import XCTest
@testable import BinarySearchTree

class BinarySearchTreeTests: XCTestCase {

    func testDataIsRetained() {
        XCTAssertEqual(4, BinarySearchTree(4).data)
    }

    func testInsertingLess() {
        var four = BinarySearchTree(4)
        four.insert(2)
        XCTAssertEqual(4, four.data)
        XCTAssertEqual(2, four.left?.data)
    }

    func testInsertingSame() {
        var four = BinarySearchTree(4)
        four.insert(4)
        XCTAssertEqual(4, four.data)
        XCTAssertEqual(4, four.left?.data)
    }

    func testInsertingRight() {
        var four = BinarySearchTree(4)
        four.insert(5)
        XCTAssertEqual(4, four.data)
        XCTAssertEqual(5, four.right?.data)
    }

    func testComplexTree() {
        var four = BinarySearchTree(4)
        four.insert(2)
        four.insert(6)
        four.insert(1)
        four.insert(3)
        four.insert(7)
        four.insert(5)
        XCTAssertEqual(4, four.data)
        XCTAssertEqual(2, four.left?.data)
        XCTAssertEqual(1, four.left?.left?.data)
        XCTAssertEqual(3, four.left?.right?.data)
        XCTAssertEqual(6, four.right?.data)
        XCTAssertEqual(5, four.right?.left?.data)
        XCTAssertEqual(7, four.right?.right?.data)
    }

    func testAllDataForOneElement() {
        XCTAssertEqual([4], BinarySearchTree(4).allData())
    }

    func testAllDataForSmallerElement() {
        var four = BinarySearchTree(4)
        four.insert(2)
        XCTAssertEqual([2, 4], four.allData())
    }

    func testAllDataForLargerElement() {
        var four = BinarySearchTree(4)
        four.insert(5)
        XCTAssertEqual([4, 5], four.allData())
    }

    func testAllDataForComplexTree() {
        var four = BinarySearchTree(4)
        four.insert(2)
        four.insert(1)
        four.insert(3)
        four.insert(6)
        four.insert(7)
        four.insert(5)
        XCTAssertEqual([1, 2, 3, 4, 5, 6, 7], four.allData())
    }

    static var allTests: [(String, (BinarySearchTreeTests) -> () throws -> Void)] {
        return [
            ("testDataIsRetained", testDataIsRetained),
            ("testInsertingLess", testInsertingLess),
            ("testInsertingSame", testInsertingSame),
            ("testInsertingRight", testInsertingRight),
            ("testComplexTree", testComplexTree),
            ("testAllDataForOneElement", testAllDataForOneElement),
            ("testAllDataForSmallerElement", testAllDataForSmallerElement),
            ("testAllDataForLargerElement", testAllDataForLargerElement),
            ("testAllDataForComplexTree", testAllDataForComplexTree),
        ]
    }
}