import { createContext, useContext, useState, type ReactNode } from "react";

// Exported to silence @typescript-eslint/no-unused-vars v8 warning
// (used for type extraction via typeof, which is a legitimate pattern)
export const DATASET_RUN_FIELDS = [
  "output",
  "scores",
  "resourceMetrics",
] as const;
export type DatasetRunField = (typeof DATASET_RUN_FIELDS)[number];

interface DatasetCompareFieldsContextValue {
  selectedFields: DatasetRunField[];
  setSelectedFields: (fields: DatasetRunField[]) => void;
  toggleField: (field: DatasetRunField) => void;
  isFieldSelected: (field: DatasetRunField) => boolean;
}

const DatasetCompareFieldsContext = createContext<
  DatasetCompareFieldsContextValue | undefined
>(undefined);

interface DatasetCompareFieldsProviderProps {
  children: ReactNode;
  defaultFields?: DatasetRunField[];
}

export function DatasetCompareFieldsProvider({
  children,
  defaultFields = ["output", "scores", "resourceMetrics"],
}: DatasetCompareFieldsProviderProps) {
  const [selectedFields, setSelectedFields] =
    useState<DatasetRunField[]>(defaultFields);

  const toggleField = (field: DatasetRunField) => {
    setSelectedFields((prev) =>
      prev.includes(field) ? prev.filter((f) => f !== field) : [...prev, field],
    );
  };

  const isFieldSelected = (field: DatasetRunField) => {
    return selectedFields.includes(field);
  };

  return (
    <DatasetCompareFieldsContext.Provider
      value={{
        selectedFields,
        setSelectedFields,
        toggleField,
        isFieldSelected,
      }}
    >
      {children}
    </DatasetCompareFieldsContext.Provider>
  );
}

export function useDatasetCompareFields() {
  const context = useContext(DatasetCompareFieldsContext);
  if (context === undefined) {
    throw new Error(
      "useDatasetCompareFields must be used within a DatasetCompareFieldsProvider",
    );
  }
  return context;
}