convertQueryResultCsvToGraphVizDotFile.sh

#!/usr/bin/env bash

# Converts a Cypher query result in CSV format to a GraphViz DOT (https://graphviz.org/doc/info/lang.html) file for Visualization including layout templates.
#
# The template file is used to define the layout of the graph. 
# It needs to contain the markers //Begin-Template and //End-Template to indicate the actual template content.
# If no template is specified, "templates/default.template.gv" is used.

# Fail on any error ("-e" = exit on first error, "-o pipefail" exist on errors within piped commands)
set -o errexit -o pipefail

## Get this "scripts/visualization" directory if not already set
# Even if $BASH_SOURCE is made for Bourne-like shells it is also supported by others and therefore here the preferred solution. 
# CDPATH reduces the scope of the cd command to potentially prevent unintended directory changes.
# This way non-standard tools like readlink aren't needed.
VISUALIZATION_SCRIPTS_DIR=${VISUALIZATION_SCRIPTS_DIR:-$( CDPATH=. cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd -P )} # Repository directory containing the shell scripts for visualization
echo "convertQueryResultCsvToGraphVizDotFile: VISUALIZATION_SCRIPTS_DIR=${VISUALIZATION_SCRIPTS_DIR}"

# Internal constants
DEFAULT_TEMPLATE_FILE="templates/default.template.gv"

# Function to display script usage
usage() {
  echo "Usage: $0 --filename path/to/query/result/file.csv [--name name-of-the-graph (default=name of the file)] [--template path/to/the/template/file (default=${DEFAULT_TEMPLATE_FILE})]"
  exit 1
}

# Default values
inputFilename=""
graphName=""
templateFile=""

# Parse command line arguments
while [ $# -gt 0 ]; do
  key="$1"
  case $key in
    --filename)
      inputFilename="$2"
      shift
      ;;
    --name)
      graphName="$2"
      shift
      ;;
    --template)
      templateFile="$2"
      shift
      ;;
    *)
      echo "convertQueryResultCsvToGraphVizDotFile: Error: Unknown option: ${key}"
      usage
      ;;
  esac
  shift
done

if [ -z "${inputFilename}" ]; then
  echo "convertQueryResultCsvToGraphVizDotFile: Error: Missing required option: --filename"
  echo "${USAGE}"
  exit 1
fi

if [ ! -f "${inputFilename}" ]; then
  echo "convertQueryResultCsvToGraphVizDotFile: Error: CSV file not found: ${inputFilename}"
  echo "${USAGE}"
  exit 1
fi

number_of_input_file_lines=$(wc -l < "${inputFilename}" | awk '{print $1}')
if [ "${number_of_input_file_lines}" -le 1 ]; then
  echo "convertQueryResultCsvToGraphVizDotFile: Info: Input file is empty. Skipping *.dot and *.svg file generation."
  return 0
fi

if [ -z "${graphName}" ]; then
  graphName=$(basename -- "${inputFilename}")
  graphName="${graphName%.*}"
  echo "convertQueryResultCsvToGraphVizDotFile: Info: Using default graph name: ${graphName}"
fi

# Replace all dashes in the graphName by underscores
graphName=${graphName//-/_}

if [ -z "${templateFile}" ]; then
  templateFile="${VISUALIZATION_SCRIPTS_DIR}/${DEFAULT_TEMPLATE_FILE}"
  echo "convertQueryResultCsvToGraphVizDotFile: Info: Using default template file: ${templateFile}"
fi

if [ ! -f "${templateFile}" ]; then
  echo "convertQueryResultCsvToGraphVizDotFile: Error: Template file not found: ${templateFile}"
  echo "${USAGE}"
  exit 1
fi

templateFileName=$(basename -- "${templateFile}")
inputFilePath=$(dirname "${inputFilename}")
templateFileNameWithoutExtension="${templateFileName%.*}"
outputFilename="${inputFilePath}/${graphName}.gv"

{
  # Add a comment to the beginning of the file to indicate that it was generated by this script
  echo "// This GraphViz dot file was generated by the script convertQueryResultCsvToGraphVizDotFile.sh with ${templateFileNameWithoutExtension}"
  echo ""
  # Start the graph definition with the graph name
  echo "strict digraph ${graphName} {"
  # Extract the template content from the template file and remove the begin and end markers
  sed -n '/\/\/Begin-Template/,/\/\/End-Template/{//!p;}' "${templateFile}"
  # Remove the first (header) line of the CSV file, remove the enclosing double quotes and replace the escaped double quotes by double quotes
  awk -F ',' 'NR>1 {print "\t" $1}' "${inputFilename}" \
    | sed 's/^\t\"\"\"/\t"/' \
    | sed 's/^\t\"\\\"\"/\t"/' \
    | sed 's/\\\"\"/"/g' \
    | sed 's/\"\"/"/g' \
    | sed 's/\"$//'
  # End the graph definition
  echo "}"
} > "${outputFilename}"