FitTrack_GarminSync/specs/002-intialspecv2/spec.md

Feature Specification: IntialSpecV2

Feature Branch: feature/intial-spec-v2 Created: 2025-10-09 Status: Draft Input: User description: "Create a detailed feature specification based on the provided context."

User Scenarios & Testing (mandatory)

User Story 1 - Garmin Connect Activity Synchronization (Priority: P1)

As a user, I want to authenticate with Garmin Connect and have my activities (FIT, GPX, TCX files) downloaded and stored in CentralDB so that I can track my fitness data.

Why this priority: This is a core function for the GarminSync service, enabling fundamental data collection.

Independent Test: Can be fully tested by authenticating with Garmin Connect, triggering an activity sync, and then verifying that activity files are correctly stored in CentralDB.

Acceptance Scenarios:

1. Given a user has successfully authenticated with Garmin Connect, When they trigger an activity sync via POST /api/sync/garmin/activities, Then their recent activities are downloaded from Garmin Connect and stored as FIT/GPX/TCX files in CentralDB.
2. Given a user has authenticated with Garmin Connect, When a sync is triggered, Then only new or updated activities are downloaded to avoid redundant data.

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User Story 2 - Garmin Connect Health Metrics Synchronization (Priority: P2)

As a user, I want my health metrics to be synchronized from Garmin Connect to CentralDB so I can have a comprehensive view of my health data.

Why this priority: Important for a holistic view of user health, complementing activity data.

Independent Test: Can be fully tested by authenticating with Garmin Connect, triggering a sync, and verifying that health metrics (e.g., heart rate, sleep data) are correctly synchronized and stored in CentralDB.

Acceptance Scenarios:

1. Given a user has successfully authenticated with Garmin Connect, When they trigger a sync, Then their health metrics are synchronized from Garmin Connect to CentralDB.

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User Story 3 - Garmin Workout Upload (Priority: P2)

As a user, I want to be able to upload workouts from the application to Garmin Connect.

Why this priority: This provides bidirectional sync functionality, enhancing the utility of the service.

Independent Test: Can be fully tested by creating a workout in the application, initiating its upload to Garmin Connect, and then verifying that the workout appears correctly on the user's Garmin Connect account.

Acceptance Scenarios:

1. Given a user has a workout defined within the application, When they initiate the workout upload to Garmin, Then the workout is successfully transmitted and appears on their Garmin Connect account.

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User Story 4 - Check Sync Status (Priority: P3)

As a user, I want to be able to check the status of my synchronization processes.

Why this priority: Provides essential feedback to the user on ongoing and completed operations, improving user experience.

Independent Test: Can be fully tested by triggering a synchronization process, then querying the /api/sync/status endpoint to verify that it accurately reflects the ongoing or completed status of the sync.

Acceptance Scenarios:

1. Given a synchronization process is in progress, When the user makes a GET request to /api/sync/status, Then the system returns the current status of the synchronization, including any progress or errors.
2. Given a synchronization process has completed, When the user makes a GET request to /api/sync/status, Then the system returns the final status of the synchronization, including success or failure details.

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Edge Cases

• What happens when the Garmin Connect API is unavailable or returns an error during activity or health metrics synchronization?
• How does the system handle exceeding rate limits imposed by the Garmin Connect API?
• What is the behavior of the system if CentralDB is unavailable or encounters an error during data storage operations?
• How does the system respond if a user revokes the OAuth2 authentication for Garmin Connect?
• What happens if there are conflicts between existing data in CentralDB and incoming data from Garmin Connect during synchronization?

Requirements (mandatory)

Functional Requirements

• FR-001: System MUST support Garmin Connect username and password authentication for user authorization.
• FR-002: System MUST download activity files (FIT, GPX, TCX) from Garmin Connect.
• FR-003: System MUST store downloaded activity files in CentralDB.
• FR-004: System MUST synchronize health metrics data from Garmin Connect to CentralDB.
• FR-005: System MUST allow users to upload workouts to Garmin Connect.
• FR-006: System MUST provide a POST /api/sync/garmin/activities API endpoint to trigger activity synchronization.
• FR-007: System MUST provide a GET /api/sync/status API endpoint to check the current status of synchronization processes.
• FR-008: System MUST process all synchronization tasks as background jobs to ensure responsiveness.
• FR-009: System MUST implement rate limiting mechanisms for all external API calls, especially to Garmin Connect.
• FR-010: System MUST include robust error handling and retry logic for transient failures during external API interactions and CentralDB operations.
• FR-011: System MUST maintain a history of synchronization events and provide mechanisms for conflict resolution using CentralDB.
• FR-012: The application MUST be designed as a single-user system.
• FR-013: The service MUST default to listening on port 8001.
• FR-014: System MUST support configuration via YAML files or environment variables.
• FR-015: System MUST reuse existing code and logic from @GarminAnalyser.md for Garmin integration where applicable.
• FR-016: System MUST utilize CentralDB for all persistent storage, including user authentication tokens (e.g., username and password hashes).
• FR-019: System WILL leverage the garth and garminconnect libraries for Garmin Connect integration, particularly for handling authentication and data synchronization.
• FR-017: System MUST integrate with the CentralDB API as defined in @DB_API_SPEC.json (with the ability to refresh the spec from http://localhost:8000/openapi.json).
• FR-018: System SHOULD support Fitbit weight data synchronization in a future iteration.

Key Entities (include if feature involves data)

• User: The single authenticated individual utilizing the GarminSync service.
• Garmin Connect Account: Represents the user's linked Garmin account, storing OAuth2 tokens and other necessary authentication credentials.
• Activity: A record of a fitness activity (e.g., running, cycling) obtained from Garmin Connect, encompassing raw data files (FIT, GPX, TCX) and metadata.
• Health Metric: A data point representing a user's health measurement (e.g., heart rate, sleep data, body composition) synchronized from Garmin Connect.
• Workout: A structured training plan or session that can be uploaded to Garmin Connect.
• Sync Job: An instance of a synchronization operation (e.g., activity sync, health metrics sync), tracking its status, progress, and any associated errors.

Success Criteria (mandatory)

Measurable Outcomes

• SC-001: 95% of all triggered Garmin Connect activity synchronizations complete successfully within 5 minutes.
• SC-002: Garmin Connect OAuth2 authentication process completes successfully for 100% of first-time users.
• SC-003: The GET /api/sync/status endpoint returns an accurate synchronization status within 5 seconds of being queried.
• SC-004: Data stored in CentralDB (activities, health metrics, tokens) maintains 99.9% integrity and availability.
• SC-005: Workout uploads to Garmin Connect succeed for 98% of attempts.