From 17ca65afbbe421e70229374a914d43bef0d28c9d Mon Sep 17 00:00:00 2001
From: sanghee <anshee97@naver.com>
Date: Sun, 12 Jun 2022 14:17:02 +0900
Subject: [PATCH] =?UTF-8?q?chore:=20CalendarViewModel=EC=97=90=20=EB=A1=9C?=
 =?UTF-8?q?=EC=A7=81=20=EC=B6=94=EA=B0=80=20(ios-h/airbnb#32)?=
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---
 .../ViewModel/CalendarViewModel.swift         | 36 ++++++++++++++++---
 1 file changed, 32 insertions(+), 4 deletions(-)

diff --git a/iOS/airbnb/Present/Main/Calendar/ViewModel/CalendarViewModel.swift b/iOS/airbnb/Present/Main/Calendar/ViewModel/CalendarViewModel.swift
index 795d29484..a07aabcb9 100644
--- a/iOS/airbnb/Present/Main/Calendar/ViewModel/CalendarViewModel.swift
+++ b/iOS/airbnb/Present/Main/Calendar/ViewModel/CalendarViewModel.swift
@@ -11,12 +11,40 @@ final class CalendarViewModel {
     static let weeks = ["일", "월", "화", "수", "목", "금", "토"]
     
     let today = Date() // 오늘의 날짜
-    let dateOfToday = Date() // 날짜를 계산하는 기준 날짜
+    var dateOfToday = Date() // 날짜를 계산하는 기준 날짜
     let dateComponents = DateComponents()
     let dateStringOfToday: String? = nil
-    let totalDates = [String]() // dates를 담는 배열
-    let daysCountInMonth = 0 // 해당 월이 며칠까지 있는지
-    let weekdayStarting = 0 // 시작일
+    var totalDates = [String]() // dates를 담는 배열
+    var daysCountInMonth = 0 // 해당 월이 며칠까지 있는지
+    var weekdayStarting = 0 // 시작일
+    let calendarManager = CalendarManager()
     
+    func previousMonth() {
+        dateOfToday = calendarManager.minusMonth(date: dateOfToday)
+        self.calculateMonth()
+    }
     
+    func nextMonth() {
+        dateOfToday = calendarManager.plusMonth(date: dateOfToday)
+        self.calculateMonth()
+    }
+    
+    // 월별 날짜를 계산하고 뷰에 표시
+    func calculateMonth() {
+        let firstDayOfMonth = calendarManager.firstOfMonth(date: dateOfToday) // 첫째날의 전 일.. 예를 들면 7월 1일 이전인 6월 30일 나옴.
+        let firstWeekday = calendarManager.weekDay(date: firstDayOfMonth) // 해당 월에서 첫번째로 시작하는 요일
+        
+        daysCountInMonth = calendarManager.calendar.range(of: .day, in: .month, for: firstDayOfMonth)!.count
+        weekdayStarting = 1 - firstWeekday
+        
+        self.totalDates.removeAll()
+        
+        for day in weekdayStarting...daysCountInMonth {
+            if day < 1 {
+                self.totalDates.append("")
+            } else {
+                self.totalDates.append(String(day))
+            }
+        }
+    }
 }