根據某個開始結束時間算出每週的開始結束時間

直接看代碼：

	/**
     * 處理週數據
     * @param $data 數據（數據中要有一個時間）
     * @return Array
     */
function getWeekData( $data , $start_time , $end_time ) {
        $week = $this->getWeekDate( $start_time , $end_time );

        # 返回數據
        $res = [];
        for ( $i = 0; $i < count( $week ); $i++ ) {
            $count = 0;
            foreach ( $data as $k => $v ) {
                if( $v['add_time'] >= $week[$i]['start'] && $v['add_time'] <= $week[$i]['end'] ) {
                    $count++;
                }
            }

            if( $count ) {
                $res[] = [
                    'day' => '第'. ( $i+1 ) .'周' ,
                    'start_time' => date( 'Y-m-d' , $week[$i]['start'] ) ,
                    'end_time' => date( 'Y-m-d' ,$week[$i]['end'] ) 
                ];
            } else {
                $res[] = [
                    'day' => '第'.( $i+1 ).'周' ,
                    'start_time' => date( 'Y-m-d' ,$week[$i]['start'] ) ,
                    'end_time' => date( 'Y-m-d' ,$week[$i]['end'] )
                ];
            }
        }

        return $res;
    }


    /**
     * 處理週日期
     * @param $start_time 開始時間
     * @param $end_time 結束時間
     * @return Array 每週的開始和結束時間戳
     */
   function getWeekDate( $start_time , $end_time ) {
        # 每週開始結束時間
        $week = [];

        # 還有幾天這周結束
        $add = 0;

        switch ( date("w",$start_time) ) {
            case 1:
                $add = 6;
                break;
            case 2:
                $add = 5;
                break;
            case 3:
                $add = 4;
                break;
            case 4:
                $add = 3;
                break;
            case 5:
                $add = 2;
                break;
            case 6:
                $add = 1;
                break;
            case 0:
                $add = 0;
                break;
        }
        # 本週開始時間
        $week_start = mktime(0,0,0,date('m' , $start_time ), 1 ,date('Y' , $start_time ) );

        # 本週結束時間
        $week_end = mktime( 23 , 59 , 59 , date( 'm' , $start_time ) , date( 'd' , $start_time ) + $add , date( 'y' , $start_time ) );

        # 取到第一週的開始結束時間戳
        $week[] = [ 'start' =>  $week_start , 'end' => $week_end ];



        # 結束時間前面有幾天
        $del = 0;

        switch ( date( 'w' , $end_time ) ) {
            case 1:
                $del = 0;
                break;
            case 2:
                $del = 1;
                break;
            case 3:
                $del = 2;
                break;
            case 4:
                $del = 3;
                break;
            case 5:
                $del = 4;
                break;
            case 6:
                $del = 5;
                break;
            case 0:
                $del = 6;
                break;
        }

        # 最後一週開始時間
        $last_start = mktime( 0 , 0 , 0 , date( 'm' , $end_time ) , date( 'd' , $end_time ) - $del , date( 'Y' , $end_time ) );

        # 最後一週結束時間
        $last_end = mktime( 23 , 0 , 0 , date( 'm' , $end_time ) , date( 'd' , $end_time ) , date( 'Y' , $end_time ) );

        $last = [ 'start' => $last_start , 'end' => $last_end ];

        # 計算中間幾個周共多少天
        $days_count = round(( $last_start - ( $week_end +1 ) ) / 86400 );

        # 第二週開始時間戳
        $start_two = $week_end+1;

        # 生成中間的幾個周的開始結束時間戳
        for ( $i = 0; $i < $days_count; $i = $i+7 ) {
            $center_start = mktime( 0 , 0 , 0 , date( 'm' , $start_two ) , date( 'd' , $start_two ) + $i , date( 'Y', $start_two ) );

            $center_end = mktime( 23 , 59 , 59 , date( 'm' , $start_two ) , date( 'd' , $start_two ) + ( $i + 6 ) , date( 'Y' , $start_two ) );

//            $start_two = $center_start;

            $week[] = [ 'start' => $center_start , 'end' => $center_end ];
        }

        $week[] = $last;

        return $week;
    }