{{NepaliDateConverter}}


local p = {};     
--This function converts nepali date to english date
-- See MOS for date format(Wikipedia:Manual of Style/Dates and numbers)
--The output can be checked by using following code in article page/template page
--{{#invoke:moduleForNepaliDateConverter|returnEnglishDate|nepaiYear=1984|nepaliMonth=6|nepaliDay=21}}-->Retruns full date
--{{#invoke:moduleForNepaliDateConverter|returnEnglishDate|nepaiYear=1984}}-->Retruns years e.g. 2007-2008

function p.returnEnglishDate(frame)  -- add a function to p
	local n_year = tonumber(frame.args.nepaliYear) 
	local n_month = tonumber(frame.args.nepaliMonth) 
	local n_day = tonumber(frame.args.nepaliDay)    
	--define variables to hold converted date
	local e_date 
	-- when nepali day or month is missing, retrun the year only
	-- or when date is out of range(2000-2089 BS), return year only
	-- or when there are error in days or months, return year only
	local e_year1
	local e_year2
	
	if (n_month== nil or n_month>12 or n_day==nil or n_day>32 or n_year < 2000 or n_year > 2089) then
		e_year1=n_year-57
		e_year2=n_year-56
		e_date=n_year .. ' [[Bikram Sambat|BS]] ('.. e_year1 .. '-' .. e_year2 .. ')'
		return e_date
	end
	-- when both month and day is given, and year is in range  and return compelte date
	--- calculate
	e_date=p.nep_to_eng(n_year, n_month, n_day)
	return e_date
end

