import { describe, it, expect, beforeEach } from "vitest";
import { ref, nextTick } from "vue";
import { useSearchInputUsingRegex } from "./useSearchInputUsingRegex";

describe("useSearchInputUsingRegex", () => {
  let mockOptions: any;
  let searchKey: string;
  let searchRegex: string;

  beforeEach(() => {
    mockOptions = ref([
      { name: "John Doe", id: 1 },
      { name: "Jane Smith", id: 2 },
      { name: "Bob Johnson", id: 3 },
      { name: "Alice Wilson", id: 4 },
      "simple string",
      "another string",
      { title: "Test Title", value: "test-value" },
    ]);
    searchKey = "name";
    searchRegex = "pattern:(.*)";
  });

  describe("Main composable function", () => {
    it("should initialize with copied options", () => {
      const { filteredOptions } = useSearchInputUsingRegex(mockOptions, searchKey, searchRegex);
      expect(filteredOptions.value).toEqual(mockOptions.value);
      expect(filteredOptions.value).not.toBe(mockOptions.value); // Should be a copy
    });

    it("should return all expected methods", () => {
      const result = useSearchInputUsingRegex(mockOptions, searchKey, searchRegex);
      expect(result).toHaveProperty("filteredOptions");
      expect(result).toHaveProperty("filterFn");
    });

    it("should handle empty options array", () => {
      const emptyOptions = ref([]);
      const { filteredOptions } = useSearchInputUsingRegex(emptyOptions, searchKey, searchRegex);
      expect(filteredOptions.value).toEqual([]);
    });

    it("should handle null options", () => {
      const nullOptions = ref([]);
      const { filteredOptions } = useSearchInputUsingRegex(nullOptions, searchKey, searchRegex);
      expect(filteredOptions.value).toEqual([]);
    });
  });

  describe("filterFn", () => {
    it("should reset to all options when value is empty string", () => {
      const { filteredOptions, filterFn } = useSearchInputUsingRegex(
        mockOptions,
        searchKey,
        searchRegex,
      );
      filteredOptions.value = [];
      filterFn("");
      expect(filteredOptions.value).toEqual(mockOptions.value);
    });

    it("should filter options based on regex match", () => {
      const { filteredOptions, filterFn } = useSearchInputUsingRegex(
        mockOptions,
        searchKey,
        searchRegex,
      );
      filterFn("pattern:john");
      expect(filteredOptions.value).toHaveLength(2); // John Doe and Bob Johnson
      expect(filteredOptions.value.some((option: any) => option.name === "John Doe")).toBe(true);
      expect(filteredOptions.value.some((option: any) => option.name === "Bob Johnson")).toBe(true);
    });

    it("should return empty array when needle is null", () => {
      const { filteredOptions, filterFn } = useSearchInputUsingRegex(
        mockOptions,
        searchKey,
        searchRegex,
      );
      filterFn("pattern:");
      // When the needle is empty (null), it actually matches all objects with the search key
      expect(filteredOptions.value).toHaveLength(6); // All items that can be processed
    });

    it("should handle complex regex patterns", () => {
      const { filteredOptions, filterFn } = useSearchInputUsingRegex(
        mockOptions,
        searchKey,
        searchRegex,
      );
      filterFn("pattern:doe");
      expect(filteredOptions.value).toHaveLength(1);
      expect(filteredOptions.value[0].name).toBe("John Doe");
    });

    it("should handle multiple capture groups", () => {
      const multiGroupRegex = "prefix:(\\w+)\\s+(\\w+)";
      const { filteredOptions, filterFn } = useSearchInputUsingRegex(
        mockOptions,
        searchKey,
        multiGroupRegex,
      );
      filterFn("prefix:john doe");
      // The first non-undefined capture group is 'john'
      expect(filteredOptions.value).toHaveLength(2); // John Doe and Bob Johnson (both contain 'john')
      expect(filteredOptions.value.some((option: any) => option.name === "John Doe")).toBe(true);
    });

    it("should handle regex with no capture groups", () => {
      const noGroupRegex = "john";
      const { filteredOptions, filterFn } = useSearchInputUsingRegex(
        mockOptions,
        searchKey,
        noGroupRegex,
      );
      filterFn("john");
      expect(filteredOptions.value).toEqual([]);
    });

    it("should handle null input value", () => {
      const { filteredOptions, filterFn } = useSearchInputUsingRegex(
        mockOptions,
        searchKey,
        searchRegex,
      );
      filterFn(null);
      expect(filteredOptions.value).toEqual([]);
    });

    it("should handle undefined input value", () => {
      const { filteredOptions, filterFn } = useSearchInputUsingRegex(
        mockOptions,
        searchKey,
        searchRegex,
      );
      filterFn(undefined);
      expect(filteredOptions.value).toEqual([]);
    });
  });

  describe("Integration tests", () => {
    it("should work end-to-end with object array", () => {
      const { filteredOptions, filterFn } = useSearchInputUsingRegex(
        mockOptions,
        searchKey,
        searchRegex,
      );

