/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

"use strict";

// This is mostly so test_peerConnection_gatherWithStun300.html and
// test_peerConnection_gatherWithStun300IPv6 can share this code. I would have
// put the ipv6 test code in the same file, but our ipv6 tester support is
// inconsistent enough that we need to be able to track the ipv6 test
// separately.

async function findStatsRelayCandidates(pc, protocol) {
  const stats = await pc.getStats();
  return [...stats.values()].filter(
    v =>
      v.type == "local-candidate" &&
      v.candidateType == "relay" &&
      v.relayProtocol == protocol
  );
}

// Trickles candidates if pcDst is set, and resolves the candidate list
async function trickleIce(pc, pcDst) {
  const candidates = [],
    addCandidatePromises = [];
  while (true) {
    const { candidate } = await new Promise(r =>
      pc.addEventListener("icecandidate", r, { once: true })
    );
    if (!candidate) {
      break;
    }
    candidates.push(candidate);
    if (pcDst) {
      addCandidatePromises.push(pcDst.addIceCandidate(candidate));
    }
  }
  await Promise.all(addCandidatePromises);
  return candidates;
}

async function gather(pc) {
  if (pc.signalingState == "stable") {
    await pc.setLocalDescription(
      await pc.createOffer({ offerToReceiveAudio: true })
    );
  } else if (pc.signalingState == "have-remote-offer") {
    await pc.setLocalDescription();
  }

  return trickleIce(pc);
}

async function gatherWithTimeout(pc, timeout, context) {
  const throwOnTimeout = async () => {
    await wait(timeout);
    throw new Error(
      `Gathering did not complete within ${timeout} ms with ${context}`
    );
  };

  return Promise.race([gather(pc), throwOnTimeout()]);
}

async function iceConnected(pc) {
  return new Promise((resolve, reject) => {
    pc.addEventListener("iceconnectionstatechange", () => {
      if (["connected", "completed"].includes(pc.iceConnectionState)) {
        resolve();
      } else if (pc.iceConnectionState == "failed") {
        reject(new Error(`ICE failed`));
      }
    });
  });
}

// Set up trickle, but does not wait for it to complete. Can be used by itself
// in cases where we do not expect any new candidates, but want to still set up
// the signal handling in case new candidates _do_ show up.
async function connectNoTrickleWait(offerer, answerer, timeout, context) {
  return connect(offerer, answerer, timeout, context, true);
}

async function connect(
  offerer,
  answerer,
  timeout,
  context,
  noTrickleWait = false
) {
  const trickle1 = trickleIce(offerer, answerer);
  const trickle2 = trickleIce(answerer, offerer);
  try {
    const offer = await offerer.createOffer({ offerToReceiveAudio: true });
    await offerer.setLocalDescription(offer);
    await answerer.setRemoteDescription(offer);
    const answer = await answerer.createAnswer();
    await Promise.all([
      offerer.setRemoteDescription(answer),
      answerer.setLocalDescription(answer),
    ]);

    const throwOnTimeout = async () => {
      if (timeout) {
        await wait(timeout);
        throw new Error(
          `ICE did not complete within ${timeout} ms with ${context}`
        );
      }
    };

    await Promise.race([
      Promise.all([iceConnected(offerer), iceConnected(answerer)]),
      throwOnTimeout(timeout, context),
    ]);
  } finally {
    if (!noTrickleWait) {
      // TODO(bug 1751509): For now, we need to let gathering finish before we
      // proceed, because there are races in ICE restart wrt gathering state.
      await Promise.all([trickle1, trickle2]);
    }
  }
}

function isV6HostCandidate(candidate) {
  const fields = candidate.candidate.split(" ");
  const type = fields[7];
  const ipAddress = fields[4];
  return type == "host" && ipAddress.includes(":");
}

async function ipv6Supported() {
  const pc = new RTCPeerConnection();
  const candidates = await gatherWithTimeout(pc, 8000);
  info(`baseline candidates: ${JSON.stringify(candidates)}`);
  pc.close();
  return candidates.some(isV6HostCandidate);
}

function makeContextString(iceServers) {
  const currentRedirectAddress = SpecialPowers.getCharPref(
    "media.peerconnection.nat_simulator.redirect_address",
    ""
  );
  const currentRedirectTargets = SpecialPowers.getCharPref(
    "media.peerconnection.nat_simulator.redirect_targets",
    ""
  );
  return `redirect rule: ${currentRedirectAddress}=>${currentRedirectTargets} iceServers: ${JSON.stringify(
    iceServers
  )}`;
}

async function checkSrflx(iceServers) {
  const context = makeContextString(iceServers);
  info(`checkSrflx ${context}`);
  const pc = new RTCPeerConnection({
    iceServers,
    bundlePolicy: "max-bundle", // Avoids extra candidates
  });
  const candidates = await gatherWithTimeout(pc, 8000, context);
  const srflxCandidates = candidates.filter(c => c.candidate.includes("srflx"));
  info(`candidates: ${JSON.stringify(srflxCandidates)}`);
  // TODO(bug 1339203): Once we support rtcpMuxPolicy, set it to "require" to
  // result in a single srflx candidate
  is(
    srflxCandidates.length,
    2,
    `Should have two srflx candidates with ${context}`
  );
  pc.close();
}

