//
//  InputTextFormatterTests.swift
//  MullvadVPNTests
//
//  Created by pronebird on 10/04/2020.
//  Copyright © 2025 Mullvad VPN AB. All rights reserved.
//

import XCTest

@MainActor
class InputTextFormatterTests: XCTestCase {
    private let accountNumber = "12345678"
    private var inputTextFormatter: InputTextFormatter!

    private let configuration = InputTextFormatter.Configuration(
        allowedInput: .numeric,
        groupSeparator: " ",
        groupSize: 4,
        maxGroups: 4
    )

    override func setUp() async throws {
        inputTextFormatter = InputTextFormatter(
            string: accountNumber,
            configuration: configuration
        )
    }

    override func tearDown() async throws {
        inputTextFormatter = nil
    }

    func testInitialValue() {
        XCTAssertEqual(inputTextFormatter.formattedString, "1234 5678")
        XCTAssertEqual(inputTextFormatter.caretPosition, 9)
    }

    func testReplacingValue() {
        inputTextFormatter.replace(with: "00000000")

        XCTAssertEqual(inputTextFormatter.formattedString, "0000 0000")
        XCTAssertEqual(inputTextFormatter.caretPosition, 9)
    }

    func testRemovingSeparator() {
        guard let range = inputTextFormatter.formattedString.range(withOffset: 4, length: 1) else {
            return XCTAssertNil("Out of range", file: #file, line: #line)
        }

        inputTextFormatter.replaceCharacters(
            in: range,
            replacementString: "",
            emptySelection: true
        )

        XCTAssertEqual(inputTextFormatter.formattedString, "1235 678")
        XCTAssertEqual(inputTextFormatter.caretPosition, 3)
    }

    func testRemovingSeparatorRange() {
        guard let range = inputTextFormatter.formattedString.range(withOffset: 4, length: 1) else {
            return XCTAssertNil("Out of range", file: #file, line: #line)
        }

        inputTextFormatter.replaceCharacters(
            in: range,
            replacementString: "",
            emptySelection: false
        )

        XCTAssertEqual(inputTextFormatter.formattedString, "1234 5678")
        XCTAssertEqual(inputTextFormatter.caretPosition, 4)
    }

    func testRemovingRange() {
        guard let range = inputTextFormatter.formattedString.range(withOffset: 7, length: 2) else {
            return XCTAssertNil("Out of range", file: #file, line: #line)
        }

        inputTextFormatter.replaceCharacters(
            in: range,
            replacementString: "",
            emptySelection: false
        )

        XCTAssertEqual(inputTextFormatter.formattedString, "1234 56")
        XCTAssertEqual(inputTextFormatter.caretPosition, 7)
    }

    func testInserting() {
        guard let range = inputTextFormatter.formattedString.range(withOffset: 5, length: 0) else {
            return XCTAssertNil("Out of range", file: #file, line: #line)
        }

        inputTextFormatter.replaceCharacters(
            in: range,
            replacementString: "0000",
            emptySelection: true
        )

        XCTAssertEqual(inputTextFormatter.formattedString, "1234 0000 5678")
        XCTAssertEqual(inputTextFormatter.caretPosition, 9)
    }

    func testReplacingRange() {
        guard let range = inputTextFormatter.formattedString.range(withOffset: 5, length: 4) else {
            return XCTAssertNil("Out of range", file: #file, line: #line)
        }

        inputTextFormatter.replaceCharacters(
            in: range,
            replacementString: "0000",
            emptySelection: false
        )

        XCTAssertEqual(inputTextFormatter.formattedString, "1234 0000")
        XCTAssertEqual(inputTextFormatter.caretPosition, 9)
    }
}

private extension String {
    func range(withOffset offset: Int, length: Int) -> Range<String.Index>? {
        guard let start = index(startIndex, offsetBy: offset, limitedBy: endIndex),
            let end = index(start, offsetBy: length, limitedBy: endIndex)
        else {
            return nil
        }
        return start..<end
    }
}