//
//  SignPost.swift
//
//  Created by Yume on 2018/12/5.
//  Copyright © 2018 Yume. All rights reserved.
//

import Foundation
import os.signpost

/// Log category:   Related operations
/// Signpost name:  An operation to measure
/// Signpost ID:    Single interval
struct SignPost {
    enum Category: String {
        case baseDataUpdate
        
        var log: OSLog {
//            if !ProcessInfo.processInfo.environment.keys.contains("SIGNPOSTS_FOR_REFRESH") {
//                return .disabled
//            }
            return OSLog(subsystem: "com.maxwin.FlowerBus", category: self.rawValue)
        }
        
        /// Signpost IDs are process-scoped
        /// Making from object is convenient if you have the same object at .begin and .end
        @available(OSX 10.14, iOS 12.0, watchOS 5.0, tvOS 12.0, *)
        func id(object: AnyObject) -> OSSignpostID {
            return OSSignpostID(log: self.log, object: object)
        }
        
        //        @available(OSX 10.14, iOS 12.0, watchOS 5.0, tvOS 12.0, *)
        //        public func os_signpost(_ type: OSSignpostType, dso: UnsafeRawPointer = #dsohandle, log: OSLog, name: StaticString, signpostID: OSSignpostID = default, _ format: StaticString, _ arguments: CVarArg...)
        // dso: UnsafeRawPointer = #dsohandle
        // _ format: StaticString, _ arguments: CVarArg...
        @available(OSX 10.14, iOS 12.0, watchOS 5.0, tvOS 12.0, *)
        func post(type: OSSignpostType, name: StaticString, id: OSSignpostID? = nil) {
            if let id = id {
                os_signpost(type, log: self.log, name: name, signpostID: id)
            } else {
                os_signpost(type, log: self.log, name: name)
            }
        }
        
        @available(OSX 10.14, iOS 12.0, watchOS 5.0, tvOS 12.0, *)
        func post(type: OSSignpostType, name: StaticString, object: AnyObject? = nil) {
            let id: OSSignpostID?
            if let object = object {
                id = self.id(object: object)
            } else {
                id = nil
            }
            self.post(type: type, name: name, id: id)
        }

        @available(OSX 10.14, iOS 12.0, watchOS 5.0, tvOS 12.0, *)
        func execute(name: StaticString, id: OSSignpostID, function: () throws -> ()) rethrows {
            self.post(type: .begin, name: name, id: id)
            try function()
            self.post(type: .end, name: name, id: id)
        }
        
        @available(OSX 10.14, iOS 12.0, watchOS 5.0, tvOS 12.0, *)
        func execute(name: StaticString, object: AnyObject? = nil, function: () throws -> ()) rethrows {
            self.post(type: .begin, name: name, object: object)
            try function()
            self.post(type: .end, name: name, object: object)
        }
    }
}