#!/usr/bin/env node
/**
 * @file Claude Code statusline for AgentHub. Reads the statusline JSON Claude
 * Code pipes on stdin and prints ONE line: model · git branch · context-window
 * bar · this session's $ (Claude Code's own `cost.total_cost_usd`) · today's $
 * across every session (the dashboard's `GET /api/pricing/cost?tz_offset=`,
 * 1-second timeout, cached for 30 s in the OS temp dir, left out whenever the
 * dashboard is down). It never throws, never waits past ~2.5 s and always
 * exits 0 — a statusline is the last place to surface an error. Installed by
 * `agenthub statusline install`; see docs/STATUSLINE.md.
 * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
 */

const fs = require("node:fs");
const os = require("node:os");
const path = require("node:path");
const { execFileSync } = require("node:child_process");

const CACHE_TTL_MS = 30_000;
const COST_TIMEOUT_MS = 1_000;

const color = (code) => (s) => `\x1b[${code}m${s}\x1b[0m`;
const CYAN = color("36");
const GREEN = color("32");
const YELLOW = color("33");
const RED = color("31");
const MAGENTA = color("35");
const DIM = color("2");

/** Percent of the context window in use, or null when the payload has none. */
function contextPercent(ctx) {
  if (!ctx || typeof ctx !== "object") return null;
  if (Number.isFinite(ctx.used_percentage)) return ctx.used_percentage;
  const u = ctx.current_usage;
  if (!u || !(ctx.context_window_size > 0)) return null;
  const used =
    (u.input_tokens || 0) + (u.cache_creation_input_tokens || 0) + (u.cache_read_input_tokens || 0);
  return (used / ctx.context_window_size) * 100;
}

const money = (n) => `$${n.toFixed(2)}`;

/** The status line for one payload. `branch` and `today` are looked up by the caller. */
function format(input, { branch, today } = {}) {
  const parts = [];
  const model = input?.model?.display_name || input?.model?.id;
  if (model) parts.push(CYAN(model));
  if (branch) parts.push(MAGENTA(branch));
  const pct = contextPercent(input?.context_window);
  if (pct !== null) {
    const p = Math.max(0, Math.min(100, Math.round(pct)));
    const filled = Math.round(p / 10);
    const paint = p >= 80 ? RED : p >= 50 ? YELLOW : GREEN;
    parts.push(paint(`${"█".repeat(filled)}${"░".repeat(10 - filled)} ${p}%`));
  }
  const session = Number(input?.cost?.total_cost_usd);
  if (input?.cost?.total_cost_usd != null && Number.isFinite(session)) parts.push(money(session));
  if (Number.isFinite(today)) parts.push(DIM(`today ${money(today)}`));
  return parts.join(DIM(" · "));
}

/** Current branch (or short sha when detached) of `cwd`, or "" — 500 ms cap. */
function gitBranch(cwd) {
  if (!cwd) return "";
  const git = (args) =>
    execFileSync("git", ["--no-optional-locks", ...args], {
      cwd,
      timeout: 500,
      stdio: ["ignore", "pipe", "ignore"],
      windowsHide: true,
    })
      .toString()
      .trim();
  try {
    return git(["symbolic-ref", "--short", "HEAD"]);
  } catch {
    try {
      return git(["rev-parse", "--short", "HEAD"]);
    } catch {
      return "";
    }
  }
}

/** YYYY-MM-DD in local time — the key daily_costs uses for this tz_offset. */
function localDate(d = new Date()) {
  const p = (n) => String(n).padStart(2, "0");
  return `${d.getFullYear()}-${p(d.getMonth() + 1)}-${p(d.getDate())}`;
}

function cachePath() {
  const uid = typeof process.getuid === "function" ? process.getuid() : os.userInfo().username;
  return path.join(os.tmpdir(), `agenthub-statusline-${uid}.json`);
}

/**
 * Today's cost across all sessions from the dashboard, or null. A failed fetch
 * is cached too, so a stopped dashboard costs one timeout per TTL, not per line.
 */
async function todayCost({ url, file = cachePath(), now = Date.now() } = {}) {
  const date = localDate(new Date(now));
  try {
    const c = JSON.parse(fs.readFileSync(file, "utf8"));
    if (c.url === url && c.date === date && now - c.at < CACHE_TTL_MS) return c.today;
  } catch {
    /* no cache yet */
  }
  let today = null;
  try {
    const headers = process.env.DASHBOARD_TOKEN
      ? { Authorization: `Bearer ${process.env.DASHBOARD_TOKEN}` }
      : {};
    // Server mode: inside a dashboard pane, act as the workspace's owner.
    if (process.env.AGENTHUB_PANE_TOKEN)
      headers["x-agenthub-pane-token"] = process.env.AGENTHUB_PANE_TOKEN;
    const offset = new Date(now).getTimezoneOffset();
    const res = await fetch(`${url}/api/pricing/cost?tz_offset=${offset}`, {
      headers,
      signal: AbortSignal.timeout(COST_TIMEOUT_MS),
    });
    if (res.ok) {
      const data = await res.json();
      const row = (data.daily_costs || []).find((d) => d.date === date);
      today = Number(row?.cost ?? 0);
    }
  } catch {
    /* dashboard down or slow — omit */
  }
  try {
    fs.writeFileSync(file, JSON.stringify({ url, date, at: now, today }), { mode: 0o600 });
  } catch {
    /* read-only tmp — fine */
  }
  return today;
}

function dashboardUrl() {
  if (process.env.AGENTHUB_URL) return process.env.AGENTHUB_URL.replace(/\/+$/, "");
  return require(path.join(__dirname, "..", "server", "lib", "dashboard-url.js")).dashboardUrl();
}

/** Read stdin to EOF, or give up after `ms`. */
function readStdin(ms) {
  return new Promise((resolve) => {
    let buf = "";
    const done = () => resolve(buf);
    setTimeout(done, ms).unref();
    process.stdin.on("data", (d) => (buf += d));
    process.stdin.on("end", done);
    process.stdin.on("error", done);
  });
}

async function main() {
  // Hard cap: whatever happens, Claude Code gets its prompt back.
  setTimeout(() => process.exit(0), 2_500).unref();
  let line = "";
  try {
    const input = JSON.parse((await readStdin(1_000)) || "{}");
    const cwd = input?.workspace?.current_dir || input?.cwd;
    let today = null;
    try {
      today = await todayCost({ url: dashboardUrl() });
    } catch {
      /* omit */
    }
    line = format(input, { branch: gitBranch(cwd), today });
  } catch {
    /* bad payload — print nothing */
  }
  process.stdout.write(line + "\n", () => process.exit(0));
}

if (require.main === module) main();

module.exports = { main, format, contextPercent, gitBranch, todayCost, localDate };