// A model for working on berry itself without spending tokens.

import type { MutableModels } from "@earendil-works/pi-ai";
import {
  fauxAssistantMessage,
  type FauxResponseFactory,
  fauxText,
  fauxThinking,
  fauxToolCall,
} from "@earendil-works/pi-ai/providers/faux";
import { fauxProvider } from "@earendil-works/pi-ai/providers/faux";

/**
 * `dev/echo` echoes, thinks a little, and runs a message of the form `js <code>` as a codemode script. Its thinking
 * about a message of the form `quiet <text>` is empty, as encrypted reasoning is.
 */
export function installDevModel(models: MutableModels) {
  const faux = fauxProvider({
    provider: "dev",
    models: [{ id: "echo", name: "dev echo", reasoning: true }],
    tokensPerSecond: 80,
  });
  const respond: FauxResponseFactory = (context) => {
    faux.appendResponses([respond]);
    // a section patch may follow the message being answered
    const last = context.messages.findLast((message) => message.role !== "system");
    if (last?.role === "toolResult") {
      return fauxAssistantMessage(
        `The script ${last.isError ? "failed" : "finished"}; its output is above.`,
      );
    }
    const text = last?.role !== "user"
      ? ""
      : typeof last.content === "string"
      ? last.content
      : last.content.flatMap((block) => (block.type === "text" ? [block.text] : [])).join("\n");
    if (text.startsWith("js ")) {
      return fauxAssistantMessage(
        [
          fauxThinking("Running that in codemode."),
          fauxToolCall("codemode", { code: text.slice(3) }),
        ],
        { stopReason: "toolUse" },
      );
    }
    return fauxAssistantMessage([
      fauxThinking(text.startsWith("quiet ") ? "" : `They wrote ${text.length} characters.`),
      fauxText(`You said:\n\n> ${text}\n\nTry \`js return await tools.bash({ command: "ls" })\`.`),
    ]);
  };
  faux.setResponses([respond]);
  models.setProvider(faux.provider);
}