Purpose

Document the shipped Hashiwokakero built-in game behavior.

Requirements

Requirement: Registry Metadata

Hashiwokakero SHALL be registered as a built-in game with canonical description "Connect the islands with bridges.", aliases hashi, bridges, variants Hashiwokakero (default 1300 Elo), and daily legacy modes easy 9x9, medium 7x7.

Scenario: Resolve Hashiwokakero

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

Requirement: Variant Elo Creation

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

Scenario: Spawn Hashiwokakero by Elo

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

Requirement: Legacy Mode Compatibility

Hashiwokakero SHALL preserve legacy named modes as compatibility presets that map to the Hashiwokakero variant and preset Elo values: Easy 7x7 (250 Elo), Medium 7x7 (500 Elo), Hard 7x7 (800 Elo), Easy 9x9 (700 Elo), Medium 9x9 (1100 Elo), Hard 9x9 (1500 Elo), Easy 11x11 (1300 Elo), Medium 11x11 (1700 Elo), Hard 11x11 (2100 Elo), Easy 13x13 (1900 Elo), Medium 13x13 (2400 Elo), Hard 13x13 (2900 Elo).

Scenario: Use legacy mode title

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

Requirement: Puzzle Rules

The Hashiwokakero runtime MUST let players connect islands with horizontal or vertical bridges so each island reaches its required bridge count, bridges never cross, at most two bridges connect a pair, and the final bridge graph is connected.

Scenario: Check solved state

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

Requirement: Save Load And Interaction

Hashiwokakero 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 bridge editing is required, and mouse click-to-focus support MUST be available.

Scenario: Resume saved Hashiwokakero

• WHEN a saved Hashiwokakero 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 Hashiwokakero print adapter SHALL render puzzle and solution data for JSONL-to-PDF workflows.

Scenario: Export Hashiwokakero

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