/**
 * Frontend test entry.
 *
 * Local runs keep the previous TAP stream (`tsx --test tests/*.test.ts tests/*.test.tsx`).
 * CI and Gitea (`CI` or `GITEA_ACTIONS`) print Node's dot reporter to stdout and
 * write the full TAP report to gate-logs/frontend-tests.tap. The dot reporter's
 * trailing "Failed tests" stack dump is not copied to the log: the same failures
 * are printed afterwards from the TAP file as the test name plus the error body
 * (at most 60 lines each). Stacks stay in the TAP file.
 * The process exit code is the test runner's exit code (BUG-995).
 */
import { spawn } from "node:child_process";
import { mkdirSync, readFileSync, readdirSync } from "node:fs";
import path from "node:path";
import { fileURLToPath } from "node:url";

const frontendDir = path.resolve(path.dirname(fileURLToPath(import.meta.url)), "..");
const repoRoot = path.resolve(frontendDir, "..");
const tsxCli = path.join(frontendDir, "node_modules", "tsx", "dist", "cli.mjs");
// Expanded here instead of handing `tests/*.test.ts` to `node --test`: Node 20
// does not expand test globs ("Could not find tests/*.test.ts"), while the old
// `tsx --test tests/*.test.ts tests/*.test.tsx` script relied on the shell. Same
// order as the shell: every *.test.ts sorted, then every *.test.tsx sorted.
function testFiles() {
  const names = readdirSync(path.join(frontendDir, "tests"));
  const pick = (suffix) => names.filter((name) => name.endsWith(suffix)).sort().map((name) => `tests/${name}`);
  return [...pick(".test.ts"), ...pick(".test.tsx")];
}
const failureBlockLimit = 60;

function envEnabled(name) {
  const value = process.env[name];
  if (value == null || value === "") return false;
  return !/^(0|false|no|off)$/i.test(value);
}

function gateMode() {
  return envEnabled("CI") || envEnabled("GITEA_ACTIONS");
}

function stripAnsi(text) {
  return text.replace(/\u001b\[[0-9;]*m/g, "");
}

function runRunner(args, { suppressFailedTestsTrailer = false } = {}) {
  return new Promise((resolve) => {
    const child = spawn(process.execPath, [tsxCli, ...args], {
      cwd: frontendDir,
      stdio: suppressFailedTestsTrailer ? ["inherit", "pipe", "inherit"] : "inherit",
      env: process.env,
      windowsHide: true,
    });
    if (suppressFailedTestsTrailer && child.stdout) {
      let pending = "";
      let dropping = false;
      const writeLine = (line) => {
        if (dropping) return;
        if (stripAnsi(line).trim() === "Failed tests:") {
          dropping = true;
          return;
        }
        process.stdout.write(line);
      };
      child.stdout.setEncoding("utf8");
      child.stdout.on("data", (chunk) => {
        pending += chunk;
        let newline = pending.indexOf("\n");
        while (newline !== -1) {
          writeLine(pending.slice(0, newline + 1));
          pending = pending.slice(newline + 1);
          newline = pending.indexOf("\n");
        }
      });
      child.stdout.on("end", () => {
        if (pending) writeLine(pending);
      });
    }
    child.on("close", (code) => {
      resolve(code == null ? 1 : code);
    });
  });
}

function failureName(raw) {
  return raw.trim().replace(/^\d+\s+(?:-\s+)?/, "");
}

function isFileSuite(name, block) {
  const base = name.replaceAll("\\", "/").split("/").pop() ?? name;
  if (/\.test\.tsx?$/.test(base)) return true;
  return block.some((line) => /^\s*type:\s*'suite'/.test(line));
}

function unquoteYaml(value) {
  const match = /^(['"])(.*)\1$/.exec(value);
  return match ? match[2] : value;
}

