import fs from "node:fs";
import path from "node:path";

function getLastChar(input) {
  const t = (input || "").trim();
  return t.length ? t[t.length - 1] : "";
}

function evaluateDecision({ config, channel, senderId, content }) {
  if (config.enabled === false) {
    return { shouldUseNoReply: false, reason: "disabled" };
  }

  const ch = (channel || "").toLowerCase();
  if (config.discordOnly !== false && ch !== "discord") {
    return { shouldUseNoReply: false, reason: "non_discord" };
  }

  if (senderId && (config.bypassUserIds || []).includes(senderId)) {
    return { shouldUseNoReply: false, reason: "bypass_sender" };
  }

  const last = getLastChar(content || "");
  if (last && (config.endSymbols || []).includes(last)) {
    return { shouldUseNoReply: false, reason: `end_symbol:${last}` };
  }

  return { shouldUseNoReply: true, reason: "rule_match_no_end_symbol" };
}

function shouldInjectEndMarker(reason) {
  return reason === "bypass_sender" || String(reason).startsWith("end_symbol:");
}

const fixturePath = path.join(process.cwd(), "docs", "rule-cases.json");
const payload = JSON.parse(fs.readFileSync(fixturePath, "utf8"));

let ok = true;
for (const c of payload.cases || []) {
  const d = evaluateDecision({
    config: payload.config,
    channel: c.channel,
    senderId: c.senderId,
    content: c.content,
  });

  const inject = shouldInjectEndMarker(d.reason);
  const pass =
    d.shouldUseNoReply === c.expect.shouldUseNoReply &&
    d.reason === c.expect.reason &&
    inject === c.expect.injectEndMarker;

  if (!pass) {
    ok = false;
    console.error(`FAIL ${c.name}`);
    console.error(`  got:    ${JSON.stringify({ ...d, injectEndMarker: inject })}`);
    console.error(`  expect: ${JSON.stringify(c.expect)}`);
  } else {
    console.log(`OK   ${c.name}`);
  }
}

if (!ok) process.exit(1);
console.log("all rule cases passed");