// lib/himalaya.ts
// SERVER-ONLY resolver for the himalaya executable.
//
// Why this exists: the send routes used to spawn a hardcoded macOS path
// (/opt/homebrew/bin/himalaya) and then a bare "himalaya". Both fail on
// Windows — the first because that path doesn't exist, the second because
// a Next.js dev server captures process.env.PATH at STARTUP, so a
// PATH entry added later (e.g. by [Environment]::SetEnvironmentVariable)
// is invisible until the server is restarted. That produced
// `Error: spawn himalaya ENOENT` while the UI still reported success.
//
// Resolution order:
//   1. HIMALAYA_BIN  — explicit override, wins if set
//   2. known install locations under the user's home dir
//   3. bare "himalaya" — last resort, relies on PATH
//
// Because 1 and 2 are pure filesystem/host checks evaluated at call time,
// this works in an already-running dev server with no restart.
import "server-only";
import { existsSync } from "fs";
import { join } from "path";
import { homedir, platform } from "os";

function resolve(): string {
  const override = process.env.HIMALAYA_BIN?.trim();
  if (override) return override;

  if (platform() === "win32") {
    const base = join(homedir(), ".local", "bin");
    for (const candidate of [join(base, "himalaya.exe"), join(base, "himalaya")]) {
      if (existsSync(candidate)) return candidate;
    }
  }

  return "himalaya";
}

/** Absolute path (or bare name) to the himalaya binary. */
export const HIMALAYA_BIN: string = resolve();

/** Standard argument vector for sending a raw RFC 5322 message on stdin.
 *
 *  v1.x syntax: `-a/--account` is a per-subcommand option, NOT a global
 *  flag — `himalaya -a acct message send` errors with
 *  "unexpected argument '-a' found".
 *
 *  The message MUST be piped on stdin. Passing it as an argument panics
 *  the binary (mail-parser 0.9.4 index-out-of-bounds). */
export function himalayaSendArgs(account: string): string[] {
  return ["message", "send", "-a", account];
}