//
//  DateUtils.swift
//  MTP2_iOS
//
//  Created by zhongyuan on 2018/6/12.
//  Copyright © 2018年 zhongyuan.All rights reserved.
//

import Foundation

/// 日期工具类
class DateUtils {
    /// 获取指定时间上一个月的时间
    ///
    /// - Parameter date: 不填时获取当前时间
    /// - Returns: 上一个月的时间
    static func getLastDate(_ date: Date = Date()) -> Date {
        var comps = DateComponents()
        comps.month = -1
        let calender = Calendar(identifier: .gregorian)
        let mdate = calender.date(byAdding: comps, to: date)
        return mdate!
    }
    
    /// 获取任一月份的时间
    /// - Parameters:
    ///   - month: month
    ///   - date: date
    static func getDiffMonthDate(month: Int, _ date: Date = Date()) -> Date {
        var comps = DateComponents()
        comps.month = month
        let calender = Calendar(identifier: .gregorian)
        let mdate = calender.date(byAdding: comps, to: date)
        return mdate!
    }
    
    /// 获取任一天数的时间
    /// - Parameters:
    ///   - month: month
    ///   - date: date
    static func getDiffDayhDate(day: Int, _ date: Date = Date()) -> Date {
        var comps = DateComponents()
        comps.day = day
        let calender = Calendar(identifier: .gregorian)
        let mdate = calender.date(byAdding: comps, to: date)
        return mdate!
    }
    
    static func getNextMonthDate(_ date: Date = Date()) -> Date {
        var comps = DateComponents()
        comps.month = 1
        let calender = Calendar(identifier: .gregorian)
        let mdate = calender.date(byAdding: comps, to: date)
        return mdate!
    }
    
    static func getSevenDaysAgo(_ date: Date = Date()) -> Date {
        var comps = DateComponents()
        comps.day = -7
        let calender = Calendar(identifier: .gregorian)
        let mdate = calender.date(byAdding: comps, to: date)
        return mdate!
    }
    
    /// 获取本年开始日期的方法
    static func startOfCurrentYear() -> Date {
        let date = Date()
        let calendar = Calendar.current
        let components = calendar.dateComponents(Set<Calendar.Component>([.year]), from: date)
        let startOfYear = calendar.date(from: components)!
        return startOfYear
    }
    
    /// 获取本月开始日期的方法
    static func startOfCurrentMonth() -> Date {
        let date = Date()
        let calendar = Calendar.current
        let components = calendar.dateComponents(Set<Calendar.Component>([.year, .month]), from: date)
        let startOfYear = calendar.date(from: components)!
        return startOfYear
    }
    
    /// 判断两个日期是否在同年的同一个月
    static func judgeSameYearMonth(target: Date, source: Date = Date()) -> Bool {
        let calendar = Calendar.current
        let targetComponents = calendar.dateComponents(Set<Calendar.Component>([.year, .month]), from: target)
        let sourceComponents = calendar.dateComponents(Set<Calendar.Component>([.year, .month]), from: source)
        if calendar.date(from: targetComponents)!.compare(calendar.date(from: sourceComponents)!) == .orderedSame {
            return true
        }
        return false
    }
    
    /// 根据时间戳获取对应的时间信息
    /// - Parameters:
    ///   - timeInterval: timeInterval
    ///   - formatter: formatter
    /// - Returns: String
    static func dateStringSince1970(_ timeInterval: TimeInterval, _ formatter: String = "yyyy-MM-dd") -> String {
        return Date(timeIntervalSince1970: timeInterval/1000).getString(formatter: formatter)
    }
    
    /// 获取带T的时间戳的时间字符串
    /// - Parameter dateString: dateString
    /// - Returns: String
    static func getTDateString(_ dateString: String, _ formatter: String = "yyyy-MM-dd") -> String {
        let dateFormatter = DateFormatter()
        let tempLocale = dateFormatter.locale
        dateFormatter.locale = Locale(identifier: "en_US_POSIX")
        dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ssZ"
        let date = dateFormatter.date(from: dateString) ?? Date()
        dateFormatter.dateFormat = formatter
        dateFormatter.locale = tempLocale 
        return dateFormatter.string(from: date)
    }
    
    /// 获取两个时间戳间隔时分秒
    /// - Parameters:
    ///   - timer1: timer1
    ///   - timer2: timer2
    ///   - count: count
    /// - Returns: String
    static func diffs(_ timer1: TimeInterval, _ timer2: TimeInterval, _ count: Double) -> DateComponents? {
        
        let formatter = DateFormatter()
        formatter.dateStyle = .medium
        formatter.timeStyle = .short
        formatter.dateFormat = "YYYY-MM-dd HH:mm:ss"
        
        let date1 = Date(timeIntervalSince1970: timer1-count)
        let date2 = Date(timeIntervalSince1970: timer2)
        
        /// 日历对象（方便比较两个日期之间的差距）
        let calendar = Calendar.current
        return calendar.dateComponents(Set<Calendar.Component>([.hour, .minute, .second]), from: date1, to: date2)
    }
}