#' Adjust and Export Pathway Analysis Results

#'

#' This function processes a dataframe containing fgsea results. It adjusts pathway names

#' by removing underscores, converting to lowercase, then capitalizing the first letter,

#' and joining the components with spaces. It selects and merges the top upregulated

#' and downregulated pathways based on enrichment score (ES) and p-value.

#'

#' @param fgseaRes Dataframe containing fgsea results with columns 'pathway', 'ES', and 'pval'.

#' @param nTop Integer, number of top pathways to select based on the p-value.

#' @return A vector containing combined top upregulated and downregulated pathways.

#' @importFrom Hmisc capitalize

#' @export

#' @examples

#' # Create a synthetic fgseaRes dataframe

#'fgseaRes <- data.frame(

#'  pathway = c("KEGG_APOPTOSIS",

#'              "GO_CELL_CYCLE",

#'              "REACTOME_DNA_REPAIR",

#'              "KEGG_METABOLISM",

#'              "GO_TRANSPORT"),

#'  ES = c(0.45, -0.22, 0.56, -0.35, 0.33),

#'  pval = c(0.001, 0.02, 0.0003, 0.05, 0.01)

#')

#'

#' # Run the function to get top pathways

#'result <- adjust_export_pathway(fgseaRes = fgseaRes, nTop = 2)

#'

adjust_export_pathway <- function(fgseaRes, nTop = 10) {

  # Adjust pathway names

  fgseaRes$pathway <- as.character(fgseaRes$pathway)

  for(i in 1:nrow(fgseaRes)){

    message("Processing row ", i)

    term = fgseaRes$pathway[i]

    ### 1. Split the string

    term = unlist(strsplit(term, split="_", fixed=TRUE))[-1]

    ### 2. Convert to lowercase, then capitalize the first letter

    term = Hmisc::capitalize(tolower(term))

    ### 3. Concatenate with spaces

    term = paste(term, collapse=" ")

    ### 4. Data export

    fgseaRes$pathway[i] = term

  }

  # Select top upregulated pathways

  topPathwaysUp <- fgseaRes[fgseaRes$ES > 0,][order(fgseaRes$pval[fgseaRes$ES > 0]), 'pathway'][1:nTop]

  # Select top downregulated pathways

  topPathwaysDown <- fgseaRes[fgseaRes$ES < 0,][order(fgseaRes$pval[fgseaRes$ES < 0]), 'pathway'][1:nTop]

  # Combine top pathways and convert any potential list to a vector

  combinedPathways <- unlist(c(topPathwaysUp, rev(topPathwaysDown)), use.names = FALSE)

  return(list(combinedPathways = combinedPathways, fgseaRes = fgseaRes))

}

#' Randomly Select Pathways with Limited Word Count

#'

#' This function randomly selects a specified number of pathways from a given list, ensuring that each selected pathway name does not exceed a specified number of words. It filters out pathways with names longer than the specified word limit before making the selection.

#'

#' @param pathways Character vector of pathways.

#' @param max_words Integer, maximum number of words allowed in the pathway name.

#' @param num_select Integer, number of pathways to randomly select.

#' @return A character vector of selected pathways.

#' @export

#' @examples

#' pathway_list <- c("pathway_one response to stimulus",

#'                   "pathway_two cell growth and death",

#'                   "pathway_three regulation of cellular process",

#'                   "pathway_four metabolic process")

#' selected_pathways <- selectPathways(pathway_list, max_words = 5, num_select = 2)

#'

selectPathways <- function(pathways, max_words = 10, num_select = 10) {

  # Check input

  if (!is.character(pathways)) {

    stop("Please provide a character vector of pathways.")

  }

  # Filter pathways with word count not exceeding max_words

  filtered_pathways <- pathways[sapply(pathways, function(x) length(strsplit(x, " ")[[1]]) <= max_words)]

  # Randomly select num_select pathways from the filtered list

  if (length(filtered_pathways) >= num_select) {

    selected_pathways <- sample(filtered_pathways, num_select)

  } else {

    warning("Not enough pathways with <= ", max_words, " words. Returning as many as possible.")

    selected_pathways <- sample(filtered_pathways, length(filtered_pathways))

  }

  return(selected_pathways)

}

#' Draw Dual-Sided Legends on a Plot

#'

#' This function creates two sets of legends, one on the left and one on the right side of a plot.