function p.nep_to_eng(yy, mm, dd)
            local def_nyy = 2000
            local def_nmm = 1
            local def_ndd = 1         -- equivalent nepali dates
            -- initializate
            local total_nDays = 0
            local i = 0
            local k = 1
            local numDay = 0
            -- array for nepali calendar
            local bs={} --declear array to hold bikram sambat calendar and fill the array
			bs[1]={2000, 30, 32, 31, 32, 31, 30, 30, 30, 29, 30, 29, 31}
			bs[2]={2001, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30}
			bs[3]={2002, 31, 31, 32, 32, 31, 30, 30, 29, 30, 29, 30, 30}
			bs[4]={2003, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 31}
			bs[5]={2004, 30, 32, 31, 32, 31, 30, 30, 30, 29, 30, 29, 31}
			bs[6]={2005, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30}
			bs[7]={2006, 31, 31, 32, 32, 31, 30, 30, 29, 30, 29, 30, 30}
			bs[8]={2007, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 31}
			bs[9]={2008, 31, 31, 31, 32, 31, 31, 29, 30, 30, 29, 29, 31}
			bs[10]={2009, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30}
			bs[11]={2010, 31, 31, 32, 32, 31, 30, 30, 29, 30, 29, 30, 30}
			bs[12]={2011, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 31}
			bs[13]={2012, 31, 31, 31, 32, 31, 31, 29, 30, 30, 29, 30, 30}
			bs[14]={2013, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30}
			bs[15]={2014, 31, 31, 32, 32, 31, 30, 30, 29, 30, 29, 30, 30}
			bs[16]={2015, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 31}
			bs[17]={2016, 31, 31, 31, 32, 31, 31, 29, 30, 30, 29, 30, 30}
			bs[18]={2017, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30}
			bs[19]={2018, 31, 32, 31, 32, 31, 30, 30, 29, 30, 29, 30, 30}
			bs[20]={2019, 31, 32, 31, 32, 31, 30, 30, 30, 29, 30, 29, 31}
			bs[21]={2020, 31, 31, 31, 32, 31, 31, 30, 29, 30, 29, 30, 30}
			bs[22]={2021, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30}
			bs[23]={2022, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 30}
			bs[24]={2023, 31, 32, 31, 32, 31, 30, 30, 30, 29, 30, 29, 31}
			bs[25]={2024, 31, 31, 31, 32, 31, 31, 30, 29, 30, 29, 30, 30}
			bs[26]={2025, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30}
			bs[27]={2026, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 31}
			bs[28]={2027, 30, 32, 31, 32, 31, 30, 30, 30, 29, 30, 29, 31}
			bs[29]={2028, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30}
			bs[30]={2029, 31, 31, 32, 31, 32, 30, 30, 29, 30, 29, 30, 30}
			bs[31]={2030, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 31}
			bs[32]={2031, 30, 32, 31, 32, 31, 30, 30, 30, 29, 30, 29, 31}
			bs[33]={2032, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30}
			bs[34]={2033, 31, 31, 32, 32, 31, 30, 30, 29, 30, 29, 30, 30}
			bs[35]={2034, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 31}
			bs[36]={2035, 30, 32, 31, 32, 31, 31, 29, 30, 30, 29, 29, 31}
			bs[37]={2036, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30}
			bs[38]={2037, 31, 31, 32, 32, 31, 30, 30, 29, 30, 29, 30, 30}
			bs[39]={2038, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 31}
			bs[40]={2039, 31, 31, 31, 32, 31, 31, 29, 30, 30, 29, 30, 30}
			bs[41]={2040, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30}
			bs[42]={2041, 31, 31, 32, 32, 31, 30, 30, 29, 30, 29, 30, 30}
			bs[43]={2042, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 31}
			bs[44]={2043, 31, 31, 31, 32, 31, 31, 29, 30, 30, 29, 30, 30}
			bs[45]={2044, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30}
			bs[46]={2045, 31, 32, 31, 32, 31, 30, 30, 29, 30, 29, 30, 30}
			bs[47]={2046, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 31}
			bs[48]={2047, 31, 31, 31, 32, 31, 31, 30, 29, 30, 29, 30, 30}
			bs[49]={2048, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30}
			bs[50]={2049, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 30}
			bs[51]={2050, 31, 32, 31, 32, 31, 30, 30, 30, 29, 30, 29, 31}
			bs[52]={2051, 31, 31, 31, 32, 31, 31, 30, 29, 30, 29, 30, 30}
			bs[53]={2052, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30}
			bs[54]={2053, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 30}
			bs[55]={2054, 31, 32, 31, 32, 31, 30, 30, 30, 29, 30, 29, 31}
			bs[56]={2055, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30}
			bs[57]={2056, 31, 31, 32, 31, 32, 30, 30, 29, 30, 29, 30, 30}
			bs[58]={2057, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 31}
			bs[59]={2058, 30, 32, 31, 32, 31, 30, 30, 30, 29, 30, 29, 31}
			bs[60]={2059, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30}
			bs[61]={2060, 31, 31, 32, 32, 31, 30, 30, 29, 30, 29, 30, 30}
			bs[62]={2061, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 31}
			bs[63]={2062, 30, 32, 31, 32, 31, 31, 29, 30, 29, 30, 29, 31}
			bs[64]={2063, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30}
			bs[65]={2064, 31, 31, 32, 32, 31, 30, 30, 29, 30, 29, 30, 30}
			bs[66]={2065, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 31}
			bs[67]={2066, 31, 31, 31, 32, 31, 31, 29, 30, 30, 29, 29, 31}
			bs[68]={2067, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30}
			bs[69]={2068, 31, 31, 32, 32, 31, 30, 30, 29, 30, 29, 30, 30}
			bs[70]={2069, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 31}
			bs[71]={2070, 31, 31, 31, 32, 31, 31, 29, 30, 30, 29, 30, 30}
			bs[72]={2071, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30}
			bs[73]={2072, 31, 32, 31, 32, 31, 30, 30, 29, 30, 29, 30, 30}
			bs[74]={2073, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 31}
			bs[75]={2074, 31, 31, 31, 32, 31, 31, 30, 29, 30, 29, 30, 30}
			bs[76]={2075, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30}
			bs[77]={2076, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 30}
			bs[78]={2077, 31, 32, 31, 32, 31, 30, 30, 30, 29, 30, 29, 31}
			bs[79]={2078, 31, 31, 31, 32, 31, 31, 30, 29, 30, 29, 30, 30}
			bs[80]={2079, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30}
			bs[81]={2080, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 30}
			bs[82]={2081, 31, 31, 32, 32, 31, 30, 30, 30, 29, 30, 30, 30}
			bs[83]={2082, 30, 32, 31, 32, 31, 30, 30, 30, 29, 30, 30, 30}
			bs[84]={2083, 31, 31, 32, 31, 31, 30, 30, 30, 29, 30, 30, 30}
			bs[85]={2084, 31, 31, 32, 31, 31, 30, 30, 30, 29, 30, 30, 30}
			bs[86]={2085, 31, 32, 31, 32, 30, 31, 30, 30, 29, 30, 30, 30}
			bs[87]={2086, 30, 32, 31, 32, 31, 30, 30, 30, 29, 30, 30, 30}
			bs[88]={2087, 31, 31, 32, 31, 31, 31, 30, 30, 29, 30, 30, 30}
			bs[89]={2088, 30, 31, 32, 32, 30, 31, 30, 30, 29, 30, 30, 30}
			bs[90]={2089, 30, 32, 31, 32, 31, 30, 30, 30, 29, 30, 30, 30}
			bs[91]={2090, 30, 32, 31, 32, 31, 30, 30, 30, 29, 30, 30, 30}

