import XCTest
@testable import PalindromeProducts

class PalindromeProductsTests: XCTestCase {
    func testLargestPalindromeFromSingleDigitFactors() {
        let palindromes = PalindromeProducts(maxFactor: 9)
        let largest = palindromes.largest
        XCTAssertEqual(9, largest.value)
        XCTAssertTrue(Set([1, 9]) == Set(largest.factor) || Set([3, 3]) == Set(largest.factor) )
    }

    func testLargestPalindromeFromDoubleDigitFactors() {
        let palindromes = PalindromeProducts(maxFactor: 99, minFactor: 10)
        let largest = palindromes.largest
        XCTAssertEqual(9009, largest.value)
        XCTAssertEqual(Set([91, 99]), Set(largest.factor))
    }

    func testSmallestPalindromeFromDoubleDigitFactors() {
        let palindromes = PalindromeProducts(maxFactor: 99, minFactor: 10)
        let smallest = palindromes.smallest
        XCTAssertEqual(121, smallest.value)
        XCTAssertEqual(Set([11, 11]), Set(smallest.factor))
    }

    func testLargestPalindromeFromTripleDigitFactors() {
        let palindromes = PalindromeProducts(maxFactor: 999, minFactor: 100)
        let largest = palindromes.largest
        XCTAssertEqual(906_609, largest.value)
        XCTAssertEqual(Set([913, 993]), Set(largest.factor))
    }

    func testSmallestPalindromeFromTripleDigitFactors() {
        let palindromes = PalindromeProducts(maxFactor: 999, minFactor: 100)
        let smallest = palindromes.smallest
        XCTAssertEqual(10_201, smallest.value)
        XCTAssertEqual(Set([101, 101]), Set(smallest.factor))
    }

    static var allTests: [(String, (PalindromeProductsTests) -> () throws -> Void)] {
        return [
            ("testLargestPalindromeFromSingleDigitFactors", testLargestPalindromeFromSingleDigitFactors),
            ("testLargestPalindromeFromDoubleDigitFactors", testLargestPalindromeFromDoubleDigitFactors),
            ("testSmallestPalindromeFromDoubleDigitFactors", testSmallestPalindromeFromDoubleDigitFactors),
            ("testLargestPalindromeFromTripleDigitFactors", testLargestPalindromeFromTripleDigitFactors),
            ("testSmallestPalindromeFromTripleDigitFactors", testSmallestPalindromeFromTripleDigitFactors),
        ]
    }
}