/**
 * ─────────────────────────────────────────────
 *  SPB Drive — Personal Cloud Drive
 * ─────────────────────────────────────────────
 *  Author  : Simon-Pierre Boucher
 *  Contact : contact@spboucher.ai
 *  File    : cli/lib.mjs
 *  Purpose : CLI shared helpers — config, API client, colors, progress bars
 *  License : MIT © Simon-Pierre Boucher
 * ─────────────────────────────────────────────
 */

import { existsSync, mkdirSync, readFileSync, writeFileSync, chmodSync } from 'node:fs';
import os from 'node:os';
import path from 'node:path';

export const CONFIG_DIR = path.join(os.homedir(), '.spbdrive');
export const CONFIG_FILE = path.join(CONFIG_DIR, 'config.json');

// Exit codes (spbgit conventions): 0 ok, 1 operation failed, 2 usage/config, 3 network/server.
export const EXIT = { OK: 0, FAIL: 1, USAGE: 2, NET: 3 };

const useColor = !process.env.NO_COLOR && process.stdout.isTTY;
const paint = (code) => (s) => (useColor ? `\x1b[${code}m${s}\x1b[0m` : String(s));
export const c = {
  bold: paint(1), dim: paint(2), red: paint(31), green: paint(32),
  yellow: paint(33), blue: paint(34), magenta: paint(35), cyan: paint(36),
};

export function fail(message, code = EXIT.FAIL) {
  console.error(c.red(`✗ ${message}`));
  process.exit(code);
}

export function loadConfig() {
  if (!existsSync(CONFIG_FILE)) {
    fail('Not configured. Run `spbdrive init` first.', EXIT.USAGE);
  }
  try {
    return JSON.parse(readFileSync(CONFIG_FILE, 'utf8'));
  } catch {
    fail(`Corrupt config at ${CONFIG_FILE}. Re-run \`spbdrive init\`.`, EXIT.USAGE);
    return null;
  }
}

export function saveConfig(cfg) {
  mkdirSync(CONFIG_DIR, { recursive: true, mode: 0o700 });
  writeFileSync(CONFIG_FILE, JSON.stringify(cfg, null, 2), { mode: 0o600 });
  chmodSync(CONFIG_FILE, 0o600);
}

/** Authenticated API request. Exits with EXIT.NET on connection failure. */
export async function req(cfg, apiPath, { method = 'GET', body, rawBody, stream = false } = {}) {
  const headers = { authorization: `Bearer ${cfg.token}` };
  let payload;
  if (rawBody !== undefined) {
    headers['content-type'] = 'application/octet-stream';
    payload = rawBody;
  } else if (body !== undefined) {
    headers['content-type'] = 'application/json';
    payload = JSON.stringify(body);
  }
  let res;
  try {
    res = await fetch(`${cfg.server}${apiPath}`, { method, headers, body: payload });
  } catch (err) {
    fail(`Cannot reach ${cfg.server}: ${err.cause?.code ?? err.message}`, EXIT.NET);
  }
  if (stream) return res;
  const data = res.headers.get('content-type')?.includes('json') ? await res.json() : null;
  if (!res.ok) {
    const msg = data?.error?.message ?? `HTTP ${res.status}`;
    fail(msg, res.status >= 500 ? EXIT.NET : EXIT.FAIL);
  }
  return data;
}

export function fmtSize(bytes) {
  const n = Number(bytes ?? 0);
  if (n < 1024) return `${n} B`;
  const units = ['KB', 'MB', 'GB', 'TB'];
  let v = n / 1024; let i = 0;
  while (v >= 1024 && i < units.length - 1) { v /= 1024; i += 1; }
  return `${v.toFixed(v >= 100 ? 0 : 1)} ${units[i]}`;
}

/** Simple single-line progress bar. */
export function progressBar(label, total) {
  let last = 0;
  const width = 26;
  return {
    update(done) {
      if (!process.stdout.isTTY) return;
      const now = Date.now();
      if (now - last < 80 && done < total) return;
      last = now;
      const ratio = total ? Math.min(done / total, 1) : 1;
      const filled = Math.round(ratio * width);
      const bar = '█'.repeat(filled) + '░'.repeat(width - filled);
      process.stdout.write(`\r  ${bar} ${String(Math.round(ratio * 100)).padStart(3)}%  ${label.slice(0, 40)}`);
    },
    done() {
      if (process.stdout.isTTY) process.stdout.write('\n');
    },
  };
}

/** Resolve a remote path → node via the API (exits if missing). */
export async function resolveRemote(cfg, remotePath, { optional = false } = {}) {
  const clean = `/${String(remotePath ?? '/').replace(/^\/+|\/+$/g, '')}`;
  try {
    const { node } = await req(cfg, `/api/v1/resolve?path=${encodeURIComponent(clean)}`);
    return node;
  } catch {
    if (optional) return null;
    throw new Error(`Remote path not found: ${clean}`);
  }
}

/** Ensure a remote folder path exists, creating segments as needed. */
export async function ensureRemoteDir(cfg, remotePath) {
  const parts = String(remotePath ?? '/').split('/').filter(Boolean);
  let { node } = await req(cfg, '/api/v1/resolve?path=%2F');
  for (const part of parts) {
    const { node: created } = await req(cfg, '/api/v1/nodes', {
      method: 'POST',
      body: { parentId: node.id, name: part, type: 'folder' },
    });
    node = created;
  }
  return node;
}