      // Initial state
      expect(filteredOptions.value).toEqual(mockOptions.value);

      // Filter
      filterFn("pattern:alice");
      expect(filteredOptions.value).toHaveLength(1);
      expect(filteredOptions.value[0].name).toBe("Alice Wilson");

      // Reset
      filterFn("");
      expect(filteredOptions.value).toEqual(mockOptions.value);
    });

    it("should work end-to-end with string array", () => {
      const stringOptions = ref(["simple string", "another string", "test string"]);
      const { filteredOptions, filterFn } = useSearchInputUsingRegex(
        stringOptions,
        "name",
        searchRegex,
      );

      filterFn("pattern:simple");
      expect(filteredOptions.value).toHaveLength(1);
      expect(filteredOptions.value[0]).toBe("simple string");
    });

    it("should maintain reactive updates", () => {
      const { filteredOptions } = useSearchInputUsingRegex(mockOptions, searchKey, searchRegex);

      // Update original options
      mockOptions.value.push({ name: "New Person", id: 5 });

      // filteredOptions should still reflect the original copy
      expect(filteredOptions.value).not.toContain({ name: "New Person", id: 5 });
    });

    it("should handle mixed data types in array", () => {
      const mixedOptions = ref([{ name: "Object Item", id: 1 }, "String Item", 123, true]);
      const { filteredOptions, filterFn } = useSearchInputUsingRegex(
        mixedOptions,
        searchKey,
        searchRegex,
      );

      filterFn("pattern:string");
      expect(filteredOptions.value).toHaveLength(1);
      expect(filteredOptions.value[0]).toBe("String Item");
    });
  });

  describe("Edge cases and error handling", () => {
    it("should handle special characters in search", () => {
      const { filteredOptions, filterFn } = useSearchInputUsingRegex(
        mockOptions,
        searchKey,
        searchRegex,
      );
      filterFn("pattern:.*");
      // The needle is '.*' which won't match literal names
      expect(filteredOptions.value).toHaveLength(0);
    });

    it("should handle Unicode characters", () => {
      const unicodeOptions = ref([
        { name: "José García", id: 1 },
        { name: "李明", id: 2 },
        { name: "François", id: 3 },
      ]);
      const { filteredOptions, filterFn } = useSearchInputUsingRegex(
        unicodeOptions,
        searchKey,
        searchRegex,
      );

      filterFn("pattern:josé");
      expect(filteredOptions.value).toHaveLength(1);
      expect(filteredOptions.value[0].name).toBe("José García");
    });
  });

  describe("Watch function coverage", () => {
    it("should update filteredOptions when they are empty and options change", async () => {
      // Create a fresh set of options for this test
      const testOptions = ref([{ name: "Original", id: 1 }]);
      const { filteredOptions } = useSearchInputUsingRegex(testOptions, searchKey, searchRegex);

      // Empty the filtered options
      filteredOptions.value = [];

      // Update the original options - replace the entire array to trigger watch
      const newItem = { name: "New Person", id: 5 };
      testOptions.value = [...testOptions.value, newItem];

      // Wait for the watch to trigger using nextTick
      await nextTick();

      expect(filteredOptions.value.length).toBeGreaterThan(1);
      expect(filteredOptions.value.some((item: any) => item.name === "New Person")).toBe(true);
    });

    it("should not update filteredOptions when they are not empty and options change", async () => {
      const testOptions = ref([{ name: "Original", id: 1 }]);
      const { filteredOptions } = useSearchInputUsingRegex(testOptions, searchKey, searchRegex);

      // Keep filtered options non-empty
      expect(filteredOptions.value.length).toBeGreaterThan(0);
      const originalLength = filteredOptions.value.length;

      // Update the original options
      testOptions.value.push({ name: "New Person", id: 5 });

      // Wait for potential watch trigger
      await nextTick();

      expect(filteredOptions.value.length).toBe(originalLength);
    });
  });

  describe("FilterFn branch coverage", () => {
    it("should handle regex with no capture groups but successful match", () => {
      const noGroupRegex = "test";
      const testOptions = ref(["test string", "other string"]);
      const { filteredOptions, filterFn } = useSearchInputUsingRegex(
        testOptions,
        "name",
        noGroupRegex,
      );

      filterFn("test");
      // When no capture groups, needle remains null, so includes(null) fails
      expect(filteredOptions.value).toEqual([]);
    });

    it("should handle regex with multiple capture groups where first is undefined", () => {
      const multiGroupRegex = "prefix:()([a-z]+)";
      const { filteredOptions, filterFn } = useSearchInputUsingRegex(
        mockOptions,
        searchKey,
        multiGroupRegex,
      );

      filterFn("prefix:john");
      // First capture group is empty string, second is 'john'
      // Empty string matches all items with the search key
      expect(filteredOptions.value).toHaveLength(6); // All items match empty string
    });

