bowling-analysis-system/src/bowling_analysis/utils/EventValidator.js

A comprehensive system for analyzing bowling techniques using video processing and metrics calculation

/**
 * @module bowling_analysis/utils/EventValidator
 * @description Centralized event validation utility
 */

const { getStandardEventName } = require('./EventNameMapper');

/**
 * Validate event sequence and adjust confidence scores
 * @param {Object} events - Events object
 * @returns {Object} Validated events with adjusted confidence scores
 */
function validateEvents(events) {
  if (!events) {
    return { valid: false, events: null, error: 'No events provided' };
  }

  // Standardize event names
  const standardizedEvents = {};
  for (const [key, value] of Object.entries(events)) {
    const standardName = getStandardEventName(key);
    standardizedEvents[standardName] = value;
  }

  const { backFootLanding, frontFootLanding, releasePoint } = standardizedEvents;

  // Check required events
  if (!backFootLanding || !frontFootLanding || !releasePoint) {
    return {
      valid: false,
      events: standardizedEvents,
      error: 'Missing required events'
    };
  }

  // Validate sequence
  const isValidSequence = (
    backFootLanding.frameIndex < frontFootLanding.frameIndex &&
    frontFootLanding.frameIndex < releasePoint.frameIndex
  );

  if (!isValidSequence) {
    // Adjust confidence scores based on sequence violation
    const adjustedEvents = { ...standardizedEvents };
    
    if (backFootLanding.frameIndex >= frontFootLanding.frameIndex) {
      adjustedEvents.backFootLanding.confidence *= 0.8;
      adjustedEvents.frontFootLanding.confidence *= 0.8;
    }
    
    if (frontFootLanding.frameIndex >= releasePoint.frameIndex) {
      adjustedEvents.frontFootLanding.confidence *= 0.8;
      adjustedEvents.releasePoint.confidence *= 0.8;
    }

    return {
      valid: false,
      events: adjustedEvents,
      error: 'Invalid event sequence'
    };
  }

  return {
    valid: true,
    events: standardizedEvents,
    error: null
  };
}

/**
 * Check if frame indices form a valid sequence
 * @param {number} backFootFrame - Back foot landing frame
 * @param {number} frontFootFrame - Front foot landing frame
 * @param {number} releaseFrame - Release point frame
 * @returns {boolean} True if sequence is valid
 */
function isValidFrameSequence(backFootFrame, frontFootFrame, releaseFrame) {
  return (
    backFootFrame < frontFootFrame &&
    frontFootFrame < releaseFrame
  );
}

module.exports = {
  validateEvents,
  isValidFrameSequence
};