import * as fc from "fast-check";

/**
 * Basic property-based testing demonstration
 * This demonstrates the concept and validates that fast-check is working
 */

describe("Basic Property-Based Testing", () => {
  describe("WordPress ID Properties", () => {
    it("should validate that positive integers remain positive after processing", () => {
      fc.assert(
        fc.property(fc.integer({ min: 1, max: 999999 }), (id) => {
          // Property: WordPress IDs should always be positive integers
          expect(id).toBeGreaterThan(0);
          expect(Number.isInteger(id)).toBe(true);

          // Property: String conversion and back should preserve value
          const stringId = id.toString();
          const parsedId = parseInt(stringId, 10);
          expect(parsedId).toBe(id);
        }),
      );
    });

    it("should reject invalid ID values consistently", () => {
      fc.assert(
        fc.property(
          fc.oneof(
            fc.constant(0),
            fc.constant(-1),
            fc.constant(null),
            fc.constant(undefined),
            fc.constant("abc"),
            fc.constant(NaN),
          ),
          (invalidId) => {
            // Property: Invalid IDs should always fail validation
            const isInvalidId =
              invalidId === 0 ||
              invalidId === -1 ||
              invalidId === null ||
              invalidId === undefined ||
              typeof invalidId === "string" ||
              isNaN(invalidId);

            expect(isInvalidId).toBe(true);

            // Additional validation for numbers
            expect(typeof invalidId === "number" ? invalidId <= 0 || isNaN(invalidId) : true).toBe(true);
          },
        ),
      );
    });
  });

  describe("String Processing Properties", () => {
    it("should handle safe strings without modification", () => {
      fc.assert(
        fc.property(
          fc.string({ minLength: 1, maxLength: 100 }).filter((s) => !s.includes("<") && !s.includes(">")),
          (safeString) => {
            // Property: Safe strings should pass through unchanged
            expect(typeof safeString).toBe("string");
            expect(safeString.length).toBeGreaterThan(0);

            // Property: No dangerous content
            expect(safeString).not.toMatch(/<script/i);
            expect(safeString).not.toMatch(/javascript:/i);
          },
        ),
      );
    });

    it("should handle malicious strings by rejecting them", () => {
      fc.assert(
        fc.property(
          fc.constantFrom(
            '<script>alert("xss")</script>',
            "javascript:alert(1)",
            "../../etc/passwd",
            "'; DROP TABLE posts; --",
          ),
          (maliciousString) => {
            // Property: Malicious strings should be identifiable
            const hasDangerousContent =
              maliciousString.includes("<script") ||
              maliciousString.includes("javascript:") ||
              maliciousString.includes("../") ||
              maliciousString.includes("DROP TABLE");

            expect(hasDangerousContent).toBe(true);
          },
        ),
      );
    });
  });

  describe("WordPress Data Structure Properties", () => {
    it("should validate post-like objects maintain required fields", () => {
      fc.assert(
        fc.property(
          fc.record({
            id: fc.integer({ min: 1, max: 999999 }),
            title: fc.string({ minLength: 1, maxLength: 200 }),
            content: fc.string({ minLength: 0, maxLength: 10000 }),
            status: fc.constantFrom("publish", "draft", "private"),
            author: fc.integer({ min: 1, max: 999999 }),
          }),
          (postObject) => {
            // Property: Required fields should always be present and valid
            expect(postObject.id).toBeGreaterThan(0);
            expect(typeof postObject.title).toBe("string");
            expect(postObject.title.length).toBeGreaterThan(0);
            expect(typeof postObject.content).toBe("string");
            expect(["publish", "draft", "private"]).toContain(postObject.status);
            expect(postObject.author).toBeGreaterThan(0);
          },
        ),
      );
    });

    it("should validate user-like objects maintain email format", () => {
      fc.assert(
        fc.property(
          fc.record({
            id: fc.integer({ min: 1, max: 999999 }),
            username: fc
              .string({ minLength: 1, maxLength: 60 })
              .map((s) => s.replace(/[^a-zA-Z0-9._@-]/g, ""))
              .filter((s) => s.length > 0),
            email: fc.emailAddress(),
          }),
          (userObject) => {
            // Property: User objects should have valid structure
            expect(userObject.id).toBeGreaterThan(0);
            expect(typeof userObject.username).toBe("string");
            expect(userObject.username.length).toBeGreaterThan(0);
            expect(userObject.username.length).toBeLessThanOrEqual(60);