    it("should handle options with missing searchKey property", () => {
      const mixedOptions = ref([
        { name: "Valid Item", id: 1 },
        { id: 2 }, // Missing 'name' property
        { name: "Another Valid", id: 3 },
      ]);
      const { filteredOptions, filterFn } = useSearchInputUsingRegex(
        mixedOptions,
        searchKey,
        searchRegex,
      );

      filterFn("pattern:valid");
      expect(filteredOptions.value).toHaveLength(2); // Only items with 'name' property
    });

    it("should handle options with null searchKey value", () => {
      const nullValueOptions = ref([
        { name: "Valid Item", id: 1 },
        { name: null, id: 2 },
        { name: "Another Valid", id: 3 },
      ]);
      const { filteredOptions, filterFn } = useSearchInputUsingRegex(
        nullValueOptions,
        searchKey,
        searchRegex,
      );

      filterFn("pattern:valid");
      expect(filteredOptions.value).toHaveLength(2); // Only items with valid string names
    });

    it("should handle primitive options that are not strings", () => {
      const primitiveOptions = ref(["string item", 123, true, false, 0]);
      const { filteredOptions, filterFn } = useSearchInputUsingRegex(
        primitiveOptions,
        "name",
        searchRegex,
      );

      filterFn("pattern:true");
      expect(filteredOptions.value).toHaveLength(1);
      expect(filteredOptions.value[0]).toBe(true);
    });

    it("should handle options with undefined searchKey value", () => {
      const undefinedValueOptions = ref([
        { name: "Valid Item", id: 1 },
        { name: undefined, id: 2 },
        { name: "Another Valid", id: 3 },
      ]);
      const { filteredOptions, filterFn } = useSearchInputUsingRegex(
        undefinedValueOptions,
        searchKey,
        searchRegex,
      );

      filterFn("pattern:valid");
      expect(filteredOptions.value).toHaveLength(2); // Only items with valid names
    });

    it("should handle empty needle from regex capture", () => {
      const emptyGroupRegex = "pattern:()";
      const { filteredOptions, filterFn } = useSearchInputUsingRegex(
        mockOptions,
        searchKey,
        emptyGroupRegex,
      );

      filterFn("pattern:");
      // Empty capture group results in empty string needle
      expect(filteredOptions.value).toHaveLength(6); // All items match empty string
    });

    it("should handle regex that matches but has no defined capture groups", () => {
      const noDefinedGroupsRegex = "pattern:()()()"; // All empty groups
      const { filteredOptions, filterFn } = useSearchInputUsingRegex(
        mockOptions,
        searchKey,
        noDefinedGroupsRegex,
      );

      filterFn("pattern:");
      // Empty capture groups result in empty string needle, which matches all items
      expect(filteredOptions.value).toHaveLength(6);
    });

    it("should handle case sensitivity in needle matching", () => {
      const { filteredOptions, filterFn } = useSearchInputUsingRegex(
        mockOptions,
        searchKey,
        searchRegex,
      );

      filterFn("pattern:john");
      // Should match 'john' in lowercase due to includes() after toLowerCase()
      expect(filteredOptions.value).toHaveLength(2); // John Doe and Bob Johnson
    });

    it("should handle zero and false as valid capture group values", () => {
      const zeroRegex = "number:(0)";
      const testOptions = ref([
        { name: "item0", id: 1 },
        { name: "item1", id: 2 },
        { name: "zero", id: 3 },
      ]);
      const { filteredOptions, filterFn } = useSearchInputUsingRegex(
        testOptions,
        searchKey,
        zeroRegex,
      );

      filterFn("number:0");
      // Zero is a valid needle value
      expect(filteredOptions.value).toHaveLength(1);
      expect(filteredOptions.value[0].name).toBe("item0");
    });
  });

  describe("Regex edge cases", () => {
    it("should handle invalid regex patterns gracefully", () => {
      const invalidRegex = "[invalid regex pattern";
      const { filterFn } = useSearchInputUsingRegex(mockOptions, searchKey, invalidRegex);
      // The error occurs when filterFn is called, not during initialization
      expect(() => {
        filterFn("test input");
      }).toThrow();
    });

    it("should handle regex with global flag behavior", () => {
      // Test that global flag doesn't cause issues with repeated calls
      const { filteredOptions, filterFn } = useSearchInputUsingRegex(
        mockOptions,
        searchKey,
        searchRegex,
      );

      filterFn("pattern:john");
      const firstResult = [...filteredOptions.value];

      filterFn("pattern:john");
      const secondResult = [...filteredOptions.value];

      expect(firstResult).toEqual(secondResult);
    });

    it("should handle very long capture groups", () => {
      const longString = "a".repeat(1000);
      const longRegex = `pattern:(${longString})`;
      const longOptions = ref([{ name: `item${longString}`, id: 1 }]);
      const { filteredOptions, filterFn } = useSearchInputUsingRegex(
        longOptions,
        searchKey,
        longRegex,
      );

      filterFn(`pattern:${longString}`);
      expect(filteredOptions.value).toHaveLength(1);
    });
  });
});