//
//  Logger.swift
//  SwiftLogger
//
//  Created by Sauvik Dolui on 03/05/2017.
//  Copyright © 2016 Innofied Solutions Pvt. Ltd. All rights reserved.
//

import Foundation

/// Enum which maps an appropiate symbol which added as prefix for each log message
///
/// - error: Log type error
/// - info: Log type info
/// - debug: Log type debug
/// - verbose: Log type verbose
/// - warning: Log type warning
/// - severe: Log type severe
enum LogEvent: String {
    case e = "[‼️]" // error
    case i = "[ℹ️]" // info
    case d = "[💬]" // debug
    case v = "[🔬]" // verbose
    case w = "[⚠️]" // warning
    case s = "[🔥]" // severe
}


/// Wrapping Swift.print() within DEBUG flag
///
/// - Note: *print()* might cause [security vulnerabilities](https://codifiedsecurity.com/mobile-app-security-testing-checklist-ios/)
///
/// - Parameter object: The object which is to be logged
///
func print(_ object: Any) {
    // Only allowing in DEBUG mode
    #if DEBUG
    Swift.print(object)
    #endif
}

class Log {
    
    static var dateFormat = "yyyy-MM-dd hh:mm:ssSSS"
    static var dateFormatter: DateFormatter {
        let formatter = DateFormatter()
        formatter.dateFormat = dateFormat
        formatter.locale = Locale.current
        formatter.timeZone = TimeZone.current
        return formatter
    }
    
    private static var isLoggingEnabled: Bool {
        #if DEBUG
        return true
        #else
        return false
        #endif
    }
    
    private static var logLevelsAllowed: [LogEvent] = [.v,
                                               .i,
                                               .d,
                                               .w,
                                               .e,
                                               .s]
    static func checkPermissionForLevel(event: LogEvent) -> Bool {
        return logLevelsAllowed.contains(event)
    }
    
    // MARK: - Loging methods
    
    
    /// Logs error messages on console with prefix [‼️]
    ///
    /// - Parameters:
    ///   - object: Object or message to be logged
    ///   - filename: File name from where loggin to be done
    ///   - line: Line number in file from where the logging is done
    ///   - column: Column number of the log message
    ///   - funcName: Name of the function from where the logging is done
    class func error( _ object: Any, filename: String = #file, line: Int = #line, column: Int = #column, funcName: String = #function) {
        if isLoggingEnabled && Log.checkPermissionForLevel(event: .e) {
            print("\(Date().toString()) \(LogEvent.e.rawValue)[\(sourceFileName(filePath: filename))]:\(line) -> \(object)")
        }
    }
    
    /// Logs info messages on console with prefix [ℹ️]
    ///
    /// - Parameters:
    ///   - object: Object or message to be logged
    ///   - filename: File name from where loggin to be done
    ///   - line: Line number in file from where the logging is done
    ///   - column: Column number of the log message
    ///   - funcName: Name of the function from where the logging is done
    class func info ( _ object: Any, filename: String = #file, line: Int = #line, column: Int = #column, funcName: String = #function) {
        if isLoggingEnabled && Log.checkPermissionForLevel(event: .i) {
            print("\(Date().toString()) \(LogEvent.i.rawValue)[\(sourceFileName(filePath: filename))]:\(line) -> \(object)")
        }
    }
    
    /// Logs debug messages on console with prefix [💬]
    ///
    /// - Parameters:
    ///   - object: Object or message to be logged
    ///   - filename: File name from where loggin to be done
    ///   - line: Line number in file from where the logging is done
    ///   - column: Column number of the log message
    ///   - funcName: Name of the function from where the logging is done
    class func debug( _ object: Any, filename: String = #file, line: Int = #line, column: Int = #column, funcName: String = #function) {
        if isLoggingEnabled && Log.checkPermissionForLevel(event: .d) {
            print("\(Date().toString()) \(LogEvent.d.rawValue)[\(sourceFileName(filePath: filename))]:\(line) -> \(object)")
        }
    }
    
    /// Logs messages verbosely on console with prefix [🔬]
    ///
    /// - Parameters:
    ///   - object: Object or message to be logged
    ///   - filename: File name from where loggin to be done
    ///   - line: Line number in file from where the logging is done
    ///   - column: Column number of the log message
    ///   - funcName: Name of the function from where the logging is done
    class func verbose( _ object: Any, filename: String = #file, line: Int = #line, column: Int = #column, funcName: String = #function) {
        if isLoggingEnabled && Log.checkPermissionForLevel(event: .v) {
            print("\(Date().toString()) \(LogEvent.v.rawValue)[\(sourceFileName(filePath: filename))]:\(line) -> \(object)")
        }
    }
    
    /// Logs warnings verbosely on console with prefix [⚠️]
    ///
    /// - Parameters:
    ///   - object: Object or message to be logged
    ///   - filename: File name from where loggin to be done
    ///   - line: Line number in file from where the logging is done
    ///   - column: Column number of the log message
    ///   - funcName: Name of the function from where the logging is done
    class func warning( _ object: Any, filename: String = #file, line: Int = #line, column: Int = #column, funcName: String = #function) {
        if isLoggingEnabled && Log.checkPermissionForLevel(event: .w) {
            print("\(Date().toString()) \(LogEvent.w.rawValue)[\(sourceFileName(filePath: filename))]:\(line) -> \(object)")
        }
    }
    
    /// Logs severe events on console with prefix [🔥]
    ///
    /// - Parameters:
    ///   - object: Object or message to be logged
    ///   - filename: File name from where loggin to be done
    ///   - line: Line number in file from where the logging is done
    ///   - column: Column number of the log message
    ///   - funcName: Name of the function from where the logging is done
    class func severe( _ object: Any, filename: String = #file, line: Int = #line, column: Int = #column, funcName: String = #function) {
        if isLoggingEnabled && Log.checkPermissionForLevel(event: .s) {
            print("\(Date().toString()) \(LogEvent.s.rawValue)[\(sourceFileName(filePath: filename))]:\(line) -> \(object)")
        }
    }
    
    /// Extract the file name from the file path
    ///
    /// - Parameter filePath: Full file path in bundle
    /// - Returns: File Name with extension
    private class func sourceFileName(filePath: String) -> String {
        let components = filePath.components(separatedBy: "/")
       
        let fileName = components.isEmpty ? "" : components.last!
        
        let name = fileName.components(separatedBy: ".").first
        
        return name!
    }
    
    // MARK: - Log Levels Configuration
    
    public static func configureLoggerLevelsDisplayed(verbose: Bool,
                                               info: Bool,
                                               debug: Bool,
                                               warning: Bool,
                                               error: Bool,
                                               severe: Bool) {
        var newLogLevelsAllowed = [LogEvent]()
        if verbose {
            newLogLevelsAllowed.append(.v)
        }
        if info {
            newLogLevelsAllowed.append(.i)
        }
        if debug {
            newLogLevelsAllowed.append(.d)
        }
        if warning {
            newLogLevelsAllowed.append(.w)
        }
        if error {
            newLogLevelsAllowed.append(.e)
        }
        if severe {
            newLogLevelsAllowed.append(.s)
        }
        Log.logLevelsAllowed = newLogLevelsAllowed
    }
}

internal extension Date {
    func toString() -> String {
        return Log.dateFormatter.string(from: self as Date)
    }
}