vns/vns

#!/bin/bash
# Vim Note System, a simple script for managing encrypted plaintext notes

readonly VNS_STORE="${VNS_STORE:-$HOME/.vns}" # Where vns expects its note store
GPG_TTY="$(tty)"                              # Sets up gpg-agent for use
export GPG_TTY

vns_raise (){

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

    local -r  VNS_RED_COLOR='\033[0;31m'
    local -r  VNS_RESET_COLOR='\033[0m'

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

}

vns_report () {

    local -r  VNS_BLUE_COLOR='\033[0;34m'
    local -r  VNS_RESET_COLOR='\033[0m'
    
    printf "${VNS_BLUE_COLOR}*${VNS_RESET_COLOR} - %s\n" "$*"
}

vns_checkDeps (){

    # checkDeps
    # Prints a list of missing dependencies

    for DEP in 'vim' 'tree' 'git'; do
        if test  ! -e "$(command -v "$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
    MISSING="$(vns_checkDeps)"

    # Inform the user of missing dependencies and exit on code 20 if any were found
    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)" 21
    fi

}

vns_init () {

    # init (GPG recipients...)
    # Prepares $VNS_STORE for use

    if [ "$#" -lt 1 ]; then
        vns_raise "No GPG Recipients Specified" 3

    elif [ -d "$VNS_STORE/.git" ]; then
    
        # Reset list of GPG recipients
        echo -n '' > "${VNS_STORE}/.gpg-id"

        vns_reencrypt "$VNS_STORE" "$@"
    else
        # Create a new VNS Store
        git init "$VNS_STORE" >/dev/null
        vns_report "Initialized new VNS store"

    fi
 
    # Store GPG Recipients for later note creation
    # whether re-encrypting, or initializing a new store
    for recipient in "$@"; do
        echo "$recipient" >> "${VNS_STORE}/.gpg-id"
    done
    vns_git add .gpg-id >/dev/null
    vns_git commit -am "Updated GPG recipients" >/dev/null
}

vns_reencrypt () {
    # reencrypt (GPG recipients...)

    # Remove script name from arguments list
    shift 

    # Construct list of arguments from provided recipients
    local -a GPG_RECIPS;
    for recipient in "$@"; do
       GPG_RECIPS=( "${GPG_RECIPS[@]}" "-r" "$recipient" )
    done

    # Find all notes and re-encrypt them 
    find "${VNS_STORE}" -name "*.gpg" | while read -r FILE; do\
        gpg --batch --decrypt "$FILE" 2>/dev/null | gpg --batch "${GPG_RECIPS[@]}" --encrypt --output "${FILE}_new".gpg >/dev/null 2>&1
        mv "${FILE}_new.gpg" "$FILE"; 
    done

    vns_report "Re-encrypted existing notes with $*"
    vns_git commit -am "Re-encrypted existing notes with ${GPG_RECIPS[*]}" >/dev/null 2>&1 
}

vns_gpgid () {

    # gpgid
    # Echo all recipients listed in .gpg-id

    # shellcheck disable=SC2002
    cat "${VNS_STORE}/.gpg-id" | while read -r recipient; do
       echo "-r"
       echo "$recipient"
    done
}

vns_printHelp (){

    # printHelp
    # Prints help information to stdout

    printf "%s"   "usage: vns [-cedlp] <notebook/section/name>"
    printf "\\n%s" "       vns -I GPG_RECIPIENT (GPG_RECIPIENTS...)"
    printf "\\n%s" "       vns -h"
    printf "\\n%s" "       vns git ..."
    printf "\\n"
    printf "\\n%s" "  -c : Create note"
    printf "\\n%s" "  -d : Delete note(s)"
    printf "\\n%s" "  -e : Open note for editing"
    printf "\\n%s" "  -h : Display this message"
    printf "\\n%s" "  -i : import file as note"
    printf "\\n%s" "  -I : Initialize note store"
    printf "\\n%s" "  -l : List all notes in <notebook>"
    printf "\\n%s" "  -m : Merge two or more notes"
    printf "\\n%s" "  -p : Print note to console"
    printf "\\n%s" "  -r : Rename/move a note"
    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

    #numNotes () { find "${VNS_STORE}" -name "*.gpg" \( ! -regex '.*/\..*' \) | wc -l; }
    
