/**
 * @file codex-cli.js
 * @description Drives the official `codex mcp …` / `codex plugin …` CLI so
 * the Codex config panel can add/remove MCP servers, marketplaces and
 * plugins without the dashboard touching Codex's TOML config directly.
 *
 * Why the CLI and not direct TOML edits: the CLI owns config.toml's schema
 * (MCP server table, plugin/marketplace registration) and rewrites it in
 * place. Reproducing that here would drift the moment the CLI's format
 * moves — the same reasoning `cc-plugin-cli.js` follows for `claude plugin`.
 *
 * Hard constraints (do not relax without a follow-up review):
 *   - `execFile` with an explicit argv array. NEVER a shell string — a
 *     server/plugin/marketplace name comes straight from a user-typed field.
 *   - A name is validated against `NAME_RE` BEFORE spawning: no leading `-`
 *     (never a flag), no `/` (never a path). This is the same guard the
 *     HTTP routes re-check. Plugin specs and URLs get their own purpose-built
 *     guards (`assertPluginSpec`, `assertUrl`) — same idea, looser shape.
 *   - Mutating calls are serialized in-process; two dashboard clicks must
 *     not interleave writes to the same config.toml.
 *   - `CODEX_HOME` is pinned to the same home `codex-discovery` reads, so
 *     the CLI writes where the dashboard looks.
 *
 * A non-zero CLI exit resolves as `{ok: false}` (data, not an error) so a
 * route can map it to HTTP 422. Only a rejected name or a missing binary
 * throws — those are programming/environment errors, not CLI outcomes.
 *
 * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
 */

const { execFile } = require("node:child_process");
const { getCodexHome } = require("./codex-home");

const DEFAULT_TIMEOUT_MS = 120_000;
const MAX_OUTPUT_BYTES = 1024 * 1024;

/** An MCP server / plugin / marketplace name. No slashes: never a path. */
const NAME_RE = /^[A-Za-z0-9][A-Za-z0-9._-]*$/;
/** `name` or `name@marketplace` — same shape as cc-plugin-cli's PLUGIN_SPEC_RE. */
const PLUGIN_SPEC_RE = /^[A-Za-z0-9][A-Za-z0-9._-]*(@[A-Za-z0-9][A-Za-z0-9._-]*)?$/;
/** An environment variable name — used for both `--env K=V` and `--bearer-token-env-var`. */
const ENV_KEY_RE = /^[A-Za-z_][A-Za-z0-9_]*$/;

function makeError(code, message) {
  const err = new Error(message);
  err.code = code;
  return err;
}

/**
 * Baseline check applied to every argv element we interpolate. A value that
 * starts with `-` would be parsed as a flag by the CLI even inside an argv
 * array, so it is rejected rather than escaped.
 */
function assertArg(value, label) {
  if (typeof value !== "string" || !value.trim()) {
    throw makeError("EBADARG", `${label} is required`);
  }
  if (value.length > 512) throw makeError("EBADARG", `${label} is too long`);
  // eslint-disable-next-line no-control-regex
  if (/[\u0000-\u001f\u007f]/.test(value)) {
    throw makeError("EBADARG", `${label} contains control characters`);
  }
  if (value.startsWith("-")) throw makeError("EBADARG", `${label} may not start with "-"`);
  return value;
}

/** An MCP server / plugin / marketplace identifier — the routes' shared guard. */
function assertName(value, label = "name") {
  assertArg(value, label);
  if (!NAME_RE.test(value)) {
    throw makeError("EBADARG", `${label} is not a valid identifier`);
  }
  return value;
}

/** `<name>` or `<name>@<marketplace>`, as `codex plugin add` accepts. */
function assertPluginSpec(value) {
  assertArg(value, "plugin spec");
  if (!PLUGIN_SPEC_RE.test(value)) {
    throw makeError("EBADARG", "plugin spec must be <name> or <name>@<marketplace>");
  }
  return value;
}

/** An environment variable NAME (never a literal secret). */
function assertEnvKey(value, label) {
  assertArg(value, label);
  if (!ENV_KEY_RE.test(value)) {
    throw makeError("EBADARG", `${label} is not a valid identifier`);
  }
  return value;
}

/** An http(s) URL — `new URL()` both validates and normalizes the parse. */
function assertUrl(value, label) {
  assertArg(value, label);
  let parsed;
  try {
    parsed = new URL(value);
  } catch {
    throw makeError("EBADARG", `${label} must be a valid http(s) URL`);
  }
  if (parsed.protocol !== "http:" && parsed.protocol !== "https:") {
    throw makeError("EBADARG", `${label} must be a valid http(s) URL`);
  }
  return value;
}

// One in-process queue for every mutating CLI call — the same reasoning as
// cc-plugin-cli.js's `mutationQueue`: this dashboard is the only Node writer,
// so a promise chain is the whole locking story. It does NOT protect against
// a human running `codex …` in a terminal at the same moment.
let mutationQueue = Promise.resolve();

function serialize(fn) {
  const run = mutationQueue.then(fn, fn);
  mutationQueue = run.then(
    () => undefined,
    () => undefined
  );
  return run;
}

