harden business rules

core/racing/domain/value-objects/MaxParticipants.ts

@@ -0,0 +1,97 @@
+/**
+ * Domain Value Object: MaxParticipants
+ * 
+ * Represents the maximum number of participants allowed in a league or race.
+ * Enforces reasonable limits and constraints.
+ */
+
+import type { IValueObject } from '@core/shared/domain';
+import { RacingDomainValidationError } from '../errors/RacingDomainError';
+
+export interface MaxParticipantsProps {
+  value: number;
+}
+
+export class MaxParticipants implements IValueObject<MaxParticipantsProps> {
+  readonly value: number;
+
+  private constructor(value: number) {
+    this.value = value;
+  }
+
+  static create(value: number): MaxParticipants {
+    if (!Number.isInteger(value) || value <= 0) {
+      throw new RacingDomainValidationError('Max participants must be a positive integer');
+    }
+    
+    // Enforce reasonable upper limit to prevent system abuse
+    if (value > 100) {
+      throw new RacingDomainValidationError('Max participants cannot exceed 100');
+    }
+
+    return new MaxParticipants(value);
+  }
+
+  /**
+   * Validate that max participants meets minimum requirements for ranked leagues
+   */
+  validateForRankedLeague(): { valid: boolean; error?: string } {
+    if (this.value < 10) {
+      return {
+        valid: false,
+        error: 'Ranked leagues must allow at least 10 participants'
+      };
+    }
+    return { valid: true };
+  }
+
+  /**
+   * Validate that max participants meets minimum requirements for unranked leagues
+   */
+  validateForUnrankedLeague(): { valid: boolean; error?: string } {
+    if (this.value < 2) {
+      return {
+        valid: false,
+        error: 'Unranked leagues must allow at least 2 participants'
+      };
+    }
+    return { valid: true };
+  }
+
+  /**
+   * Check if max participants is sufficient for the given participant count
+   */
+  canAccommodate(participantCount: number): boolean {
+    return participantCount <= this.value;
+  }
+
+  /**
+   * Check if max participants is at least the given minimum
+   */
+  isAtLeast(min: number): boolean {
+    return this.value >= min;
+  }
+
+  /**
+   * Check if max participants is exactly the given value
+   */
+  isExactly(value: number): boolean {
+    return this.value === value;
+  }
+
+  get props(): MaxParticipantsProps {
+    return { value: this.value };
+  }
+
+  equals(other: IValueObject<MaxParticipantsProps>): boolean {
+    return this.value === other.props.value;
+  }
+
+  toString(): string {
+    return this.value.toString();
+  }
+
+  toNumber(): number {
+    return this.value;
+  }
+}