/**
 * @file cc-profiles.js
 * @description Named Claude Code auth profiles — swap which Anthropic account
 * (and therefore which quota) the local `claude` CLI runs as, without touching
 * anything else in the Claude home.
 *
 * A profile is exactly the two identity artifacts and nothing more:
 *   - `claudeAiOauth` out of `<CLAUDE_HOME>/.credentials.json` — or, on macOS,
 *     out of the login Keychain item the CLI actually reads there
 *   - `oauthAccount` + `userID` out of the `.claude.json` config file(s)
 * Skills, subagents, commands, memory, plugins, marketplaces, MCP servers,
 * settings and session history all live elsewhere under CLAUDE_HOME and are
 * deliberately never read or written here — that is what makes a switch keep
 * the whole workspace and change only the account.
 *
 * Profiles are stored one JSON file per profile under
 * `<CLAUDE_HOME>/agenthub-profiles/` (dir 0700, files 0600). They hold live OAuth
 * tokens, so **no route ever returns token material** — `listProfiles` returns
 * identity metadata only. This module cannot mint credentials: a new profile is
 * captured by logging in with `claude auth login` and snapshotting what the CLI
 * wrote.
 *
 * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
 */

const fs = require("node:fs");
const os = require("node:os");
const path = require("node:path");
const cp = require("node:child_process");

const { getClaudeHome } = require("./claude-home");

/**
 * On macOS the `claude` CLI keeps `claudeAiOauth` in the login Keychain, NOT in
 * `<CLAUDE_HOME>/.credentials.json` — a file there is absent or a stale leftover
 * from an older build. Reading/writing only the file on a Mac is why a switch
 * reported success while the CLI kept running as the previous account.
 */
const KEYCHAIN_SERVICE = "Claude Code-credentials";
const KEYCHAIN_LABEL = `macOS Keychain (${KEYCHAIN_SERVICE})`;

/** Off with AGENTHUB_CC_KEYCHAIN=0 — tests, and anyone pinning the file. */
function keychainEnabled() {
  return process.platform === "darwin" && process.env.AGENTHUB_CC_KEYCHAIN !== "0";
}

function keychainArgs(verb) {
  return [verb, "-s", KEYCHAIN_SERVICE, "-a", os.userInfo().username];
}

/** The keychain item's JSON, or null when there is none / it is unreadable. */
function readKeychain() {
  try {
    const out = cp.execFileSync(
      "/usr/bin/security",
      [...keychainArgs("find-generic-password"), "-w"],
      {
        encoding: "utf8",
        stdio: ["ignore", "pipe", "ignore"],
      }
    );
    const parsed = JSON.parse(out.trim());
    return parsed && typeof parsed === "object" ? parsed : null;
  } catch {
    return null;
  }
}

function writeKeychain(value) {
  // ponytail: the secret rides in argv (`security` has no stdin mode), so it is
  // briefly visible in `ps` on a shared machine. Upgrade path is a native
  // keychain binding if that ever matters.
  cp.execFileSync(
    "/usr/bin/security",
    [...keychainArgs("add-generic-password"), "-U", "-w", JSON.stringify(value)],
    { stdio: "ignore" }
  );
}

/**
 * A profile's `name` is its filename, so the charset is deliberately narrow.
 * It is an internal identifier: what the user reads and edits is `label`, which
 * accepts spaces and diacritics precisely because it never touches a path.
 */
const NAME_RE = /^[a-zA-Z0-9][a-zA-Z0-9._-]{0,39}$/;

const LABEL_MAX = 60;

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

function profilesDir() {
  return path.join(getClaudeHome(), "agenthub-profiles");
}

function credentialsPath() {
  return path.join(getClaudeHome(), ".credentials.json");
}

/**
 * Every `.claude.json` that could carry the account identity. Claude Code has
 * shipped both locations (`~/.claude.json` beside the home, and one inside it);
 * a stale copy left behind with the OLD account's `oauthAccount` is exactly the
 * kind of contradiction that makes a switch look like it half-worked, so both
 * are rewritten when they exist.
 */
function configPaths() {
  const home = getClaudeHome();
  return [`${home}.json`, path.join(home, ".claude.json")];
}

function readJson(file) {
  let raw;
  try {
    raw = fs.readFileSync(file, "utf8");
  } catch {
    return null;
  }
  try {
    return JSON.parse(raw);
  } catch {
    throw err("EBADJSON", `${file} is not valid JSON - fix it by hand first`);
  }
}

