import XCTest
import Foundation
@testable import ForgeOffload

final class MHLTests: XCTestCase {

    var root: String!

    override func setUpWithError() throws {
        root = NSTemporaryDirectory() + "forge-mhl-\(UUID().uuidString)"
        try FileManager.default.createDirectory(atPath: root + "/CLIPS", withIntermediateDirectories: true)
        try Data("clip one contents".utf8).write(to: URL(fileURLWithPath: root + "/CLIPS/C001.mov"))
        try Data("clip two contents, longer".utf8).write(to: URL(fileURLWithPath: root + "/CLIPS/C002.mov"))
    }

    override func tearDown() {
        try? FileManager.default.removeItem(atPath: root)
    }

    // MHL XML structure: hashlist root, creatorinfo, hash entries with file/size/xxh64.
    func testWriteStructure() throws {
        let xml = try MHL.generate(root: root, creator: "Forge 0.1", files: ["CLIPS/C001.mov", "CLIPS/C002.mov"])
        XCTAssertTrue(xml.hasPrefix("<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<hashlist version=\"2.0\">"))
        XCTAssertTrue(xml.contains("<creatorinfo>"))
        XCTAssertTrue(xml.contains("<tool>Forge 0.1</tool>"))
        XCTAssertTrue(xml.contains("<path>CLIPS/C001.mov</path>"))
        XCTAssertTrue(xml.contains("<size>17</size>"))
        XCTAssertTrue(xml.contains("<xxh64>"))
        XCTAssertTrue(xml.hasSuffix("</hashlist>\n"))
    }

    // Verify: clean tree passes.
    func testVerifyClean() throws {
        let xml = try MHL.generate(root: root, creator: "Forge", files: ["CLIPS/C001.mov", "CLIPS/C002.mov"])
        let result = try MHL.verify(manifest: xml, root: root)
        XCTAssertTrue(result.passed)
        XCTAssertEqual(result.checked, 2)
        XCTAssertTrue(result.failures.isEmpty)
    }

    // Tamper detection: flipped byte fails that file.
    func testVerifyTamperDetected() throws {
        let xml = try MHL.generate(root: root, creator: "Forge", files: ["CLIPS/C001.mov", "CLIPS/C002.mov"])
        try Data("clip one CONTENTS".utf8).write(to: URL(fileURLWithPath: root + "/CLIPS/C001.mov"))
        let result = try MHL.verify(manifest: xml, root: root)
        XCTAssertFalse(result.passed)
        XCTAssertEqual(result.failures.count, 1)
        XCTAssertEqual(result.failures[0].path, "CLIPS/C001.mov")
        XCTAssertEqual(result.failures[0].reason, .hashMismatch)
    }

    // Missing file fails verify.
    func testVerifyMissingFile() throws {
        let xml = try MHL.generate(root: root, creator: "Forge", files: ["CLIPS/C001.mov", "CLIPS/C002.mov"])
        try FileManager.default.removeItem(atPath: root + "/CLIPS/C002.mov")
        let result = try MHL.verify(manifest: xml, root: root)
        XCTAssertFalse(result.passed)
        XCTAssertEqual(result.failures[0].reason, .missing)
    }

    // Round trip through file on disk.
    func testManifestFileRoundTrip() throws {
        let mhlPath = root + "/A001.mhl"
        try MHL.write(root: root!, creator: "Forge", files: ["CLIPS/C001.mov"], to: mhlPath)
        let loaded = try String(contentsOfFile: mhlPath, encoding: .utf8)
        let result = try MHL.verify(manifest: loaded, root: root)
        XCTAssertTrue(result.passed)
    }

    // Malformed manifest rejected.
    func testMalformedManifestRejected() {
        XCTAssertThrowsError(try MHL.verify(manifest: "<not-mhl/>", root: root))
    }

    // XML escaping in paths.
    func testPathEscaping() throws {
        try Data("x".utf8).write(to: URL(fileURLWithPath: root + "/a&b.mov"))
        let xml = try MHL.generate(root: root, creator: "Forge", files: ["a&b.mov"])
        XCTAssertTrue(xml.contains("<path>a&amp;b.mov</path>"))
        let result = try MHL.verify(manifest: xml, root: root)
        XCTAssertTrue(result.passed)
    }
}