import Foundation
import Testing
import RemoteCore
@testable import GestureCore

private func sample(_ t: Double, _ x: Double = 0, _ y: Double = 0, _ q: Double = 1) -> NormalizedMotionSample {
    NormalizedMotionSample(timestamp: t, x: x, y: y, quality: q)
}

@Test func requiresStableNeutralAndEmitsOneDirectionalEvent() {
    var configuration = GestureRecognitionConfiguration(); configuration.maximumSampleGap = 0.3
    var recognizer = CalibratedGestureRecognizer(configuration: configuration)
    let id = UUID(); recognizer.arm(sessionID: id, at: 0)
    #expect(recognizer.process(sample(0)) == nil)
    #expect(recognizer.process(sample(0.21)) == nil)
    #expect(recognizer.process(sample(0.30, 0.65, 0)) == nil)
    #expect(recognizer.process(sample(0.41, 0.8, 0)) == nil)
    let result = recognizer.process(sample(0.50, 0.9, 0))
    #expect(result?.command == .right)
    #expect(result?.sessionID == id)
    #expect(recognizer.process(sample(0.55, 0.9, 0)) == nil)
}

@Test func diagonalLowConfidenceGapAndOutOfOrderAreRejected() {
    var recognizer = CalibratedGestureRecognizer()
    recognizer.arm(sessionID: UUID(), at: 0)
    _ = recognizer.process(sample(0)); _ = recognizer.process(sample(0.21))
    _ = recognizer.process(sample(0.35, 0.8, 0.75))
    #expect(recognizer.process(sample(0.50, 0.8, 0.75)) == nil) // ambiguous
    #expect(recognizer.process(sample(0.49, 0.9, 0)) == nil) // stale
    _ = recognizer.process(sample(0.70))
    #expect(recognizer.process(sample(0.90, 0.9, 0, 0.2)) == nil)
}

@Test func cooldownAndReturnToNeutralSuppressReverseMotion() {
    var configuration = GestureRecognitionConfiguration(); configuration.maximumSampleGap = 0.3
    var recognizer = CalibratedGestureRecognizer(configuration: configuration)
    recognizer.arm(sessionID: UUID(), at: 0)
    _ = recognizer.process(sample(0)); _ = recognizer.process(sample(0.21))
    #expect(recognizer.process(sample(0.30, 0.9, 0)) == nil)
    #expect(recognizer.process(sample(0.41, 0.9, 0)) == nil)
    #expect(recognizer.process(sample(0.50, 0.9, 0))?.command == .right)
    _ = recognizer.process(sample(0.60)); _ = recognizer.process(sample(0.70)); _ = recognizer.process(sample(0.80))
    _ = recognizer.process(sample(0.90)); _ = recognizer.process(sample(0.95))
    #expect(recognizer.process(sample(1.05, -0.9, 0)) == nil)
    #expect(recognizer.process(sample(1.15, -0.9, 0)) == nil)
    #expect(recognizer.process(sample(1.25, -0.9, 0))?.command == .left)
}

@Test func disarmClearsSessionAndNoReplayAfterRearm() {
    var recognizer = CalibratedGestureRecognizer()
    recognizer.arm(sessionID: UUID(), at: 0); _ = recognizer.process(sample(0)); _ = recognizer.process(sample(0.21))
    recognizer.disarm()
    #expect(recognizer.process(sample(1, 0.9, 0)) == nil)
    recognizer.arm(sessionID: UUID(), at: 2)
    #expect(recognizer.process(sample(2.1, 0.9, 0)) == nil)
}

@Test func invalidSampleDiscardsCandidateUntilFreshNeutral() {
    var recognizer = CalibratedGestureRecognizer()
    recognizer.arm(sessionID: UUID(), at: 0)
    for index in 0...20 {
        _ = recognizer.process(.init(timestamp: Double(index) / 50, x: 0, y: 0))
    }
    _ = recognizer.process(.init(timestamp: 0.42, x: 0.8, y: 0))
    _ = recognizer.process(.init(timestamp: 0.44, x: .nan, y: 0))
    for index in 23...40 {
        #expect(recognizer.process(.init(timestamp: Double(index) / 50, x: 0.8, y: 0)) == nil)
    }
}