import { isValidObservationForBaseline } from './health-baseline-maturity.mjs';

const METRIC_LABELS = Object.freeze({
  bp_systolic: '收缩压',
  bp_diastolic: '舒张压',
  hr: '心率',
  spo2: '血氧',
  weight: '体重',
  temperature: '体温',
  sleep_minutes: '睡眠',
  symptom: '症状',
});

function dayKey(observedAt) {
  const date = new Date(Number(observedAt));
  if (Number.isNaN(date.getTime())) return 'unknown';
  return date.toISOString().slice(0, 10);
}

function formatMetricValue(row) {
  if (row.metricType === 'symptom') {
    return row.valueText ?? '—';
  }
  if (row.valueNum == null) return '—';
  const unit = row.unit ? ` ${row.unit}` : '';
  return `${row.valueNum}${unit}`;
}

export function buildHealthTimeline(observations = [], { limitDays = 30 } = {}) {
  const valid = observations.filter(isValidObservationForBaseline);
  const byDay = new Map();

  for (const row of valid) {
    const key = dayKey(row.observedAt);
    if (!byDay.has(key)) byDay.set(key, []);
    byDay.get(key).push(row);
  }

  const days = [...byDay.keys()].sort((a, b) => b.localeCompare(a)).slice(0, limitDays);
  return days.map((date) => {
    const rows = byDay.get(date) ?? [];
    const metrics = {};
    for (const row of rows) {
      const label = METRIC_LABELS[row.metricType] ?? row.metricType;
      metrics[row.metricType] = {
        label,
        value: formatMetricValue(row),
        context: row.context ?? null,
        qualityFlag: row.qualityFlag ?? 'ok',
        observedAt: row.observedAt,
      };
    }
    return { date, metrics, count: rows.length };
  });
}

export function summarizeTimelineForAssess(timeline = []) {
  if (!timeline.length) {
    return '还没有足够的健康记录。请先连续录入几天晨间血压、睡眠和症状，基线成熟后才能做评估。';
  }
  const latest = timeline[0];
  const lines = [`最近一天（${latest.date}）:`];
  for (const item of Object.values(latest.metrics)) {
    lines.push(`- ${item.label}: ${item.value}`);
  }
  if (timeline.length >= 7) {
    lines.push('', `近 ${Math.min(timeline.length, 14)} 天已有 ${timeline.length} 天记录，可开始观察个人基线变化。`);
  } else {
    lines.push('', `当前仅 ${timeline.length} 天记录，建议至少连续 7 天后再看趋势。`);
  }
  lines.push('', '这不是医疗诊断；如有不适请及时就医。');
  return lines.join('\n');
}