import { END } from "@uncaged/nerve-core";
import type { Moderator } from "@uncaged/nerve-core";
import type { IntakeMeta } from "./roles/intake/index.js";
import type { IssueReaderMeta } from "./roles/issue-reader/index.js";
import type { PlannerMeta } from "./roles/planner/index.js";
import type { ImplementerMeta } from "./roles/implementer/index.js";
import type { ReviewerMeta } from "./roles/reviewer/index.js";
import type { TesterMeta } from "./roles/tester/index.js";
import type { PrPublisherMeta } from "./roles/pr-publisher/index.js";

export type WorkflowMeta = {
  intake: IntakeMeta;
  "issue-reader": IssueReaderMeta;
  planner: PlannerMeta;
  implementer: ImplementerMeta;
  reviewer: ReviewerMeta;
  tester: TesterMeta;
  "pr-publisher": PrPublisherMeta;
};

const MAX_IMPLEMENTER_SELF_ITERATIONS = 5;
const MAX_REVIEWER_REJECTIONS = 3;
const MAX_TESTER_REJECTIONS = 3;

function countRejections(steps: { role: string; meta: unknown }[], rejector: string, metaKey: string): number {
  return steps.filter((s) => s.role === rejector && !(s.meta as Record<string, boolean>)[metaKey]).length;
}

function countImplementerSelfIterations(steps: { role: string; meta: unknown }[]): number {
  return steps.filter((s) => s.role === "implementer" && !(s.meta as Record<string, boolean>).implementationOk).length;
}

export const moderator: Moderator<WorkflowMeta> = (context) => {
  if (context.steps.length === 0) {
    return "intake";
  }

  const last = context.steps[context.steps.length - 1];

  if (last.role === "intake") {
    const meta = last.meta as WorkflowMeta["intake"];
    return meta.valid ? "issue-reader" : END;
  }

  if (last.role === "issue-reader") {
    const meta = last.meta as WorkflowMeta["issue-reader"];
    return meta.fetchOk ? "planner" : END;
  }

  if (last.role === "planner") {
    const meta = last.meta as WorkflowMeta["planner"];
    return meta.planningOk ? "implementer" : END;
  }

  if (last.role === "implementer") {
    const meta = last.meta as WorkflowMeta["implementer"];
    if (meta.implementationOk) return "reviewer";
    return countImplementerSelfIterations(context.steps) < MAX_IMPLEMENTER_SELF_ITERATIONS ? "implementer" : END;
  }

  if (last.role === "reviewer") {
    if (last.meta.approved) return "tester";
    return countRejections(context.steps, "reviewer", "approved") < MAX_REVIEWER_REJECTIONS ? "implementer" : END;
  }

  if (last.role === "tester") {
    const meta = last.meta as WorkflowMeta["tester"];
    if (meta.passed) return "pr-publisher";
    return countRejections(context.steps, "tester", "passed") < MAX_TESTER_REJECTIONS ? "implementer" : END;
  }

  if (last.role === "pr-publisher") {
    return END;
  }

  return END;
};