implement date_range

Author: steveoni

src/danfojs-base/core/daterange.ts

@@ -0,0 +1,235 @@
+import { ArrayType1D, ArrayType2D } from "../shared/types"
+import Utils from "../shared/utils";
+
+const utils = new Utils();
+
+interface Params  {
+  start?: string;
+  offset?: number;
+  end?: string;
+  freq?: string;
+  period?: number
+}
+export default class DateRange {
+  private offset: number | undefined = null
+  private start: string | undefined
+  private end: string | undefined
+  private freq: string | undefined
+  private period: number | undefined
+  private freqList: string[]
+
+  constructor(params: Params) {
+    this.start = params.start
+    this.end = params.end
+    this.offset = params.offset
+    this.freq = params.freq
+    this.period = params.period
+    this.freqList  = [ "M", "D", "s", "H", "m", "Y" ]
+
+    if (this.freq.length == 1){
+      if (!this.freqList.includes(this.freq)){
+        throw new Error(`invalid freq ${this.freq}`);
+      }
+    } else {
+      this.offset = parseInt(this.freq.slice(0, -1));
+      if (!Number.isFinite(this.offset)){
+        throw new Error(`invalid freq offset ${this.freq.slice(0, -1)}`);
+      }
+      this.freq = this.freq.slice(-1);
+      if (!this.freqList.includes(this.freq)){
+        throw new Error(`invalid freq ${this.freq}`);
+      }
+    }
+
+
+  }
+
+  range({start, end, period, offset}: Params) {
+    let startDate: Date
+    let endDate: Date
+    let startRange: number
+    let endRange: number
+    if (start && end) {
+      startDate = new Date(start)
+      startRange = this.freqType(startDate, this.freq)
+      endDate = new Date(end)
+      endRange = this.freqType(endDate, this.freq)
+
+      let startYear = startDate.getFullYear()
+      let endYear = endDate.getFullYear()
+      if ((startYear <= endYear) && (startDate.getMonth() !== endDate.getMonth())){
+        if (this.freq == "M") {
+          endRange = this.monthEnd(startDate, endDate)
+        }
+        else if (this.freq === "D") {
+          endRange = this.dayEnd(startDate, endDate) - startRange
+        }
+      }
+      let rangeArray = utils.range(startRange, endRange)
+      if ( offset ) {
+        rangeArray =  this.offsetCount(rangeArray, offset)
+      }
+      let dateRange = rangeArray.map((x) => {
+        return this.setDateProps(startDate, this.freq, x)
+      })
+      dateRange[dateRange.length -1] = endDate
+      let dateString = this.toLocalString(dateRange)
+      return dateString
+    }
+    else if ( start && !(end) ) {
+      startDate = new Date(start)
+      startRange = this.freqType(startDate, this.freq)
+      endRange = offset ? ((period * offset) - 1) : period -1;
+
+      if ( startRange > endRange ) {
+        endRange = endRange + startRange
+      }
+      let rangeArray = utils.range(startRange, endRange)
+
+      if ( offset ) {
+        rangeArray = this.offsetCount(rangeArray, offset)
+      }
+      let dateRange = rangeArray.map((x) => {
+        return this.setDateProps(startDate, this.freq, x)
+      })
+
+      let dateString = this.toLocalString(dateRange)
+      return dateString
+    }
+    else if (end && !(start)) {
+      endDate = new Date(end)
+      endRange = this.freqType(endDate, this.freq)
+      startRange = (endRange - period) + 1
+      let rangeArray = utils.range(startRange, endRange)
+
+      if ( offset ) {
+        rangeArray = this.offsetCount(rangeArray, offset)
+      }
+      let dateRange = rangeArray.map((x) => {
+        return this.setDateProps(endDate, this.freq, x)
+      })
+      let dateString = this.toLocalString(dateRange)
+      return dateString
+    }
+  }
+
+  private freqType(date: Date, ftype: string): number{
+    let rslt: number = null;
+    switch (ftype){
+
+    case "M":
+      rslt = date.getMonth();
+      break;
+    case "Y":
+      rslt = date.getFullYear();
+      break;
+    case "s":
+      rslt = date.getSeconds();
+      break;
+    case "D":
+      rslt = date.getDate();
+      break;
+    case "H":
+      rslt = date.getHours();
+      break;
+    case "m":
+      rslt = date.getMinutes();
+      break;
+    }
+    return rslt;
+  }
+
+
+  private offsetCount(dArray: number[], offset: number) :number[] {
+    let rArray: number[] = []
+    for (let i = 0; i < dArray.length; i += offset){
+      rArray.push(dArray[i]);
+    }
+    return rArray;
+  }
+
+  private setDateProps(date: Date, ftype: string, val: number[] | number): Date {
+    let newDate = new Date(date.valueOf())
+    switch (ftype){
+      case "M":
+        if (Array.isArray(val)){
+  
+          newDate.setYear(newDate.getFullYear() + val[0]);
+          newDate.setMonth(val[1]);
+        } else {
+          newDate.setMonth(val);
+        }
+        break;
+      case "Y":
+        newDate.setYear(val as number);
+        break;
+      case "s":
+        newDate.setSeconds(val as number);
+        break;
+      case "D":
+        newDate.setDate(val as number);
+        break;
+      case "H":
+        newDate.setHours(val as number);
+        break;
+      case "m":
+        newDate.setMinutes(val as number);
+        break;
+      }
+      return newDate;
+  }
+
+
+  private toLocalString(dArray: Date[]) {
+    let r_array = dArray.map((x) => {
+      return x.toLocaleString();
+    });
+    return r_array;
+  }
+
+  private monthEnd(startDate: Date, endDate: Date) {
+    let endMonth = endDate.getMonth()
+    let diffYear = endDate.getFullYear() - startDate.getFullYear()
+    let endRange = (12 * diffYear) + endMonth
+    return endRange
+  }
+
+  private monthRange(range: number[]): number[][] {
+    let minus: number;
+    let yVal = 0
+    let dateRange: number[][] = range.map((x) => {
+      if (x > 11) {
+        if ( x % 12 == 0) {
+          minus = x
+          yVal = x / 12
+          return [yVal, (x - minus)]
+        }
+        else {
+          return [yVal, (x -minus)]
+        }
+      }
+      return [yVal, x]
+    })
+    return dateRange
+  }
+
+  private dayEnd(startDate: Date, endDate: Date): number{
+    let monthEnd = this.monthEnd(startDate, endDate)
+    let range = utils.range(startDate.getMonth(), monthEnd)
+    let mRange = this.monthRange(range)
+
+    let sum = 0
+    for (let i=0; i < mRange.length; i++) {
+      let val = mRange[i]
+      let dDate: number
+      if (i === mRange.length - 1) {
+        dDate = new Date(startDate.getUTCFullYear() + val[0], val[1], endDate.getDate()).getDate()
+      }
+      else {
+        dDate = new Date(startDate.getUTCFullYear() + val[0], val[1], 0).getDate()
+      }
+      sum += dDate
+    }
+    return sum
+  }
+}