import XCTest

@_spi(Fixtures) @testable import CallsKit

/// The warm rim (0.4.3, "T5, warm soft breath"): the four layers'
/// opacity and blur for a level, exactly the mock-up's box-shadow recipe;
/// its colours; when it is on; and Reduce Motion.
final class WarmRimTests: XCTestCase {
  private func level(db: Float) -> Float { pow(10, db / 20) }

  func testTheFourLayersFollowTheLevel() {
    for lvl in stride(from: 0.0, through: 1, by: 0.05) {
      let rim = WarmRim(on: true, level: lvl)
      XCTAssertEqual(rim.rimOpacity, 0.10 + lvl * 0.45, accuracy: 1e-12, "rim at \(lvl)")
      XCTAssertEqual(rim.topOpacity, 0, "T5 has no top highlight")
      XCTAssertEqual(rim.innerOpacity, 0.06 + lvl * 0.30, accuracy: 1e-12, "inner at \(lvl)")
      XCTAssertEqual(rim.innerBlur, 3 + lvl * 6, accuracy: 1e-12)
      XCTAssertEqual(rim.outerOpacity, lvl * 0.25, accuracy: 1e-12, "outer at \(lvl)")
      XCTAssertEqual(rim.outerBlur, 1 + lvl * 7, accuracy: 1e-12)
    }
    // The ends, spelled out.
    let quiet = WarmRim(on: true, level: 0)
    XCTAssertEqual(quiet.rimOpacity, 0.10, accuracy: 1e-12)
    XCTAssertEqual(quiet.innerOpacity, 0.06, accuracy: 1e-12)
    XCTAssertEqual(quiet.innerBlur, 3)
    XCTAssertEqual(quiet.outerOpacity, 0, "no breath until the voice rises")
    XCTAssertEqual(quiet.outerBlur, 1)
    let loud = WarmRim(on: true, level: 1)
    XCTAssertEqual(loud.rimOpacity, 0.55, accuracy: 1e-12)
    XCTAssertEqual(loud.innerOpacity, 0.36, accuracy: 1e-12)
    XCTAssertEqual(loud.innerBlur, 9)
    XCTAssertEqual(loud.outerOpacity, 0.25, accuracy: 1e-12)
    XCTAssertEqual(loud.outerBlur, 8)
    XCTAssertEqual(WarmRim.rimWidth, 1)
  }

  func testOffIsNothingAtAnyLevel() {
    for lvl in [0, 0.3, 1.0] {
      let rim = WarmRim(on: false, level: lvl)
      XCTAssertEqual(rim.rimOpacity, 0)
      XCTAssertEqual(rim.innerOpacity, 0)
      XCTAssertEqual(rim.outerOpacity, 0)
    }
    XCTAssertEqual(WarmRim.off, WarmRim(on: false, level: 0))
  }

  func testALevelOutOfRangeIsHeldToIt() {
    XCTAssertEqual(WarmRim(on: true, level: 2), WarmRim(on: true, level: 1))
    XCTAssertEqual(WarmRim(on: true, level: -1), WarmRim(on: true, level: 0))
    XCTAssertEqual(WarmRim(on: true, level: .nan), WarmRim(on: true, level: 0))
  }

  func testTheColoursAreWarmWhite() {
    // hsl(38°, 80 %, 82 / 72 / 66 %), as Chromium computes them.
    func check(_ l: Double, _ r: Int, _ g: Int, _ b: Int) {
      let c = WarmRim.rgb(hue: WarmRim.hue, saturation: WarmRim.saturation, lightness: l)
      XCTAssertEqual(Int((c.red * 255).rounded()), r, "red at \(l)")
      XCTAssertEqual(Int((c.green * 255).rounded()), g, "green at \(l)")
      XCTAssertEqual(Int((c.blue * 255).rounded()), b, "blue at \(l)")
    }
    check(WarmRim.rimLightness, 246, 219, 172)
    check(WarmRim.innerLightness, 241, 199, 126)
    check(WarmRim.outerLightness, 238, 187, 99)
    XCTAssertEqual(WarmRim.hue, 38)
    XCTAssertEqual(WarmRim.saturation, 0.80)
  }

  func testSpeechTurnsItOnAndItFadesOut() {
    var glow = SpeakingGlow()
    XCTAssertEqual(glow.rim(at: 0), .off, "silence: nothing")
    let loud = level(db: -12)
    glow.update(level: loud, speaking: true, now: 0)
    XCTAssertFalse(glow.on(at: 0), "not before the onset")
    glow.update(level: loud, speaking: true, now: 0.2)
    XCTAssertTrue(glow.on(at: 0.2))
    // Lit, the level rises over the attack from nothing.
    XCTAssertEqual(glow.rim(at: 0.2), WarmRim(on: true, level: 0))
    XCTAssertEqual(glow.rim(at: 0.2 + SpeakingGlow.attack).level, 1 - exp(-1), accuracy: 1e-6)
    XCTAssertEqual(glow.rim(at: 5).level, 1, accuracy: 1e-6)
    // Silence: still on while the level falls over the release, and off
    // once it is under `outBelow` — not at once.
    glow.update(level: 0, speaking: false, now: 5)
    XCTAssertFalse(glow.lit)
    XCTAssertTrue(glow.on(at: 5 + SpeakingGlow.release), "fading")
    let out = 5 + SpeakingGlow.release * log(1 / SpeakingGlow.outBelow)
    XCTAssertTrue(glow.on(at: out - 0.01))
    XCTAssertFalse(glow.on(at: out + 0.01))
    let gone = glow.rim(at: out + 0.01)
    XCTAssertFalse(gone.on)
    XCTAssertEqual([gone.rimOpacity, gone.innerOpacity, gone.outerOpacity], [0, 0, 0], "nothing drawn")
    XCTAssertLessThan(out, glow.settles, "and the view is still redrawing when it goes off")
  }

  func testReduceMotionIsASteadyRimAtPointSix() {
    var glow = SpeakingGlow()
    XCTAssertEqual(glow.rim(at: 0, reduceMotion: true), .off)
    glow.update(level: level(db: -10), speaking: true, now: 0)
    glow.update(level: level(db: -10), speaking: true, now: 0.2)
    for (db, t) in [(-10, 0.3), (-35, 0.4), (-20, 0.5)] as [(Float, Double)] {
      glow.update(level: level(db: db), speaking: true, now: t)
      for dt in [0, 0.01, 0.1, 1.0] {
        XCTAssertEqual(glow.rim(at: t + dt, reduceMotion: true), WarmRim(on: true, level: 0.6))
      }
    }
    XCTAssertEqual(SpeakingGlow.steady, 0.6)
    // Out at once, with no fade.
    glow.update(level: 0, speaking: false, now: 1)
    XCTAssertEqual(glow.rim(at: 1, reduceMotion: true), .off)
  }

  func testTheFixturesLevels() {
    XCTAssertEqual(SpeakingGlow.fixture(level: level(db: FixtureSpeaking.silent.decibels)).rim(at: 0), .off)
    let expected: [(FixtureSpeaking, Double)] = [(.low, 13.0 / 30), (.mid, 21.0 / 30), (.high, 1)]
    for (fixture, lvl) in expected {
      let rim = SpeakingGlow.fixture(level: level(db: fixture.decibels)).rim(at: 0)
      XCTAssertTrue(rim.on, "\(fixture)")
      XCTAssertEqual(rim.level, lvl, accuracy: 1e-5, "\(fixture)")
    }
  }
}