/**
 * Effort Score Calculation Algorithms
 *
 * Implements the core effort calculation algorithms from the Ruby aac-metrics tool.
 * These algorithms calculate how difficult it is to access each button based on
 * distance, visual scanning, grid complexity, and motor planning support.
 */
/**
 * Constants for effort score calculation
 * Values match the Ruby implementation exactly
 */
export declare const EFFORT_CONSTANTS: {
    readonly SQRT2: number;
    readonly BUTTON_SIZE_MULTIPLIER: 0.09;
    readonly FIELD_SIZE_MULTIPLIER: 0.005;
    readonly VISUAL_SCAN_MULTIPLIER: 0.015;
    readonly BOARD_CHANGE_PROCESSING_EFFORT: 1;
    readonly BOARD_HOME_EFFORT: 1;
    readonly COMBINED_WORDS_REMEMBERING_EFFORT: 1;
    readonly DISTANCE_MULTIPLIER: 0.4;
    readonly DISTANCE_THRESHOLD_TO_SKIP_VISUAL_SCAN: 0.1;
    readonly SKIPPED_VISUAL_SCAN_DISTANCE_MULTIPLIER: 0.5;
    readonly SAME_LOCATION_AS_PRIOR_DISCOUNT: 0.1;
    readonly RECOGNIZABLE_SEMANTIC_FROM_PRIOR_DISCOUNT: 0.5;
    readonly RECOGNIZABLE_SEMANTIC_FROM_OTHER_DISCOUNT: 0.5;
    readonly REUSED_SEMANTIC_FROM_OTHER_BONUS: 0.0025;
    readonly RECOGNIZABLE_CLONE_FROM_PRIOR_DISCOUNT: 0.33;
    readonly RECOGNIZABLE_CLONE_FROM_OTHER_DISCOUNT: 0.33;
    readonly REUSED_CLONE_FROM_OTHER_BONUS: 0.005;
    readonly SCAN_STEP_COST: 0.015;
    readonly SCAN_SELECTION_COST: 0.1;
    readonly DEFAULT_SCAN_ERROR_RATE: 0.1;
    readonly SCAN_RETRY_PENALTY: 1;
    readonly SUGGEST_WORDS_SELECTION_EFFORT: 0.5;
    readonly TDSNAP_GRAMMAR_OVERLAY_EFFORT: 0.1;
};
/**
 * Calculate button size effort based on grid dimensions
 * Larger grids require more visual scanning and discrimination
 *
 * @param rows - Number of rows in the grid
 * @param cols - Number of columns in the grid
 * @returns Button size effort score
 */
export declare function buttonSizeEffort(rows: number, cols: number): number;
/**
 * Calculate field size effort based on number of visible buttons
 * More buttons = more visual clutter = higher effort
 *
 * @param buttonCount - Number of visible buttons on the board
 * @returns Field size effort score
 */
export declare function fieldSizeEffort(buttonCount: number): number;
/**
 * Calculate visual scanning effort
 * Effort increases with each button that must be scanned before reaching target
 *
 * @param priorButtons - Number of buttons visually scanned before target
 * @returns Visual scan effort score
 */
export declare function visualScanEffort(priorButtons: number): number;
/**
 * Calculate distance effort from entry point to button center
 * Uses Euclidean distance normalized by sqrt(2)
 *
 * @param x - Button center X coordinate (0-1 normalized)
 * @param y - Button center Y coordinate (0-1 normalized)
 * @param entryX - Entry point X coordinate (0-1 normalized, default 1.0 = bottom-right)
 * @param entryY - Entry point Y coordinate (0-1 normalized, default 1.0 = bottom-right)
 * @returns Distance effort score
 */
export declare function distanceEffort(x: number, y: number, entryX?: number, entryY?: number): number;
/**
 * Calculate spelling effort for words not available in the board set
 *
 * @param word - The word to spell
 * @param entryEffort - Effort to reach the spelling/keyboard page
 * @param perLetterEffort - Average effort per letter on the keyboard
 * @returns Spelling effort score
 */
export declare function spellingEffort(word: string, entryEffort?: number, perLetterEffort?: number): number;
/**
 * Calculate effort to access a word via prediction
 *
 * When prediction is available, the user:
 * 1. Navigates to the spelling/keyboard page (entryEffort)
 * 2. Types first 1-3 letters to trigger predictions
 * 3. Selects from 1-3 predictions (average selections)
 *
 * @param entryEffort - Effort to reach the spelling/keyboard page
 * @param perLetterEffort - Average effort per letter on the keyboard
 * @param avgSelections - Average number of predictions to check (default 1.5)
 * @param lettersToType - Letters to type before prediction appears (default 2)
 * @returns Prediction effort score
 */
export declare function predictionEffort(entryEffort?: number, perLetterEffort?: number, avgSelections?: number, lettersToType?: number): number;
/**
 * Calculate base board effort
 * Combines button size and field size efforts
 *
 * @param rows - Number of rows in the grid
 * @param cols - Number of columns in the grid
 * @param buttonCount - Number of visible buttons
 * @returns Base board effort score
 */
export declare function baseBoardEffort(rows: number, cols: number, buttonCount: number): number;
/**
 * Apply reuse discount based on semantic_id/clone_id frequency
 *
 * @param boardEffort - Current board effort
 * @param reuseDiscount - Calculated reuse discount
 * @returns Adjusted board effort
 */
export declare function applyReuseDiscount(boardEffort: number, reuseDiscount: number): number;
/**
 * Calculate button-level effort with motor planning discounts
 *
 * @param baseEffort - Base board effort
 * @param boardPcts - Percentage of links matching semantic_id/clone_id
 * @param button - Button data
 * @returns Adjusted button effort
 */
export declare function calculateButtonEffort(baseEffort: number, boardPcts: {
    [id: string]: number;
}, button: {
    semantic_id?: string;
    clone_id?: string;
}): number;
/**
 * Calculate distance with motor planning discounts
 *
 * @param distance - Raw distance effort
 * @param boardPcts - Percentage of links matching semantic_id/clone_id
 * @param button - Button data
 * @param setPcts - Percentage of boards containing semantic_id/clone_id
 * @returns Adjusted distance effort
 */
export declare function calculateDistanceWithDiscounts(distance: number, boardPcts: {
    [id: string]: number;
}, button: {
    semantic_id?: string;
    clone_id?: string;
}, setPcts: {
    [id: string]: number;
}): number;
/**
 * Check if visual scan should be skipped (button close to previous)
 *
 * @param distance - Distance from previous button
 * @returns True if close enough to skip full visual scan
 */
export declare function shouldSkipVisualScan(distance: number): boolean;
/**
 * Calculate local scan effort when buttons are close
 *
 * @param distance - Distance between buttons
 * @returns Local scan effort
 */
export declare function localScanEffort(distance: number): number;
/**
 * Calculate effort for switch scanning
 *
 * @param steps - Number of scan steps to reach target
 * @param selections - Number of switch selections required
 * @param stepCost - Optional override for scan step cost
 * @param selectionCost - Optional override for scan selection cost
 * @returns Scanning effort score
 */
export declare function scanningEffort(steps: number, selections: number, stepCost?: number, selectionCost?: number): number;