vns/vns

#!/usr/bin/env bash
XL_PRODUCT="Vim Note System"
XL_VER="1.0b1"

# Environment Constants
readonly VNS_STORE="$HOME/.config/vns"

readonly IFS=$'\n\t'

# ASCII Color Codes
readonly VNS_RED_COLOR='\033[0;31m'
readonly VNS_BLUE_COLOR='\033[0;34m'
readonly VNS_RESET_COLOR='\033[0m'

# Fail on unsuccessful command pipes and unset variables
set -euo pipefail

#               Erroneous Exit Codes 
# |Code| Meaning                                 | 
# |----|-----------------------------------------|
# |  5 | The vns store needs to be initialized   |
# | 11 | Insufficient arguments                  |
# | 15 | No editor specified in environment      |
# | 20 | Missing dependency                      |
# | 31 | Note already exists                     |
# | 41 | Note not found                          |

vns_raise (){
    
    # raise (message) (exit code)
    # Prints error (message) to stderr, then exits with (exit code)

    printf "%s, %s\n\n" "$XL_PRODUCT" "$XL_VER"
    printf "$VNS_RED_COLOR!$VNS_RESET_COLOR - %s\n" "$1" 1>&2
    exit "$2"

}

vns_checkDeps (){
    
    # checkDeps
    # Prints a list of unbound variables
    
    readonly VNS_DEPS=("vim" "gpg2" "tree" "git")
    
    for DEP in "${VNS_DEPS[@]}"; do
        if test  ! -e "$(which "$DEP" 2>/dev/null)"; then
            printf "%s " "$DEP"
        fi
    done
    
}

vns_sanityCheck () {
    
    # sanityCheck
    # Terminates script if environment is not suitable for vns
    
    # --- Dependencies ---
        # Get list of missing dependencies
          local MISSING; MISSING="$(vns_checkDeps)"
          
        # If that list is not empty, inform the user and exit on code 20
          if [ -n "$MISSING" ]; then
              vns_raise "Missing Dependencies: $MISSING" 20
          fi
      
    # --- Store ---
        # Verify that the note store has been initialized
          if [ ! -d "$VNS_STORE" ]; then
              vns_raise "The vns store needs to be initialized (hint: -i)" 5
          fi
          
}

#----
vns_init () {
    
    # initStore
    # Prepares $VNS_STORE for use
  
    mkdir -p "$VNS_STORE"
    cd "$VNS_STORE" || exit
    git init >/dev/null

}

vns_printHelp (){

    # printHelp
    # Prints help information to stdout
        
    printf "%s" "usage: vns [-cedlp] <notebook/section/name>"
    printf "\n%s" "       vns -i <gnupg recipient>"
    printf "\n%s" "       vns -h"
    printf "\n%s%s%s" "usage: vns " "git" " ..."

    printf "\n%s" "  -c | --create : Create note"
    printf "\n%s" "  -d | --delete : Delete note"
    printf "\n%s" "  -e | --edit   : Open note for editing"
    printf "\n%s" "  -h | --help   : Display this message"
    printf "\n%s" "  -i | --init   : Write default config and initalize VNS store"
    printf "\n%s" "  -l | --list   : List all notes in NOTEBOOK"
    printf "\n%s" "  -p | --print  : Print note to console"
    printf "\n\n"

}

vns_list () {

    # list (notebook)
    # Prints a tree containing all notes in the notebook 
    # If no notebook is specified, the entire store is used
    
    # Check for default behavior
      if [ -z "${@:1:1}" ]; then
          readonly NOTEBOOK=""
          printf "%s\n" "Store"
    else                       
          readonly NOTEBOOK="$1"
          printf "%s\n" "$1"
    fi
    
    tree -C --noreport --prune "$VNS_STORE/$NOTEBOOK"\
    | tail -n +2\
    | sed s/\.gpg//g
    