async function checkNoSrflx(iceServers) {
  const context = makeContextString(iceServers);
  info(`checkNoSrflx ${context}`);
  const pc = new RTCPeerConnection({
    iceServers,
    bundlePolicy: "max-bundle", // Avoids extra candidates
  });
  const candidates = await gatherWithTimeout(pc, 8000, context);
  const srflxCandidates = candidates.filter(c => c.candidate.includes("srflx"));
  info(`candidates: ${JSON.stringify(srflxCandidates)}`);
  is(
    srflxCandidates.length,
    0,
    `Should have no srflx candidates with ${context}`
  );
  pc.close();
}

async function checkRelayUdp(iceServers) {
  const context = makeContextString(iceServers);
  info(`checkRelayUdp ${context}`);
  const pc = new RTCPeerConnection({
    iceServers,
    bundlePolicy: "max-bundle", // Avoids extra candidates
  });
  const candidates = await gatherWithTimeout(pc, 8000, context);
  const relayCandidates = candidates.filter(c => c.candidate.includes("relay"));
  info(`candidates: ${JSON.stringify(relayCandidates)}`);
  // TODO(bug 1339203): Once we support rtcpMuxPolicy, set it to "require" to
  // result in a single relay candidate
  is(
    relayCandidates.length,
    2,
    `Should have two relay candidates with ${context}`
  );
  // It would be nice if RTCIceCandidate had a field telling us what the
  // "related protocol" is (similar to relatedAddress and relatedPort).
  // Because there is no such thing, we need to go through the stats API,
  // which _does_ have that information.
  is(
    (await findStatsRelayCandidates(pc, "tcp")).length,
    0,
    `No TCP relay candidates should be present with ${context}`
  );
  pc.close();
}

async function checkRelayTcp(iceServers) {
  const context = makeContextString(iceServers);
  info(`checkRelayTcp ${context}`);
  const pc = new RTCPeerConnection({
    iceServers,
    bundlePolicy: "max-bundle", // Avoids extra candidates
  });
  const candidates = await gatherWithTimeout(pc, 8000, context);
  const relayCandidates = candidates.filter(c => c.candidate.includes("relay"));
  info(`candidates: ${JSON.stringify(relayCandidates)}`);
  // TODO(bug 1339203): Once we support rtcpMuxPolicy, set it to "require" to
  // result in a single relay candidate
  is(
    relayCandidates.length,
    2,
    `Should have two relay candidates with ${context}`
  );
  // It would be nice if RTCIceCandidate had a field telling us what the
  // "related protocol" is (similar to relatedAddress and relatedPort).
  // Because there is no such thing, we need to go through the stats API,
  // which _does_ have that information.
  is(
    (await findStatsRelayCandidates(pc, "udp")).length,
    0,
    `No UDP relay candidates should be present with ${context}`
  );
  pc.close();
}

async function checkRelayUdpTcp(iceServers) {
  const context = makeContextString(iceServers);
  info(`checkRelayUdpTcp ${context}`);
  const pc = new RTCPeerConnection({
    iceServers,
    bundlePolicy: "max-bundle", // Avoids extra candidates
  });
  const candidates = await gatherWithTimeout(pc, 8000, context);
  const relayCandidates = candidates.filter(c => c.candidate.includes("relay"));
  info(`candidates: ${JSON.stringify(relayCandidates)}`);
  // TODO(bug 1339203): Once we support rtcpMuxPolicy, set it to "require" to
  // result in a single relay candidate each for UDP and TCP
  is(
    relayCandidates.length,
    4,
    `Should have two relay candidates for each protocol with ${context}`
  );
  // It would be nice if RTCIceCandidate had a field telling us what the
  // "related protocol" is (similar to relatedAddress and relatedPort).
  // Because there is no such thing, we need to go through the stats API,
  // which _does_ have that information.
  is(
    (await findStatsRelayCandidates(pc, "udp")).length,
    2,
    `Two UDP relay candidates should be present with ${context}`
  );
  // TODO(bug 1705563): This is 1 because of bug 1705563
  is(
    (await findStatsRelayCandidates(pc, "tcp")).length,
    1,
    `One TCP relay candidates should be present with ${context}`
  );
  pc.close();
}

async function checkNoRelay(iceServers) {
  const context = makeContextString(iceServers);
  info(`checkNoRelay ${context}`);
  const pc = new RTCPeerConnection({
    iceServers,
    bundlePolicy: "max-bundle", // Avoids extra candidates
  });
  const candidates = await gatherWithTimeout(pc, 8000, context);
  const relayCandidates = candidates.filter(c => c.candidate.includes("relay"));
  info(`candidates: ${JSON.stringify(relayCandidates)}`);
  is(
    relayCandidates.length,
    0,
    `Should have no relay candidates with ${context}`
  );
  pc.close();
}