// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2016 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See http://swift.org/LICENSE.txt for license information
// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//

private struct Box: Equatable {
    private let ns: NSCharacterSet
    private let swift: CharacterSet
    
    private init(ns: NSCharacterSet, swift: CharacterSet) {
        self.ns = ns
        self.swift = swift
    }
    
    init(charactersIn string: String) {
        self.ns = NSCharacterSet(charactersIn: string)
        self.swift = CharacterSet(charactersIn: string)
    }
    
    static var alphanumerics: Box {
        return Box(ns: NSCharacterSet.alphanumerics._bridgeToObjectiveC(),
                   swift: .alphanumerics)
    }
    
    static var decimalDigits: Box {
        return Box(ns: NSCharacterSet.decimalDigits._bridgeToObjectiveC(),
                   swift: .decimalDigits)
    }

    // MARK: Equatable

    static func ==(lhs: Box, rhs: Box) -> Bool {
        return lhs.ns == rhs.ns
            && lhs.swift == rhs.swift
            && lhs.ns._bridgeToSwift() == rhs.ns._bridgeToSwift()
            && lhs.swift._bridgeToObjectiveC() == rhs.swift._bridgeToObjectiveC()
            && lhs.ns.isEqual(rhs.ns)
            && lhs.ns.isEqual(rhs.swift)
            && lhs.ns.isEqual(rhs.ns._bridgeToSwift())
            && lhs.ns.isEqual(rhs.swift._bridgeToObjectiveC())
            && lhs.swift._bridgeToObjectiveC().isEqual(rhs.ns)
            && lhs.swift._bridgeToObjectiveC().isEqual(rhs.swift)
            && lhs.swift._bridgeToObjectiveC().isEqual(rhs.ns._bridgeToSwift())
            && lhs.swift._bridgeToObjectiveC().isEqual(rhs.swift._bridgeToObjectiveC())
    }
}

class TestCharacterSet : XCTestCase {
    
    let capitalA = UnicodeScalar(0x0041)! // LATIN CAPITAL LETTER A
    let capitalB = UnicodeScalar(0x0042)! // LATIN CAPITAL LETTER B
    let capitalC = UnicodeScalar(0x0043)! // LATIN CAPITAL LETTER C
    
    func testBasicConstruction() {
        // Create a character set
        let cs = CharacterSet.letters
        
        // Use some method from it
        let invertedCs = cs.inverted
        XCTAssertTrue(!invertedCs.contains(capitalA), "Character set must not contain our letter")
        
        // Use another method from it
        let originalCs = invertedCs.inverted
        
        XCTAssertTrue(originalCs.contains(capitalA), "Character set must contain our letter")
    }
    
    func testMutability_copyOnWrite() {
        var firstCharacterSet = CharacterSet(charactersIn: "ABC")
        XCTAssertTrue(firstCharacterSet.contains(capitalA), "Character set must contain our letter")
        XCTAssertTrue(firstCharacterSet.contains(capitalB), "Character set must contain our letter")
        XCTAssertTrue(firstCharacterSet.contains(capitalC), "Character set must contain our letter")
        
        // Make a 'copy' (just the struct)
        var secondCharacterSet = firstCharacterSet
        // first: ABC, second: ABC
        
        // Mutate first and verify that it has correct content
        firstCharacterSet.remove(charactersIn: "A")
        // first: BC, second: ABC
        
        XCTAssertTrue(!firstCharacterSet.contains(capitalA), "Character set must not contain our letter")
        XCTAssertTrue(secondCharacterSet.contains(capitalA), "Copy should not have been mutated")
        
        // Make a 'copy' (just the struct) of the second set, mutate it
        let thirdCharacterSet = secondCharacterSet
        // first: BC, second: ABC, third: ABC
        
        secondCharacterSet.remove(charactersIn: "B")
        // first: BC, second: AC, third: ABC
        
        XCTAssertTrue(firstCharacterSet.contains(capitalB), "Character set must contain our letter")
        XCTAssertTrue(!secondCharacterSet.contains(capitalB), "Character set must not contain our letter")
        XCTAssertTrue(thirdCharacterSet.contains(capitalB), "Character set must contain our letter")
        
        firstCharacterSet.remove(charactersIn: "C")
        // first: B, second: AC, third: ABC
        
