import type { Role, StartStep, WorkflowMessage } from "@uncaged/nerve-core";
import type { LlmExtractorConfig } from "@uncaged/nerve-workflow-utils";
import { llmExtract, nerveCommandEnv, spawnSafe } from "@uncaged/nerve-workflow-utils";
import { z } from "zod";

import { resolveWorkdir } from "../lib/workdir.js";

import type { QuestionerMeta } from "./questioner.js";

export const answererMetaSchema = z.object({
  results: z.array(
    z.object({
      id: z.string(),
      found: z.boolean(),
      source: z.string(),
      note: z.string(),
    }),
  ),
  has_unanswered: z.boolean(),
});

export type AnswererMeta = z.infer<typeof answererMetaSchema>;

export type CreateAnswererRoleDeps = {
  extract: LlmExtractorConfig;
};

function lastQuestionerMeta(messages: WorkflowMessage[]): QuestionerMeta | undefined {
  for (let i = messages.length - 1; i >= 0; i--) {
    if (messages[i].role === "questioner") {
      return messages[i].meta as QuestionerMeta;
    }
  }
  return undefined;
}

export function createAnswererRole(deps: CreateAnswererRoleDeps): Role<AnswererMeta> {
  const { extract } = deps;

  return async (start: StartStep, messages: WorkflowMessage[]) => {
    const cwd = resolveWorkdir(start);
    const qm = lastQuestionerMeta(messages);
    if (!qm || qm.questions.length === 0) {
      return {
        content: "answerer: no questions from questioner; skipping CLI lookup.",
        meta: { results: [], has_unanswered: false },
      };
    }

    const blocks: string[] = [];
    for (const q of qm.questions) {
      if (start.meta.dryRun) {
        blocks.push(`### ${q.id}\n[dryRun] skipped nerve knowledge query\n`);
        continue;
      }
      const res = await spawnSafe(
        "nerve",
        ["knowledge", "query", q.question],
        {
          cwd,
          env: nerveCommandEnv(),
          timeoutMs: 120_000,
          dryRun: false,
          abortSignal: null,
        },
      );
      if (res.ok) {
        blocks.push(`### ${q.id} (${q.domain})\nQuestion: ${q.question}\n---\n${res.value.stdout}\n`);
      } else {
        const err = res.error;
        const detail =
          err.kind === "non_zero_exit"
            ? `exit ${err.exitCode}\n${err.stderr}`
            : err.kind === "timeout"
              ? `timeout\n${err.stderr}`
              : err.kind === "spawn_failed"
                ? err.message
                : "aborted";
        blocks.push(`### ${q.id}\nnerve knowledge query failed: ${detail}\n`);
      }
    }

    const bundle = [
      "You are the **answerer**. You MUST NOT read repository source code — only the CLI retrieval excerpts below.",
      "For each question id, decide whether the knowledge base already answers it.",
      "Set found=true only when the excerpt supports a confident answer; otherwise found=false.",
      "Set has_unanswered=true if any question remains unanswered by the knowledge base.",
      "",
      ...blocks,
    ].join("\n");

    const metaR = await llmExtract({
      text: bundle,
      schema: answererMetaSchema,
      provider: extract.provider,
      dryRun: start.meta.dryRun,
    });
    if (!metaR.ok) {
      throw new Error(`answerer llmExtract: ${JSON.stringify(metaR.error)}`);
    }

    return { content: bundle, meta: metaR.value };
  };
}