library("shiny")
library("ggplot2")
library("DT")
library("reshape2")
## load data ##

aqi = read.csv(file = "C:/Users/stan/Desktop/AIR/month.csv",
               header = T, sep = ",")
str(aqi)
colnames(aqi) = c("num","month",
                  "PM10","PM2.5","NO","NO2")
## ui.R ##

ui = fluidPage(
  titlePanel('AIR'),
  sidebarLayout(
    sidebarPanel(
      selectInput('month',
                  'Choose a month:',
                  c('All', unique(as.character(aqi$month)
                  ))),
      selectInput('PM10',
                  'Number of :PM10',
                  c('All', unique(as.character(aqi$PM10)
                  ))),
      selectInput('PM2.5',
                  'Number of PM2.5:',
                  c('All',unique(as.character(aqi$PM2.5)
                  ))),
      selectizeInput("AIR",
                     "Select Contaminant:",
                     choices = c( "PM2.5",
                                  "PM10"),
                     selected = "PM2..5",
                     multiple = TRUE )
  ),

    mainPanel(
      dataTableOutput('table'),
      plotOutput("plot")
    )
  )
)


## server.R ##

server = function(input, output) {
  # Filter data based on selections
  output$table <- DT::renderDataTable(DT::datatable({
    data <- aqi
    if (input$month != "All") {
      data <- data[aqi$month == input$month,]
    }
    if (input$PM10 != "All") {
      data <- data[aqi$PM10 == input$PM10,]
    }
    data
    if (input$PM2.5 != "All") {
      data <- data[aqi$PM2.5 == input$PM2.5,]
    }
    data
  }))
  output$plot = renderPlot({
    plot.data <- melt(aqi, id.vars= "month")
    #not sure if input$cnt is a list or a vector
    #may need to manipulate that before passing
    plot.data <- plot.data[plot.data$variable %in% input$AIR, ]
    ggplot(plot.data) +
      geom_line(mapping = aes(x = month, y = value , colour =variable)) +
      labs (x = "month", y = "value", title = "AIR") +
      scale_colour_discrete(name = "AIR")
  })
}

shinyApp(ui, server)