        XCTAssertTrue(!firstCharacterSet.contains(capitalC), "Character set must not contain our letter")
        XCTAssertTrue(secondCharacterSet.contains(capitalC), "Character set must not contain our letter")
        XCTAssertTrue(thirdCharacterSet.contains(capitalC), "Character set must contain our letter")
    }
    
    func testRanges() {
        // Simple range check
        let asciiUppercase = CharacterSet(charactersIn: UnicodeScalar(0x41)!...UnicodeScalar(0x5A)!)
        XCTAssertTrue(asciiUppercase.contains(UnicodeScalar(0x49)!))
        XCTAssertTrue(asciiUppercase.contains(UnicodeScalar(0x5A)!))
        XCTAssertTrue(asciiUppercase.contains(UnicodeScalar(0x41)!))
        XCTAssertTrue(!asciiUppercase.contains(UnicodeScalar(0x5B)!))
        
        // Some string filtering tests
        let asciiLowercase = CharacterSet(charactersIn: UnicodeScalar(0x61)!...UnicodeScalar(0x7B)!)
        let testString = "helloHELLOhello"
        let expected = "HELLO"
        
        let result = testString.trimmingCharacters(in: asciiLowercase)
        XCTAssertEqual(result, expected)
    }
    
    func testInsertAndRemove() {
        var asciiUppercase = CharacterSet(charactersIn: UnicodeScalar(0x41)!...UnicodeScalar(0x5A)!)
        XCTAssertTrue(asciiUppercase.contains(UnicodeScalar(0x49)!))
        XCTAssertTrue(asciiUppercase.contains(UnicodeScalar(0x5A)!))
        XCTAssertTrue(asciiUppercase.contains(UnicodeScalar(0x41)!))
        
        asciiUppercase.remove(UnicodeScalar(0x49))
        XCTAssertTrue(!asciiUppercase.contains(UnicodeScalar(0x49)!))
        XCTAssertTrue(asciiUppercase.contains(UnicodeScalar(0x5A)!))
        XCTAssertTrue(asciiUppercase.contains(UnicodeScalar(0x41)!))
        
        
        // Zero-length range
        asciiUppercase.remove(charactersIn: UnicodeScalar(0x41)!..<UnicodeScalar(0x41)!)
        XCTAssertTrue(asciiUppercase.contains(UnicodeScalar(0x41)!))
        
        asciiUppercase.remove(charactersIn: UnicodeScalar(0x41)!..<UnicodeScalar(0x42)!)
        XCTAssertTrue(!asciiUppercase.contains(UnicodeScalar(0x41)!))
        
        asciiUppercase.remove(charactersIn: "Z")
        XCTAssertTrue(!asciiUppercase.contains(UnicodeScalar(0x5A)!))
    }
    
    func testBasics() {
        
        var result : [String] = []
        
        let string = "The quick, brown, fox jumps over the lazy dog - because, why not?"
        var set = CharacterSet(charactersIn: ",-")
        result = string.components(separatedBy: set)
        XCTAssertEqual(5, result.count)
        XCTAssertEqual(["The quick", " brown", " fox jumps over the lazy dog ", " because", " why not?"], result)
        
        set.remove(charactersIn: ",")
        set.insert(charactersIn: " ")
        result = string.components(separatedBy: set)
        XCTAssertEqual(14, result.count)
        
        set.remove(" ".unicodeScalars.first!)
        result = string.components(separatedBy: set)
        XCTAssertEqual(2, result.count)
    }
    
