#!/bin/bash

# Script to concatenate all files in a directory and its subdirectories
# into a single markdown file with filenames and content preserved.
# Usage: ./concatenate_files_to_markdown.sh [source_directory] [output_file.md]
# Defaults: source_directory = current directory, output_file.md = consolidated.md

SOURCE_DIR="${1:-.}"
OUTPUT_FILE="${2:-consolidated.md}"

# Empty or create the output file
> "$OUTPUT_FILE"

# Function to get the file extension for markdown code block language
get_file_extension() {
    local filename="$1"
    local ext="\${filename##*.}"
    # If no extension or filename equals ext, return empty string
    if [[ "\$filename" == "\$ext" ]]; then
        echo ""
    else
        # sanitize extension to avoid weird chars
        echo "\$ext" | tr '[:upper:]' '[:lower:]'
    fi
}

# Export function in case subshell required (not strictly necessary here)
export -f get_file_extension

# Find all files, sort them for consistent order
find "\$SOURCE_DIR" -type f | sort | while IFS= read -r file; do
    # Get relative path
    relpath="\${file#\$SOURCE_DIR/}"
    # fallback if prefix not found
    if [[ "\$relpath" == "\$file" ]]; then
        relpath="\$file"
    fi

    # Get file extension for code block language
    lang=\$(get_file_extension "\$file")

    # Append filename as markdown header with inline code formatting
    echo "" >> "\$OUTPUT_FILE"
    echo "### \`\$relpath\`" >> "\$OUTPUT_FILE"
    echo "" >> "\$OUTPUT_FILE"

    # Append code block start with language if available
    if [[ -n "\$lang" ]]; then
        echo "~~~\$lang" >> "\$OUTPUT_FILE"
    else
        echo "~~~" >> "\$OUTPUT_FILE"
    fi

    # Append file content
    cat "\$file" >> "\$OUTPUT_FILE"

    # Append code block end
    echo "~~~" >> "\$OUTPUT_FILE"

done

echo "All files concatenated into \$OUTPUT_FILE"