import { readFile } from "node:fs/promises";
import { fileURLToPath } from "node:url";
import type { BlockContext, ProcessorConfig } from "@suaveplan/audio-core";
import type {
    ChainContext,
    ChainHandle,
} from "@suaveplan/audio-fx-plugin-base/base";
import { defaultAmbientState } from "@suaveplan/audio-fx-plugin-base/chain";
import { describe, expect, it } from "@suaveplan/testing/runner";
import { SpessaSynthPlugin } from "../src/plugin/spessasynth-plugin.js";

const FIXTURE_URL = new URL("./fixtures/tiny-piano.sf2", import.meta.url);
const FIXTURE_PATH = fileURLToPath(FIXTURE_URL);

const SR = 48_000;
const BLOCK = 512;

function newCtx(): ChainContext {
    const chain: ChainHandle = {
        id: "integration",
        name: "integration",
        channels: 2,
        sampleRate: SR,
        blockSize: BLOCK,
        slotCount: 1,
    };
    return {
        chain,
        position: { index: 0, total: 1 },
        predecessors: [],
        successors: [],
        ambient: defaultAmbientState(),
        buses: { get: () => undefined, list: () => [] },
    };
}

function newConfig(): ProcessorConfig {
    return { sampleRate: SR, channels: 2, blockSize: BLOCK };
}

function blockCtx(): BlockContext {
    return {
        blockOffsetSamples: 0,
        sampleRate: SR,
        channels: 2,
        opts: {},
    };
}

function rms(buf: Float32Array): number {
    let sum = 0;
    for (let i = 0; i < buf.length; i++) sum += buf[i]! ** 2;
    return Math.sqrt(sum / buf.length);
}

describe("integration: render via the vendored tiny-piano SF2 fixture", () => {
    it("renders a C-major chord with non-zero RMS through process()", {
        timeout: 30_000,
    }, async () => {
        const bytes = new Uint8Array(await readFile(FIXTURE_PATH));
        const plugin = new SpessaSynthPlugin();
        await plugin.init({
            soundFontBytes: bytes,
            sampleRate: SR,
        });
        await plugin.setup(newConfig(), newCtx());

        // C major: C4, E4, G4.
        for (const note of [60, 64, 67]) {
            plugin.sendMidi({
                type: "noteOn",
                channel: 0,
                note,
                velocity: 100,
            });
        }

        // Render half a second.
        const blocks = Math.ceil(SR / 2 / BLOCK);
        const merged = new Float32Array(blocks * BLOCK);
        for (let b = 0; b < blocks; b++) {
            const out: Float32Array[] = [
                new Float32Array(BLOCK),
                new Float32Array(BLOCK),
            ];
            plugin.process([], out, blockCtx());
            merged.set(out[0]!, b * BLOCK);
        }
        const r = rms(merged);
        expect(r).toBeGreaterThan(0);
        plugin.dispose();
    });
});