import Foundation

/// Single source of truth for countdown pulse timing. Used by both default and debug modes
/// First 30s: blink every 10s; next 15s: every 5s; next 10s: every 2s; last 5s: solid.
enum CountdownPulseSchedule {

    /// Whether we are in the "flashing" phase (remaining within countdown window).
    static func isInCountdownPhase(remainingSeconds: Int, countdownDuration: Int, workTimerDuration: Int) -> Bool {
        let effective = min(countdownDuration, workTimerDuration)
        return remainingSeconds <= effective && remainingSeconds > 0
    }

    /// Whether to trigger a blink this second. Same logic for debug and default.
    /// First 30s remaining: every 10s; next 15s: every 5s; next 10s: every 2s; last 5s: solid.
    static func shouldBlink(remainingSeconds: Int) -> Bool {
        let s = remainingSeconds
        if s <= 5 { return false }           // last 5: solid
        if s <= 15 { return s % 2 == 0 }     // next 10: every 2s (14,12,10,8,6)
        if s <= 30 { return s % 5 == 0 }     // next 15: every 5s (30,25,20,15)
        return s % 10 == 0                   // first 30: every 10s (60,50,40,30,…)
    }

    /// When remaining <= 5, show solid overlay instead of blinking.
    static func shouldBeSolid(remainingSeconds: Int) -> Bool {
        return remainingSeconds > 0 && remainingSeconds <= 5
    }

    /// Blink animation durations (seconds). Single place so overlay timing matches schedule.
    struct BlinkDurations {
        var fadeIn: Double
        var hold: Double
        var fadeOut: Double
    }

    static func blinkDurations(remainingSeconds: Int, durationScale: Double) -> BlinkDurations {
        let scale = durationScale
        if remainingSeconds > 60 {
            return BlinkDurations(fadeIn: 1.0 * scale, hold: 0.8 * scale, fadeOut: 1.0 * scale)
        }
        if remainingSeconds > 30 {
            return BlinkDurations(fadeIn: 0.8 * scale, hold: 0.6 * scale, fadeOut: 0.8 * scale)
        }
        if remainingSeconds > 10 {
            return BlinkDurations(fadeIn: 0.5 * scale, hold: 0.4 * scale, fadeOut: 0.6 * scale)
        }
        return BlinkDurations(fadeIn: 0.3 * scale, hold: 0.3 * scale, fadeOut: 0.4 * scale)
    }
}