/** Write JSON at 0600 through a temp file, so a crash never truncates the original. */
function writeJson(file, value) {
  fs.mkdirSync(path.dirname(file), { recursive: true });
  const tmp = `${file}.agenthub-tmp`;
  fs.writeFileSync(tmp, `${JSON.stringify(value, null, 2)}\n`, { mode: 0o600 });
  fs.renameSync(tmp, file);
}

/**
 * The live credentials blob and where it came from. The Keychain wins on macOS
 * when it holds an item; everything else (and a Mac whose CLI still uses the
 * file) falls back to `.credentials.json`.
 */
function readCredentials() {
  if (keychainEnabled()) {
    const kc = readKeychain();
    if (kc) return { creds: kc, keychain: true };
  }
  return { creds: readJson(credentialsPath()), keychain: false };
}

/** Write credentials back to the store they were read from. Returns what was written. */
function writeCredentials(creds, keychain) {
  if (!keychain) {
    writeJson(credentialsPath(), creds);
    return [credentialsPath()];
  }
  writeKeychain(creds);
  // A stale file beside the Keychain would still name the old account; keep it
  // in step when it exists, never create one.
  if (fs.existsSync(credentialsPath())) {
    writeJson(credentialsPath(), creds);
    return [KEYCHAIN_LABEL, credentialsPath()];
  }
  return [KEYCHAIN_LABEL];
}

/** The account identity currently on disk. `oauth`/`account` may be null. */
function readActiveAuth() {
  const { creds, keychain } = readCredentials();
  let account = null;
  let userID = null;
  for (const file of configPaths()) {
    const cfg = readJson(file);
    if (cfg && cfg.oauthAccount) {
      account = cfg.oauthAccount;
      userID = typeof cfg.userID === "string" ? cfg.userID : null;
      break;
    }
  }
  return { oauth: (creds && creds.claudeAiOauth) || null, account, userID, keychain };
}

/** Token-free description of an account, safe to send to the browser. */
function identityOf({ oauth, account }) {
  return {
    accountUuid: (account && account.accountUuid) || null,
    email: (account && account.emailAddress) || null,
    displayName: (account && account.displayName) || null,
    organization: (account && account.organizationName) || null,
    seatTier: (account && account.seatTier) || null,
    subscriptionType: (oauth && oauth.subscriptionType) || null,
    /** When the stored access token expires; a switch still works after that
     *  (the refresh token is stored too), it just refreshes on first use. */
    expiresAt: (oauth && oauth.expiresAt) || null,
  };
}

function profileFile(name) {
  if (typeof name !== "string" || !NAME_RE.test(name)) {
    throw err("EBADNAME", "name must be 1-40 chars of letters, digits, dot, dash or underscore");
  }
  return path.join(profilesDir(), `${name}.json`);
}

/**
 * Validate a user-supplied display label. Anything printable is allowed —
 * spaces and diacritics included — because a label is never used as a path.
 * Control characters are not: they would corrupt both the stored JSON line and
 * the row rendered in the UI.
 */
function normalizeLabel(label) {
  const clean = typeof label === "string" ? label.trim() : "";
  if (!clean || clean.length > LABEL_MAX || /[\u0000-\u001f\u007f]/.test(clean)) {
    throw err("EBADLABEL", `label must be 1-${LABEL_MAX} characters and no control characters`);
  }
  return clean;
}

/** Reduce any text to the narrow NAME_RE charset, for use as a filename. */
function slugify(text) {
  const base = String(text || "")
    .normalize("NFD")
    .replace(/[\u0300-\u036f]/g, "") // drop the combining accents NFD split off
    .replace(/[^a-zA-Z0-9]+/g, "-")
    .replace(/^-+|-+$/g, "")
    .slice(0, 32);
  return NAME_RE.test(base) ? base : "profile";
}

/** `base`, or `base-2`, `base-3`… — the first that is not already a file. */
function freeName(base) {
  let name = base;
  for (let n = 2; fs.existsSync(path.join(profilesDir(), `${name}.json`)); n += 1) {
    name = `${base}-${n}`;
  }
  return name;
}

