library(shiny)
library(RODBC)

# Copied from https://github.com/szilard/shinyvalidinp/blob/master/R/shinyvalidinp.R
# Fixed by Security XIII to work on Linux
validinp_character <- function(x, pattern="^[[:alnum:]. _-]*$", many=FALSE) {
  if(many && is.null(x)) return(character(0))  ## hack for checkboxGroupInput
  if(!( is.character(x) && (many || length(x)==1) && 
        all(!is.na(x)) && all(grepl(pattern,x)) )) {
    stop("Illegal characters in the user name")
  }
  x
}

# Define UI for application that draws a histogram
ui <- fluidPage(
  
  # Application title
  titlePanel("Golos - check current post bandwidth"),
  
  # Sidebar with a slider input for number of bins 
  verticalLayout(
    textInput("name",
              "User name:",
              width = '200px'),
    actionButton("goButton", "Go!"),
    # TODO make submit on Enter https://github.com/daattali/advanced-shiny/blob/master/proxy-click/app.R
    textOutput("message"),
    HTML("<br /><br />This app is developed by <a href=http://golos.io/@oxygendependant>@oxygendependant</A> and is using GolosSQL server, thanks to <a href=http://golos.io/@arcange>@arcange</a>.
         <br /><a href=https://github.com/oxyen/golos-post-bandwidth>Source code at github</A>")
    )
  )


# Define server logic required to draw a histogram
server <- function(input, output) {
  output$message<-renderText({
    name<-validinp_character(input$name)
    if (input$goButton == 0)
      return()
    msg<-isolate({
      dbhandle <- odbcDriverConnect('Driver=FreeTDS;TDS_Version=7.0;Server=sql.golos.cloud;Port=1433;Uid=golos;Pwd=golos')
      # TODO Need a check if the username exists at all (and there wasn't a typo)
      last.created <- sqlQuery(dbhandle, 
                               paste0('SELECT Top 1 created FROM Comments WHERE depth=0
                                      AND author=\'', name, '\'
                                      ORDER BY Created DESC'))[[1]]
      last.created <- sqlQuery(dbhandle, 
                               paste0('SELECT Top 1 created FROM Comments WHERE depth=0
                                      AND author=\'', name, '\'
                                      ORDER BY Created DESC'))[[1]]
      in30min <- sqlQuery(dbhandle, 
                          paste0('SELECT COUNT(*) FROM Comments WHERE depth=0
                                 AND author=\'', name, '\'
                                 AND created >= DateAdd(mi, -30, GETUTCDATE())'))[[1]]
      last.bandw <- sqlQuery(dbhandle, 
                             paste0('SELECT Top 1 post_bandwidth FROM Accounts
                                    WHERE name=\'', name, '\''))[[1]]
      
      orig.time <- Sys.time()
      gmttime <- function(x) as.character(as.POSIXlt(x, tz="GMT"))
      curtime <- gmttime(orig.time)
      passed <- as.integer(difftime(curtime, last.created, units="secs"))
      bandw <- round(last.bandw * (1 - min(passed, 86400) / 86400))
      
      acceptable.age <- round(86400 - 2592000000 / max(last.bandw, 30000))
      # 2592000000 = 30k * (60 * 60 * 24)
      
      extra.bandw <- max(bandw - 30000, 0)
      
      msg<-paste0("Currently consumed bandwidth is ",
                  bandw,
                  " (be sure that GolosSQL has catched up on the latest ones - it knows of ",
                  in30min,
                  " posts from the last 30 minutes).",
                  if(extra.bandw > 0) {
                    remaining_time_min <-  (acceptable.age - passed) / 60
                    penalty <- round(100 * (1 - (40000 / (bandw + 10000)) ^ 2))
                    paste0(" Remaining time is ",
                           remaining_time_min%/%60,
                           " hours ",
                           round(remaining_time_min%%60),
                           " minutes. If you were to post right now, penalty would be ",
                           penalty,
                           "%.")
                  }
                  else
                    ". It's ok to post now."
      )
      odbcClose(dbhandle)
      return(msg)
    })
  })
}
# Run the application 
shinyApp(ui = ui, server = server)

# For debug
# sqlQuery(dbhandle, 'SELECT top 1 url FROM Comments WHERE reward_weight < 10000 ORDER BY Created DESC'