import { notificationToDesktopText, type NotificationInput } from "./notify-protocol.ts";
import type { Runtime } from "./runtime.ts";
import { $which } from "./which.ts";

export function resolveWindowsNotifier(runtime: Runtime, preferredPath?: string): string | null {
  if (preferredPath) return preferredPath;
  return $which("powershell.exe", runtime);
}

function base64Utf16(value: string): string {
  return Buffer.from(value, "utf16le").toString("base64");
}

/**
 * The script is intentionally static apart from base64 data literals. Text is
 * inserted through DOM APIs rather than PowerShell/XML syntax.
 */
export function buildWindowsNotifyCommand(input: NotificationInput, powershellPath: string): string[] {
  const { title, body } = notificationToDesktopText(input);
  const title64 = base64Utf16(title);
  const body64 = base64Utf16(body);
  const script = [
    "$ErrorActionPreference='Stop';",
    `$t=[Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('${title64}'));`,
    `$b=[Text.Encoding]::Unicode.GetString([Convert]::FromBase64String('${body64}'));`,
    "try {",
    "Add-Type -AssemblyName System.Runtime.WindowsRuntime;",
    "[void][Windows.UI.Notifications.ToastNotificationManager,Windows.UI.Notifications,ContentType=WindowsRuntime];",
    "$xml=New-Object Windows.Data.Xml.Dom.XmlDocument;",
    "$toast=$xml.CreateElement('toast'); $visual=$xml.CreateElement('visual'); $binding=$xml.CreateElement('binding');",
    "$binding.SetAttribute('template','ToastText02');",
    "$line1=$xml.CreateElement('text'); $line1.InnerText=$t; $line2=$xml.CreateElement('text'); $line2.InnerText=$b;",
    "$null=$binding.AppendChild($line1); $null=$binding.AppendChild($line2); $null=$visual.AppendChild($binding); $null=$toast.AppendChild($visual);",
    "$notification=New-Object Windows.UI.Notifications.ToastNotification($xml);",
    "$notifier=[Windows.UI.Notifications.ToastNotificationManager]::CreateToastNotifier();",
    "$notifier.Show($notification);",
    "} catch { }",
  ].join("");
  return [powershellPath, "-NoProfile", "-NonInteractive", "-Command", script];
}

export function resolveWindowsDesktopCommand(input: NotificationInput, runtime: Runtime, preferredPath?: string): { command: string; args: string[] } | null {
  const path = resolveWindowsNotifier(runtime, preferredPath);
  if (!path) return null;
  const argv = buildWindowsNotifyCommand(input, path);
  return { command: argv[0]!, args: argv.slice(1) };
}

export function sendWindowsDesktopNotification(input: NotificationInput, runtime: Runtime, preferredPath?: string): boolean {
  const resolved = resolveWindowsDesktopCommand(input, runtime, preferredPath);
  if (!resolved) return false;
  runtime.spawnDetached(resolved.command, resolved.args);
  return true;
}