actual API responses.
  - Implemented proper error handling by rejecting promises on failures.
  - Added a stale response check to prevent race conditions.

- **Fixed Conditional Logic:**
  - Rewrote the `if` statement to individually check each required channel's existence in `result.data`.
  - Used strict equality (`===`) for `this.showPhases` to ensure type-safe comparison.

## **Why These Changes?**

- **Accurate Data Representation:** Ensures charts display real and complete historical data, improving reliability.
- **Elimination of Logical Errors:** Correct conditional checks prevent unintended code execution, maintaining data integrity.
- **Enhanced Error Handling:** Properly managing API errors prevents the application from masking issues and aids in debugging.
- **Improved Code Quality:** Addressing TypeScript warnings leads to cleaner, more maintainable code.

## **Testing**

- Verified that charts now display correct data when API responses are received.
- Confirmed that conditional statements behave as expected without triggering TypeScript warnings.
- Ensured that error scenarios gracefully initialize empty charts without breaking the application.

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**Please review the changes and approve the merge to enhance the reliability and accuracy of our history chart components.**