dplyr - mutate , subset and group_by

add missing dates and fill NAs

#Padr package method
#https://statisticsglobe.com/insert-rows-for-missing-dates-in-r
#install.packages("padr")
library(padr)
offerdata_padr <- pad(offerdata)
View(offerdata_padr)
#https://www.statology.org/dplyr-replace-na-with-zero/
#Add rows for missing dates and replace NAs with zero
offerdata2<- offerdata%>%
complete(Date = seq.Date(min(Date), max(Date), by="day"))%>%
replace(is.na(.), 0)
View(offerdata2)

dplyr - mutate , subset and group_by.r

#Create column 'inoffer' where  > Mark rows as in offer or not 
#(only John Wick or John Wick 2)
#Also, Date must be > 2021-01-01

offerdata<- data%>%
mutate(inOffer=
ifelse(str_detect(Item,"^John Wick$|^John Wick 2$"),
"In offer",
"Not in offer")) %>%
subset(inOffer=="In offer"&
data$Date>as.Date("2021-01-01")) %>%
group_by(Date) %>%
summarise(Quantity_sold=sum(Quantity_sold))