update_readme.sh

#!/bin/bash
set -euo pipefail

# Function to get language icon with link
get_language_icon_with_link() {
  local extension=$1
  local path=$2
  local icon=""
  local asset=""
  case $extension in
  cpp)
    icon="C++"
    asset="c++.svg"
    ;;
  go)
    icon="Go"
    asset="go.svg"
    ;;
  rs)
    icon="Rust"
    asset="rust.svg"
    ;;
  *)
    icon="Unknown"
    asset="unknown.svg"
    ;;
  esac
  echo "[![$icon](assets/$asset)]($path)"
}

# Check if README.md exists
if [ ! -f README.md ]; then
  echo "Error: README.md not found in the current directory."
  exit 1
fi

# Get the list of staged files
STAGED_FILES=$(git diff --cached --name-only)

# Filter for Solution.* files
CHANGED_SOLUTIONS=$(echo "$STAGED_FILES" | grep -E 'Solution\.[^/]+$' || true)

# If no solution files have changed, exit early
if [ -z "$CHANGED_SOLUTIONS" ]; then
  exit 0
fi

# Function to insert or update a row in the table
update_table() {
  local number="$1"
  local problem_name="$2"
  local language_icon="$3"
  local temp_file=$(mktemp)

  awk -v num="$number" -v name="$problem_name" -v icon="$language_icon" '
  BEGIN { updated = 0; in_table = 0 }
  /^\| *ID * \| *Problem Name * \| *Languages * \|/ { in_table = 1; print; next }
  in_table && /^\| *:?-+:? *\| *:?-+:? *\| *:?-+:? *\|/ { print; next }
  in_table && /^\|/ {
    split($0, a, "|")
    if (a[2] + 0 == num) {
      if (index($0, icon) == 0) {  # If icon not present, add it
        gsub(/\|[ \t]*$/, "", $0)  # Remove trailing |
        printf("%s %s |\n", $0, icon)
      } else {  # If icon present, keep existing line
        print $0
      }
      updated = 1
    } else if ((a[2] + 0 > num) && !updated) {
      printf("| %s | %s | %s |\n", num, name, icon)
      print $0
      updated = 1
    } else {
      print $0
    }
    next
  }
  in_table && /^$/ {
    if (!updated) {
      printf("| %s | %s | %s |\n", num, name, icon)
    }
    in_table = 0
  }
  { print }
  END {
    if (in_table && !updated) {
      printf("| %s | %s | %s |\n", num, name, icon)
    }
  }
  ' README.md >"$temp_file"

  mv "$temp_file" README.md
}

# Process changed files
echo "$CHANGED_SOLUTIONS" | while read -r file; do
  if [[ $file =~ ([^/]+)/([0-9]{4})-([^/]+)/Solution\.(.+)$ ]]; then
    NUMBER=$((10#${BASH_REMATCH[2]})) # Convert to base 10 to drop leading zeroes.
    PROBLEM_NAME=${BASH_REMATCH[3]}
    EXTENSION=${BASH_REMATCH[4]}
    LANGUAGE_ICON=$(get_language_icon_with_link "$EXTENSION" "$file")
    update_table "$NUMBER" "$PROBLEM_NAME" "$LANGUAGE_ICON"
    npx prettier --write README.md # Run prettier to format README
  fi
done