import type { Confidence } from './types';

type CostEvent = { dataSource: string };
type RevenueEvent = { dataSource: string };

const HIGH_QUALITY_COST_SOURCES = new Set(['plane_actual', 'manual']);

/**
 * 对一个时间窗的事件计算置信度:
 * - High:  成本事件 80%+ 来自 plane_actual / manual,且收益事件存在
 * - Low:   只有成本无收益,或所有成本都来自 auto_commits/auto_tasks 估算
 * - Medium: 其他情况
 */
export function evaluateConfidence(
  costEvents: CostEvent[],
  revenueEvents: RevenueEvent[]
): Confidence {
  const totalCost = costEvents.length;
  const totalRevenue = revenueEvents.length;

  if (totalCost === 0 && totalRevenue === 0) return 'low';

  // 无收益 = 直接 low(无法判断盈亏)
  if (totalRevenue === 0) return 'low';

  // 全自动估算 = low
  const highQualityCount = costEvents.filter(e => HIGH_QUALITY_COST_SOURCES.has(e.dataSource)).length;
  if (totalCost > 0 && highQualityCount === 0) return 'low';

  // 80%+ 高质量 = high
  if (totalCost > 0 && highQualityCount / totalCost >= 0.8) return 'high';

  return 'medium';
}