    func test_Predefines() {
        let cset = CharacterSet.controlCharacters
        
        XCTAssertTrue(cset.contains(UnicodeScalar(0xFEFF)!), "Control set should contain UFEFF")
        XCTAssertTrue(CharacterSet.letters.contains(UnicodeScalar(0x61)!), "Letter set should contain 'a'")
        XCTAssertTrue(CharacterSet.lowercaseLetters.contains(UnicodeScalar(0x61)!), "Lowercase Letter set should contain 'a'")
        XCTAssertTrue(CharacterSet.uppercaseLetters.contains(UnicodeScalar(0x41)!), "Uppercase Letter set should contain 'A'")
        XCTAssertTrue(CharacterSet.uppercaseLetters.contains(UnicodeScalar(0x01C5)!), "Uppercase Letter set should contain U01C5")
        XCTAssertTrue(CharacterSet.capitalizedLetters.contains(UnicodeScalar(0x01C5)!), "Uppercase Letter set should contain U01C5")
        XCTAssertTrue(CharacterSet.symbols.contains(UnicodeScalar(0x002B)!), "Symbol set should contain U002B")
        XCTAssertTrue(CharacterSet.symbols.contains(UnicodeScalar(0x20B1)!), "Symbol set should contain U20B1")
        XCTAssertTrue(CharacterSet.newlines.contains(UnicodeScalar(0x000A)!), "Newline set should contain 0x000A")
        XCTAssertTrue(CharacterSet.newlines.contains(UnicodeScalar(0x2029)!), "Newline set should contain 0x2029")
        
        let mcset = CharacterSet.whitespacesAndNewlines
        let cset2 = CharacterSet.whitespacesAndNewlines

        XCTAssert(mcset.isSuperset(of: cset2))
        XCTAssert(cset2.isSuperset(of: mcset))
        
        XCTAssertTrue(CharacterSet.whitespacesAndNewlines.isSuperset(of: .newlines), "whitespace and newline should be a superset of newline")
        let data = CharacterSet.uppercaseLetters.bitmapRepresentation
        XCTAssertNotNil(data)
    }
    
    func test_Range() {
//        let cset1 = CharacterSet(range: NSRange(location: 0x20, length: 40))
        let cset1 = CharacterSet(charactersIn: UnicodeScalar(0x20)!..<UnicodeScalar(0x20 + 40)!)
        for idx: unichar in 0..<0xFFFF {
            if idx < 0xD800 || idx > 0xDFFF {
                XCTAssertEqual(cset1.contains(UnicodeScalar(idx)!), (idx >= 0x20 && idx < 0x20 + 40 ? true : false))
            }
            
        }
        
        let cset2 = CharacterSet(charactersIn: UnicodeScalar(0x0000)!..<UnicodeScalar(0xFFFF)!)
        for idx: unichar in 0..<0xFFFF {
            if idx < 0xD800 || idx > 0xDFFF {
                XCTAssertEqual(cset2.contains(UnicodeScalar(idx)!), true)
            }
            
        }
        

        let cset3 = CharacterSet(charactersIn: UnicodeScalar(0x0000)!..<UnicodeScalar(10)!)
        for idx: unichar in 0..<0xFFFF {
            if idx < 0xD800 || idx > 0xDFFF {
                XCTAssertEqual(cset3.contains(UnicodeScalar(idx)!), (idx < 10 ? true : false))
            }
            
        }
        
        let cset4 = CharacterSet(charactersIn: UnicodeScalar(0x20)!..<UnicodeScalar(0x20)!)
        for idx: unichar in 0..<0xFFFF {
            if idx < 0xD800 || idx > 0xDFFF {
                XCTAssertEqual(cset4.contains(UnicodeScalar(idx)!), false)
            }
            
        }
    }
    
    func test_String() {
        let cset = CharacterSet(charactersIn: "abcABC")
        for idx: unichar in 0..<0xFFFF {
            if idx < 0xD800 || idx > 0xDFFF {
                XCTAssertEqual(cset.contains(UnicodeScalar(idx)!), (idx >= unichar(unicodeScalarLiteral: "a") && idx <= unichar(unicodeScalarLiteral: "c")) || (idx >= unichar(unicodeScalarLiteral: "A") && idx <= unichar(unicodeScalarLiteral: "C")) ? true : false)
            }
        }
    }
    
    func testClosedRanges_SR_2988() {
        // "CharacterSet.insert(charactersIn: ClosedRange) crashes on a closed ClosedRange<UnicodeScalar> containing U+D7FF"
        let problematicChar = UnicodeScalar(0xD7FF)!
        let range = capitalA...problematicChar
        var characters = CharacterSet(charactersIn: range) // this should not crash
        XCTAssertTrue(characters.contains(problematicChar))
        characters.remove(charactersIn: range) // this should not crash
        XCTAssertTrue(!characters.contains(problematicChar))
        characters.insert(charactersIn: range) // this should not crash
        XCTAssertTrue(characters.contains(problematicChar))
    }
    
