The Converter

The converter is the step in the data processing pipeline responsible for transforming the standardized DiveLog ADT into a set of tabular columns for the final output file.

Its primary responsibilities are:

1. Generating Column Headers: It creates a standard set of 24 column headers, appending the correct unit suffixes (e.g., (ft) vs. (m), (psi) vs. (bar)) based on the DiveMetadata from the DiveLog.
2. Formatting Data: It transforms the data from the DiveSample list into string representations suitable for a CSV file. This includes key transformations like:
   • Negating depth values (e.g., 30.5 becomes -30.5).
   • Formatting numeric values to a consistent number of decimal places.
   • Handling null values from the domain model and representing them as empty strings in the output.
3. Producing a Base Telemetry Set: It generates the foundational set of 24 columns that form the core of the final output.

This step acts as the bridge between the pure, typed domain model of the dive and the specific, formatted representation required by Telemetry Overlay.

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Interaction with Output Plugins

While the pipeline diagram shows a simple linear flow, the interaction between the converter and the OutputPlugin chain is a parallel process:

                          -> convert -> [Base 24 Columns]   \
[DiveLogPlugin chain] -> DiveLog                             -> merge -> [Final Columns] -> write
                          -> [OutputPlugin chain] -> [Custom Columns]  /

1. The final DiveLog object (after all DiveLogPlugin transformations) is used as the input for both the converter and the OutputPlugin chain.
2. The converter processes the DiveLog to create the base 24 columns.
3. Simultaneously, each OutputPlugin in the chain processes the exact same DiveLog to generate its own set of custom columns.
4. Finally, the pipeline merges the converter's base columns with the columns from all output plugins to produce the final set of columns that gets written to the output file.

OutputPlugins do not receive the output of the converter; they work on the same input data to ensure all calculations are based on the same source of truth.

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Base Output Columns

The converter generates the following 24 columns. The unit suffixes ($depthSuffix, $tempSuffix, $pressureSuffix) are dynamically replaced based on the dive's metadata.

1. Time (s)
2. Actual Depth ($depthSuffix)
3. First Stop Depth
4. Time To Surface
5. Average PP02 (text)
6. Fraction O2 (text)
7. Fraction He (text)
8. First Stop Time
9. Current NDL
10. Current Circuit Mode
11. Water Temp ($tempSuffix)
12. Gas Switch Needed
13. External PPO2
14. Tank 1 pressure ($pressureSuffix)
15. Tank 2 pressure ($pressureSuffix)
16. Tank 3 pressure ($pressureSuffix)
17. Tank 4 pressure ($pressureSuffix)
18. Seconds
19. Display Minutes (text)
20. Display Seconds (text)
21. Max Depth (text)
22. Actual Time (text)
23. AM/PM Indicator (text)
24. Gas Mixture (text)