"use strict";

const assert = require("assert");
const { WebSocket } = require("ws");
const { parseClientMessage, sanitizeChat, sanitizeEvent, MAX_MESSAGE_BYTES } = require("../backend/protocol");
const { OverlayFeed, MAX_QUEUE, matchesSelectedSource } = require("../backend/feed");
const { isReadableTextChannel } = require("../backend/sources");

function run() {
  verifyProtocol();
  verifyCapabilityGate();
  verifyFilteringAndNoBacklog();
  verifyDiscordReadability();
  verifyBoundedQueueAndDeduplication();
  verifySanitization();
  console.log("Lumi native overlay verification passed: protocol limits, server-side filtering, no backlog, reconnect-safe deduplication, bounded queues, and payload sanitization.");
}

function verifyDiscordReadability() {
  const discord = { user: { id: "bot" } };
  const channel = {
    guild: { id: "guild" },
    isTextBased: () => true,
    permissionsFor: () => ({ has: (flag) => flag === 1024n })
  };
  assert.equal(isReadableTextChannel(channel, discord), true);
  assert.equal(isReadableTextChannel({ ...channel, permissionsFor: () => ({ has: () => false }) }, discord), false);
  assert.equal(isReadableTextChannel({ ...channel, isTextBased: () => false }, discord), false);
}

function verifyCapabilityGate() {
  const feed = Object.create(OverlayFeed.prototype);
  let response = "";
  const socket = {
    write(value) { response += value; },
    destroy() {}
  };
  feed.devices = { authenticate: (_header, capability) => {
    assert.equal(capability, "overlay.read.v1");
    return { allowed: false, reason: "missing_credentials" };
  } };
  feed.upgrade({ headers: {}, socket: {} }, socket, Buffer.alloc(0));
  assert.match(response, /^HTTP\/1.1 401/);
  response = "";
  feed.devices = { authenticate: () => ({ allowed: false, reason: "capability_revoked" }) };
  feed.upgrade({ headers: { authorization: "redacted" }, socket: {} }, socket, Buffer.alloc(0));
  assert.match(response, /^HTTP\/1.1 403/);
}

function verifyProtocol() {
  assert.deepEqual(parseClientMessage(JSON.stringify({
    type: "subscribe",
    sources: ["twitch:lumi", "twitch:lumi", "discord:guild:channel"],
    events: ["twitch.follow"]
  })), {
    type: "subscribe",
    sources: ["twitch:lumi", "discord:guild:channel"],
    events: ["twitch.follow"]
  });
  assert.throws(() => parseClientMessage(JSON.stringify({ type: "history" })), /Unsupported/);
  assert.throws(() => parseClientMessage(Buffer.alloc(MAX_MESSAGE_BYTES + 1)), /too large/);
}

function verifyFilteringAndNoBacklog() {
  const feed = Object.create(OverlayFeed.prototype);
  feed.sessions = new Set();
  feed.sequence = 0;
  feed.publishedSeen = new Map();
  feed.publishChat({ id: "before", platform: "twitch", channel: { name: "lumi" } });
  const sent = [];
  const session = sessionFor(sent, ["twitch:lumi"]);
  feed.sessions.add(session);
  assert.equal(sent.length, 0, "opening/subscribing must not replay a pre-connection message");
  feed.publishChat({
    id: "selected", platform: "twitch", text: "hello", timestamp: 1,
    channel: { id: "1", name: "lumi", key: "lumi" },
    author: { id: "viewer", name: "Viewer", badges: [] }, emotes: []
  });
  feed.publishChat({
    id: "selected", platform: "twitch", text: "duplicate", timestamp: 3,
    channel: { id: "1", name: "lumi", key: "lumi" },
    author: { id: "viewer", name: "Viewer", badges: [] }, emotes: []
  });
  feed.publishChat({
    id: "other", platform: "twitch", text: "hidden", timestamp: 2,
    channel: { id: "2", name: "other", key: "other" },
    author: { id: "viewer", name: "Viewer", badges: [] }, emotes: []
  });
  assert.equal(sent.length, 1, "provider duplicates must remain suppressed across feed sessions/reconnects");
  assert.equal(JSON.parse(sent[0]).message.id, "selected");
  assert.equal(matchesSelectedSource(new Set(["discord:guild:channel"]), "discord:guild:*"), true);
}

function verifyBoundedQueueAndDeduplication() {
  const feed = Object.create(OverlayFeed.prototype);
  feed.sequence = 0;
  const session = sessionFor([], ["twitch:lumi"], WebSocket.CLOSED);
  for (let index = 0; index < MAX_QUEUE + 40; index += 1)
    feed.enqueue(session, "chat", { index }, `message:${index}`);
  assert.equal(session.queue.length, MAX_QUEUE);
  assert.equal(session.queue[0].index, 40, "overflow must deterministically drop the oldest queued item");
  feed.enqueue(session, "chat", { index: 999 }, `message:${MAX_QUEUE + 39}`);
  assert.equal(session.queue.length, MAX_QUEUE, "a duplicate event must not enter the queue twice");
}

function verifySanitization() {
  const chat = sanitizeChat({
    id: "id", platform: "twitch", text: "<script>plain text</script>",
    channel: {}, author: { id: "user", name: "Viewer", avatar: "http://insecure.test/avatar.png" },
    emotes: [{ start: 0, end: 1, image: "https://cdn.test/emote.png" }]
  });
  assert.equal(chat.text, "<script>plain text</script>", "content remains plain data and is not interpreted server-side");
  assert.equal(chat.author.avatar, null);
  assert.equal(chat.emotes[0].image, "https://cdn.test/emote.png");
  const discord = sanitizeChat({
    id: "discord-id", platform: "discord", text: "<a:wave:1>", channel: {},
    author: { id: "discord-user", name: "Discord viewer", badges: [] },
    emotes: [{ start: 0, end: 9, label: ":wave:", image: "https://cdn.test/wave.gif" }],
    media: [{ url: "https://cdn.test/reaction.gif", type: "image", alt: "Reaction" }]
  });
  assert.equal(discord.emotes[0].image, "https://cdn.test/wave.gif", "Discord emotes must reach the Companion feed");
  assert.equal(discord.media[0].url, "https://cdn.test/reaction.gif", "Discord GIFs must reach the Companion feed");
  const event = sanitizeEvent({ id: "event", type: "twitch.follow", payload: { user_name: "Viewer", access_token: "secret" } });
  assert.equal(event.payload.access_token, undefined);
  assert.equal(event.payload.user_name, "Viewer");
}

function sessionFor(sent, sources, state = WebSocket.OPEN) {
  return {
    socket: { readyState: state, send(value) { sent.push(value); } },
    device: {}, sources: new Set(sources), events: new Set(), subscribed: true,
    queue: [], draining: false, seen: new Map(), lastPong: Date.now()
  };
}

run();