// Use Spec0015.nui // Functions StringIsDate and StringIsDateTime
Use Strings.nui  // String manipulation for VDF and 3.1 (No User Interface)
Use Dates.nui    // Date routines (No User Interface)

// Function returns DFTRUE if the string contains a legal date.
function StringIsDate global string lsValue integer liDateSep integer liFormat returns integer
  integer liCurrentDF liCurrentSep liLen
  string lsDateSep lsYear lsMonth lsDay
  move (trim(lsValue)) to lsValue
  move (length(lsValue)) to liLen
  if liLen eq 0 function_return DFTRUE

  ifnot liDateSep begin
    if (length(lsValue)=7) move (append("0",lsValue)) to lsValue
    if (liFormat=DF_DATE_MILITARY) begin // YMD 05061962
      insert "#" in lsValue at 7
      insert "#" in lsValue at 5
    end
    else begin
      insert "#" in lsValue at 5
      insert "#" in lsValue at 3
    end
    move "#" to lsDateSep
    if (liLen<7 or liLen>8) function_return DFFALSE
  end
  else begin
    move (character(liDateSep)) to lsDateSep
    if (liLen<5 or liLen>10) function_return DFFALSE
  end
  if (HowManyWords(lsValue,lsDateSep)<>3) function_return DFFALSE

  if (liFormat=DF_DATE_EUROPEAN) begin // DMY
    move (ExtractWord(lsValue,lsDateSep,1)) to lsDay
    move (ExtractWord(lsValue,lsDateSep,2)) to lsMonth
    move (ExtractWord(lsValue,lsDateSep,3)) to lsYear
  end
  if (liFormat=DF_DATE_USA) begin      // MDY
    move (ExtractWord(lsValue,lsDateSep,1)) to lsMonth
    move (ExtractWord(lsValue,lsDateSep,2)) to lsDay
    move (ExtractWord(lsValue,lsDateSep,3)) to lsYear
  end
  if (liFormat=DF_DATE_MILITARY) begin // YMD
    move (ExtractWord(lsValue,lsDateSep,1)) to lsYear
    move (ExtractWord(lsValue,lsDateSep,2)) to lsMonth
    move (ExtractWord(lsValue,lsDateSep,3)) to lsDay
  end
  ifnot (StringIsInteger(lsDay)) function_return DFFALSE
  ifnot (StringIsInteger(lsMonth)) function_return DFFALSE
  ifnot (StringIsInteger(lsYear)) function_return DFFALSE
  function_return (DateIsLegalComponents(lsDay,lsMonth,lsYear))
end_function

function StringFormatToDate global string lsValue integer liDateSep integer liFormat returns date
  integer liDay liMonth liYear
  if (liFormat=DF_DATE_EUROPEAN) begin // DMY
    move (ExtractInteger(lsValue,1)) to liDay
    move (ExtractInteger(lsValue,2)) to liMonth
    move (ExtractInteger(lsValue,3)) to liYear
  end
  if (liFormat=DF_DATE_USA) begin      // MDY
    move (ExtractInteger(lsValue,1)) to liMonth
    move (ExtractInteger(lsValue,2)) to liDay
    move (ExtractInteger(lsValue,3)) to liYear
  end
  if (liFormat=DF_DATE_MILITARY) begin // YMD
    move (ExtractInteger(lsValue,1)) to liYear
    move (ExtractInteger(lsValue,2)) to liMonth
    move (ExtractInteger(lsValue,3)) to liDay
  end
  function_return (DateCompose(liDay,liMonth,liYear))
end_function

function StringIsDateCurrentFormat global string lsValue returns boolean
  integer liDateFormat liSep
  get_attribute DF_DATE_SEPARATOR to liSep
  get_attribute DF_DATE_FORMAT to liDateFormat
  function_return (StringIsDate(lsValue,liSep,liDateFormat))
end_function

function StringIsDateTime global string lsValue integer liDateSep integer liFormat returns integer
  string lsDate lsTime lsHour lsMinute lsSecond
  if (trim(lsValue)="") function_return DFTRUE
  if (HowManyWords(lsValue," ")=2) begin
    move (ExtractWord(lsValue," ",1)) to lsDate
    move (ExtractWord(lsValue," ",2)) to lsTime
    if (HowManyWords(lsTime,":")=3) begin
      move (ExtractWord(lsTime,":",1)) to lsHour
      move (ExtractWord(lsTime,":",2)) to lsMinute
      move (ExtractWord(lsTime,":",3)) to lsSecond
      ifnot (StringIsInteger(lsHour)) function_return DFFALSE
      ifnot (StringIsInteger(lsMinute)) function_return DFFALSE
      ifnot (StringIsInteger(lsSecond)) function_return DFFALSE
      if (integer(lsHour)<24 and integer(lsMinute)<60 and integer(lsSecond)<60) function_return (StringIsDate(lsDate,liDateSep,liFormat))
    end
  end
  function_return DFFALSE
end_function