/**
 * The LIVE credentials when `stored` is the account logged in right now, else
 * null.
 *
 * A saved profile is a copy, and an OAuth refresh token is single use: every
 * time Claude Code refreshes the account it is logged into, the copy sitting in
 * the profile file is retired. So for the active account the saved credentials
 * are the one set guaranteed NOT to work, and `.credentials.json` — which the
 * CLI keeps current — is the only usable source. Nothing here writes: rotating
 * the token the live session is holding would log the user out of their own
 * terminal.
 *
 * @param stored a profile as returned by `readProfile`
 * @returns the live `claudeAiOauth` block, or null when this is not that account
 */
function liveCredentialsFor(stored) {
  const live = readActiveAuth();
  if (!live.oauth) return null;
  const mine = identityOf(live).accountUuid;
  const theirs = identityOf({ oauth: stored.credentials, account: stored.account }).accountUuid;
  return mine && mine === theirs ? live.oauth : null;
}

/** Read one stored profile, or null when it does not exist. */
function readProfile(name) {
  const stored = readJson(profileFile(name));
  return stored && typeof stored === "object" ? stored : null;
}

/**
 * Every stored profile plus the account that is live right now.
 * @returns `{ items, active }` — `items[].active` marks the one whose
 *   `accountUuid` matches the live config. Tokens are never included.
 */
function listProfiles() {
  const active = identityOf(readActiveAuth());
  let names = [];
  try {
    names = fs
      .readdirSync(profilesDir())
      .filter((f) => f.endsWith(".json"))
      .map((f) => f.slice(0, -5));
  } catch {
    /* no profiles saved yet */
  }
  const items = [];
  for (const name of names) {
    if (!NAME_RE.test(name)) continue;
    let stored;
    try {
      stored = readProfile(name);
    } catch {
      continue; // a corrupt profile file is skipped, not fatal for the list
    }
    if (!stored) continue;
    const identity = identityOf({ oauth: stored.credentials, account: stored.account });
    items.push({
      name,
      // Profiles saved before labels existed fall back to their identifier, so
      // the UI always has something to show and to put in the rename field.
      label: typeof stored.label === "string" && stored.label.trim() ? stored.label.trim() : name,
      savedAt: stored.savedAt || null,
      active: Boolean(identity.accountUuid) && identity.accountUuid === active.accountUuid,
      ...identity,
    });
  }
  // Label first (that is what the UI shows), name as the tiebreaker so two
  // profiles sharing a label still come back in a stable order.
  items.sort((a, b) => a.label.localeCompare(b.label) || a.name.localeCompare(b.name));
  return { items, active: active.accountUuid || active.email ? active : null };
}

/**
 * Snapshot the currently logged-in account into a profile.
 *
 * One account is one profile: saving an account that some other profile
 * already holds is refused (`EDUPLICATE`) rather than silently making a second
 * copy, because two profiles of one account both report themselves active and
 * there is then nothing to switch between. Re-saving into the account's OWN
 * profile is the refresh path and stays allowed.
 *
 * @param name Optional identifier/filename. Omitted, one is derived from the
 *   account, which is what the UI does — the user renames the `label`
 *   afterwards instead of having to invent a filename up front.
 * @returns `{ ok, name, label, ...identity }`
 */
function saveProfile(name) {
  const auth = readActiveAuth();
  if (!auth.oauth) {
    throw err(
      "ENOAUTH",
      "no Claude account is logged in on this machine - run `claude auth login` first"
    );
  }
  const identity = identityOf(auth);
  const readable = identity.displayName || (identity.email || "").split("@")[0] || "profile";
  // An explicit name is both identifier and initial label; a derived one keeps
  // the readable form as the label and only the filename gets flattened.
  const explicit = name !== undefined && name !== null;
  let target;
  if (explicit) {
    profileFile(name); // validates the charset, throwing EBADNAME
    target = name;
  } else {
    target = freeName(slugify(readable));
  }

  const clash = listProfiles().items.find(
    (p) => p.accountUuid && p.accountUuid === identity.accountUuid && p.name !== target
  );
  if (clash) {
    throw err(
      "EDUPLICATE",
      `this account is already saved as "${clash.label}" (${clash.name}) - rename that profile instead of saving a second copy of it`
    );
  }

  // A re-save must not clobber a label the user has since edited.
  const existing = readProfile(target);
  const label = (existing && existing.label) || (explicit ? target : readable);

  fs.mkdirSync(profilesDir(), { recursive: true, mode: 0o700 });
  writeJson(profileFile(target), {
    name: target,
    label,
    savedAt: Date.now(),
    credentials: auth.oauth,
    account: auth.account,
    userID: auth.userID,
  });
  return { ok: true, name: target, label, ...identity };
}