            // Property: Email should be valid format
            expect(typeof userObject.email).toBe("string");
            expect(userObject.email).toMatch(/^[^\s@]+@[^\s@]+\.[^\s@]+$/);
          },
        ),
      );
    });
  });

  describe("Array and Collection Properties", () => {
    it("should handle arrays of IDs consistently", () => {
      fc.assert(
        fc.property(fc.array(fc.integer({ min: 1, max: 999999 }), { maxLength: 10 }), (idArray) => {
          // Property: All elements should be valid IDs
          expect(Array.isArray(idArray)).toBe(true);

          idArray.forEach((id) => {
            expect(id).toBeGreaterThan(0);
            expect(Number.isInteger(id)).toBe(true);
          });

          // Property: Array operations should preserve validity
          const filtered = idArray.filter((id) => id > 0);
          expect(filtered).toHaveLength(idArray.length);
        }),
      );
    });

    it("should maintain uniqueness when required", () => {
      fc.assert(
        fc.property(
          fc.array(fc.integer({ min: 1, max: 100 }), {
            minLength: 5,
            maxLength: 10,
          }),
          (numbers) => {
            // Property: Deduplication should work correctly
            const unique = [...new Set(numbers)];
            expect(unique.length).toBeLessThanOrEqual(numbers.length);

            // Property: All unique elements should be from original array
            unique.forEach((num) => {
              expect(numbers).toContain(num);
            });
          },
        ),
      );
    });
  });

  describe("Query Parameter Properties", () => {
    it("should handle pagination parameters correctly", () => {
      fc.assert(
        fc.property(
          fc.record({
            page: fc.option(fc.integer({ min: 1, max: 100 })),
            per_page: fc.option(fc.integer({ min: 1, max: 100 })),
            offset: fc.option(fc.integer({ min: 0, max: 1000 })),
          }),
          (paginationParams) => {
            // Property: Pagination parameters should be valid when present
            const pageValid =
              paginationParams.page === null ||
              paginationParams.page === undefined ||
              (paginationParams.page > 0 && paginationParams.page <= 100);
            expect(pageValid).toBe(true);

            const perPageValid =
              paginationParams.per_page === null ||
              paginationParams.per_page === undefined ||
              (paginationParams.per_page > 0 && paginationParams.per_page <= 100);
            expect(perPageValid).toBe(true);

            const offsetValid =
              paginationParams.offset === null ||
              paginationParams.offset === undefined ||
              (paginationParams.offset >= 0 && paginationParams.offset <= 1000);
            expect(offsetValid).toBe(true);
          },
        ),
      );
    });
  });

  describe("Error Handling Properties", () => {
    it("should handle edge case inputs gracefully", () => {
      fc.assert(
        fc.property(
          fc.oneof(
            fc.constant(""),
            fc.constant(" "),
            fc.constant("\n"),
            fc.constant("\t"),
            fc.string({ maxLength: 0 }),
          ),
          (edgeCaseString) => {
            // Property: Edge case strings should be handled predictably
            expect(typeof edgeCaseString).toBe("string");
            expect(edgeCaseString.length).toBeLessThanOrEqual(10); // Reasonable limit
          },
        ),
      );
    });

    it("should maintain type consistency across operations", () => {
      fc.assert(
        fc.property(
          fc.record({
            stringField: fc.string(),
            numberField: fc.integer(),
            booleanField: fc.boolean(),
            arrayField: fc.array(fc.string(), { maxLength: 5 }),
          }),
          (mixedObject) => {
            // Property: Types should remain consistent
            expect(typeof mixedObject.stringField).toBe("string");
            expect(typeof mixedObject.numberField).toBe("number");
            expect(typeof mixedObject.booleanField).toBe("boolean");
            expect(Array.isArray(mixedObject.arrayField)).toBe(true);
            expect(mixedObject.arrayField.length).toBeLessThanOrEqual(5);
          },
        ),
      );
    });
  });

  describe("Performance Properties", () => {
    it("should complete operations within reasonable time", () => {
      fc.assert(
        fc.property(fc.array(fc.string({ maxLength: 100 }), { maxLength: 100 }), (stringArray) => {
          const startTime = Date.now();

          // Simulate some processing
          const processed = stringArray
            .filter((s) => s.length > 0)
            .map((s) => s.toLowerCase())
            .slice(0, 50);

          const endTime = Date.now();
          const duration = endTime - startTime;

          // Property: Operations should complete quickly
          expect(duration).toBeLessThan(50); // 50ms threshold
          expect(processed.length).toBeLessThanOrEqual(stringArray.length);
        }),
      );
    });
  });
});
