/**
 * The framing a pushed frame arrives in, and what a malformed one must do.
 *
 * Run: `bun src/lib/media.check.ts` (there is no unit runner; the suite in
 * `tests/` drives a running stack).
 */
import assert from "node:assert/strict"

import { describeArtifact, isRef, parseMediaFrame } from "./media"

function frame(header: object, payload: Uint8Array): ArrayBuffer {
  const encoded = new TextEncoder().encode(JSON.stringify(header))
  const out = new Uint8Array(4 + encoded.length + payload.length)
  new DataView(out.buffer).setUint32(0, encoded.length)
  out.set(encoded, 4)
  out.set(payload, 4 + encoded.length)
  return out.buffer
}

const bytes = new Uint8Array([0x89, 0x50, 0x4e, 0x47])
const parsed = parseMediaFrame(
  frame(
    {
      type: "media",
      name: "cam.frame",
      digest: `sha256:${"a".repeat(64)}`,
      media_type: "image/png",
      ts: 1,
    },
    bytes,
  ),
)
assert.ok(parsed)
assert.equal(parsed.header.name, "cam.frame")
assert.equal(parsed.header.media_type, "image/png")
assert.equal(parsed.bytes.size, 4)
assert.equal(parsed.bytes.type, "image/png")

// A frame the client cannot read is dropped, never thrown on: this runs on
// every socket message.
assert.equal(parseMediaFrame(new ArrayBuffer(0)), null)
assert.equal(parseMediaFrame(new ArrayBuffer(2)), null)
assert.equal(parseMediaFrame(frame({ name: "n" }, bytes)), null)
// A length longer than the frame is truncation, not a payload.
const short = new Uint8Array(8)
new DataView(short.buffer).setUint32(0, 999)
assert.equal(parseMediaFrame(short.buffer), null)

assert.ok(isRef({ digest: `sha256:${"b".repeat(64)}` }))
assert.equal(isRef({ digest: "nope" }), false)
assert.equal(isRef(null), false)

assert.equal(
  describeArtifact({ media_type: "image/png", name: "f.png", size: 48000 }),
  "image/png · f.png · 48kB",
)
// No media type is still worth summarising as something.
assert.equal(
  describeArtifact({ media_type: "application/octet-stream", size: 12 }),
  "artifact · 12B",
)

console.log("media.check.ts ok")