import Foundation
import Testing
@testable import Music

// Verifies the shared file-stat helper reads size/mod-date from disk and
// produces a fileHash identical to Track.computeHash (the existing canonical formula).
struct TrackFileStatsTests {
    @Test func compute_matchesTrackComputeHash() throws {
        // Step 1: write a temp file with known bytes.
        let url = URL(fileURLWithPath: NSTemporaryDirectory())
            .appendingPathComponent(UUID().uuidString + ".bin")
        try Data(repeating: 0xAB, count: 1234).write(to: url)
        defer { try? FileManager.default.removeItem(at: url) }

        // Step 2: compute stats via the helper.
        let stats = try TrackFileStats.compute(for: url)

        // Step 3: independently read attrs and assert the helper agrees.
        let attrs = try FileManager.default.attributesOfItem(atPath: url.path)
        let size = attrs[.size] as? Int64 ?? -1
        let mod = attrs[.modificationDate] as? Date ?? Date.distantPast
        #expect(stats.fileSize == size)
        #expect(stats.dateModified == mod)
        #expect(stats.fileHash == Track.computeHash(fileSize: size, modificationDate: mod))
    }
}