/**
 * Admin view of the anonymous rectification telemetry
 * (TASK-rectification-telemetry-20260926, D3).
 *
 * The database function `rectification_telemetry_summary` returns aggregates
 * only; this module turns its jsonb into a fixed shape and holds the labels.
 * There is no per-row type here on purpose: the admin never sees a row.
 */

export const TELEMETRY_SUMMARY_WEEK_OPTIONS = [4, 12, 26] as const;
export const TELEMETRY_SUMMARY_DEFAULT_WEEKS = 12;

export type TelemetryBucket = Readonly<{ key: string; count: number }>;

export type TelemetryWeek = Readonly<{
  week: string;
  sessions: number;
  rangeWidthMinutesP50: number | null;
  questionsTotalP50: number | null;
  precisionGateMet: number;
  precisionGateKnown: number;
}>;

export type TelemetryVersionRow = Readonly<{
  algorithmVersion: string | null;
  policyVersion: string | null;
  skillVersion: string | null;
  count: number;
}>;

export type RectificationTelemetrySummary = Readonly<{
  weeks: number;
  since: string | null;
  retentionDays: number;
  sessions: number;
  medians: Readonly<{
    rangeWidthMinutesP50: number | null;
    rangeWidthMinutesP90: number | null;
    questionsTotalP50: number | null;
    questionsTotalP90: number | null;
    experiencesAddedP50: number | null;
    candidateCountP50: number | null;
    windowRadiusMinutesP50: number | null;
    durationSecondsP50: number | null;
    durationSecondsP90: number | null;
  }>;
  questionTypes: Readonly<{
    targeted: number;
    guided: number;
    datedProbe: number;
    personality: number;
    open: number;
    other: number;
    guidedAskedSessions: number;
  }>;
  widthDistribution: readonly TelemetryBucket[];
  questionDistribution: readonly TelemetryBucket[];
  gapDistribution: readonly TelemetryBucket[];
  stopReasons: readonly TelemetryBucket[];
  birthTimeSources: readonly TelemetryBucket[];
  precisionGate: Readonly<{ met: number; notMet: number; unknown: number }>;
  weekly: readonly TelemetryWeek[];
  versions: readonly TelemetryVersionRow[];
}>;

export const TELEMETRY_STOP_REASON_LABEL: Readonly<Record<string, string>> = {
  converged: "收敛（精度门槛达标）",
  pool_exhausted: "题源问空",
  user_no_more: "用户说没有了 / 多半说不好",
  round_cap: "8 轮上限",
  user_stopped: "用户中止",
  error: "错误",
};

export const TELEMETRY_BIRTH_TIME_SOURCE_LABEL: Readonly<Record<string, string>> = {
  hospital_record: "出生记录",
  approximate: "大概时间",
  period_only: "时间段",
  unknown: "不知道",
};

export const TELEMETRY_WIDTH_BUCKET_LABEL: Readonly<Record<string, string>> = {
  "0": "0 分钟（单点）",
  "1-5": "1–5 分钟",
  "6-10": "6–10 分钟",
  "11-20": "11–20 分钟",
  "21-30": "21–30 分钟",
  "31-60": "31–60 分钟",
  "61+": "60 分钟以上",
  unknown: "未知",
};

export const TELEMETRY_QUESTION_BUCKET_LABEL: Readonly<Record<string, string>> = {
  "0-3": "0–3 题",
  "4-6": "4–6 题",
  "7-9": "7–9 题",
  "10-12": "10–12 题",
  "13-15": "13–15 题",
  "16+": "16 题以上",
};

/**
 * Gap buckets line up with the card's percent rule (`RANGE_DELIVERY_PERCENT_MIN_GAP`
 * = 5): the 5–9 and 10+ buckets are the sessions whose card showed percentages.
 */
export const TELEMETRY_GAP_BUCKET_LABEL: Readonly<Record<string, string>> = {
  "0-2": "0–2 个百分点（打平）",
  "3-4": "3–4 个百分点（不显示百分比）",
  "5-9": "5–9 个百分点（显示百分比）",
  "10+": "10 个百分点以上（显示百分比）",
  single: "只有一个候选",
};

export const TELEMETRY_PERCENT_SHOWN_BUCKETS: readonly string[] = ["5-9", "10+"];

