import type {
  Role,
  RoleSpec,
  StartStep,
  WorkflowContext,
  WorkflowMessage,
} from "@uncaged/nerve-core";
import type { LlmProvider } from "@uncaged/nerve-workflow-utils";
import { extractMetaOrThrow, type ZodMetaSchema } from "@uncaged/nerve-workflow-utils";
import type { z } from "zod";

export function zodMeta<T>(zod: z.ZodType<T>): ZodMetaSchema<T> {
  return { witness: null, zod };
}

export type CompileRoleSpecDeps = {
  provider: LlmProvider;
  createContext: (start: StartStep, messages: WorkflowMessage[]) => WorkflowContext;
};

/**
 * RFC-003 RoleSpec → runtime Role (extract uses global nerve.yaml provider via `provider`;
 * dryRun follows each invocation's start frame).
 */
export function compileRoleSpec<M extends Record<string, unknown>>(
  spec: RoleSpec<M>,
  deps: CompileRoleSpecDeps,
): Role<M> {
  return async (start, messages) => {
    const ctx = deps.createContext(start, messages);
    const promptText =
      typeof spec.prompt === "string" ? spec.prompt : await spec.prompt(start, messages);
    const raw = await spec.adapter(promptText, ctx);
    const zod = (spec.meta as ZodMetaSchema<M>).zod;
    const meta = await extractMetaOrThrow(raw, zod, {
      provider: deps.provider,
      dryRun: start.meta.dryRun,
    });
    return { content: raw, meta };
  };
}

export function defaultAgentCreateContext(
  workdir: string,
): (start: StartStep, messages: WorkflowMessage[]) => WorkflowContext {
  return (start, messages) => ({
    start,
    messages,
    workdir,
    signal: new AbortController().signal,
  });
}