			-- if additional calander becomes available, please put here
            --count total days for upto given year
                for i = 0, yy - def_nyy-1 do
                    for j = 2, 13 do
                        total_nDays = total_nDays + bs[k][j]
                    end
                    k = k + 1
                end
           --count and add days for the months 
                for j = 2, mm - 1+1 do
                    total_nDays = total_nDays + bs[k][j]
                end
                
            --count and add total days within the month
                total_nDays = total_nDays + dd
               aaa= total_nDays
            --=======================================
            ---calculation of equivalent english date--
            --========================================
            local def_eyy = 1943
            local def_emm = 4
            local def_edd = 14 - 1   -- 1 Baisakh 2000 BS=14 April , 1943 AD
            -- array for english calendar
            local month = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31} --normal english year
            local lmonth = { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31} --leap english year
            local a = 0 -- to hold days of a month during calculation
            local total_eDays = def_edd
            local day = 4 - 1  
            
               local m = def_emm
               local y = def_eyy
                while (total_nDays ~= 0)
                do
                    if (p.is_leap_year(y)) then
                         a = lmonth[m]
                    else
                        a = month[m]
                    end
                    total_eDays = total_eDays + 1
                    day = day + 1
                    if (total_eDays > a) then
                        m = m + 1
                        total_eDays = 1
                        if (m > 12) then
                            y = y + 1
                            m = 1
                        end
                    end
                    if (day > 7) then 
                    	day = 1
                    end
                    total_nDays = total_nDays - 1
                end
                numDay = day
                local monthNameEnglish={'January','February','March','April','May','June','July','August','September','October','November','December'}
                local monthNameNepali={'Baisakh','Jesth','Ashad','Shrawan','Bhadra','Ashwin','Kartik','Mangsir','Poush','Magh','Falgun','Chaitra'}
                returnVal=total_eDays..' '..monthNameEnglish[m]..' '..y..' ('.. dd ..' '.. monthNameNepali[mm]..' '.. yy..' [[Bikram Sambat|BS]])'
                 return returnVal
end

function p.is_leap_year(year)
	--this function checks if the given year is a leap year or not
	local returnVal
    local a = tonumber(year)
    if math.fmod(a,100) == 0 then
            if math.fmod(a,400) == 0 then
                returnVal = true
            else
                returnVal = false
            end
     else
            if math.fmod(a,4)==0 then
               returnVal = true
            else
                returnVal = false
            end
    end
    return returnVal
end
        
   
return p    --All modules end by returning the variable containing their functions to Wikipedia.