#!/usr/bin/env bash

#############
# Variables #
#############
# Define formatting variables
fb="$(tput bold)" ; readonly fb
fr="$(tput sgr0)" ; readonly fr

# Define name regular expression
name_regex='[^a-zA-Z0-9]' ; readonly name_regex

scripts_dir="" ; readonly scripts_dir  # Scripts directory
# Script Editor
script_editor="" ; readonly script_editor

# Define menu string
menu_str='\n'
menu_str+='*************************\n'
menu_str+='\n'
menu_str+='New Script\n'
menu_str+='---------------\n'
menu_str+='1) Bash\n'
menu_str+='2) Python\n'
menu_str+='q) Quit\n'
menu_str+='\n'
menu_str+='Enter menu selection:'


#############
# Functions #
#############
display_usage() {
    local help_msg  # Define local variable
    help_msg="Usage: ${0}

Purpose: Create new script.

Variables to set:
    scripts_dir
        Location of scripts directory.
    script_editor
        Program to use for editing files.

        By default, the script will respect your environment's ${fb}EDITOR${fr}
        value. If this value is not configured, you can set
        ${fb}script_editor${fr} to your editor of choice."

    echo "${help_msg}"
}


# Sanitize name
clean_name() {
    local cleaned
    # Replace most non-alphanumeric characters with underscores
    cleaned="${1//${name_regex}/_}"
    # Squeeze underscores and lowercase name
    cleaned="$(echo -n "${cleaned}" | tr -s '_' | tr '[:upper:]' '[:lower:]')"
    echo "${cleaned}"
}


# Add front matter to Bash script
bash_front_matter() {
    local header
    header="#!/usr/bin/env bash
# Purpose: ${script_purpose}
# Usage:

###########
# Aliases #
###########
#shopt -s expand_aliases  # Enable alias expansion

#############
# Variables #
#############



#############
# Functions #
#############
# Define starting point for execution of the program
main() {

}


###########
# Program #
###########
main \"\${@}\"  # Start program

exit 0  # Exit script with successful exit status"

    echo "${header}" > "${scripts_dir}/${script_name}.${script_ext}"
}


# Add front matter to Python script
python_front_matter() {
    local header
    header="#!/usr/bin/env python3
'''
${script_purpose}

Classes:

    * 

Functions:

    * main() - Define starting point for execution of the program.

Requires
----------------


Variables to set:
----------------


Options:
----------------

'''
###########
# Modules #
###########
# Enable access to some variables/functions used/maintained by the interpreter
import sys

#############
# Variables #
#############



###########
# Classes #
###########



#############
# Functions #
#############
def main() -> None:
    '''Define starting point for execution of the program.'''



###########
# Program #
###########
if __name__ == '__main__':
    main()  # Start program

    sys.exit(0)  # Exit program with successful exit status"

    echo "${header}" > "${scripts_dir}/${script_name}.${script_ext}"
}


# Present menu
menu() {
    local menu_answer  # Define local variable

    echo -e "${menu_str}"  # Display menu options

    # Save menu choice
    read -r menu_answer

    # Evaluate menu selection
    case "${menu_answer}" in
        '1')
            script_ext='bash'  # Set Bash extension
            ;;
        '2')
            script_ext='py'  # Set Python extension
            ;;
        'q')
            exit 1
            ;;
        *)
            # Prompt for valid input
            echo -e "\n${fb}Please enter a valid menu selection.${fr}" 1>&2
            
            menu
            ;;
    esac
}


# Define starting point for execution of the program
main() {
    # Parse arguments
    parsed_args="$(getopt \
        -n "${0##*/}" \
        -o h \
        --long help \
        -- "${@}")"

    inv_ents="${?}"  # Check for invalid entries
    if [[ "${inv_ents}" -ne 0 ]]; then
        echo ''
        display_usage
        exit 1
    fi

    # Set positional parameters using parsed argument string
    eval set -- "${parsed_args}"

    # Evaluate options
    while true; do
        case "${1}" in
            '-h' | '--help')
                display_usage
                exit 0
                ;;
            '--')
                ## End of options
                shift
                break
                ;;
        esac
    done

    # Override EDITOR with script_editor
    if [[ "${script_editor}" ]]; then
        EDITOR="${script_editor}"
    fi
    # Verify that an editor is set
    if ! [[ "${EDITOR}" || "${script_editor}" ]]; then
        # Prompt user to set required variable and exit
        err_msg="\nSet either ${fb}EDITOR${fr} or ${fb}script_editor${fr} "
        err_msg+='before running the script again.'
        echo -e "${err_msg}" 1>&2
        exit 1
    fi

    # Verify that required variable is set
    if ! [[ "${scripts_dir}" ]]; then
        # Prompt user to set required variable and exit
        err_msg="\nSet ${fb}scripts_dir${fr} before running the script again."
        echo -e "${err_msg}" 1>&2
        exit 1
    fi

    menu  # Call menu function

    # Prompt for script name, save to variable
    echo ''
    read -p 'Enter script name: ' -r script_name
    script_name="$(clean_name "${script_name}")"  # Sanitize input

    # Prompt for script purpose, save to variable
    read -p 'Enter script purpose: ' -r script_purpose

    # Call appropriate front matter function based on script extension
    if [[ "${script_ext}" == 'bash' ]]; then
        bash_front_matter
    elif [[ "${script_ext}" == 'py' ]]; then
        python_front_matter
    fi

    # Make script executable
    chmod 700 "${scripts_dir}/${script_name}.${script_ext}"

    # Open script in editor
    "${EDITOR}" "${scripts_dir}/${script_name}.${script_ext}"
}


###########
# Program #
###########
main "${@}"  # Start program

exit 0  # Exit script with successful exit status