function record(value: unknown): Readonly<Record<string, unknown>> {
  return value && typeof value === "object" && !Array.isArray(value)
    ? value as Record<string, unknown>
    : {};
}

function numberOrNull(value: unknown): number | null {
  if (typeof value === "number" && Number.isFinite(value)) return value;
  if (typeof value === "string" && value.trim() !== "" && Number.isFinite(Number(value))) return Number(value);
  return null;
}

function numberOrZero(value: unknown): number {
  return numberOrNull(value) ?? 0;
}

function textOrNull(value: unknown): string | null {
  return typeof value === "string" && value.trim() ? value : null;
}

function buckets(value: unknown): TelemetryBucket[] {
  if (!Array.isArray(value)) return [];
  return value.flatMap((item) => {
    const row = record(item);
    const key = textOrNull(row.key);
    return key ? [{ key, count: numberOrZero(row.count) }] : [];
  });
}

export function parseRectificationTelemetrySummary(value: unknown): RectificationTelemetrySummary {
  const row = record(value);
  const medians = record(row.medians);
  const types = record(row.question_types);
  const gate = record(row.precision_gate);
  return {
    weeks: numberOrNull(row.weeks) ?? TELEMETRY_SUMMARY_DEFAULT_WEEKS,
    since: textOrNull(row.since),
    retentionDays: numberOrNull(row.retention_days) ?? 180,
    sessions: numberOrZero(row.sessions),
    medians: {
      rangeWidthMinutesP50: numberOrNull(medians.range_width_minutes_p50),
      rangeWidthMinutesP90: numberOrNull(medians.range_width_minutes_p90),
      questionsTotalP50: numberOrNull(medians.questions_total_p50),
      questionsTotalP90: numberOrNull(medians.questions_total_p90),
      experiencesAddedP50: numberOrNull(medians.experiences_added_p50),
      candidateCountP50: numberOrNull(medians.candidate_count_p50),
      windowRadiusMinutesP50: numberOrNull(medians.window_radius_minutes_p50),
      durationSecondsP50: numberOrNull(medians.duration_seconds_p50),
      durationSecondsP90: numberOrNull(medians.duration_seconds_p90),
    },
    questionTypes: {
      targeted: numberOrZero(types.targeted),
      guided: numberOrZero(types.guided),
      datedProbe: numberOrZero(types.dated_probe),
      personality: numberOrZero(types.personality),
      open: numberOrZero(types.open),
      other: numberOrZero(types.other),
      guidedAskedSessions: numberOrZero(types.guided_asked_sessions),
    },
    widthDistribution: buckets(row.width_distribution),
    questionDistribution: buckets(row.question_distribution),
    gapDistribution: buckets(row.gap_distribution),
    stopReasons: buckets(row.stop_reasons),
    birthTimeSources: buckets(row.birth_time_sources),
    precisionGate: {
      met: numberOrZero(gate.met),
      notMet: numberOrZero(gate.not_met),
      unknown: numberOrZero(gate.unknown),
    },
    weekly: Array.isArray(row.weekly)
      ? row.weekly.flatMap((item) => {
        const week = record(item);
        const label = textOrNull(week.week);
        return label
          ? [{
            week: label,
            sessions: numberOrZero(week.sessions),
            rangeWidthMinutesP50: numberOrNull(week.range_width_minutes_p50),
            questionsTotalP50: numberOrNull(week.questions_total_p50),
            precisionGateMet: numberOrZero(week.precision_gate_met),
            precisionGateKnown: numberOrZero(week.precision_gate_known),
          }]
          : [];
      })
      : [],
    versions: Array.isArray(row.versions)
      ? row.versions.map((item) => {
        const version = record(item);
        return {
          algorithmVersion: textOrNull(version.algorithm_version),
          policyVersion: textOrNull(version.policy_version),
          skillVersion: textOrNull(version.skill_version),
          count: numberOrZero(version.count),
        };
      })
      : [],
  };
}

export function parseTelemetrySummaryWeeks(value: string | null): number {
  const parsed = Number(value);
  return (TELEMETRY_SUMMARY_WEEK_OPTIONS as readonly number[]).includes(parsed)
    ? parsed
    : TELEMETRY_SUMMARY_DEFAULT_WEEKS;
}

export function share(part: number, whole: number): number | null {
  return whole > 0 ? part / whole : null;
}