import fs from "node:fs";
import path from "node:path";
import { ImageResponse } from "next/og";
import { fmtParams, getRun, getRuns, limitOf } from "@/lib/results";

/**
 * Shareable score card as a PNG.
 *
 * One image serves two jobs: the download button and the OpenGraph tag, so a
 * pasted link unfurls as the card itself. Fonts are bundled rather than
 * fetched at request time — satori needs real font buffers, and a network
 * dependency inside image generation fails in exactly the situations where
 * you want a share link to work.
 *
 * Note: satori supports flexbox only. Every container needs an explicit
 * display value; CSS grid silently renders nothing.
 */

export const dynamic = "force-static";

export function generateStaticParams() {
  return getRuns().map((r) => ({ id: r.run_id.slice(0, 8) }));
}

const FONT_DIR = path.join(process.cwd(), "assets", "fonts");
const font = (file: string) => fs.readFileSync(path.join(FONT_DIR, file));

const VOID = "#08090b";
const RULE = "#1e232b";
const INK = "#e8e6e1";
const DIM = "#79818d";
const DIMMER = "#4a515b";
const SIGNAL = "#f2b134";
const REFERENCE = "#5896ae";

function Stat({
  label,
  value,
  unit,
  color = INK,
  hint,
}: {
  label: string;
  value: string;
  unit?: string;
  color?: string;
  hint?: string;
}) {
  return (
    <div style={{ display: "flex", flexDirection: "column", flex: 1 }}>
      <div style={{ fontSize: 15, letterSpacing: 3, color: DIMMER, textTransform: "uppercase" }}>
        {label}
      </div>
      <div style={{ display: "flex", alignItems: "baseline", marginTop: 12 }}>
        <span style={{ fontFamily: "Instrument", fontSize: 62, color, lineHeight: 1 }}>{value}</span>
        {unit && <span style={{ fontSize: 17, color: DIMMER, marginLeft: 7 }}>{unit}</span>}
      </div>
      {hint && <div style={{ fontSize: 14, color: DIMMER, marginTop: 8 }}>{hint}</div>}
    </div>
  );
}

export async function GET(
  _req: Request,
  { params }: { params: Promise<{ id: string }> },
) {
  const { id } = await params;
  const run = getRun(id);
  if (!run) return new Response("not found", { status: 404 });

  const v = run.verdict;
  const limit = limitOf(run);
  const perf = run.perf?.points ?? [];
  const single = perf.find((p) => p.concurrency === 1);
  const peak = perf.length
    ? perf.reduce((a, b) => (b.output_tps_total > a.output_tps_total ? b : a))
    : null;

  return new ImageResponse(
    (
      <div
        style={{
          width: "100%",
          height: "100%",
          display: "flex",
          flexDirection: "column",
          background: VOID,
          fontFamily: "Plex",
          color: INK,
          padding: 56,
        }}
      >
        {/* header */}
        <div style={{ display: "flex", justifyContent: "space-between", alignItems: "baseline" }}>
          <div style={{ display: "flex", alignItems: "baseline" }}>
            <span style={{ fontFamily: "Instrument", fontSize: 30 }}>bench</span>
            <span style={{ fontFamily: "Instrument", fontSize: 30, color: DIMMER }}>.karti.ai</span>
          </div>
          <span style={{ fontSize: 15, letterSpacing: 3, color: DIMMER, textTransform: "uppercase" }}>
            {run.timestamp.slice(0, 10)}
          </span>
        </div>

        <div style={{ display: "flex", height: 1, background: RULE, marginTop: 24, marginBottom: 40 }} />

        {/* title */}
        <div style={{ display: "flex", flexDirection: "column" }}>
          <span style={{ fontFamily: "Instrument", fontSize: 68, lineHeight: 1.05 }}>
            {run.target.display_name}
          </span>
          <span style={{ fontSize: 18, color: DIM, marginTop: 16 }}>
            {run.host.hardware} · {fmtParams(run.target)} ·{" "}
            {run.target.quant?.toUpperCase()} · {run.target.serving.engine}
          </span>
        </div>

        {/* stats */}
        <div style={{ display: "flex", marginTop: "auto", gap: 24 }}>
          <Stat
            label="signal"
            value={v.signal_score != null ? v.signal_score.toFixed(3) : "—"}
            color={SIGNAL}
            hint="our workloads"
          />
          <Stat
            label="reference"
            value={v.reference_score != null ? v.reference_score.toFixed(3) : "—"}
            color={REFERENCE}
            hint={limit ? `capped ${limit}` : "calibration"}
          />
          <Stat
            label="single stream"
            value={single ? single.output_tps_per_stream.toFixed(1) : "—"}
            unit="tok/s"
            hint={single?.ttft_p50_ms ? `ttft ${Math.round(single.ttft_p50_ms)}ms` : undefined}
          />
          <Stat
            label="peak"
            value={peak ? peak.output_tps_total.toFixed(0) : "—"}
            unit="tok/s"
            hint={peak ? `at ×${peak.concurrency}` : undefined}
          />
        </div>

        {/* tick strip — a measurement scale across the full plate */}
        <div style={{ display: "flex", marginTop: 40, justifyContent: "space-between", width: "100%" }}>
          {Array.from({ length: 96 }).map((_, i) => (
            <div
              key={i}
              style={{
                display: "flex",
                width: 1,
                height: 8,
                background: i % 6 === 0 ? SIGNAL : RULE,
              }}
            />
          ))}
        </div>
      </div>
    ),
    {
      width: 1200,
      height: 630,
      fonts: [
        { name: "Instrument", data: font("InstrumentSerif-Regular.ttf"), style: "normal", weight: 400 },
        { name: "Plex", data: font("IBMPlexMono-Regular.ttf"), style: "normal", weight: 400 },
        { name: "Plex", data: font("IBMPlexMono-SemiBold.ttf"), style: "normal", weight: 600 },
      ],
    },
  );
}