/**
 * Run `codex <args…>` and resolve with the outcome. A non-zero exit is a
 * normal result (`ok:false`), not a rejection. When stdout parses as JSON
 * the parsed value is attached as `data`.
 *
 * @param {string[]} args argv AFTER the binary name; every element pre-validated.
 * @param {{timeoutMs?:number}} [opts]
 * @returns {Promise<{ok:boolean, code:number|null, stdout:string, stderr:string, data?:object}>}
 */
function runCodex(args, opts = {}) {
  const timeout = opts.timeoutMs || DEFAULT_TIMEOUT_MS;
  return new Promise((resolve, reject) => {
    const child = execFile(
      "codex",
      args,
      {
        timeout,
        maxBuffer: MAX_OUTPUT_BYTES,
        // Pin the CLI to the same home codex-discovery reads, so a write
        // made here is a write the dashboard can see.
        env: { ...process.env, CODEX_HOME: getCodexHome() },
      },
      (err, stdout, stderr) => {
        const out = String(stdout || "");
        const errOut = String(stderr || "");
        if (err && (err.code === "ENOENT" || err.code === "EACCES")) {
          return reject(
            makeError(
              "ECLINOTFOUND",
              "the `codex` CLI was not found on PATH — install Codex or add it to the dashboard's PATH"
            )
          );
        }
        if (err && err.killed) {
          return reject(makeError("ETIMEOUT", `codex ${args[0]} timed out after ${timeout}ms`));
        }
        const code = err ? (typeof err.code === "number" ? err.code : 1) : 0;
        const result = { ok: !err, code, stdout: out, stderr: errOut };
        try {
          result.data = JSON.parse(out.trim());
        } catch {
          /* not every command emits JSON */
        }
        resolve(result);
      }
    );
    // Every command here is non-interactive. Closing stdin turns a would-be
    // prompt into an immediate CLI error instead of a hang until `timeout`.
    try {
      child.stdin?.end();
    } catch {
      /* the child may already have exited */
    }
  });
}

// ── MCP servers ────────────────────────────────────────────────────────

async function mcpList() {
  return runCodex(["mcp", "list", "--json"]);
}

/**
 * `codex mcp add` has two mutually exclusive forms: a streamable HTTP server
 * (`--url`, optionally `--bearer-token-env-var`) or a stdio server
 * (`-- <command> <args…>`, optionally `--env K=V`). `--env` is invalid on
 * the `--url` form per the CLI's own `--help`, so `{url, env}` together is
 * rejected rather than silently dropping one of them.
 */
async function mcpAdd({ name, url, bearerTokenEnvVar, command, args = [], env }) {
  const n = assertName(name);
  if (url && command) {
    throw makeError("EBADARG", "mcpAdd accepts either url or command, not both");
  }
  if (!url && !command) {
    throw makeError("EBADARG", "mcpAdd requires either url or command");
  }

  if (url) {
    if (env) throw makeError("EBADARG", "env is not valid together with url (stdio-only)");
    const u = assertUrl(url, "url");
    const flags = bearerTokenEnvVar
      ? ["--bearer-token-env-var", assertEnvKey(bearerTokenEnvVar, "bearerTokenEnvVar")]
      : [];
    return serialize(() => runCodex(["mcp", "add", n, ...flags, "--url", u]));
  }

  const cmd = assertArg(command, "command");
  const cmdArgs = args.map((a, i) => assertArg(a, `args[${i}]`));
  const envFlags = Object.entries(env || {}).flatMap(([k, v]) => {
    const key = assertEnvKey(k, "env key");
    assertArg(String(v), `env.${k}`);
    return ["--env", `${key}=${v}`];
  });
  return serialize(() => runCodex(["mcp", "add", n, ...envFlags, "--", cmd, ...cmdArgs]));
}

async function mcpRemove(name) {
  const n = assertName(name);
  return serialize(() => runCodex(["mcp", "remove", n]));
}

// ── Plugins ────────────────────────────────────────────────────────────

async function pluginList() {
  return runCodex(["plugin", "list", "--json"]);
}

async function pluginAdd(spec) {
  const s = assertPluginSpec(spec);
  return serialize(() => runCodex(["plugin", "add", s]));
}

async function pluginRemove(name) {
  const n = assertName(name);
  return serialize(() => runCodex(["plugin", "remove", n]));
}

// ── Marketplaces ───────────────────────────────────────────────────────

async function marketplaceList() {
  return runCodex(["plugin", "marketplace", "list", "--json"]);
}

async function marketplaceAdd(url) {
  const u = assertUrl(url, "marketplace url");
  return serialize(() => runCodex(["plugin", "marketplace", "add", u]));
}

async function marketplaceRemove(name) {
  const n = assertName(name);
  return serialize(() => runCodex(["plugin", "marketplace", "remove", n]));
}

module.exports = {
  runCodex,
  mcpList,
  mcpAdd,
  mcpRemove,
  pluginList,
  pluginAdd,
  pluginRemove,
  marketplaceList,
  marketplaceAdd,
  marketplaceRemove,
  NAME_RE,
  PLUGIN_SPEC_RE,
  assertPluginSpec,
  assertUrl,
};