/**
 * @file The AI Tools catalog: which AI coding CLIs AgentHub can run in a lane
 * (`server/data/ai-tools/*.json`, the newer release's copy synced by
 * ai-tools-sync.js, and overrides in `DASHBOARD_AI_TOOLS_DIR`, in rising
 * precedence), how each is installed/updated (built-in and release files only),
 * which of them are installed (a walk of the PATH directories — no process per
 * tool), and the user's enable/default choice (`<data dir>/ai-tools.json`).
 * A catalog file is data only: its args and env reach an argv in pty-run.js,
 * never a shell, and a custom file may not claim a hand-written `launcher` nor
 * an `install`/`update` — an Install click would run whatever it named.
 * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
 */

const fs = require("node:fs");
const path = require("node:path");
const { getDataDir } = require("./claude-home");

const BUILTIN_DIR = path.join(__dirname, "..", "data", "ai-tools");
const ID_RE = /^[a-z0-9][a-z0-9-]{0,39}$/;
const CMD_RE = /^[A-Za-z0-9._+-]+$/;
const ENV_RE = /^[A-Za-z_][A-Za-z0-9_]*$/;
const LAUNCHERS = new Set(["claude", "codex"]);
const PROMPT_MODES = new Set(["argv", "flag", "after-start"]);
const ROUTER_CAPABLE = new Set(["claude", "codex"]);
const PKG_RE = /^(@[a-z0-9][a-z0-9._-]*\/)?[a-z0-9][a-z0-9._-]*$/;
// Files shipped in a release (built-in, or synced from the newest release) are
// trusted to name a launcher and an install/update; a custom file is not.
const TRUSTED = new Set(["builtin", "remote"]);

let dirsOverride = null;
let catalog = null; // Map id -> tool, in catalog order
const detected = new Map();

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

const isStrArray = (v, re) =>
  Array.isArray(v) && v.every((s) => typeof s === "string" && s && (!re || re.test(s)));

// ponytail: compares the last two host labels, not a public suffix list —
// wrong for co.uk-style hosts (none in the catalog); swap in a PSL if one comes.
const siteOf = (host) => host.toLowerCase().split(".").slice(-2).join(".");

/** The script URL, when it is https on the homepage's site; else null. */
function scriptUrl(url, homepageUrl) {
  try {
    const u = new URL(url);
    const home = new URL(homepageUrl);
    if (u.protocol !== "https:" || u.username || u.password || u.port) return null;
    return siteOf(u.hostname) === siteOf(home.hostname) ? u.href : null;
  } catch {
    return null;
  }
}

/** `{install, update}` normalised, or null when either is malformed. */
function installFields(doc) {
  let install = null;
  if (doc.install !== undefined) {
    const i = doc.install;
    if (i?.kind === "npm" && typeof i.package === "string" && PKG_RE.test(i.package)) {
      install = { kind: "npm", package: i.package };
    } else if (i?.kind === "script" && typeof i.url === "string") {
      const url = scriptUrl(i.url, doc.homepageUrl);
      if (!url) return null;
      install = { kind: "script", url };
    } else return null;
  }
  let update = null;
  if (doc.update !== undefined) {
    const u = doc.update;
    if ((u?.kind === "npm" || u?.kind === "script") && install?.kind === u.kind) {
      update = { kind: u.kind };
    } else if (u?.kind === "self" && isStrArray(u.args) && u.args.length) {
      update = { kind: "self", args: u.args };
    } else return null;
  }
  return { install, update };
}

