// Runs the CPU-bound methods (plain JS and both WASM kernels) off the main
// thread — naive JS/WASM at n=2048 take long enough (~10s) to freeze the tab
// otherwise. Regenerates inputs from the (n, seed) pair rather than
// receiving them over postMessage, since that's cheaper than structured-
// cloning multi-megabyte Float64Arrays for every run.
import { generateMatrix } from './random'
import { jsMatmul } from './jsMatmul'
import { wasmNaiveMatmul, wasmBlockedMatmul } from './wasmMatmul'
import type { MatmulMethod } from './types'

const METHODS: Record<string, MatmulMethod> = {
  js: jsMatmul,
  'wasm-naive': wasmNaiveMatmul,
  'wasm-blocked': wasmBlockedMatmul,
}

export interface WorkerRequest {
  id: number
  methodId: string
  n: number
  seedA: number
  seedB: number
}

export type WorkerResponse =
  | { id: number; ms: number; sample: number }
  | { id: number; error: string }

self.onmessage = async (e: MessageEvent<WorkerRequest>) => {
  const { id, methodId, n, seedA, seedB } = e.data
  try {
    const method = METHODS[methodId]
    if (!method?.run) throw new Error(`Unknown method: ${methodId}`)
    const a = generateMatrix(n, seedA)
    const b = generateMatrix(n, seedB)
    const { ms, sample } = await method.run(n, a, b)
    self.postMessage({ id, ms, sample } satisfies WorkerResponse)
  } catch (err) {
    self.postMessage({ id, error: err instanceof Error ? err.message : String(err) } satisfies WorkerResponse)
  }
}