import Foundation
import IOKit
import IOKit.pwr_mgt
import IOKit.ps

final class SleepManager {
    private var displayAssertionID: IOPMAssertionID = 0
    private var systemAssertionID: IOPMAssertionID = 0
    private(set) var isDisplayActive = false
    private(set) var isSystemActive = false
    private(set) var activatedAt: Date?

    var preventDisplaySleep = true
    var preventSystemSleep = true

    func activate() {
        deactivate()

        if preventDisplaySleep {
            let reason = "KPopBird: preventing display sleep" as CFString
            let result = IOPMAssertionCreateWithName(
                kIOPMAssertionTypePreventUserIdleDisplaySleep as CFString,
                IOPMAssertionLevel(kIOPMAssertionLevelOn),
                reason,
                &displayAssertionID
            )
            isDisplayActive = (result == kIOReturnSuccess)
        }

        if preventSystemSleep {
            let reason = "KPopBird: preventing system sleep" as CFString
            let result = IOPMAssertionCreateWithName(
                kIOPMAssertionTypePreventUserIdleSystemSleep as CFString,
                IOPMAssertionLevel(kIOPMAssertionLevelOn),
                reason,
                &systemAssertionID
            )
            isSystemActive = (result == kIOReturnSuccess)
        }

        activatedAt = Date()
    }

    func deactivate() {
        if isDisplayActive {
            IOPMAssertionRelease(displayAssertionID)
            isDisplayActive = false
            displayAssertionID = 0
        }
        if isSystemActive {
            IOPMAssertionRelease(systemAssertionID)
            isSystemActive = false
            systemAssertionID = 0
        }
        activatedAt = nil
    }

    var isActive: Bool {
        isDisplayActive || isSystemActive
    }

    static func isOnACPower() -> Bool {
        guard let info = IOPSCopyPowerSourcesInfo()?.takeRetainedValue(),
              let providing = IOPSGetProvidingPowerSourceType(info)?.takeUnretainedValue()
        else { return true }
        return (providing as String) == kIOPMACPowerKey
    }
}