//
//  PTPUtilitiesTests.swift
//  suixinkanTests
//

import XCTest
@testable import suixinkan

/// PTP Container 构建与解析测试。
final class PTPUtilitiesTests: XCTestCase {
    /// 测试 buildCommand 与 parseContainer 往返一致。
    func testBuildAndParseCommandRoundTrip() throws {
        let command = PTPHelper.buildCommand(
            code: PTPStandardCommand.getObject,
            transactionID: 42,
            parameters: [1, 2, 3]
        )

        let parsed = try PTPHelper.parseContainer(command)
        XCTAssertEqual(parsed.length, UInt32(12 + 4 * 3))
        XCTAssertEqual(parsed.type, PTPContainerType.command.rawValue)
        XCTAssertEqual(parsed.code, PTPStandardCommand.getObject)
        XCTAssertEqual(parsed.transactionID, 42)
        XCTAssertEqual(parsed.params, [1, 2, 3])
    }

    /// 测试数据过短时抛出 tooShort。
    func testParseContainerTooShortThrows() {
        XCTAssertThrowsError(try PTPHelper.parseContainer(Data([0x01, 0x02]))) { error in
            XCTAssertEqual(error as? PTPParseError, .tooShort)
        }
    }

    /// 测试 length 与 buffer 不一致时抛出 invalidLength。
    func testParseContainerInvalidLengthThrows() {
        var data = Data(count: 12)
        data[0] = 32
        XCTAssertThrowsError(try PTPHelper.parseContainer(data)) { error in
            XCTAssertEqual(error as? PTPParseError, .invalidLength)
        }
    }

    /// 测试 objectSignature 拼接规则。
    func testObjectSignature() {
        XCTAssertEqual(PTPHelper.objectSignature(filename: "DSC_0001.JPG", size: 2048), "DSC_0001.JPG_2048")
    }

    /// 测试 sanitizeFilename 去除非法路径字符。
    func testSanitizeFilename() {
        XCTAssertEqual(PTPHelper.sanitizeFilename("DSC/0001.JPG"), "DSC_0001.JPG")
        XCTAssertEqual(PTPHelper.sanitizeFilename("   "), "photo.jpg")
    }

    /// 测试从 ObjectInfo 固定偏移解析压缩大小。
    func testParseObjectCompressedSize() {
        var data = Data(count: 12)
        data[8] = 0x00
        data[9] = 0x10
        data[10] = 0x00
        data[11] = 0x00
        XCTAssertEqual(PTPHelper.parseObjectCompressedSize(data), 4096)
    }

    /// 测试 ResponseOK 判断。
    func testIsResponseOK() throws {
        let okResponse = PTPHelper.buildCommand(
            code: PTPStandardCommand.responseOK,
            transactionID: 1,
            parameters: []
        )
        var responseData = okResponse
        responseData[4] = UInt8(PTPContainerType.response.rawValue & 0xFF)
        responseData[5] = UInt8((PTPContainerType.response.rawValue >> 8) & 0xFF)
        XCTAssertTrue(PTPHelper.isResponseOK(responseData))
    }
}