}

vns_rm () {
    
    # rm (note)
    # removes (note) from the store
    
    # Verify $1 is bound
      if [ -z "${@:1:1}" ]; then vns_raise "Insufficient arguments" 11; fi
    
    # Verify the note exists
      if [ ! -r "$VNS_STORE/$1.gpg" ]; then
          vns_raise "Note does not exist" 41; 
      fi
    # Delete the Note
      git rm "$VNS_STORE/$1.gpg" > /dev/null
      git commit -m "Deleted $1" > /dev/null
      
    # Report success
      printf "%s, %s\n\n" "$XL_PRODUCT" "$XL_VER"
      printf "$VNS_BLUE_COLOR!$VNS_RESET_COLOR - %s\n" "Deleted $VNS_STORE/$1"
    
}

vns_create () {
    
    # create (note)
    # Edit a previously non-existant note

    # Verify $1 is bound    
      if [ -z "${@:1:1}" ]; then vns_raise "Insufficient arguments" 11; fi
    
    # Refuse to overwrite a note
      if [ -r "$VNS_STORE/$1.gpg" ]; then vns_raise "Note already exists" 31; fi
    
    # If the note belongs to a new notebook, create the notebook
      if [ ! -d "$(dirname "$1")" ]; then mkdir -p "$VNS_STORE/$(dirname "$1")"; fi
    
    # Create-Edit the note
      vim "$VNS_STORE/$1.gpg"
    
    # Update Git
      git add "$VNS_STORE/$1.gpg" > /dev/null
      git commit -m "Added $1" > /dev/null
    
}

vns_edit () {

    # edit (note)
    # edit (note) in the store

    # Verify $1 is bound    
      if [ -z "${@:1:1}" ]; then vns_raise "Insufficient arguments" 11; fi
    
    # Refuse to edit non-existant notes
      if [ ! -r "$VNS_STORE/$1.gpg" ]; then vns_raise "Note not found: $1" 41; fi
  
    # Edit the specified note
      vim "$VNS_STORE/$1.gpg"
    
    # Warn the user if the note failed to encrypt
      if ! grep "PGP" <<< "$(file "$VNS_STORE/$1")" > /dev/null; then
          printf "$VNS_RED_COLOR!$VNS_RESET_COLOR - %s\n    %s\n"\
              "The created note was not encrypted."\
              "Check your vim-gnupg setup."
    
    # Update Git
      git add "$VNS_STORE/$1.gpg" > /dev/null
      git commit -m "Edited $1" > /dev/null
}

vns_print () {

    # print (note)
    # print the given note to stdout
 
    # Verify $1 is bound    
      if [ -z "${@:1:1}" ]; then vns_raise "Insufficient arguments" 11; fi
   
    # Decrypt the specified note
      gpg2 -d "$VNS_STORE/$1.gpg"

}

# ----
vns () {
    
    # Bypass sanity check if told to initialize store
      if [ "$*" != "-i" ]; then 
         vns_sanityCheck;
         # Change Directory to Store for Git passthrough
           cd $VNS_STORE || exit; 
      fi
    


    # Default action is to list all notes
      if [ -z "${@:1:1}" ]; then vns_list ""; exit 0; fi
    
    # List of valid arguments  
      declare -A -r ACTIONS=( ["-c"]="vns_create"    ["-d"]="vns_rm"\
                              ["-e"]="vns_edit"      ["-l"]="vns_list"\
                              ["-h"]="vns_printHelp" ["-i"]="vns_init"\
                              ["-p"]="vns_print"\
                              ["git"]="git"       )
    
    # If given an invalid argument, inform the user and exit on code 10
    # Otherwise, perform the corresponding action
      if ! test "${ACTIONS["$1"]+isset}"; then
         vns_raise "Invalid argument: $1" 10
      else 
          "${ACTIONS["$1"]}" "${@:2}"
      fi
    
    # Print an extra newline just in case
    # printf "\n";
    
    exit 0;
}

vns "$@"