import { APP_CONFIG, VALIDATION_MESSAGES } from './constants';
import type { NewGameData } from './types';

export interface ValidationResult {
  isValid: boolean;
  errors: string[];
}

export function validatePlayerName(name: string): ValidationResult {
  const errors: string[] = [];
  const trimmedName = name.trim();

  if (!trimmedName) {
    errors.push(VALIDATION_MESSAGES.PLAYER_NAME_REQUIRED);
  }

  if (trimmedName.length > APP_CONFIG.MAX_PLAYER_NAME_LENGTH) {
    errors.push(VALIDATION_MESSAGES.PLAYER_NAME_TOO_LONG);
  }

  return {
    isValid: errors.length === 0,
    errors,
  };
}

export function validateGameData(data: NewGameData): ValidationResult {
  const errors: string[] = [];

  try {
    // Validate player names
    const player1Validation = validatePlayerName(data.player1);
    const player2Validation = validatePlayerName(data.player2);
    
    errors.push(...player1Validation.errors);
    errors.push(...player2Validation.errors);

    // Check for duplicate player names
    const playerNames = [data.player1.trim(), data.player2.trim()];
    if (data.player3?.trim()) {
      const player3Validation = validatePlayerName(data.player3);
      errors.push(...player3Validation.errors);
      playerNames.push(data.player3.trim());
    }

    const uniqueNames = new Set(playerNames.filter(name => name.length > 0));
    if (uniqueNames.size !== playerNames.filter(name => name.length > 0).length) {
      errors.push(VALIDATION_MESSAGES.DUPLICATE_PLAYER_NAMES);
    }

    // Validate game type
    if (!data.gameType?.trim()) {
      errors.push(VALIDATION_MESSAGES.GAME_TYPE_REQUIRED);
    }

    // Validate race to
    if (!data.raceTo?.trim()) {
      errors.push(VALIDATION_MESSAGES.RACE_TO_REQUIRED);
    } else {
      const raceToNumber = parseInt(data.raceTo, 10);
      if (isNaN(raceToNumber) || raceToNumber <= 0) {
        errors.push(VALIDATION_MESSAGES.RACE_TO_INVALID);
      }
    }
  } catch (error) {
    console.error('Validation error:', error);
    errors.push('Ein unerwarteter Validierungsfehler ist aufgetreten');
  }

  return {
    isValid: errors.length === 0,
    errors,
  };
}

export function sanitizePlayerName(name: string): string {
  return name
    .trim()
    .slice(0, APP_CONFIG.MAX_PLAYER_NAME_LENGTH)
    .replace(/[^\w\s-]/g, ''); // Remove special characters except spaces and hyphens
}

export function validateRaceTo(value: string): ValidationResult {
  const errors: string[] = [];
  
  if (!value?.trim()) {
    errors.push(VALIDATION_MESSAGES.RACE_TO_REQUIRED);
  } else {
    const numValue = parseInt(value, 10);
    if (isNaN(numValue) || numValue <= 0) {
      errors.push(VALIDATION_MESSAGES.RACE_TO_INVALID);
    }
  }

  return {
    isValid: errors.length === 0,
    errors,
  };
}