import type { ExtensionAPI } from "@earendil-works/pi-coding-agent";
import { Text } from "@earendil-works/pi-tui";

import { formatAnswers, normalizeQuestions } from "./normalize.ts";
import { AskUserParamsSchema } from "./schema.ts";
import { runRpcQuestions } from "./rpc.ts";
import type { AskUserResult, QuestionInput } from "./types.ts";
import { AskUserView } from "./view.ts";

function fallbackText(result: { content: Array<{ type: string; text?: string }> }): string {
  return result.content.find((item) => item.type === "text")?.text ?? "";
}

export function registerAskUserTool(pi: ExtensionAPI): void {
  pi.registerTool({
    name: "ask_user_question",
    label: "Ask User",
    description:
      "Ask the user one or more structured questions in an interactive UI when their input is genuinely needed to continue. Supports TUI and RPC clients, choices, free-form text, optional custom answers, and cancellation. Do not ask for information already stated by the user.",
    promptSnippet: "Use ask_user_question to pause and collect missing user decisions instead of guessing",
    parameters: AskUserParamsSchema,
    executionMode: "sequential",

    async execute(_toolCallId, params, signal, _onUpdate, ctx) {
      const questions = normalizeQuestions(params.questions as QuestionInput[]);
      if (!ctx.hasUI || (ctx.mode !== "tui" && ctx.mode !== "rpc")) {
        throw new Error("ask_user_question requires interactive TUI or RPC UI mode");
      }

      if (signal?.aborted) {
        const result: AskUserResult = { version: 1, cancelled: true, questions, answers: [] };
        return { content: [{ type: "text", text: "User interaction was cancelled" }], details: result };
      }

      const result = ctx.mode === "tui"
        ? await ctx.ui.custom<AskUserResult>((tui, theme, _keybindings, done) =>
          new AskUserView(tui, theme, questions, done, signal),
        )
        : await runRpcQuestions(ctx.ui, questions, signal);

      if (result.cancelled) {
        return {
          content: [{ type: "text", text: "User cancelled the questions" }],
          details: result,
        };
      }
      return {
        content: [{ type: "text", text: formatAnswers(result.answers) }],
        details: result,
      };
    },

    renderCall(args, theme) {
      const questions = Array.isArray(args.questions) ? args.questions as Array<{ id?: unknown; label?: unknown }> : [];
      const labels = questions
        .map((question) => typeof question.label === "string" ? question.label : typeof question.id === "string" ? question.id : "question")
        .join(", ");
      let text = theme.fg("toolTitle", theme.bold("ask user "));
      text += theme.fg("muted", `${questions.length} question${questions.length === 1 ? "" : "s"}`);
      if (labels) text += theme.fg("dim", ` (${labels})`);
      return new Text(text, 0, 0);
    },

    renderResult(result, _options, theme) {
      const details = result.details as AskUserResult | undefined;
      if (!details) return new Text(fallbackText(result), 0, 0);
      if (details.cancelled) return new Text(theme.fg("warning", "Cancelled"), 0, 0);
      const lines = details.answers.map((answer) => {
        const value = answer.skipped
          ? theme.fg("muted", "Skipped")
          : `${answer.custom || answer.type === "text" ? theme.fg("muted", "(wrote) ") : ""}${theme.fg("accent", answer.label)}`;
        return `${theme.fg("success", "✓ ")}${theme.fg("accent", answer.id)}: ${value}`;
      });
      return new Text(lines.join("\n"), 0, 0);
    },
  });
}