/**
 * Research analysis hooks — reads and mutates the
 * `analysis-and-research.md` file that backs each case's compose screen.
 *
 * Schema mirrors research_md.parse() in the FastAPI backend. Kept as
 * hand-typed interfaces because the endpoint does not declare a
 * response_model in the OpenAPI schema.
 */

import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
import { apiRequest } from "./client";

export type ResearchField = {
  label: string;
  content: string;
};

export type ResearchSubsection = {
  id: string; // e.g. "threshold_1" or "issue_3"
  number: string;
  title: string;
  fields: ResearchField[];
  chair_position?: string;
};

export type ResearchAnalysis = {
  header?: {
    date?: string;
    modified_at?: string;
    [k: string]: unknown;
  };
  represented_party?: string;
  procedural_background?: string;
  agreed_facts?: string;
  disputed_facts?: string;
  threshold_claims?: ResearchSubsection[];
  issues?: ResearchSubsection[];
  conclusions?: string;
  other_sections?: Array<{ title: string; body: string }>;
};

export const researchKeys = {
  all: ["research"] as const,
  analysis: (caseNumber: string) =>
    [...researchKeys.all, "analysis", caseNumber] as const,
};

export function useResearchAnalysis(caseNumber: string | undefined) {
  return useQuery({
    queryKey: researchKeys.analysis(caseNumber ?? ""),
    queryFn: ({ signal }) =>
      apiRequest<ResearchAnalysis>(
        `/api/cases/${caseNumber}/research/analysis`,
        { signal },
      ),
    enabled: Boolean(caseNumber),
    /* No polling — the user is editing; refetching would clobber focus */
    staleTime: 60_000,
  });
}

export function useSaveChairPosition(caseNumber: string | undefined) {
  const qc = useQueryClient();
  return useMutation({
    mutationFn: async (vars: { sectionId: string; position: string }) =>
      apiRequest<unknown>(
        `/api/cases/${caseNumber}/research/analysis/chair-position`,
        {
          method: "PATCH",
          body: { section_id: vars.sectionId, position: vars.position },
        },
      ),
    onSuccess: (_res, vars) => {
      /* Locally patch the cached analysis so other consumers stay in sync
         without an immediate refetch that would steal focus from the editor. */
      qc.setQueryData<ResearchAnalysis | undefined>(
        researchKeys.analysis(caseNumber ?? ""),
        (prev) => {
          if (!prev) return prev;
          const patch = (arr?: ResearchSubsection[]) =>
            arr?.map((s) =>
              s.id === vars.sectionId
                ? { ...s, chair_position: vars.position }
                : s,
            );
          return {
            ...prev,
            threshold_claims: patch(prev.threshold_claims),
            issues: patch(prev.issues),
          };
        },
      );
    },
  });
}