/**
 * Rulebook View Data Builder
 *
 * Transforms API DTO to ViewData for templates.
 */

import type { RulebookViewData } from '@/lib/view-data/RulebookViewData';
import { ViewDataBuilder } from "../../contracts/builders/ViewDataBuilder";

interface RulebookApiDto {
  leagueId: string;
  scoringConfig: {
    gameName: string;
    scoringPresetName: string;
    championships: Array<{
      type: string;
      sessionTypes: string[];
      pointsPreview: Array<{
        sessionType: string;
        position: number;
        points: number;
      }>;
      bonusSummary: string[];
    }>;
    dropPolicySummary: string;
  };
}

export class RulebookViewDataBuilder {
  /**
   * Transform API DTO to ViewData
   * 
   * @param apiDto - The DTO from the service
   * @returns ViewData for the rulebook page
   */
  public static build(apiDto: RulebookApiDto): RulebookViewData {
    const primaryChampionship = apiDto.scoringConfig.championships.find(c => c.type === 'driver') ?? apiDto.scoringConfig.championships[0];
    
    const positionPoints: { position: number; points: number }[] = (primaryChampionship?.pointsPreview || [])
      .filter((p: unknown): p is { sessionType: string; position: number; points: number } => {
        const point = p as { sessionType?: string; position?: number; points?: number };
        return point.sessionType === primaryChampionship?.sessionTypes[0];
      })
      .map(p => ({ position: p.position, points: p.points }))
      .sort((a, b) => a.position - b.position);

    return {
      leagueId: apiDto.leagueId,
      gameName: apiDto.scoringConfig.gameName,
      scoringPresetName: apiDto.scoringConfig.scoringPresetName || 'Custom',
      championshipsCount: apiDto.scoringConfig.championships.length,
      sessionTypes: primaryChampionship?.sessionTypes.join(', ') || 'Main',
      dropPolicySummary: apiDto.scoringConfig.dropPolicySummary,
      hasActiveDropPolicy: !!apiDto.scoringConfig.dropPolicySummary && !apiDto.scoringConfig.dropPolicySummary.toLowerCase().includes('all'),
      positionPoints,
      bonusPoints: primaryChampionship?.bonusSummary || [],
      hasBonusPoints: (primaryChampionship?.bonusSummary.length || 0) > 0,
    };
  }
}

RulebookViewDataBuilder satisfies ViewDataBuilder<RulebookApiDto, RulebookViewData>;