import type { Role, RoleResult, RoleSpec, StartStep, WorkflowMessage } from "@uncaged/nerve-core";
import { createCursorAdapter } from "@uncaged/nerve-adapter-cursor";
import type { LlmProvider } from "@uncaged/nerve-workflow-utils";
import { z } from "zod";

import { compileRoleSpec, zodMeta } from "../../../_shared/rfc003-compile.js";

import { resolveRepoCwd } from "../../lib/repo-context.js";
import { buildImplementPrompt } from "./prompt.js";

export const implementMetaSchema = z.object({
  done: z.boolean().describe("true when changes are complete and build passes this round"),
});
export type ImplementMeta = z.infer<typeof implementMetaSchema>;

export type BuildImplementDeps = {
  provider: LlmProvider;
  nerveRoot: string;
};

const CURSOR_TIMEOUT_MS = 300_000;

export function buildImplementRole({ provider, nerveRoot }: BuildImplementDeps): Role<ImplementMeta> {
  const innerSpec = {
    adapter: createCursorAdapter({
      type: "cursor",
      model: "auto",
      timeout: CURSOR_TIMEOUT_MS,
    }),
    prompt: async (start: StartStep) =>
      buildImplementPrompt({
        threadId: start.meta.threadId,
        nerveRoot,
      }),
    meta: zodMeta(implementMetaSchema),
  } satisfies RoleSpec<ImplementMeta>;

  return async (start: StartStep, messages: WorkflowMessage[]): Promise<RoleResult<ImplementMeta>> => {
    const cwd = resolveRepoCwd(messages);
    if (cwd === null) {
      return {
        content: "implement cannot run: missing repo path in thread markers",
        meta: { done: false },
      };
    }

    const run = compileRoleSpec(innerSpec, {
      provider,
      createContext: (s, m) => ({
        start: s,
        messages: m,
        workdir: cwd,
        signal: new AbortController().signal,
      }),
    });

    try {
      return await run(start, messages);
    } catch (e) {
      const msg = e instanceof Error ? e.message : String(e);
      return {
        content: `implement failed: ${msg}`,
        meta: { done: false },
      };
    }
  };
}