# Java script function to replace gene IDs with Ensembl gene links.
js_link <- DT::JS("function(row, data) {
    let id = data[1];
    var name = data[2];
    if (!name) name = 'Unknown';
    let url = `https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=${id}`;
    $('td:eq(1)', row).html(`<a href=\"${url}\" target=\"_blank\">${name}</a>`);
}")

#' Create a server function for the application.
#'
#' @param options Global application options.
#' @noRd
server <- function(options) {
  function(input, output, session) {
    preset <- input_page_server("input_page", options)

    comparison_gene_ids <- comparison_editor_server(
      "comparison_editor",
      preset,
      options
    )

    observe({
      updateNavbarPage(
        session,
        "main_page",
        selected = "Results"
      )
    }) |> bindEvent(preset(), ignoreInit = TRUE)

    # Compute the results according to the preset.
    analysis <- reactive({
      withProgress(
        message = "Analyzing genes",
        value = 0.0,
        { # nolint
          geposan::analyze(
            preset(),
            progress = function(progress) {
              setProgress(progress)
            },
            include_results = FALSE
          )
        }
      )
    }) |> bindCache(preset())

    # Rank the results.
    ranking <- methods_server("methods", analysis, comparison_gene_ids)

    genes_with_distances <- merge(
      geposan::genes,
      geposan::distances[species == "hsapiens"],
      by.x = "id",
      by.y = "gene"
    )

    # Add gene information to the results.
    results <- reactive({
      merge(
        ranking(),
        genes_with_distances,
        by.x = "gene",
        by.y = "id",
        sort = FALSE
      )
    })

    # Apply the filters.
    results_filtered <- filters_server("filters", results)

    # Server for the detailed results panel.
    results_server("results", results_filtered)

    output$rank_plot <- plotly::renderPlotly({
      preset <- preset()
      gene_sets <- list("Reference genes" = preset$reference_gene_ids)
      comparison_gene_ids <- comparison_gene_ids()

      if (length(comparison_gene_ids) >= 1) {
        gene_sets <- c(
          gene_sets,
          list("Comparison genes" = comparison_gene_ids)
        )
      }

      geposan::plot_scores(ranking(), gene_sets = gene_sets)
    })

    output$rankings_plot <- plotly::renderPlotly({
      preset <- preset()

      rankings <- list()
      methods <- preset$methods
      all <- ranking()

      for (method in methods) {
        weights <- list()
        weights[[method$id]] <- 1.0
        rankings[[method$name]] <- geposan::ranking(all, weights)
      }

      rankings[["Combined"]] <- all

      gene_sets <- list("Reference genes" = preset$reference_gene_ids)
      comparison_gene_ids <- comparison_gene_ids()

      if (length(comparison_gene_ids) >= 1) {
        gene_sets <- c(
          gene_sets,
          list("Comparison genes" = comparison_gene_ids)
        )
      }

      geposan::plot_rankings(rankings, gene_sets)
    })

    output$comparison_text <- renderUI({
      reference <- geposan::compare(
        ranking(),
        preset()$reference_gene_ids
      )

      comparison <- if (!is.null(comparison_gene_ids())) {
        geposan::compare(ranking(), comparison_gene_ids())
      }

      num <- function(x, digits) {
        format(
          round(x, digits = digits),
          nsmall = digits,
          scientific = FALSE
        )
      }

      comparison_text <- function(name, comparison) {
        glue::glue(
          "The {name} have a mean score of ",
          "<b>{num(comparison$mean_score, 4)}</b> ",
          "resulting in a mean rank of ",
          "<b>{num(comparison$mean_rank, 1)}</b>. ",
          "This corresponds to a percent rank of ",
          "<b>{num(100 * comparison$mean_percentile, 2)}%</b>. ",
          "A Wilcoxon rank sum test gives an estimated score difference ",
          "between <b>{num(comparison$test_result$conf.int[1], 3)}</b> and ",
          "<b>{num(comparison$test_result$conf.int[2], 3)}</b> with a 95% ",
          "confidence. This corresponds to a p-value of ",
          "<b>{num(comparison$test_result$p.value, 4)}</b>."
        )
      }

      reference_div <- div(HTML(
        comparison_text("reference genes", reference)
      ))

      if (!is.null(comparison)) {
        div(
          reference_div,
          div(HTML(comparison_text("comparison genes", comparison)))
        )
      } else {
        reference_div
      }
    })

    output$boxplot <- plotly::renderPlotly({
      preset <- preset()
      gene_sets <- list("Reference genes" = preset$reference_gene_ids)
      comparison_gene_ids <- comparison_gene_ids()

      if (length(comparison_gene_ids) >= 1) {
        gene_sets <- c(
          gene_sets,
          list("Comparison genes" = comparison_gene_ids)
        )
      }

      geposan::plot_boxplot(ranking(), gene_sets)
    })

    output$positions_plot <- plotly::renderPlotly({
      preset <- preset()
      gene_sets <- list("Reference genes" = preset$reference_gene_ids)
      comparison_gene_ids <- comparison_gene_ids()

      if (length(comparison_gene_ids) >= 1) {
        gene_sets <- c(
          gene_sets,
          list("Comparison genes" = comparison_gene_ids)
        )
      }

      chromosome <- if (input$positions_plot_chromosome_name == "all") {
        NULL
      } else {
        input$positions_plot_chromosome_name
      }

      geposan::plot_scores_by_position(
        ranking(),
        chromosome_name = chromosome,
        gene_sets = gene_sets
      )
    })

    gost <- reactive({
      withProgress(
        message = "Querying g:Profiler",
        value = 0.0,
        { # nolint
          setProgress(0.2)
          gprofiler2::gost(
            results_filtered()[, gene],
            custom_bg = preset()$gene_ids,
            domain_scope = "custom_annotated"
          )
        }
      )
    }) |> bindCache(results_filtered(), preset())

    output$gost_plot <- plotly::renderPlotly({
      gprofiler2::gostplot(
        gost(),
        capped = FALSE,
        interactive = TRUE
      )
    })

    output$gost_details <- DT::renderDT({
      data <- data.table(gost()$result)
      setorder(data, p_value)

      data[, total_ratio := term_size / effective_domain_size]
      data[, query_ratio := intersection_size / query_size]
      data[, increase := (query_ratio - total_ratio) / total_ratio]

      data <- data[, .(
        source,
        term_name,
        total_ratio,
        query_ratio,
        increase,
        p_value
      )]

      dt <- DT::datatable(
        data,
        rownames = FALSE,
        colnames = c(
          "Source",
          "Term",
          "Total ratio",
          "Query ratio",
          "Increase",
          "p-value"
        ),
        options = list(
          pageLength = 25
        )
      ) |>
        DT::formatRound("p_value", digits = 4) |>
        DT::formatPercentage(
          c("total_ratio", "query_ratio", "increase"),
          digits = 2
        )
    })
  }
}