import type { AgentFn, Role, RoleResult, StartStep, WorkflowMessage } from "@uncaged/nerve-core";
import type { LlmExtractorConfig } from "@uncaged/nerve-workflow-utils";
import { createRole } from "@uncaged/nerve-workflow-utils";
import { z } from "zod";

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

export const planMetaSchema = z.object({
  ready: z.boolean().describe("true if plan is clear and actionable"),
});
export type PlanMeta = z.infer<typeof planMetaSchema>;

export type CreatePlanRoleDeps = {
  extract: LlmExtractorConfig;
  nerveRoot: string;
};

export function createPlanRole(
  adapter: AgentFn,
  { extract, nerveRoot }: CreatePlanRoleDeps,
): Role<PlanMeta> {
  return async (start: StartStep, messages: WorkflowMessage[]): Promise<RoleResult<PlanMeta>> => {
    const cwd = resolveRepoCwd(messages);
    if (cwd === null) {
      return {
        content: "plan cannot run: missing ---SOLVE_ISSUE_REPO--- or ---SOLVE_ISSUE_PARSE--- in thread",
        meta: { ready: false },
      };
    }

    const innerRole = createRole(
      adapter,
      async (innerStart: StartStep) =>
        buildPlanPrompt({
          threadId: innerStart.meta.threadId,
          nerveRoot,
        }),
      planMetaSchema,
      extract,
    );

    const innerStart = {
      ...start,
      meta: { ...start.meta, workdir: cwd },
    } as StartStep;

    try {
      return await innerRole(innerStart, messages);
    } catch (e) {
      const msg = e instanceof Error ? e.message : String(e);
      return {
        content: `plan failed: ${msg}`,
        meta: { ready: false },
      };
    }
  };
}