Purpose

Document the shipped Shikaku built-in game behavior.

Requirements

Requirement: Registry Metadata

Shikaku SHALL be registered as a built-in game with canonical description "Divide the grid into rectangles with set sizes.", aliases rectangles, variants Shikaku (default 1400 Elo), and daily legacy modes easy 7x7, medium 8x8.

Scenario: Resolve Shikaku

• WHEN the registry resolves the canonical name or any alias
• THEN it returns the Shikaku entry with help text, import behavior, variant metadata, and legacy mode compatibility

Requirement: Variant Elo Creation

Shikaku MUST support the current variant plus target Elo creation path, using the variant default Elo when no explicit target is supplied.

Scenario: Spawn Shikaku by Elo

• WHEN the user selects the Shikaku variant and a target Elo from 0 through 3000
• THEN PuzzleTea spawns a deterministic Shikaku puzzle and records target, actual, and confidence metadata when generation reports it

Requirement: Legacy Mode Compatibility

Shikaku SHALL preserve legacy named modes as compatibility presets that map to the Shikaku variant and preset Elo values: Mini 5x5 (300 Elo), Easy 7x7 (800 Elo), Medium 8x8 (1400 Elo), Hard 10x10 (2100 Elo), Expert 12x12 (2700 Elo).

Scenario: Use legacy mode title

• WHEN the user supplies a legacy Shikaku mode title through CLI or deterministic daily metadata
• THEN PuzzleTea resolves it to the Shikaku variant and the registered preset Elo

Requirement: Puzzle Rules

The Shikaku runtime MUST let players partition the grid into rectangles, each rectangle containing exactly one clue and having area equal to that clue.

Scenario: Check solved state

• WHEN the player fills the board or word state
• THEN Shikaku reports solved only when all rule constraints are satisfied

Requirement: Save Load And Interaction

Shikaku SHALL serialize enough state for resume/import, reset to its initial puzzle, expose debug and full-help data, and support its shipped interaction model. Keyboard rectangle editing is required, and mouse drag support MUST be available.

Scenario: Resume saved Shikaku

• WHEN a saved Shikaku payload is imported
• THEN the restored game preserves givens, player entries, cursor/selection state where applicable, and solved-state behavior

Requirement: Print Export Support

The Shikaku print adapter SHALL render puzzle and solution data for JSONL-to-PDF workflows.

Scenario: Export Shikaku

• WHEN Shikaku is included in a JSONL or PDF export flow
• THEN PuzzleTea follows the registered print support behavior for that game