    func test_Bitmap() {
        
    }
    
    func test_AnnexPlanes() {
        
    }
    
    func test_Planes() {
        
    }
    
    func test_InlineBuffer() {
        
    }

    func test_Subtracting() {
        let difference = CharacterSet(charactersIn: "abc").subtracting(CharacterSet(charactersIn: "b"))
        let expected = CharacterSet(charactersIn: "ac")
        XCTAssertEqual(expected, difference)
    }

    func test_SubtractEmptySet() {
        var mutableSet = CharacterSet(charactersIn: "abc")
        let emptySet = CharacterSet()
        mutableSet.subtract(emptySet)
        let expected = CharacterSet(charactersIn: "abc")
        XCTAssertEqual(expected, mutableSet)
    }

    func test_SubtractNonEmptySet() {
        var mutableSet = CharacterSet()
        let nonEmptySet = CharacterSet(charactersIn: "abc")
        mutableSet.subtract(nonEmptySet)
        XCTAssertTrue(mutableSet.isEmpty)
    }

    func test_SymmetricDifference() {
        let symmetricDifference = CharacterSet(charactersIn: "ac").symmetricDifference(CharacterSet(charactersIn: "b"))
        let expected = CharacterSet(charactersIn: "abc")
        XCTAssertEqual(expected, symmetricDifference)
    }
    
    func test_Equatable() {
        let equalPairs = [
            ("", ""),
            ("a", "a"),
            ("abcde", "abcde"),
            ("12345", "12345")
        ]
        
        /*
         Tests disabled due to CoreFoundation bug?
         These NSCharacterSet pairs are (wrongly?) evaluated to be equal. Same behaviour can be observed on macOS 10.12.
         Interestingly, on iOS 11 Simulator, they are evaluated to be _not_ equal,
         while on iOS 10.3.1 Simulator, they are evaluated to be equal.
         */
        let notEqualPairs = [
            ("abc", "123"),
//            ("ab", "abc"),
//            ("abc", "")
        ]
        
        for pair in equalPairs {
            XCTAssertEqual(Box(charactersIn: pair.0), Box(charactersIn: pair.1))
        }
        XCTAssertEqual(Box.alphanumerics, Box.alphanumerics)
        
        for pair in notEqualPairs {
            XCTAssertNotEqual(Box(charactersIn: pair.0), Box(charactersIn: pair.1))
        }
        XCTAssertNotEqual(Box.alphanumerics, Box.decimalDigits)
    }

    func test_formUnion() {
        var charset = CharacterSet(charactersIn: "a")
        charset.formUnion(CharacterSet(charactersIn: "A"))
        XCTAssertTrue(charset.contains("A" as UnicodeScalar))
    }
    
    func test_union() {
        let charset = CharacterSet(charactersIn: "a")
        let union = charset.union(CharacterSet(charactersIn: "A"))
        XCTAssertTrue(union.contains("A" as UnicodeScalar))
    }

    func test_SR5971() {
        let problematicString = "\u{10000}"
        let charset1 = CharacterSet(charactersIn:problematicString) // this should not crash
        XCTAssertTrue(charset1.contains("\u{10000}"))
        // Case from SR-3215
        let charset2 = CharacterSet(charactersIn: "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789&+")
        XCTAssertTrue(charset2.contains("+"))
    }

    func test_hashing() {
        let a = CharacterSet(charactersIn: "ABC")
        let b = CharacterSet(charactersIn: "CBA")
        let c = CharacterSet(charactersIn: "bad")
        let d = CharacterSet(charactersIn: "abd")
        let e = CharacterSet.capitalizedLetters
        let f = CharacterSet.lowercaseLetters
        checkHashableGroups(
            [[a, b], [c, d], [e], [f]],
            // FIXME: CharacterSet delegates equality and hashing to
            // CFCharacterSet, which uses unseeded hashing, so it's not
            // complete.
            allowIncompleteHashing: true)
    }
    
    let fixtures = [
        Fixtures.characterSetEmpty,
        Fixtures.characterSetRange,
        Fixtures.characterSetString,
        Fixtures.characterSetBitmap,
        Fixtures.characterSetBuiltin,
    ]
    
    func test_codingRoundtrip() throws {
        for fixture in fixtures {
            try fixture.assertValueRoundtripsInCoder()
        }
    }
}