/**
 * Change a profile's display label. The `name` (its filename, and the id every
 * other route takes) deliberately does not move: renaming is a cosmetic edit,
 * not a re-keying, so it cannot fail halfway and leave a profile unreachable.
 *
 * @param name Profile to rename.
 * @param label New display label; spaces and diacritics are fine.
 * @returns `{ ok, name, label }`
 */
function renameProfile(name, label) {
  const file = profileFile(name);
  const stored = readProfile(name);
  if (!stored) throw err("ENOTFOUND", `no profile named "${name}"`);
  const clean = normalizeLabel(label);

  const taken = listProfiles().items.find(
    (p) => p.name !== name && p.label.toLowerCase() === clean.toLowerCase()
  );
  if (taken) {
    throw err("ELABELTAKEN", `another profile is already called "${taken.label}"`);
  }

  writeJson(file, { ...stored, label: clean });
  return { ok: true, name, label: clean };
}

/**
 * Make a stored profile the live account.
 *
 * The outgoing account is snapshotted back into whichever profile it came from
 * first, so its refreshed tokens are not lost — and a switch away from an
 * account that was never saved is refused rather than silently discarding the
 * only copy of its credentials.
 *
 * @param name Profile to activate.
 * @returns `{ ok, name, savedOutgoing, written }`
 */
function activateProfile(name) {
  const target = readProfile(name);
  if (!target || !target.credentials) throw err("ENOTFOUND", `no profile named "${name}"`);

  const current = readActiveAuth();
  let savedOutgoing = null;
  if (current.oauth) {
    const mine = listProfiles().items.find((p) => p.active);
    if (!mine) {
      throw err(
        "EUNSAVED",
        "the account logged in right now is not saved as a profile - save it first, or its credentials are lost on switch"
      );
    }
    if (mine.name !== name) savedOutgoing = saveProfile(mine.name).name;
  }

  const written = [];
  const { creds: live, keychain } = readCredentials();
  const creds = live || {};
  // Only the Claude account slot moves; `mcpOAuth` holds this machine's MCP
  // server tokens, which are not part of the account identity.
  creds.claudeAiOauth = target.credentials;
  written.push(...writeCredentials(creds, keychain));

  for (const file of configPaths()) {
    const cfg = readJson(file);
    if (!cfg) continue;
    if (target.account) cfg.oauthAccount = target.account;
    else delete cfg.oauthAccount;
    if (target.userID) cfg.userID = target.userID;
    writeJson(file, cfg);
    written.push(file);
  }

  return { ok: true, name, savedOutgoing, written };
}

/**
 * Delete a stored profile.
 *
 * Refused only when it holds the LAST saved copy of the live account: that copy
 * is the credentials' only home outside the files a switch is about to
 * overwrite. A redundant copy of the live account is deletable, which is what
 * makes an accidental duplicate cleanable — with a blanket active-guard, two
 * profiles of one account would both be undeletable forever.
 */
function deleteProfile(name) {
  const file = profileFile(name);
  if (!readProfile(name)) throw err("ENOTFOUND", `no profile named "${name}"`);
  const items = listProfiles().items;
  const entry = items.find((p) => p.name === name);
  if (entry && entry.active) {
    const otherCopy = items.some((p) => p.name !== name && p.accountUuid === entry.accountUuid);
    if (!otherCopy) {
      throw err(
        "EACTIVE",
        "cannot delete the only saved copy of the account that is logged in right now - switch away first"
      );
    }
  }
  fs.rmSync(file, { force: true });
  return { ok: true, name };
}

/**
 * Overwrite a stored profile wholesale. The one caller is `cc-usage.js`, which
 * has to write a rotated OAuth token pair straight back: the exchange retires
 * the refresh token it was given, so a profile whose refreshed credentials are
 * not persisted is a profile that can no longer be activated.
 */
function writeProfile(name, value) {
  writeJson(profileFile(name), value);
  return { ok: true, name };
}

module.exports = {
  listProfiles,
  saveProfile,
  renameProfile,
  activateProfile,
  deleteProfile,
  // Token-bearing reads/writes: for cc-usage.js, never for a route.
  readProfile,
  writeProfile,
  liveCredentialsFor,
  readActiveAuth,
  // exported for tests
  profilesDir,
  configPaths,
};