import { describe, it, expect, beforeEach, vi } from "vitest";
import type { MessageCategory } from "../../src/shared/types.js";
import { ALL_CATEGORIES, DEFAULT_HIDDEN_CATEGORIES } from "../../src/shared/types.js";

// Test the localStorage persistence logic used by useFilters
const STORAGE_KEY_CATEGORIES = "session-viewer:enabledCategories";
const STORAGE_KEY_AUTOREDACT = "session-viewer:autoRedact";

function loadEnabledCategories(): Set<MessageCategory> {
  try {
    const stored = localStorage.getItem(STORAGE_KEY_CATEGORIES);
    if (stored) {
      const arr = JSON.parse(stored) as string[];
      const valid = arr.filter((c) =>
        ALL_CATEGORIES.includes(c as MessageCategory)
      ) as MessageCategory[];
      if (valid.length > 0) return new Set(valid);
    }
  } catch {
    // Fall through to default
  }
  const set = new Set(ALL_CATEGORIES);
  for (const cat of DEFAULT_HIDDEN_CATEGORIES) {
    set.delete(cat);
  }
  return set;
}

function loadAutoRedact(): boolean {
  try {
    const stored = localStorage.getItem(STORAGE_KEY_AUTOREDACT);
    if (stored !== null) return stored === "true";
  } catch {
    // Fall through to default
  }
  return false;
}

// Mock localStorage
const store: Record<string, string> = {};
const localStorageMock = {
  getItem: vi.fn((key: string) => store[key] ?? null),
  setItem: vi.fn((key: string, value: string) => { store[key] = value; }),
  removeItem: vi.fn((key: string) => { delete store[key]; }),
  clear: vi.fn(() => { for (const key in store) delete store[key]; }),
  get length() { return Object.keys(store).length; },
  key: vi.fn((i: number) => Object.keys(store)[i] ?? null),
};

Object.defineProperty(globalThis, "localStorage", { value: localStorageMock });

describe("filter persistence", () => {
  beforeEach(() => {
    localStorageMock.clear();
    vi.clearAllMocks();
  });

  describe("loadEnabledCategories", () => {
    it("returns default categories when localStorage is empty", () => {
      const result = loadEnabledCategories();
      const expected = new Set(ALL_CATEGORIES);
      for (const cat of DEFAULT_HIDDEN_CATEGORIES) {
        expected.delete(cat);
      }
      expect(result).toEqual(expected);
    });

    it("restores categories from localStorage", () => {
      const saved: MessageCategory[] = ["user_message", "assistant_text"];
      store[STORAGE_KEY_CATEGORIES] = JSON.stringify(saved);

      const result = loadEnabledCategories();
      expect(result).toEqual(new Set(saved));
    });

    it("filters out invalid category values from localStorage", () => {
      const saved = ["user_message", "invalid_category", "thinking"];
      store[STORAGE_KEY_CATEGORIES] = JSON.stringify(saved);

      const result = loadEnabledCategories();
      expect(result.has("user_message")).toBe(true);
      expect(result.has("thinking")).toBe(true);
      expect(result.size).toBe(2);
    });

    it("falls back to defaults on corrupted localStorage data", () => {
      store[STORAGE_KEY_CATEGORIES] = "not valid json";

      const result = loadEnabledCategories();
      const expected = new Set(ALL_CATEGORIES);
      for (const cat of DEFAULT_HIDDEN_CATEGORIES) {
        expected.delete(cat);
      }
      expect(result).toEqual(expected);
    });

    it("falls back to defaults when stored array is all invalid", () => {
      store[STORAGE_KEY_CATEGORIES] = JSON.stringify(["fake1", "fake2"]);

      const result = loadEnabledCategories();
      const expected = new Set(ALL_CATEGORIES);
      for (const cat of DEFAULT_HIDDEN_CATEGORIES) {
        expected.delete(cat);
      }
      expect(result).toEqual(expected);
    });
  });

  describe("loadAutoRedact", () => {
    it("returns false when localStorage is empty", () => {
      expect(loadAutoRedact()).toBe(false);
    });

    it("returns true when stored as 'true'", () => {
      store[STORAGE_KEY_AUTOREDACT] = "true";
      expect(loadAutoRedact()).toBe(true);
    });

    it("returns false when stored as 'false'", () => {
      store[STORAGE_KEY_AUTOREDACT] = "false";
      expect(loadAutoRedact()).toBe(false);
    });

    it("returns false for any non-'true' string", () => {
      store[STORAGE_KEY_AUTOREDACT] = "yes";
      expect(loadAutoRedact()).toBe(false);
    });
  });
});