box::use(
  utils[head, read.csv2],
  shiny[div, moduleServer, downloadLink, downloadHandler, sliderInput, tagList, req, reactiveVal, actionButton, fileInput, observeEvent, h1, h3, p, NS, selectizeInput, HTML, tags],
  bslib[page_fillable, page_sidebar, nav_panel, page_navbar, layout_columns, card, card_header, card_body, layout_column_wrap, value_box, input_dark_mode, nav_item],
  shinyWidgets[pickerInput],
  waiter[useWaiter, autoWaiter, waiter_show, spin_fading_circles, waiter_hide, waiterShowOnLoad, waiter_on_busy],
  spacyr[spacy_install],
  data.table[fread, fwrite],
)

box::use(
  view / mod_search_books,
  view / mod_recommend_books,
  view / mod_data_analysis
)


#' @export
ui <- function(id) {
  ns <- NS(id)
  page_navbar(
    title = "Book Recommender",
    sidebar = my_sidebar(ns),
    fillable = FALSE,
    nav_panel(
      useWaiter(),
      waiter_on_busy(html = tagList(div(class = "main-waiter", h3("Give me a second to read all those books..."), spin_fading_circles()))),
      # waiterShowOnLoad(html = tagList(div(class = "main-waiter", h3("Give me a second to read all those books..."), spin_fading_circles()))),
      title = "Recommendations",
      tags$main(
        class = "main-container",
        tags$section(
          h1("Discover books you will love!", class = "align-text-center"),
          div(class = "text-main align-text-center", p(" Enter books you like and the site will analyse the contents of the books to provide book recommendations and suggestions for what to read next.")),
          mod_search_books$ui(ns("search_books")),
          mod_recommend_books$ui(ns("recommend_books"))
        )
      )
    ),
    nav_panel(
      "Data analysis",
      mod_data_analysis$ui(ns("data_analysis"))
    ),
    # nav_item(
    #   fileInput(ns("upload_goodreads"), NULL, buttonLabel = "Upload goodreads", multiple = FALSE)
    # ),
  )
}

#' @export
server <- function(id) {
  moduleServer(id, function(input, output, session) {
    gargoyle::init("start_recommend_event")

    # LOAD DATA ---------------------------------------------------------------

    data <- load_data("data/dataset_goodreads_filtered.csv")
    item_item_df <- fread("data/item_to_item_similarity_dataframe_full.csv")
    user_ratings_tab <- readRDS("data/ratings_filtered.rds")
    corp_dfm <- readRDS("data/ref_corp_tfidf_new.rds")
    SVD_model <- readRDS("data/svdf.rds")
    # spacy_install()

    selected_books_ids <- mod_search_books$server("search_books", data$title, data$image_url, data$book_id)
    mod_data_analysis$server("data_analysis")

    output$downloadData <- downloadHandler(
      filename = function() {
        "system_recommendations_log.csv"
      },
      content = function(file) {
        data <- fread("system_recommendations_log.csv")
        fwrite(data, file)
      }
    )
    
    observeEvent(input$method, {
      mod_recommend_books$server(
        "recommend_books",
        user_ratings_tab,
        SVD_model,
        corp_dfm,
        item_item_df,
        selected_books_ids,
        data,
        input$how_many_recommends_slider,
        input$simil_metrics,
        input$method
      )
    })

    observeEvent(input$how_many_recommends_slider, {
      mod_recommend_books$server(
        "recommend_books",
        user_ratings_tab,
        SVD_model,
        corp_dfm,
        item_item_df,
        selected_books_ids,
        data,
        input$how_many_recommends_slider,
        input$simil_metrics,
        input$method
      )
      gargoyle::trigger("start_recommend_event")
    })
  })
}


load_data <- function(path) {
  data <- data.table::fread(path)
  data[, genres := strsplit(genre, split = ",")]
  data[, average_rating := as.numeric(average_rating)]
  data$genre <- NULL
  data$similar_books <- NULL
  return(data)
}


my_sidebar <- function(ns) {
  tagList(
    sliderInput(ns("how_many_recommends_slider"), "Number of books to recommend", 1, 100, 10, step = 1),
    pickerInput(
      inputId = ns("method"),
      label = "recommendation method",
      selected = "ALL",
      choices = c("SVD", "TFIDF", "item-item", "ALL")
    ),
    downloadLink(ns("downloadData"), "Download logs")
  )
}