# ADR-0001: Language and TUI framework

## Status

Accepted

## Context

RDBMS Playground is a cross-platform terminal application aimed at
learners. It needs to feel fast, polished, and colourful, install
cleanly on Linux, macOS, and Windows, and ship as a single binary
with no runtime dependencies.

Beyond TUI rendering, the application has substantial SQL-handling
needs: syntax highlighting, parsing user input to distinguish app
DSL commands from SQL, rewriting simplified types into backend
types, and analysing query plans for the teaching features.

Two stacks were realistic candidates:

1. **Rust + Ratatui + Crossterm** — strong cross-platform terminal
   support, single static binary, mature ecosystem. Crucially,
   `sqlparser-rs` is a high-quality dialect-aware SQL parser
   directly applicable to the parsing, highlighting, and query
   analysis features.
2. **Go + Bubble Tea (Charm)** — excellent default aesthetics,
   single static binary, easy distribution. Lacks an equivalent to
   `sqlparser-rs`; SQL parsing would need to be written from
   scratch or wrap a less suitable library.

## Decision

Use **Rust with Ratatui and Crossterm** for the TUI, with
`sqlparser-rs` for SQL parsing and `rusqlite` for the database
layer. Distribute as prebuilt binaries via GitHub releases plus
package managers (`cargo binstall`, Homebrew, Scoop, `winget`).

## Consequences

- Single static binary on all three target platforms.
- Strong fit between SQL-heavy features and the Rust SQL ecosystem
  (`sqlparser-rs`, `rusqlite`).
- Slightly steeper contributor on-ramp for developers unfamiliar
  with Rust compared to Go.
- TUI styling will require explicit work to match the polish that
  Bubble Tea / Lipgloss give for free; budget for it in the design
  pass.

## Amendment 1 — Distribution channel is open after the Gitea migration (2026-06-09)

The *Decision* block above assumed prebuilt binaries would ship "via
GitHub releases plus package managers." Since then the repository has
been migrated off GitHub to a self-hosted Gitea instance
(`git.lazyeval.net/oli/rdbms-playground`), and `tea` is the forge CLI
in use. The "GitHub releases" half of that sentence is therefore no
longer a settled assumption.

This amendment does **not** pick a replacement. Binary distribution is
not built yet (no release pipeline, no CI — `requirements.md` TT5/E*
remain open), so the channel for prebuilt binaries is an **open
choice** — Gitea releases, a GitHub mirror's releases, or both — to be
settled by a dedicated ADR when distribution is actually implemented.
The package-manager channels named in the Decision (`cargo binstall`,
Homebrew, Scoop, `winget`) are independent of the forge and are
unaffected.

(For the same supersede-don't-rewrite reason, the Decision block also
still names `sqlparser-rs`, which ADRs 0030–0036 replaced with a
hand-rolled grammar; that is recorded there, not by editing this ADR.)