/** A normalised tool, or null when the file breaks any rule. */
function validate(doc, source) {
  if (!doc || typeof doc !== "object") return null;
  if (typeof doc.id !== "string" || !ID_RE.test(doc.id)) return null;
  if (typeof doc.label !== "string" || !doc.label.trim()) return null;
  if (!isStrArray(doc.detect, CMD_RE) || !doc.detect.length) return null;
  if (doc.requires !== undefined && !isStrArray(doc.requires, CMD_RE)) return null;
  for (const k of ["args", "resume", "bypass"]) {
    if (doc[k] !== undefined && !isStrArray(doc[k])) return null;
  }
  if (doc.bypassEnv !== undefined) {
    const e = doc.bypassEnv;
    if (!e || typeof e !== "object" || Array.isArray(e)) return null;
    if (!Object.entries(e).every(([k, v]) => ENV_RE.test(k) && typeof v === "string")) return null;
  }
  let launcher = null;
  if (doc.launcher !== undefined) {
    if (!TRUSTED.has(source) || !LAUNCHERS.has(doc.launcher) || doc.launcher !== doc.id)
      return null;
    launcher = doc.launcher;
  }
  if ((doc.install !== undefined || doc.update !== undefined) && !TRUSTED.has(source)) return null;
  const config = configFiles(doc.config, source);
  if (!config) return null;
  const fields = installFields(doc);
  if (!fields) return null;
  let prompt = null;
  if (!launcher) {
    const p = doc.prompt;
    if (!p || !PROMPT_MODES.has(p.mode)) return null;
    if (p.mode === "flag" && (typeof p.flag !== "string" || !p.flag.startsWith("-"))) return null;
    if (p.mode === "argv" && p.separator !== undefined && p.separator !== "--") return null;
    prompt = { mode: p.mode };
    if (p.mode === "flag") prompt.flag = p.flag;
    if (p.mode === "argv" && p.separator) prompt.separator = p.separator;
    if (p.mode === "after-start") {
      const d = Number(p.delayMs);
      prompt.delayMs = Number.isFinite(d) && d >= 0 && d <= 60000 ? d : 3000;
    }
  }
  // `model`: how a run picks a model on this CLI. Only a flag name and a
  // vendor (which pricing rows to offer as choices) — the value itself is
  // the user's, validated by validModel() at spawn time.
  let model = null;
  if (doc.model !== undefined) {
    const m = doc.model;
    if (!m || typeof m.flag !== "string" || !/^--?[a-z][a-z0-9-]*$/.test(m.flag)) return null;
    if (m.vendor !== undefined && !MODEL_VENDORS.has(m.vendor)) return null;
    model = { flag: m.flag, vendor: m.vendor || null };
  }
  return {
    id: doc.id,
    label: doc.label.trim(),
    model,
    detect: doc.detect,
    requires: doc.requires || [],
    args: doc.args || [],
    homepageUrl:
      typeof doc.homepageUrl === "string" && /^https:\/\//.test(doc.homepageUrl)
        ? doc.homepageUrl
        : null,
    faviconDomain: typeof doc.faviconDomain === "string" ? doc.faviconDomain : null,
    prompt,
    resume: doc.resume || null,
    bypass: doc.bypass || null,
    bypassEnv: doc.bypassEnv || null,
    launcher,
    install: fields.install,
    update: fields.update,
    config,
    source,
  };
}

/** A name no config editor may open: logins, tokens, keys. */
const CONFIG_SECRET_RE =
  /(auth|credential|token|secret|oauth|cookie|passw|api[-_]?key|\.env$|\.pem$|\.key$|id_rsa)/i;
const CONFIG_FORMATS = new Set(["json", "jsonc", "text"]);

/**
 * `config`: the tool's own config files its Settings tab may edit — like
 * `install`, only from a trusted file. Each is `~/`-relative, never climbs
 * out with `..`, and never names a credential. Answers [] when absent, null
 * when invalid.
 */
function configFiles(raw, source) {
  if (raw === undefined) return [];
  if (!TRUSTED.has(source) || !Array.isArray(raw) || raw.length > 8) return null;
  const out = [];
  for (const c of raw) {
    const p = c && c.path;
    if (typeof p !== "string" || !p.startsWith("~/") || p.includes("\0")) return null;
    if (p.split("/").some((seg) => seg === "..") || CONFIG_SECRET_RE.test(path.basename(p)))
      return null;
    const format = c.format ?? (/\.jsonc$/.test(p) ? "jsonc" : /\.json$/.test(p) ? "json" : "text");
    if (!CONFIG_FORMATS.has(format)) return null;
    out.push({ path: p, format });
  }
  return out;
}

const MODEL_VENDORS = new Set(["claude", "openai", "google"]);

