Demo — console Klondike solitaire (user-requested entertainment test app)

• Type: feature
• Status: done
• Owner: Track B agent (reuses klondike engine + screen lib)
• Opened: 2026-06-19 (user-called: "as user, I am calling solitaire")
• Relation: demo-class, but a deliberate exception to the catalog's headless / pure-oracle filter in idea-demo-app-candidates — admitted because it is the most entertaining test app for a human tester on a Linux host. Distinct from the rejected visual/audio "please-user" demos (ray-tracer / Mandelbrot / chiptune): solitaire is text + stateful logic, not a pixel/audio toy. Shares the line-UI shape of the sudoku game.

Goal

Playable Klondike solitaire in the terminal: shuffle a seeded deck, deal the tableau, and let a human play (draw, move runs, send to foundations) until win.

The ncurses / ESP32 question (resolved)

• No ncurses binding. ANSI escape codes are just bytes written to stdout (ESC[2J clear, ESC[r;cH cursor) — render via plain managed strings, no C library, no header import. Keeps the dependency story clean.
• Input: raw single-key input needs termios (a small platform dep). Avoid it by default with line commands (e.g. d draw, m ws t3 waste→tableau 3, m t1 f tableau 1→foundation, u undo, n new, q quit). Line I/O is fully portable and works over ESP32 serial, so the demo is not ESP-excluded.
• Optional later: an ANSI full-screen + raw-key layer (this is where a small TUI helper library could eventually be spun out — note it, do not ticket it yet).

Surface / shape

• enums: suit (♣♦♥♠ / CDHS), rank (A..K), color
• record TCard (suit, rank, faceUp)
• piles: stock / waste / 4 foundations / 7 tableau columns — dynamic-array stacks, the natural data structure stress
• seeded PRNG shuffle (app-local, as in the sudoku game)
• move validation (alternating-color descending tableau, ascending same-suit foundations), undo stack (records)
• renderer: ASCII board (plain) or ANSI (optional)

Coverage

enums · records · dynamic arrays as stacks (push/pop heavy) · managed strings (render + command parse) · state machine + move legality (short-circuit) · seeded integer PRNG · undo (record history). Solid mid-size surface; integer-only.

Acceptance / oracle (the honest caveat)

Interactive → weaker oracle than chess/perft. Pin it down with:

• Seeded deal is reproducible: seed → exact initial layout, byte-identical across targets.
• Scripted transcript: a fixed stdin move sequence → fixed final board / "you win" output (same harness shape as the sudoku-game scripted test).
• Optional: an auto-play solver for a seed → deterministic solvable/stuck verdict (a real oracle if added).
• Demo: examples/solitaire/ — interactive on a Linux host; scripted transcript in make test.

Constraints

Platonic source; no compiler changes; no ncurses. Primary target = Linux host entertainment; ESP-serial via line mode. No self-host / cross regression.

Log

• 2026-06-19 — Opened on user request. Resolved the ncurses worry up front (ANSI = strings, line-input avoids termios) so the demo stays dependency-free and ESP-serial-capable; flagged the oracle caveat + the seeded-deal / scripted transcript test hooks.

Log

• 2026-06-23 — Done. examples/solitaire/console_solitaire.pas: playable terminal Klondike on the tested klondike engine + the screen TUI manager (lib/rtl/screen.pas). Column cursor (arrows), space acts (stock=draw, else pick source then destination → largest legal run), u=undo a=auto n=new q/Esc= quit; red/black suits, fanned tableau, move counter + win line. Keys via ScreenWaitKey so piped input drives it headlessly (EOF=KEY_NONE quits). Scripted smoke in make lib-test: printf 'aq' on seed 1 sends AS+AH to foundations -> moves=2 won=0. No GTK/display needed (pure terminal).

Landed in commit d251206.