#' It displays color-coded legends with labels corresponding to different data categories.

#' Each legend entry consists of a colored rectangle and a text label. The left side legend has

#' text aligned to the right of the color block, while the right side legend has text aligned

#' to the left of the color block.

#'

#' @param labels Vector of labels for the legends.

#' @param colors Vector of colors corresponding to the labels.

#' @param legend_width The width of each legend viewport expressed in grid units.

#' @param x_positions Numeric vector of length 2 specifying the x-positions of the left and right legends.

#' @param y_position The y-position common for both legends, expressed as a fraction of the plot height.

#' @param just_positions List of two vectors, each specifying the horizontal and vertical justification for the legends.

#' @param text_alignments List of two character strings specifying text alignments for the legends ('left' or 'right').

#' @param font_size Numeric value specifying the font size for the legend labels.

#' @return Invisible. This function is called for its side effects of drawing legends on a plot.

#' @importFrom grid pushViewport viewport grid.roundrect grid.text upViewport unit

#' @export

#' @examples

#' labels <- c("Label1", "Label2", "Label3", "Label4", "Label5", "Label6")

#' colors <- c("#ff0000", "#00ff00", "#0000ff", "#ffff00", "#ff00ff", "#00ffff")

#'

#' # Convert to 'unit' objects for grid

#' grid::grid.roundrect(

#'   x = grid::unit(0.5, "npc"),  # "npc" stands for normalized parent coordinates

#'   y = grid::unit(0.5, "npc"),

#'   width = grid::unit(0.1, "npc"),

#'   height = grid::unit(0.05, "npc"),

#'   gp = grid::gpar(fill = "red"),

#'   r = grid::unit(0.1, "npc")  # rounding radius

#' )

#'

#' # Example of drawing legends with specific labels and colors

#' drawLegends(labels, colors, grid::unit(2, "cm"), c(0.225, 0.75), 0.5,

#'             list(c("left", "center"), c("right", "center")),

#'             list("right", "left"), 10)

#'

drawLegends <- function(labels, colors, legend_width, x_positions, y_position, just_positions, text_alignments, font_size) {

  half_length <- length(labels) / 2

  legend_height <- grid::unit(1, "lines") * half_length

  # Draw left-side legend

  grid::pushViewport(grid::viewport(

    width = legend_width,

    height = legend_height,

    x = x_positions[1],

    y = y_position,

    just = just_positions[[1]]

  ))

  for (i in seq_len(half_length)) {

    grid::grid.roundrect(

      x = grid::unit(1, "npc") - grid::unit(0.5, "cm"),

      y = grid::unit(1, "npc") - grid::unit(i / half_length, "npc") + grid::unit(0.5 / half_length, "npc"),

      width = grid::unit(0.7, "cm"),

      height = grid::unit(0.9 / half_length, "npc"),

      gp = grid::gpar(fill = colors[i], col = NA),

      r = grid::unit(0.3, "snpc")

    )

    grid::grid.text(

      labels[i],

      x = grid::unit(1, "npc") - grid::unit(1, "cm"),

      y = grid::unit(1, "npc") - grid::unit(i / half_length, "npc") + grid::unit(0.5 / half_length, "npc"),

      gp = grid::gpar(col = colors[i], fontsize = font_size),

      just = text_alignments[[1]]

    )

  }

  grid::upViewport()

  # Draw right-side legend

  grid::pushViewport(grid::viewport(

    width = legend_width,

    height = legend_height,

    x = x_positions[2],

    y = y_position,

    just = just_positions[[2]]

  ))

  for (i in (half_length + 1):length(labels)) {

    grid::grid.roundrect(

      x = grid::unit(1, "npc") - grid::unit(0.6, "cm"),

      y = grid::unit(1, "npc") - grid::unit((i - half_length) / half_length, "npc") + grid::unit(0.5 / half_length, "npc"),

      width = grid::unit(0.7, "cm"),

      height = grid::unit(0.9 / half_length, "npc"),

      gp = grid::gpar(fill = colors[i], col = NA),

      r = grid::unit(0.3, "snpc")

