import { derived, writable } from "svelte/store";

const KNOWN_SCOPES = new Set(["files", "movies", "tv"]);

const initialState = {
  scope: "files",
  terms: {
    files: "",
    movies: "",
    tv: ""
  }
};

export const searchState = writable(initialState);

export const activeScope = derived(searchState, ($state) => $state.scope);

export const activeSearchTerm = derived(
  searchState,
  ($state) => $state.terms[$state.scope] || ""
);

const PLACEHOLDERS = {
  files: "Dosya ara...",
  movies: "Film ara...",
  tv: "Dizi ara..."
};

export const activePlaceholder = derived(
  searchState,
  ($state) => PLACEHOLDERS[$state.scope] || "Ara..."
);

export function setSearchScope(scope) {
  const normalized = KNOWN_SCOPES.has(scope) ? scope : "files";
  searchState.update((state) => {
    const hasScope = Object.prototype.hasOwnProperty.call(state.terms, normalized);
    const terms = hasScope ? state.terms : { ...state.terms, [normalized]: "" };
    if (state.scope === normalized && terms === state.terms) {
      return state;
    }
    return {
      scope: normalized,
      terms
    };
  });
}

export function updateSearchTerm(term) {
  searchState.update((state) => {
    const scope = state.scope;
    const nextTerms = {
      ...state.terms,
      [scope]: term
    };
    if (nextTerms[scope] === state.terms[scope]) {
      return state;
    }
    return {
      scope,
      terms: nextTerms
    };
  });
}

export function clearSearch(scope) {
  searchState.update((state) => {
    const targetScope = scope && KNOWN_SCOPES.has(scope) ? scope : state.scope;
    if ((state.terms[targetScope] || "") === "") {
      return state;
    }
    return {
      scope: state.scope,
      terms: {
        ...state.terms,
        [targetScope]: ""
      }
    };
  });
}