/**
 * A model id that may follow a model flag as one argv element: a letter or
 * digit first (never `-`, so it can not become a flag of its own), then the
 * characters real ids use — `opus[1m]`, `openai/gpt-5.5`, `gemini-3.1-pro`.
 */
function validModel(m) {
  return typeof m === "string" && /^[A-Za-z0-9][A-Za-z0-9._:/@+[\]-]{0,127}$/.test(m);
}

const RANK = { builtin: 0, remote: 1, custom: 2 };

/** `[dir, source]` pairs, lowest precedence first. */
function catalogDirs() {
  if (dirsOverride) {
    const names =
      dirsOverride.length === 2 ? ["builtin", "custom"] : ["builtin", "remote", "custom"];
    return dirsOverride.map((d, i) => [d, names[i]]);
  }
  // Lazy: ai-tools-sync.js requires this module for validate().
  const remote = require("./ai-tools-sync").activeRemoteDir();
  return [
    [BUILTIN_DIR, "builtin"],
    [remote, "remote"],
    [process.env.DASHBOARD_AI_TOOLS_DIR, "custom"],
  ].filter(([d]) => d);
}

function load() {
  const byId = new Map();
  catalogDirs().forEach(([dir, source]) => {
    let files = [];
    try {
      files = fs
        .readdirSync(dir)
        .filter((f) => f.endsWith(".json"))
        .sort();
    } catch {
      return; // dir absent — fine
    }
    for (const f of files) {
      let tool = null;
      try {
        tool = validate(JSON.parse(fs.readFileSync(path.join(dir, f), "utf8")), source);
      } catch {
        /* fall through to the log line */
      }
      if (!tool) {
        console.warn(`ai-tools: skipping invalid catalog file ${path.join(dir, f)}`);
        continue;
      }
      // A later tier beats an earlier one; within one dir the first file wins.
      if (!byId.has(tool.id) || RANK[source] > RANK[byId.get(tool.id).source]) {
        byId.set(tool.id, tool);
      }
    }
  });
  const rank = (t) => (t.id === "claude" ? 0 : t.id === "codex" ? 1 : 2);
  const sorted = [...byId.values()].sort(
    (a, b) => rank(a) - rank(b) || a.label.localeCompare(b.label)
  );
  return new Map(sorted.map((t) => [t.id, t]));
}

function cat() {
  if (!catalog) catalog = load();
  return catalog;
}

const list = () => [...cat().values()];
const get = (id) => cat().get(id) || null;
const has = (id) => typeof id === "string" && cat().has(id);

/** First executable `name` on `pathStr` (default: the server's PATH). */
function which(name, pathStr = process.env.PATH || "") {
  for (const dir of pathStr.split(path.delimiter)) {
    if (!dir) continue;
    const p = path.join(dir, name);
    try {
      if (fs.statSync(p).isFile()) {
        fs.accessSync(p, fs.constants.X_OK);
        return p;
      }
    } catch {
      /* not here */
    }
  }
  return null;
}

/** `{installed, path, command}` for one tool, cached until refresh() unless `fresh`. */
function detect(id, { fresh = false } = {}) {
  if (!fresh && detected.has(id)) return detected.get(id);
  const tool = get(id);
  let out = { installed: false, path: null, command: tool ? tool.detect[0] : null };
  if (tool) {
    for (const name of tool.detect) {
      const p = which(name);
      if (p) {
        out = { installed: tool.requires.every((r) => which(r)), path: p, command: name };
        break;
      }
    }
  }
  detected.set(id, out);
  return out;
}

function refresh() {
  catalog = null;
  detected.clear();
}

const statePath = () => path.join(getDataDir(), "ai-tools.json");

