/** biome-ignore-all lint/suspicious/noConsole: CLI script output */
/**
 * GPU parity over every fixture frame: each detector gates the frame, then
 * parses it twice — synchronously on the CPU (runSync) and through the WebGPU
 * matcher (separate detector instances, so memo state never crosses). Both
 * drivers score exactly, so the two event lists must be byte-identical, raw
 * scores included. Also checks the GPU frame upscale
 * (worker/gpu-frame-scaler.ts) pixel-for-pixel against normalizeFrame on each
 * frame. WebGPU comes from Dawn (node/webgpu.ts: WEBGPU_NODE).
 *
 * Usage: pnpm scanner:gpu-parity [--verbose]
 */
import { readdirSync, statSync } from "node:fs";
import { join } from "node:path";
import { loadOpenCV, type Mat } from "../../app/features/scanner/core/cv";
import { createAllDetectors } from "../../app/features/scanner/core/detectors/registry";
import { normalizeFrame, toMat } from "../../app/features/scanner/core/image";
import { FIXTURES_DIR } from "../../app/features/scanner/node/fixtures";
import { readImage } from "../../app/features/scanner/node/image-io";
import { loadScoreboardResources } from "../../app/features/scanner/node/resources";
import { nodeGpu } from "../../app/features/scanner/node/webgpu";
import { createGpuFrameScaler } from "../../app/features/scanner/worker/gpu-frame-scaler";
import { createGpuMatcher } from "../../app/features/scanner/worker/gpu-matcher";

/** Fields that carry raw match scores; everything else is a decision. */
const SCORE_FIELDS = new Set([
	"confidence",
	"score",
	"ncc",
	"teamColor",
	"debug",
]);

const verbose = process.argv.includes("--verbose");

await loadOpenCV();
const resources = await loadScoreboardResources();
const matcher = await createGpuMatcher(nodeGpu());
const scaler = await createGpuFrameScaler(matcher.device);

let rows = 0;
let identicalRows = 0;
let decisionRows = 0;
let pixelMismatchFrames = 0;
const failures: string[] = [];
let cpuMs = 0;
let gpuMs = 0;

for (const group of fixtureGroups()) {
	// fresh instances per fixture folder, like the suites: memos and layout
	// latches never carry from one detector's cases into another's
	const cpuDetectors = createAllDetectors(resources);
	const gpuDetectors = createAllDetectors(resources);
	for (const path of group) {
		const src = toMat(await readImage(path));
		const frame = normalizeFrame(src);
		const scaled = await scaler.normalize(src);
		if (!samePixels(frame, scaled)) {
			pixelMismatchFrames++;
			failures.push(`${path}: GPU upscale differs from normalizeFrame`);
		}
		scaled.delete();
		src.delete();
		for (const [i, cpuDetector] of cpuDetectors.entries()) {
			const gpuDetector = gpuDetectors[i]!;
			const gate = cpuDetector.gate(frame);
			gpuDetector.gate(frame);
			rows++;
			if (!gate.pass) {
				identicalRows++;
				decisionRows++;
				continue;
			}
			let start = performance.now();
			const cpuEvents = cpuDetector.parse(frame, 0, gate);
			cpuMs += performance.now() - start;
			start = performance.now();
			const gpuEvents = await matcher.run(
				gpuDetector.parseSteps(frame, 0, gate, true),
			);
			gpuMs += performance.now() - start;
			if (decisions(cpuEvents) === decisions(gpuEvents)) decisionRows++;
			if (JSON.stringify(cpuEvents) === JSON.stringify(gpuEvents)) {
				identicalRows++;
			} else {
				failures.push(`${path} ${cpuDetector.id}: events differ`);
				if (verbose) {
					console.log("CPU", JSON.stringify(cpuEvents));
					console.log("GPU", JSON.stringify(gpuEvents));
				}
			}
		}
		frame.delete();
	}
}

for (const failure of failures) console.log(failure);
console.log(
	`${rows} detector × frame rows: ${identicalRows} byte-identical, ${decisionRows} with identical decisions; ${pixelMismatchFrames} frames with upscale mismatches`,
);
console.log(
	`parse time: CPU ${(cpuMs / 1000).toFixed(1)} s, GPU ${(gpuMs / 1000).toFixed(1)} s · ${JSON.stringify(matcher.stats)}`,
);
matcher.destroy();
process.exit(failures.length === 0 ? 0 : 1);

/** Fixture frames grouped by detector folder, in a stable order. */
function fixtureGroups(): string[][] {
	return readdirSync(FIXTURES_DIR)
		.filter((dir) => statSync(join(FIXTURES_DIR, dir)).isDirectory())
		.sort()
		.map((dir) =>
			readdirSync(join(FIXTURES_DIR, dir))
				.sort()
				.flatMap((fixture) =>
					["frame.png", "frame.webp", "frame.jpg", "frame.jpeg"]
						.map((name) => join(FIXTURES_DIR, dir, fixture, name))
						.filter((path) => {
							try {
								return statSync(path).isFile();
							} catch {
								return false;
							}
						})
						.slice(0, 1),
				),
		);
}

function decisions(events: unknown): string {
	return JSON.stringify(events, (key, value) =>
		SCORE_FIELDS.has(key) ? undefined : value,
	);
}

function samePixels(a: Mat, b: Mat): boolean {
	const x = a.data as Uint8Array;
	const y = b.data as Uint8Array;
	if (x.length !== y.length) return false;
	for (let i = 0; i < x.length; i++) if (x[i] !== y[i]) return false;
	return true;
}