    # Check for default behavior
    if [ "$#" -lt 1 ]; then
        local -r "NOTEBOOK"=""
            printf "%s\\n" "vns"
    else                       
        readonly NOTEBOOK="$1"
            printf "%s\\n" "$1"
            fi

            tree --noreport --prune "$VNS_STORE/$NOTEBOOK"\
            | tail -n +2\
            | sed s/\.gpg//g

}

vns_rm () {

    # rm (note)
    # removes (note) from the store

    while [ "$#" -gt 0 ]; do
        # Verify $1 is bound
        if [ "$#" -lt 1 ]; then vns_raise "Insufficient arguments" 30; fi

        # Verify the note exists
        if [ ! -r "$VNS_STORE/$1.gpg" ]; then
            vns_raise "Note does not exist" 31; 
        fi
        
        # Delete the Note
        vns_git rm "$VNS_STORE/$1.gpg" > /dev/null
        vns_git commit -m "Deleted $1" > /dev/null

        # Report success
        vns_report "Deleted $1"

        # Move to the next item
        shift
    done

}

vns_header () {
    # header (title)
    # Print note title and date in Markdown format

    if [ "$#" -lt 1 ]; then
        vns_raise "header: no note title provided" 4
    else
        echo "# $1"
        printf "## %s" "$(date)"
    fi
}

vns_create () {

    # create (note)
    # Create a new note and open it for editing

    local -r  VNS_RED_COLOR='\033[0;31m'
    local -r  VNS_RESET_COLOR='\033[0m'

    if [ "$#" -lt 1 ]; then 
        printf "usage: %s %s\n" "$(basename "$0")" "-c [notebook/section/](name)"
        return
    fi

    # Refuse to overwrite a note
    if [ -r "$VNS_STORE/$1.gpg" ]; then vns_raise "Note already exists" 41; 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 empty note
    mkdir -p "$(dirname "$VNS_STORE/$1.gpg")"
    vns_header "$(basename "$1")" | gpg --batch "$(vns_gpgid)" --encrypt -o "$VNS_STORE/$1.gpg" 2>/dev/null

    # Edit the note
    vim "$VNS_STORE/$1.gpg"

    # Update vns_git
    vns_git add "$VNS_STORE/$1.gpg" > /dev/null
    vns_git commit -m "Added $1" > /dev/null

}

vns_edit () {

    # edit (note)
    # Open (note) for editing in Vim

    # Verify $1 is bound    
    if [ "$#" -lt 1 ]; then vns_raise "Insufficient arguments" 50; fi

    # Refuse to edit non-existent notes
    if [ ! -r "$VNS_STORE/$1.gpg" ]; then vns_raise "Note not found: $1" 51; fi

    # Edit the specified note
    vim "$VNS_STORE/$1.gpg"

    # Update vns_git
    vns_git add "$VNS_STORE/$1.gpg" > /dev/null
    vns_git commit -m "Edited $1" > /dev/null
}

vns_import () {

    # import (src) (dest)
    # If src is the path to a file, and dest is a valid note name,
    # import src dest copies an encrypted version of src to the note store

    if [ "$#" -lt 2 ]; then
        printf "usage: %s %s\n" "$(basename "$0")" "-i (source) (destination)"
        return
    fi
                
    if [ ! -f "$1" ]; then
        vns_raise "Cannot read $1" 92

    elif [ -f "$VNS_STORE/$2" ]; then
        printf "%s" "Note already exists. Overwrite? (Y/N) "
        local response=''; read -r response
        case "$response" in
            Y|y)
                rm "$VNS_STORE/$2";;
            *)
                vns_raise "User declined overwrite" 0;;
        esac
    fi

    printf "%s:" "Specify GPG Public Key: "
    local gpg_key=''; read -r gpg_key

    gpg2 --batch -r "$gpg_key" -o "$VNS_STORE/$2.gpg" -e "$1"

    vns_git add "$VNS_STORE/$2.gpg"
    vns_git commit -m "Imported file $1 as $2"

