import type { JsonValue } from "@berry/api";
import { code, type ToolRenderer, type ToolView } from "@berry/api/web.ts";
import * as j from "@char/justin";
import { ansiOutput } from "./ansi-view.ts";

const argsOf = j.validation.compile(
  j.obj({ command: j.optional(j.string), timeout: j.optional(j.number) }),
);
const outputOf = j.validation.compile(j.obj({ output: j.string }));
const rawOutputOf = j.validation.compile(j.obj({ rawOutput: j.string }));
const exitCodeOf = j.validation.compile(j.obj({ exitCode: j.number }));

export function bashView(language = "bash"): ToolView {
  const prompt = <div class="command" />;
  const rendered = <pre hidden /> as HTMLPreElement;
  const showOutput = ansiOutput(rendered);
  const exit = <span class="exit" hidden /> as HTMLSpanElement;
  let shown: { command: string; streaming: boolean } | null = null;
  return {
    element: (
      <div class="tool-body">
        {prompt}
        {rendered}
        {exit}
      </div>
    ),
    update(call) {
      const args = argsOf(call.args).value;
      const command = args?.command ?? "";
      const streaming = call.status === "streaming";
      // highlighted once the model has written all of it
      if (command !== shown?.command || streaming !== shown.streaming) {
        prompt.replaceChildren(
          code(command, {
            ...(streaming ? {} : { language }),
            gutter: (i) => (i === 0 ? "$" : ""),
          }),
        );
      }
      // a direct call's result is the text the model saw, which carries the exit code itself
      const result = call.result;
      const output = (typeof result === "string" ? result : outputOf(result).value?.output) ??
        rawOutputOf(call.details).value?.rawOutput ?? call.output ?? call.error ?? "";
      showOutput(output);
      shown = { command, streaming };
      const exitCode = exitCodeOf(result).value?.exitCode;
      exit.textContent = exitCode === undefined || exitCode === 0 ? "" : `exit ${exitCode}`;
      exit.hidden = exit.textContent === "";
    },
  };
}

/** The exit code a call ended with: in a script's result, or at the end of the text a direct call's model saw. */
function exitCode(result: JsonValue | null): number | null {
  if (typeof result === "string") {
    const code = result.match(/\[exit code (-?\d+)(?:;[^\]]*)?\]\s*$/)?.[1];
    return code === undefined ? null : Number(code);
  }
  return exitCodeOf(result).value?.exitCode ?? null;
}

export const bashRenderer: ToolRenderer = {
  summary: (args) => argsOf(args).value?.command?.split("\n")[0] ?? null,
  timeout: (args) => argsOf(args).value?.timeout ?? null,
  outcome: (call) => {
    const code = exitCode(call.result);
    return code === null || code === 0 ? null : `exit ${code}`;
  },
  body: () => bashView(),
};

export const powershellRenderer: ToolRenderer = {
  ...bashRenderer,
  body: () => bashView("powershell"),
};