import { query } from "./db";
import { CACHE_CREATION, CACHE_READ, REAL_MODEL, cacheKey, cached, timeWhere } from "./query-shared";

// ── 趋势 ──────────────────────────────────────────────────────

export interface TrendPoint {
  date: string;
  calls: number;
  prompt_tokens: number;
  completion_tokens: number;
  cache_creation_tokens: number;
  cache_read_tokens: number;
  total_tokens: number;
  quota: number;
}

export type TrendGranularity = "hour" | "day" | "week" | "month";

export interface TrendFilters {
  username?: string;
  model?: string;
  channelId?: number;
}

function appendTrendFilters(
  where: string,
  params: (string | number | boolean | null)[],
  filters: TrendFilters = {}
): string {
  if (filters.username) {
    params.push(filters.username);
    where += ` AND username = $${params.length}`;
  }
  if (filters.model) {
    params.push(filters.model);
    where += ` AND ${REAL_MODEL} = $${params.length}`;
  }
  if (filters.channelId !== undefined) {
    params.push(filters.channelId);
    where += ` AND channel_id = $${params.length}`;
  }
  return where;
}

export function getTrends(
  granularity: TrendGranularity = "day",
  startTs?: number,
  endTs?: number,
  filters: TrendFilters = {}
): Promise<TrendPoint[]> {
  return cached(cacheKey("trends", granularity, startTs, endTs, filters.username, filters.model, filters.channelId), async () => {
  const params: (string | number | boolean | null)[] = [];
  const where = appendTrendFilters(timeWhere(params, startTs, endTs), params, filters);

  const truncExpr =
    granularity === "hour"
      ? `to_char(date_trunc('hour', to_timestamp(created_at) AT TIME ZONE 'Asia/Shanghai'), 'YYYY-MM-DD HH24:00')`
      : granularity === "day"
        ? `((to_timestamp(created_at) AT TIME ZONE 'Asia/Shanghai')::date)::text`
        : `(date_trunc('${granularity}', to_timestamp(created_at) AT TIME ZONE 'Asia/Shanghai')::date)::text`;

  const rows = await query(
    `SELECT
       ${truncExpr} as date,
       COUNT(*)::int as calls,
       COALESCE(SUM(prompt_tokens), 0)::bigint as prompt_tokens,
       COALESCE(SUM(completion_tokens), 0)::bigint as completion_tokens,
       COALESCE(SUM(${CACHE_CREATION}), 0)::bigint as cache_creation_tokens,
       COALESCE(SUM(${CACHE_READ}), 0)::bigint as cache_read_tokens,
       COALESCE(SUM(quota), 0)::bigint as quota
     FROM logs WHERE ${where}
     GROUP BY date ORDER BY date`,
    params
  );

  return rows.map((r) => ({
    date: String(r.date).slice(0, granularity === "hour" ? 16 : 10),
    calls: Number(r.calls),
    prompt_tokens: Number(r.prompt_tokens),
    completion_tokens: Number(r.completion_tokens),
    cache_creation_tokens: Number(r.cache_creation_tokens),
    cache_read_tokens: Number(r.cache_read_tokens),
    total_tokens: Number(r.prompt_tokens) + Number(r.completion_tokens) + Number(r.cache_creation_tokens) + Number(r.cache_read_tokens),
    quota: Number(r.quota),
  }));
  });
}