/**
 * Decision-blocks domain hooks.
 *
 * The 12-block decision content lives in the `decision_blocks` table and was
 * previously only reachable via DOCX export. These hooks back the interactive
 * block viewer/editor on the case page:
 *   GET  /api/cases/{n}/decision-blocks          → all 12 blocks (empty included)
 *   PUT  /api/cases/{n}/decision-blocks/{block}  → save inline-edited content
 *
 * The endpoints aren't declared with response models on the FastAPI side, so
 * we maintain local types here (same convention as cases.ts).
 */

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

export type BlockStatus = "empty" | "draft" | "review" | "final";

export type DecisionBlock = {
  block_id: string;
  block_index: number;
  title: string;
  content: string;
  word_count: number;
  status: BlockStatus;
  generation_type: string;
  model_used: string;
  /** ISO timestamp; null when the block was never written */
  updated_at: string | null;
};

export type DecisionBlocksResponse = {
  case_number: string;
  has_decision: boolean;
  decision_id: string | null;
  active_draft_path: string | null;
  source_of_truth: "docx" | "blocks";
  blocks: DecisionBlock[];
};

export type SaveBlockResponse = {
  block: DecisionBlock;
  active_draft_warning: boolean;
};

export const decisionBlocksKeys = {
  all: ["decision-blocks"] as const,
  case: (caseNumber: string) =>
    [...decisionBlocksKeys.all, caseNumber] as const,
};

export function useDecisionBlocks(caseNumber: string) {
  return useQuery({
    queryKey: decisionBlocksKeys.case(caseNumber),
    queryFn: ({ signal }) =>
      apiRequest<DecisionBlocksResponse>(
        `/api/cases/${caseNumber}/decision-blocks`,
        { signal },
      ),
  });
}

export function useSaveBlock(caseNumber: string) {
  const qc = useQueryClient();
  return useMutation({
    mutationFn: ({ blockId, content }: { blockId: string; content: string }) =>
      apiRequest<SaveBlockResponse>(
        `/api/cases/${caseNumber}/decision-blocks/${blockId}`,
        { method: "PUT", body: { content } },
      ),
    onSuccess: () => {
      qc.invalidateQueries({ queryKey: decisionBlocksKeys.case(caseNumber) });
    },
  });
}