Math exercises for a 8 yrs old in Hungarian language

matek.R

## TODO R package
## TODO internation via yaml that also provides the list of languages for the UI
## TODO cli --ui hu --control en --number 1:20 ...

library(logger)
library(crayon)
library(reticulate)
num2words <- import('num2words')

## rich-iannone/UnidecodeR
library(UnidecodeR)

logpath <- '/tmp'
logpath <- getwd()
logfile <- file.path(logpath, paste0(as.integer(Sys.time()), '.log'))
log_appender(appender_file(logfile))
log_threshold(INFO)

n <- 10
cat('Hány feladatot szeretnél megoldani? ')

n <- suppressWarnings(as.numeric(readLines("stdin", n = 1)))
if (is.na(n)) {
    stop('HIBA!! Számot adj meg.')
}
log_info('Starting {n} exercises')

## TODO praise pkg
SUCCESS <- c(
    'Ügyes vagy!',
    "Szép munka!",
    "Ez az, csak így tovább!",
    "Juhúúú, ez is sikerült!",
    "Nagyon megy ez!"
)
FAIL <- c(
    "Ajaj, ez sajnos most nem sikerült.",
    "Húha, sajnos nem jó választ adtál!",
    "Hm, legközelebb jobban gondold át!"
)

number <- function(n = 1,
                   numbers = 0:20,
                   probs = c(1, 1:9, 2, 5:1, rep(1/2, 5))) {
    sample(numbers, n, replace = TRUE, prob = probs)
}
lhs <- function(exercise) {
    paste(exercise, '= ')
}

ask <- function(text) {
    ## readline
    cat(text)
    readLines("stdin", n = 1)
}
german <- function(number) {
    if (missing(number) || is.na(number) || number == '') {
        return(NA)
    }
    ## sub(' Komma null', '', system(paste('num2words -l de', number), intern = TRUE))
    num2words$num2words(number, lang = 'de')
}

scores <- 0
for (i in seq_len(n)) {

    type <- sample(c('+', '-', '*', '/'), 1, prob = c(1, 2, 4, 1))
    log_debug('Exercise type for #{i}: {type}')

    if (type == '+') {
        numbers  <- number(sample(2:3, 1, prob = c(4, 1)))
        question <- lhs(paste(numbers, collapse = ' + '))
        answer   <- sum(numbers)
    }

    if (type == '-') {
        numbers  <- number(2)
        question <- lhs(paste(numbers[2], numbers[1], sep = ' - '))
        answer   <- diff(numbers)
    }

    if (type == '*') {
        numbers  <- number(2)
        if (sum(nchar(numbers)) > 3) {
            numbers  <- number(2)
        }
        question <- lhs(paste(numbers[2], numbers[1], sep = ' × '))
        answer   <- numbers[1] * numbers[2]
    }

    if (type == '/') {
        numbers  <- number(2, numbers = 2:9, probs = c(2:9))
        question <- lhs(paste(numbers[1] * numbers[2], numbers[1], sep = ' : '))
        answer   <- numbers[2]
    }

    log_debug('Exercise #{i}: {question}')
    cat('[', i, '/', n, ']  ', sep = '')
    response <- ask(question)
    pass <- response == answer | response == unidecode(data = german(answer), language = 'de')
    log_debug('Response for #{i}: {response} ({pass})')
    log_info('Exercise #{i}: {question}{response} ({pass})')

    if (isTRUE(pass)) {
        scores <- scores + 1 + (response == unidecode(data = german(answer), language = 'de'))
        cat(green(sample(SUCCESS, 1), '\n'))
    } else {
        cat(red(sample(FAIL, 1), '\n'))
        cat('A helyes megoldás: ', answer, "", shQuote(german(answer)), '\n')
    }

}

log_info(paste('Score: ', scores, ' / ', n, ' (', round(scores / n * 100, 2), '%)', sep = ''))
cat('Pontszám: ', scores, ' / ', n, ' (', round(scores / n * 100, 2), '%)\n', sep = '')