lessopen

#!/usr/bin/env bash

# lessopen - LESSOPEN preprocessor for JSON files
# Usage: Set LESSOPEN="|lessopen %s" in your shell

set -euo pipefail

# Check if jq is available
if ! command -v jq >/dev/null 2>&1; then
  exit 1
fi

# Get the input file
input_file="${1:-}"

# If no file provided, exit
if [[ -z "$input_file" ]]; then
  exit 1
fi

# Function to check if content is valid JSON
is_json() {
  local file="$1"

  # Handle stdin case (when file is "-")
  if [[ "$file" == "-" ]]; then
    jq empty 2>/dev/null
    return $?
  fi

  # Check if file exists and is readable
  if [[ ! -f "$file" || ! -r "$file" ]]; then
    return 1
  fi

  # Try to parse with jq
  jq empty "$file" 2>/dev/null
  return $?
}

# Function to format JSON with jq
format_json() {
  local file="$1"

  if [[ "$file" == "-" ]]; then
    jq --color-output '.'
  else
    jq --color-output '.' "$file"
  fi
}

# Check if input looks like JSON by extension
case "${input_file,,}" in
*.json | *.jsonl | *.ndjson)
  # File has JSON extension, try to format it
  if is_json "$input_file"; then
    format_json "$input_file"
    exit 0
  else
    # Invalid JSON, let less handle the original file
    exit 1
  fi
  ;;
*.md)
  glow "$input_file"
  ;;
*)
  # Check if content is actually JSON even without extension
  if is_json "$input_file"; then
    format_json "$input_file"
    exit 0
  else
    # Not JSON, let less handle the original file
    exit 1
  fi
  ;;
esac