# Implementation Plan: [FEATURE]

**Branch**: `[###-feature-name]` | **Date**: [DATE] | **Spec**: [link]
**Input**: Feature specification from `/specs/[###-feature-name]/spec.md`

**Note**: This template is filled in by the `/speckit.plan` command. See `.specify/templates/commands/plan.md` for the execution workflow.

## Summary

This feature updates the GET /api/analysis/{analysis_id}/charts and GET /api/analysis/{analysis_id}/summary endpoints to automatically fetch and analyze workout files from a CentralDB.

## Technical Context

<!--
  ACTION REQUIRED: Replace the content in this section with the technical details
  for the project. The structure here is presented in advisory capacity to guide
  the iteration process.
-->

**Language/Version**: Python 3.11  
**Primary Dependencies**: FastAPI, pandas, numpy, scipy, matplotlib, fitparse, tcxparser, gpxpy, requests  
**Storage**: Ephemeral in-memory cache (last 5), CentralDB (long-term)  
**Testing**: pytest  
**Target Platform**: Linux server
**Project Type**: web  
**Performance Goals**: 95% of cached requests < 500ms; new analyses < 45s for a 2-hour workout.  
**Constraints**: `analysis_id` must match CentralDB activity ID.  
**Scale/Scope**: 50 concurrent analysis requests.

## Constitution Check

*GATE: Must pass before Phase 0 research. Re-check after Phase 1 design.*

| Principle | Status | Justification (if violation) |
|---|---|---|
| I. Library-First | Aligned | The new functionality will be part of the existing library structure. |
| II. CLI Interface | VIOLATION | The feature is API-only, which is the primary interface for this web service. |
| III. Test-First (NON-NEGOTIABLE) | Aligned | The spec has acceptance scenarios that can be tested first. |
| IV. Integration Testing | Aligned | The feature requires integration with CentralDB. |
| V. Observability | Aligned | No new observability requirements for this feature. |
| VI. Versioning & Breaking Changes | Aligned | No breaking changes are expected. |
| VII. Simplicity | Aligned | The feature simplifies the user workflow by removing the need for manual file uploads. |

## Project Structure

### Documentation (this feature)

```
specs/[###-feature]/
├── plan.md              # This file (/speckit.plan command output)
├── research.md          # Phase 0 output (/speckit.plan command)
├── data-model.md        # Phase 1 output (/speckit.plan command)
├── quickstart.md        # Phase 1 output (/speckit.plan command)
├── contracts/           # Phase 1 output (/speckit.plan command)
└── tasks.md             # Phase 2 output (/speckit.tasks command - NOT created by /speckit.plan)
```

### Source Code (repository root)
<!--
  ACTION REQUIRED: Replace the placeholder tree below with the concrete layout
  for this feature. Delete unused options and expand the chosen structure with
  real paths (e.g., apps/admin, packages/something). The delivered plan must
  not include Option labels.
-->

```
src/
├── core/
│   ├── batch_processor.py
│   ├── chart_generator.py
│   ├── file_parser.py
│   ├── logger.py
│   ├── report_generator.py
│   ├── workout_analyzer.py
│   └── workout_data.py
├── db/
│   ├── models.py
│   └── session.py
└── utils/
    └── zone_calculator.py

api/
├── routers/
│   └── analysis.py
├── main.py
└── schemas.py

tests/
├── unit/
├── integration/
├── contract/
└── performance/
```

**Structure Decision**: The project will continue to use the existing structure, which separates the core logic, API, and tests into `src`, `api`, and `tests` directories respectively.

## Complexity Tracking

*Fill ONLY if Constitution Check has violations that must be justified*

| Violation | Why Needed | Simpler Alternative Rejected Because |
|-----------|------------|-------------------------------------|
| Violation | Why Needed | Simpler Alternative Rejected Because |
|---|---|---|
| II. CLI Interface | The primary interface for this feature is a REST API, as it is extending an existing web service. | A CLI is not the primary interface for this service and would add unnecessary complexity at this stage. |