    )

    grid::grid.text(

      labels[i],

      x = grid::unit(1, "npc") - grid::unit(0.1, "cm"),

      y = grid::unit(1, "npc") - grid::unit((i - half_length) / half_length, "npc") + grid::unit(0.5 / half_length, "npc"),

      gp = grid::gpar(col = colors[i], fontsize = font_size),

      just = text_alignments[[2]]

    )

  }

  grid::upViewport()

}

#' Draw Chord Diagram with Legends

#'

#' This function creates a chord diagram from a specified dataframe and draws two sets of legends for it.

#' It adjusts the track height of the chord diagram to optimize space and uses specified colors for the grid.

#' Legends are drawn at specified positions with configurable text alignments and font sizes.

#'

#' @param all_combined_df A dataframe containing the matrix for the chord diagram.

#' @param original_colors A vector of colors for the grid columns of the chord diagram.

#' @param labels A vector of labels for the first legend.

#' @param colors A vector of colors corresponding to the first legend's labels.

#' @param labels2 A vector of labels for the second legend.

#' @param colors2 A vector of colors corresponding to the second legend's labels.

#' @param font_size The font size used for legend texts, defaults to 10.

#' @return Invisible, primarily used for its side effects of drawing on a graphics device.

#' @importFrom circlize chordDiagram

#' @importFrom grid unit

#' @importFrom graphics strwidth

#' @export

#' @examples

#' # Sample Chord Diagram Matrix

#' all_combined_df <- data.frame(

#'   A = c(10, 20, 30),

#'   B = c(15, 25, 35),

#'   C = c(5, 10, 15)

#' )

#' rownames(all_combined_df) <- c("A", "B", "C")

#'

#' # Colors for the grid of the chord diagram (corresponding to columns of the matrix)

#' original_colors <- c("red", "green", "blue")

#'

#' # Name the colors according to the sectors (A, B, C)

#' names(original_colors) <- colnames(all_combined_df)

#'

#' # Labels and Colors for the First Legend

#' labels <- c("Label 1", "Label 2", "Label 3")

#' colors <- c("yellow", "purple", "cyan")

#'

#' # Labels and Colors for the Second Legend

#' labels2 <- c("Label A", "Label B", "Label C")

#' colors2 <- c("orange", "pink", "brown")

#'

#' # Font size for the legend texts (optional, default is 10)

#' font_size <- 10

#'

#' # Call the enrichment_circlize function with the sample data

#' # This is just an example; the plot will be rendered in an appropriate graphics context

#' # such as RStudio's plot pane or an external plotting window.

#' plot1 <- enrichment_circlize(all_combined_df,

#'                              original_colors,

#'                              labels,

#'                              colors,

#'                              labels2,

#'                              colors2,

#'                              font_size

#'                              )

#'

enrichment_circlize <- function(all_combined_df, original_colors, labels, colors,

                                       labels2, colors2, font_size = 10) {

  # Calculate adjusted height for the chord diagram

  max_height <- max(graphics::strwidth(unlist(dimnames(all_combined_df)), "inches")) * 1.2

  # Draw the chord diagram

  circlize::chordDiagram(all_combined_df, grid.col = original_colors, annotationTrack = "grid",

                         directional = -1, direction.type = c("diffHeight", "arrows"),

                         link.arr.type = "big.arrow", preAllocateTracks = list(track.height = max_height))

  # Draw the first set of legends

  legend_width <- grid::unit(2, "cm")

  x_positions <- c(0.225, 0.75)

  y_position <- 0.5

  just_positions <- list(c("left", "center"), c("right", "center"))

  text_alignments <- list("right", "left")

  drawLegends(labels, colors, legend_width, x_positions, y_position, just_positions, text_alignments, font_size)

  # Draw the second set of legends

  x_positions2 <- c(0.3, 0.68)

  y_position2 <- 0.7

  drawLegends(labels2, colors2, legend_width, x_positions2, y_position2, just_positions, text_alignments, font_size)

}