}

vns_print () {

    # print (note)
    # print the given note to stdout

    # Verify $1 is bound    
    if [ "$#" -lt 1 ]; then 
        vns_raise "Insufficient arguments" 11
    
    # Verify $1 exists
    elif ! [ -r "$VNS_STORE/$1.gpg" ]; then
        vns_raise "Could not read $1" 12
    
    else
        # Decrypt the specified note
        gpg2 --batch -d "$VNS_STORE/$1.gpg"
    fi
}

vns_mv () {

    # mv (src) (dest)
    # If (src) is a note in the vns store, mv src dest moves src to dest
    
    # Ensure two arguments were provided
    if [ "$#" -lt 2 ]; then vns_raise "Insufficient arguments" 70; fi

    # Ensure source can be read
    if [ ! -r "$VNS_STORE/$1.gpg" ]; then vns_raise "Cannot read $1" 71; fi

    # Refuse to overwrite existing notes
    if [ -r "$VNS_STORE/$2.gpg"   ]; then vns_raise "Note $2 already exists" 72; fi

    vns_git mv "$VNS_STORE/$1.gpg" "$VNS_STORE/$2.gpg"

}

vns_merge () {

    # merge (output) (notes[])
    # If notes[] is an array of note names and output is a new note name,
    # merge (output) (notes[]) concatenates notes[] into output.
    if [ "$#" -lt 2 ]; then
        printf "usage: %s %s\n" "$(basename "$0")" "-m (output) (notes...)"
        return
    fi

    if [ -r "$VNS_STORE/$1.gpg" ]; then vns_raise "Output file already exists." 82; fi
    if [ ! -r "$VNS_STORE/$2.gpg" ]; then vns_raise "Could not read $2" 83; fi

    local -r NOTE_NAME="$1"
    local -r OUTPUT="${VNS_STORE}/${1}.gpg"
    shift

    vns_gpgcat () {
        for note in "$@"; do
            if [ ! -r "$VNS_STORE/$note.gpg" ]; then
                rm "$VNS_STORE/$1.gpg"    
                vns_raise "Could not read $note" 83;
            fi

            printf "File: %s\n" "$note"
            gpg2 --batch -d "$VNS_STORE/$note.gpg" 2>/dev/null
            printf "\n"
        done
    }

    vns_gpgcat "$@" | gpg2 --batch --yes "$(vns_gpgid)" --encrypt -o "$OUTPUT" 

    printf "%s" "Remove old notes? (y/N) "
    local response=''; read -r response
    case "$response" in
        Y|y)
            for note in "$@"; do
                vns_git rm "$VNS_STORE/$note.gpg"    
            done;;
     esac
     vns_git add "$OUTPUT" >/dev/null 2>&1
     vns_git commit -m "merged files $* into $NOTE_NAME" >/dev/null 2>&1
     vns_report "Successfully merged files $* into $NOTE_NAME"
}

vns_duplicate () {

    if [ "$#" -lt 2 ]; then
        vns_report "usage: $(basename "$0") -u (source) (destination)"
        return
    fi

    if [ ! -f "$VNS_STORE/$1.gpg" ]; then
        vns_raise "Cannot read $1" 102

    elif [ -f "$VNS_STORE/$2.gpg" ]; then
        printf "%s" "Note already exists. Overwrite? (Y/N) "
        response=''; read -r response
        case "$response" in
            Y|y)
                rm "$VNS_STORE/$2.gpg";;
            *)
                vns_raise "User declined overwrite" 0;;
        esac
    fi

    cp "$VNS_STORE/$1.gpg" "$VNS_STORE/$2.gpg"
    vns_git add "$VNS_STORE/$2.gpg"
}

vns_git () {
    # Simple passthrough for executing git commands in the VNS store
    git -C "$VNS_STORE" "$@"
}

vns () {

    # Bypass sanity check if told to initialize store
    if [ "$1" != "-I" ]; then 
        vns_sanityCheck;
    fi

    case "$1" in
        "-c")
            shift
            vns_create "$@"
            ;;
        "-d")
            shift
            vns_rm "$@"
            ;;
        "-e")
            shift
            vns_edit "$@"
            ;;
        "-l")
            shift
            vns_list "$@"
            ;;
        "-h")
            shift
            vns_printHelp "$@"
            ;;
        "-I")
            shift
            vns_init "$@"
            ;;
        "-i")
            shift
            vns_import "$@"
            ;;
        "-m")
            shift
            vns_merge "$@"
            ;;
        "-p")
            shift
            vns_print "$@"
            ;;
        "-r")
            shift
            vns_mv "$@"
            ;;
        "-u")
            shift
            vns_duplicate "$@"
            ;;
        "git")
            shift
            vns_git "$@"
            ;;
        *)
            vns_list "$@"
    esac

    exit 0;
}

vns "$@"