import type {
  AdapterContext,
  BrowserActKind,
  BrowserActStep,
  BrowserProvider,
  ComputerRef,
} from "@rakazo/adapter-kit";

const MAX_BROWSER_ACTIONS = 24;

export async function browserNavigateFromTool(
  browser: BrowserProvider,
  computer: ComputerRef,
  context: AdapterContext,
  args: Record<string, unknown>,
) {
  const url = String(args.url ?? "").trim();
  try {
    const parsed = new URL(url);
    if (!/^https?:$/.test(parsed.protocol) || parsed.username || parsed.password) {
      return {
        error: "An HTTP(S) URL without embedded credentials is required",
        fallback: "computer_act" as const,
      };
    }
    const result = await browser.navigate(computer, { url, signal: context.signal }, context);
    return formatBrowserResult(result);
  } catch (error) {
    context.signal.throwIfAborted();
    return {
      error: error instanceof Error ? error.message : String(error),
      fallback: "computer_act" as const,
    };
  }
}

export async function browserSnapshotFromTool(
  browser: BrowserProvider,
  computer: ComputerRef,
  context: AdapterContext,
  args: Record<string, unknown>,
) {
  void args;
  try {
    const result = await browser.snapshot(computer, { signal: context.signal }, context);
    return formatBrowserResult(result);
  } catch (error) {
    context.signal.throwIfAborted();
    return {
      error: error instanceof Error ? error.message : String(error),
      fallback: "computer_act" as const,
    };
  }
}

export async function browserActFromTool(
  browser: BrowserProvider,
  computer: ComputerRef,
  context: AdapterContext,
  args: Record<string, unknown>,
) {
  try {
    const actions = parseBrowserActions(args.actions);
    const result = await browser.act(computer, { actions, signal: context.signal }, context);
    return formatBrowserResult(result);
  } catch (error) {
    context.signal.throwIfAborted();
    return {
      ok: false,
      uncertain: true,
      error: error instanceof Error ? error.message : String(error),
      fallback: "computer_act" as const,
    };
  }
}

export function parseBrowserActions(value: unknown): BrowserActStep[] {
  if (!Array.isArray(value) || value.length === 0) {
    throw new Error("browser_act requires at least one action");
  }
  if (value.length > MAX_BROWSER_ACTIONS) {
    throw new Error(`browser_act accepts at most ${MAX_BROWSER_ACTIONS} actions`);
  }
  return value.map((raw, index) => {
    if (!raw || typeof raw !== "object") {
      throw new Error(`browser_act action ${index} must be an object`);
    }
    const action = raw as Record<string, unknown>;
    const kind = String(action.kind ?? "") as BrowserActKind;
    if (kind !== "click" && kind !== "fill" && kind !== "type") {
      throw new Error(`browser_act action ${index} has unsupported kind`);
    }
    const ref = String(action.ref ?? "").trim();
    if (!ref) throw new Error(`browser_act action ${index} requires ref`);
    if (kind === "fill" || kind === "type") {
      if (typeof action.text !== "string") {
        throw new Error(`browser_act ${kind} requires text`);
      }
      return { kind, ref, text: String(action.text) };
    }
    return { kind, ref };
  });
}

function formatBrowserResult<T extends { fallback?: "computer_act"; error?: string }>(result: T) {
  if (result.fallback === "computer_act") {
    return {
      ...result,
      note: "Page browser could not complete this step. Inspect the current state before continuing with computer_act if available, otherwise request_takeover. Do not replay completed or uncertain actions.",
    };
  }
  return result;
}