function readState() {
  try {
    const s = JSON.parse(fs.readFileSync(statePath(), "utf8"));
    const models = {};
    if (s.models && typeof s.models === "object") {
      for (const [id, m] of Object.entries(s.models)) if (validModel(m)) models[id] = m;
    }
    return {
      disabled: Array.isArray(s.disabled) ? s.disabled.filter((x) => typeof x === "string") : [],
      default: typeof s.default === "string" ? s.default : null,
      models,
    };
  } catch {
    return { disabled: [], default: null, models: {} };
  }
}

function writeState(state) {
  fs.mkdirSync(path.dirname(statePath()), { recursive: true });
  const tmp = `${statePath()}.${process.pid}.tmp`;
  fs.writeFileSync(tmp, JSON.stringify(state, null, 2) + "\n");
  fs.renameSync(tmp, statePath());
}

const isEnabled = (id) => !readState().disabled.includes(id);

function requireTool(id) {
  if (!has(id)) throw makeErr("ENOTOOL", `unknown AI tool: ${id}`);
}

function setEnabled(id, enabled) {
  requireTool(id);
  const s = readState();
  s.disabled = s.disabled.filter((x) => x !== id);
  if (!enabled) {
    s.disabled.push(id);
    if (s.default === id) s.default = null;
  }
  writeState(s);
}

function setDefault(id) {
  requireTool(id);
  if (!detect(id).installed || !isEnabled(id)) {
    throw makeErr("EBADDEFAULT", `${id} must be installed and enabled to be the default`);
  }
  writeState({ ...readState(), default: id });
}

/** The model a new run of `id` starts with; null clears it (the CLI's own). */
function setDefaultModel(id, model) {
  requireTool(id);
  if (model !== null && !validModel(model)) {
    throw makeErr("EBADMODEL", "not a valid model id");
  }
  const s = readState();
  if (model === null) delete s.models[id];
  else s.models[id] = model;
  writeState(s);
}

function effectiveDefault() {
  const s = readState();
  const ok = (id) => has(id) && detect(id).installed && !s.disabled.includes(id);
  if (s.default && ok(s.default)) return s.default;
  if (ok("claude")) return "claude";
  return list().find((t) => ok(t.id))?.id || null;
}

/** The GET /api/ai-tools body — flags only, never the arg arrays. */
function view() {
  const state = readState();
  const disabled = new Set(state.disabled);
  return {
    tools: list().map((t) => {
      const d = detect(t.id);
      return {
        id: t.id,
        label: t.label,
        command: d.command,
        homepageUrl: t.homepageUrl,
        installed: d.installed,
        path: d.path,
        enabled: !disabled.has(t.id),
        source: t.source,
        launcher: t.launcher,
        prompt: t.prompt ? { mode: t.prompt.mode } : null,
        resume: !!t.resume,
        bypass: !!(t.bypass || t.bypassEnv),
        routerCapable: ROUTER_CAPABLE.has(t.id),
        // claude/codex take a model through their own argv builders.
        modelFlag: Boolean(t.model || t.launcher),
        defaultModel: state.models[t.id] || null,
        modelVendor: t.model?.vendor || null,
        configFiles: t.config.length,
        install: t.install,
        update: t.update,
      };
    }),
    default: effectiveDefault(),
    catalog: dirsOverride
      ? { source: "builtin", tag: null, fetchedAt: null }
      : require("./ai-tools-sync").catalogMeta(),
  };
}

/** Test seam: `[builtin, custom]` or `[builtin, remote, custom]`, or null for the real ones. */
function __setCatalogDirs(dirs) {
  dirsOverride = dirs;
  refresh();
}

module.exports = {
  list,
  get,
  has,
  detect,
  refresh,
  readState,
  isEnabled,
  setEnabled,
  setDefault,
  setDefaultModel,
  validModel,
  effectiveDefault,
  view,
  validate,
  which,
  siteOf,
  ROUTER_CAPABLE,
  CONFIG_SECRET_RE,
  __setCatalogDirs,
};