# Solution Strategy

## Technology Decisions

| Decision       | Choice                                    | Rationale                                                                              |
| -------------- | ----------------------------------------- | -------------------------------------------------------------------------------------- |
| Bot runtime    | Node.js + TypeScript + discord.js         | Strong ecosystem, typed Discord interactions, shared language across backend/dashboard |
| Persistence    | PostgreSQL (`pg`)                         | Reliable relational storage for mileage, schedules, and settings                       |
| Admin API      | Express                                   | Lightweight routing and middleware model for operational endpoints                     |
| Dashboard      | React + Vite + TypeScript                 | Fast iteration and typed API integration                                               |
| Authentication | Bearer token (admin API) + Discord OAuth2 | Secure machine-to-machine admin calls plus user identity bridge                        |
| Deployment     | Coolify + Gitea Actions                   | Simple CI/CD path with webhook-triggered production rollout                            |

## Architectural Strategy

System uses modular monolith strategy in single backend process:

- Bot core orchestrates Discord gateway and command/event handling.
- Domain services encapsulate call-sheet onboarding, tour queue, mileage, and dailies.
- Operational interfaces exposed through Admin API and OAuth bridge.
- Shared configuration layer centralizes environment parsing and validation.
- Separate dashboard SPA consumes API without direct DB access.

## Quality Strategies

- Availability: graceful startup/shutdown, service initialization guards, process-level health endpoint.
- Consistency: transactional mileage writes, strict DB row guards, idempotent schedule updates.
- Security: token-based admin auth, OAuth code exchange on server side, no token logging.
- Extensibility: adapter interface for new dailies sources and isolated service modules.
- Operability: CI checks (lint/build/test) for bot and dashboard before deploy trigger.

## Trade-offs

- In-memory OAuth sessions reduce complexity but require re-authentication after process restart.
- Modular monolith minimizes operational overhead now, while preserving service boundaries for future extraction.