/*

    Copyright (C) 2018 Apple Inc. All Rights Reserved.

    See LICENSE.txt for this sample’s licensing information

    Abstract:

    Tests for the line framing code.

 */

import XCTest

@testable import TCPTransports_iOS

class LineFramingTests : XCTestCase {

    func testFramer() {

        let framer = LineFramer()

        XCTAssertEqual(framer.data(for: []), "".data(using: .utf8)!)

        XCTAssertEqual(framer.data(for: [""]), "\r\n".data(using: .utf8)!)

        XCTAssertEqual(framer.data(for: ["", ""]), "\r\n\r\n".data(using: .utf8)!)

        XCTAssertEqual(framer.data(for: ["abc", ""]), "abc\r\n\r\n".data(using: .utf8)!)

        XCTAssertEqual(framer.data(for: ["", "def"]), "\r\ndef\r\n".data(using: .utf8)!)

        XCTAssertEqual(framer.data(for: ["abc", "def"]), "abc\r\ndef\r\n".data(using: .utf8)!)

        XCTAssertEqual(framer.data(for: ["abc", "def", "hij"]), "abc\r\ndef\r\nhij\r\n".data(using: .utf8)!)

        XCTAssertEqual(framer.data(for: ["abc", "", "hij"]), "abc\r\n\r\nhij\r\n".data(using: .utf8)!)

    }

    func testUnframer() {

        func test(_ chunks: [String], maxLineLength: Int = 1024) -> [String] {

            var unframer = LineUnframer(maxLineLength: maxLineLength)

            return chunks.map {

                try! (unframer.lines(for: $0.data(using: .utf8)!)).joined(separator: "/")

            }

        }

        XCTAssertEqual(test([]), [])

        XCTAssertEqual(test(["abc"]), [""])   // no lines because no CR LF

        XCTAssertEqual(test(["abc\r\ndef\r\n"]), ["abc/def"])

        XCTAssertEqual(test(["abc\r\n", "def\r\n"]), ["abc", "def"])

        XCTAssertEqual(test(["a", "b", "c", "\r", "\n", "d", "e", "f", "\r", "\n"]), ["", "", "", "", "abc", "", "", "", "", "def"])

        XCTAssertEqual(test(["abc\rdef\r\n"]), ["abc\rdef"])            // 'naked' CR doesn't get lost

        XCTAssertEqual(test(["abc\r", "def\r\n"]), ["", "abc\rdef"])

        XCTAssertEqual(test(["1234\r\n"], maxLineLength: 4), ["1234"])

        XCTAssertEqual(test(["12", "34\r\n"], maxLineLength: 4), ["", "1234"])

        XCTAssertEqual(test(["12", "34", "\r\n"], maxLineLength: 4), ["", "", "1234"])

        XCTAssertEqual(test(["AB\r\n1234\r\n"], maxLineLength: 4), ["AB/1234"])

        XCTAssertEqual(test(["AB\r\n12", "34\r\n"], maxLineLength: 4), ["AB", "1234"])

        XCTAssertEqual(test(["AB\r\n12", "34", "\r\n"], maxLineLength: 4), ["AB", "", "1234"])

    }

    func testUnframerError() {

        func test(_ chunks: [String], _ expected: [String], _ expectedError: LineUnframer.Error) -> Bool {

            var unframer = LineUnframer(maxLineLength: 4)

            var actual: [String] = []

            var actualError: LineUnframer.Error? = nil

            for chunk in chunks {

                do {

                    actual.append(try unframer.lines(for: chunk.data(using: .utf8)!).joined(separator: "/"))

                } catch let error as LineUnframer.Error {

                    actualError = error

                    break

                } catch {

                    NSLog("error: %@", "\(error)")

                    return false

                }

            }

            guard actualError != nil else {

                NSLog("no error!")

                return false

            }

            guard actual == expected else {

                NSLog("expected: %@", expected)

                NSLog("actual: %@", actual)

                return false

            }

            guard actualError! == expectedError else {

                NSLog("expected: %@", "\(expectedError)")

                NSLog("actual: %@", "\(actualError!)")

                return false

            }

            return true

        }

        XCTAssertTrue(test(["12345"], [], .init(code: .lineTooLong, linesSoFar: [])))

        XCTAssertTrue(test(["12345\r\n"], [], .init(code: .lineTooLong, linesSoFar: [])))

        XCTAssertTrue(test(["12345\r\nef\r\n"], [], .init(code: .lineTooLong, linesSoFar: [])))

        XCTAssertTrue(test(["123", "45"], [""], .init(code: .lineTooLong, linesSoFar: [])))

        XCTAssertTrue(test(["ab\r\ncd\r\n12345"], [], .init(code: .lineTooLong, linesSoFar: ["ab", "cd"])))

        XCTAssertTrue(test(["ab\r\ncd\r\n12345\r\nef\r\n"], [], .init(code: .lineTooLong, linesSoFar: ["ab", "cd"])))

        XCTAssertTrue(test(["AB\r\n", "12345"], ["AB"], .init(code: .lineTooLong, linesSoFar: [])))

        XCTAssertTrue(test(["AB\r\n", "12345\r\n"], ["AB"], .init(code: .lineTooLong, linesSoFar: [])))

        XCTAssertTrue(test(["AB\r\n", "12345\r\nef\r\n"], ["AB"], .init(code: .lineTooLong, linesSoFar: [])))

        XCTAssertTrue(test(["AB\r\n", "123", "45"], ["AB", ""], .init(code: .lineTooLong, linesSoFar: [])))

        XCTAssertTrue(test(["AB\r\n", "ab\r\ncd\r\n12345"], ["AB"], .init(code: .lineTooLong, linesSoFar: ["ab", "cd"])))

        XCTAssertTrue(test(["AB\r\n", "ab\r\ncd\r\n12345\r\nef\r\n"], ["AB"], .init(code: .lineTooLong, linesSoFar: ["ab", "cd"])))

        XCTAssertTrue(test(["1234\r\r\n"], [], .init(code: .lineTooLong, linesSoFar: [])))

    }

}