export function errorBody(block) {
  const lines = [];
  let inError = false;
  let errorIndent = 0;
  const push = (line) => {
    if (lines.length < failureBlockLimit) lines.push(line);
  };
  for (const raw of block) {
    if (lines.length >= failureBlockLimit) break;
    if (!inError) {
      const error = /^(\s*)error:\s*(.*)$/.exec(raw);
      if (error) {
        const rest = error[2].trim();
        if (rest === "|-" || rest === "|" || rest === ">" || rest === ">-") {
          inError = true;
          errorIndent = error[1].length + 2;
          continue;
        }
        if (rest) push(unquoteYaml(rest));
        continue;
      }
      const code = /^\s*code:\s*(.+)$/.exec(raw);
      if (code && lines.length > 0) push(`code: ${code[1].trim()}`);
      continue;
    }
    if (raw.trim() === "") {
      push("");
      continue;
    }
    const indent = raw.match(/^(\s*)/)?.[1].length ?? 0;
    if (indent >= errorIndent) {
      push(raw.slice(errorIndent).replace(/\s+$/, ""));
      continue;
    }
    inError = false;
    const code = /^\s*code:\s*(.+)$/.exec(raw);
    if (code) push(`code: ${code[1].trim()}`);
  }
  while (lines.length > 0 && lines[lines.length - 1] === "") lines.pop();
  if (lines.length > 0) return lines;

  const fallback = [];
  for (const raw of block) {
    if (/^\s*(?:duration_ms|type|location|failureType|name|expected|actual|operator|stack|error):/.test(raw)) continue;
    const trimmed = raw.trim();
    if (!trimmed || trimmed === "---" || trimmed === "..." || trimmed.startsWith("#")) continue;
    fallback.push(trimmed);
    if (fallback.length >= failureBlockLimit) break;
  }
  return fallback;
}

export function summarizeTap(text) {
  const lines = text.split(/\r?\n/);
  const counts = {};
  for (const line of lines) {
    const match = /^# (tests|pass|fail|cancelled) (\d+)\s*$/.exec(line);
    if (match) counts[match[1]] = match[2];
  }
  const failures = [];
  for (let index = 0; index < lines.length; index += 1) {
    const match = /^(\s*)not ok\b(.*)$/.exec(lines[index]);
    if (!match) continue;
    const block = [];
    for (let cursor = index + 1; cursor < lines.length && block.length < failureBlockLimit; cursor += 1) {
      const next = lines[cursor];
      if (/^\s*(?:not )?ok\b/.test(next)) break;
      if (/^# (?:tests|suites|pass|fail|cancelled|skipped|todo|duration_ms)\b/.test(next)) break;
      block.push(next);
    }
    const name = failureName(match[2]);
    if (isFileSuite(name, block)) continue;
    failures.push({ name, block: errorBody(block) });
  }
  return { counts, failures };
}

function printSummary(tapPath) {
  const text = readFileSync(tapPath, "utf8");
  const { counts, failures } = summarizeTap(text);
  const tests = counts.tests ?? "?";
  const pass = counts.pass ?? "?";
  const fail = counts.fail ?? "?";
  const cancelled = counts.cancelled ?? "?";
  console.log(`# tests ${tests}`);
  console.log(`# pass ${pass}`);
  console.log(`# fail ${fail}`);
  console.log(`# cancelled ${cancelled}`);
  console.log("# tap gate-logs/frontend-tests.tap");
  for (const failure of failures) {
    console.log(`not ok - ${failure.name}`);
    for (const line of failure.block) console.log(line);
  }
  return failures.length;
}

function invokedDirectly() {
  const entry = process.argv[1];
  if (!entry) return false;
  return path.resolve(entry) === fileURLToPath(import.meta.url);
}

async function runTests() {
  const extra = process.argv.slice(2);
  if (!gateMode()) {
    const code = await runRunner(["--test", ...testFiles(), ...extra]);
    process.exit(code);
  }

  const logDir = path.join(repoRoot, "gate-logs");
  mkdirSync(logDir, { recursive: true });
  const tapPath = path.join(logDir, "frontend-tests.tap");
  const code = await runRunner(
    [
      "--test",
      "--test-reporter=dot",
      "--test-reporter-destination=stdout",
      "--test-reporter=tap",
      "--test-reporter-destination",
      tapPath,
      ...testFiles(),
      ...extra,
    ],
    { suppressFailedTestsTrailer: true },
  );
  try {
    printSummary(tapPath);
  } catch (error) {
    const message = error instanceof Error ? error.message : String(error);
    console.error(`failed to read ${tapPath}: ${message}`);
    process.exit(code === 0 ? 1 : code);
  }
  process.exit(code);
}

if (invokedDirectly()) {
  await runTests();
}