# frozen_string_literal: true

module SnippetsHelper
  def snippets_upload_path(snippet, user)
    return unless user

    if snippet&.persisted?
      upload_path('personal_snippet', id: snippet.id)
    else
      upload_path('user', id: user.id)
    end
  end

  def reliable_snippet_path(snippet, opts = nil)
    if snippet.project_id?
      project_snippet_path(snippet.project, snippet, opts)
    else
      snippet_path(snippet, opts)
    end
  end

  def download_snippet_path(snippet)
    if snippet.project_id
      raw_project_snippet_path(@project, snippet, inline: false)
    else
      raw_snippet_path(snippet, inline: false)
    end
  end

  # Return the path of a snippets index for a user or for a project
  #
  # @returns String, path to snippet index
  def subject_snippets_path(subject = nil, opts = nil)
    if subject.is_a?(Project)
      project_snippets_path(subject, opts)
    else # assume subject === User
      dashboard_snippets_path(opts)
    end
  end

  # Get an array of line numbers surrounding a matching
  # line, bounded by min/max.
  #
  # @returns Array of line numbers
  def bounded_line_numbers(line, min, max, surrounding_lines)
    lower = line - surrounding_lines > min ? line - surrounding_lines : min
    upper = line + surrounding_lines < max ? line + surrounding_lines : max
    (lower..upper).to_a
  end

  # Returns a sorted set of lines to be included in a snippet preview.
  # This ensures matching adjacent lines do not display duplicated
  # surrounding code.
  #
  # @returns Array, unique and sorted.
  def matching_lines(lined_content, surrounding_lines, query)
    used_lines = []
    lined_content.each_with_index do |line, line_number|
      used_lines.concat bounded_line_numbers(
        line_number,
        0,
        lined_content.size,
        surrounding_lines
      ) if line.downcase.include?(query.downcase)
    end

    used_lines.uniq.sort
  end

  # 'Chunkify' entire snippet.  Splits the snippet data into matching lines +
  # surrounding_lines() worth of unmatching lines.
  #
  # @returns a hash with {snippet_object, snippet_chunks:{data,start_line}}
  def chunk_snippet(snippet, query, surrounding_lines = 3)
    lined_content = snippet.content.split("\n")
    used_lines = matching_lines(lined_content, surrounding_lines, query)

    snippet_chunk = []
    snippet_chunks = []
    snippet_start_line = 0
    last_line = -1

    # Go through each used line, and add consecutive lines as a single chunk
    # to the snippet chunk array.
    used_lines.each do |line_number|
      if last_line < 0
        # Start a new chunk.
        snippet_start_line = line_number
        snippet_chunk << lined_content[line_number]
      elsif last_line == line_number - 1
        # Consecutive line, continue chunk.
        snippet_chunk << lined_content[line_number]
      else
        # Non-consecutive line, add chunk to chunk array.
        snippet_chunks << {
          data: snippet_chunk.join("\n"),
          start_line: snippet_start_line + 1
        }

        # Start a new chunk.
        snippet_chunk = [lined_content[line_number]]
        snippet_start_line = line_number
      end

      last_line = line_number
    end
    # Add final chunk to chunk array
    snippet_chunks << {
      data: snippet_chunk.join("\n"),
      start_line: snippet_start_line + 1
    }

    # Return snippet with chunk array
    { snippet_object: snippet, snippet_chunks: snippet_chunks }
  end

  def snippet_embed
    "<script src=\"#{url_for(only_path: false, overwrite_params: nil)}.js\"></script>"
  end

  def embedded_snippet_raw_button
    blob = @snippet.blob
    return if blob.empty? || blob.binary? || blob.stored_externally?

    snippet_raw_url = if @snippet.is_a?(PersonalSnippet)
                        raw_snippet_url(@snippet)
                      else
                        raw_project_snippet_url(@snippet.project, @snippet)
                      end

    link_to external_snippet_icon('doc-code'), snippet_raw_url, class: 'btn', target: '_blank', rel: 'noopener noreferrer', title: 'Open raw'
  end

  def embedded_snippet_download_button
    download_url = if @snippet.is_a?(PersonalSnippet)
                     raw_snippet_url(@snippet, inline: false)
                   else
                     raw_project_snippet_url(@snippet.project, @snippet, inline: false)
                   end

    link_to external_snippet_icon('download'), download_url, class: 'btn', target: '_blank', title: 'Download', rel: 'noopener noreferrer'
  end
end