import assert from "node:assert/strict";
import fs from "node:fs";
import os from "node:os";
import path from "node:path";
import test from "node:test";
import { pathToFileURL } from "node:url";
import ts from "typescript";

const root = path.resolve(import.meta.dirname, "../../..");
const temporary = fs.mkdtempSync(path.join(os.tmpdir(), "sequencer-audio-recovery-unit-"));
const protocolPath = path.join(root, "web/protocol/sequencer-audio-session.ts");
const runtimePath = path.join(root, "web/app/src/sequencer/SequencerAudioSession.ts");

function transpile(source, fileName) {
  const result = ts.transpileModule(source, {
    compilerOptions: { module: ts.ModuleKind.ES2022, target: ts.ScriptTarget.ES2022 },
    fileName,
    reportDiagnostics: true,
  });
  assert.deepEqual(result.diagnostics, []);
  return result.outputText;
}

fs.writeFileSync(
  path.join(temporary, "sequencer-audio-session.mjs"),
  transpile(fs.readFileSync(protocolPath, "utf8").replace('import type { ErrorCode } from "./error";\n', ""), protocolPath),
);
fs.writeFileSync(
  path.join(temporary, "SequencerAudioSession.mjs"),
  transpile(
    fs.readFileSync(runtimePath, "utf8").replace(
      'from "../../../protocol/sequencer-audio-session";',
      'from "./sequencer-audio-session.mjs";',
    ),
    runtimePath,
  ),
);

const protocol = await import(pathToFileURL(path.join(temporary, "sequencer-audio-session.mjs")));
const runtime = await import(pathToFileURL(path.join(temporary, "SequencerAudioSession.mjs")));
const golden = JSON.parse(fs.readFileSync(path.join(root, "tests/golden/M11-13/sequencer-audio-recovery.json"), "utf8"));

class FakeAudioParam {
  value = 1;
  events = [];
  cancelScheduledValues(time) { this.events.push(["cancel", time]); }
  setValueAtTime(value, time) { this.value = value; this.events.push(["set", value, time]); }
}

class FakeGainNode {
  gain = new FakeAudioParam();
  connected = false;
  disconnected = false;
  connect() { this.connected = true; }
  disconnect() { this.disconnected = true; }
}

class FakeAudioContext {
  static instances = [];
  state = "suspended";
  currentTime = 1;
  destination = {};
  output = new FakeGainNode();
  closeCount = 0;
  constructor() { FakeAudioContext.instances.push(this); }
  createGain() { return this.output; }
  async resume() { this.state = "running"; }
  async suspend() { this.state = "suspended"; }
  async close() { this.closeCount += 1; this.state = "closed"; }
}

const summary = (report) => [
  report.contextState,
  report.outputState,
  report.muted,
  report.outputGain,
  report.issueCode,
];

test("M11-13 restores output after real session suspend and mute transitions", async () => {
  FakeAudioContext.instances.length = 0;
  const session = new runtime.SequencerAudioSession({
    scope: { AudioContext: FakeAudioContext },
    outputGain: golden.outputGain,
  });
  const reports = [];
  reports.push(await session.initialize());
  reports.push(session.setMuted(true));
  reports.push(await session.resume());
  reports.push(session.setMuted(false));
  reports.push(await session.suspend());
  reports.push(await session.resume());
  reports.push(await session.close());

  assert.deepEqual(reports.map(summary), golden.lifecycle);
  assert.deepEqual(reports.map((report) => report.revision), [1, 2, 3, 4, 5, 6, 7]);
  const context = FakeAudioContext.instances[0];
  assert.equal(context.output.gain.value, 0);
  assert.equal(context.output.connected, true);
  assert.equal(context.output.disconnected, true);
  assert.equal(context.closeCount, 1);
  assert.ok(context.output.gain.events.some((event) => event[0] === "set" && event[1] === 0));
  assert.ok(context.output.gain.events.some((event) => event[0] === "set" && event[1] === golden.outputGain));
});

test("M11-13 blocks a missing audio device and can retry after the runtime becomes available", async () => {
  FakeAudioContext.instances.length = 0;
  const scope = {};
  const session = new runtime.SequencerAudioSession({ scope, outputGain: golden.outputGain });
  const missing = await session.initialize();
  assert.deepEqual(
    [missing.contextState, missing.outputState, missing.issueCode],
    golden.missingDevice,
  );
  assert.deepEqual(session.snapshot(), missing);

  scope.AudioContext = FakeAudioContext;
  const recovered = await session.recoverDevice();
  assert.deepEqual(summary(recovered), golden.lifecycle[0]);
  const resumed = await session.resume();
  assert.deepEqual(summary(resumed), ["RUNNING", "ENABLED", false, golden.outputGain, null]);
  await session.close();
});

test("M11-13 keeps failed resume and malformed reports silent and structured", async () => {
  class ResumeFailureContext extends FakeAudioContext {
    async resume() { throw new Error("injected resume failure"); }
  }
  const failed = new runtime.SequencerAudioSession({
    contextFactory: () => new ResumeFailureContext(),
    outputGain: golden.outputGain,
  });
  await failed.initialize();
  const resumeFailure = await failed.resume();
  assert.deepEqual(
    [resumeFailure.contextState, resumeFailure.outputState, resumeFailure.issueCode],
    golden.resumeFailure,
  );
  await failed.close();

  const unavailable = new runtime.SequencerAudioSession({
    contextFactory: () => { throw new Error("no output device"); },
  });
  assert.deepEqual(
    [
      (await unavailable.initialize()).contextState,
      unavailable.snapshot().outputState,
      unavailable.snapshot().issueCode,
    ],
    golden.missingDevice,
  );
  assert.throws(() => new runtime.SequencerAudioSession({ outputGain: 0 }), {
    code: "SEQUENCER_AUDIO_CONTEXT_INVALID",
  });
  assert.throws(() => protocol.parseSequencerAudioSessionReport({
    schemaVersion: 1,
    revision: 1,
    contextState: "RUNNING",
    outputState: "ENABLED",
    muted: true,
    outputGain: 1,
    issueCode: null,
  }), { code: "SEQUENCER_AUDIO_CONTEXT_INVALID" });
});