#!/bin/bash
#==========================================================
# Simple Note System, v2.0a6
# Copyright 2014, Xenese Labs/Sicron-Perion XNF
#==========================================================

if [ -z "$HOME" ]; then HOME=/home/"$(whoami)"; fi

PROD_STR="Simple Note System"
readonly VER_STR="v2.0a6"
readonly ROOT_DIR="$HOME"/.config/xenlabs/sns
readonly BASE_DIR="$ROOT_DIR"/notes
readonly TMP_DIR="$ROOT_DIR"/tmp
readonly CONFIG_FILE="$ROOT_DIR/sns.conf"


# Section: Functions
function w_conf {

if [ ! -r "$ROOT_DIR" ]; then mkdir -p "$ROOT_DIR"; fi
if [ ! -d "$TMP_DIR"  ]; then mkdir -p "$TMP_DIR" ; fi


cat > "$CONFIG_FILE" << EOF
#==========================================================
# Simple Note System Config, v2.0a5
# Copyright 2014, Xenese Labs/Sicron-Perion XNF
#==========================================================

#File extension to use (for listing notes)
EXT=note

#Preferred Editor
if [ -z "$EDITOR" ]; then
    EDITOR=vim
fi

#Encryption
#WARNING: ANY PREVIOUSLY UNENCRYPTED NOTES WILL BE LOST

#ENCRYPTION="TRUE"
ENCRYPTION="FALSE"

PUBKEY=""
EOF

chmod 600 "$CONFIG_FILE"
}
function pause {
    read -rp "  Press [Enter] to continue."
    echo ""
}
function help {
    echo ""
    echo "usage: sns [-ce] NAME NOTEBOOK SECTION"
    echo "       sns [-d ] NAME NOTEBOOK SECTION"
    echo "       sns [-lp] NOTEBOOK"
    echo "       sns [-w ]"
    echo "       sns [-h ]"

    echo ""
    echo "  -c | --create : Create note"
    echo "  -d | --delete : Delete note"
    echo "  -e | --edit   : Open note for editing"
    echo "  -h | --help   : Display this message"
    echo "  -p | --print  : Print note to console"
    echo "  -l | --list   : List all notes in NOTEBOOK"
    echo "  -w | --wconf  : Rewrite default configuration"
    echo ""
}
function p_header(){
    printf "TITLE: %s\nDATE: %s\n" "$NAME" "$(date)"
}
function encrypt(){
# This function, given a recipient, $PUBKEY; a file to encrypt, $TARGET; and an
# output file, "$NOTE", will encrypt $TARGET to $NOTE against $PUBKEY's private
# GPG key.

gpg -r "$PUBKEY" -o "$NOTE" -e "$TARGET"

}

function decrypt(){
# This function, given a recipient, $PUBKEY; a file to decrypt, $TARGET; and an
# output file, "$NOTE", will decrpyt $TARGET to $NOTE against $PUBKEY's private
# GPG key.

    if [ ! -d "$ROOT_DIR"/tmp ]; then mkdir "$ROOT_DIR"/tmp; fi
    TARGET="$TMP_DIR/$RANDOM"
    gpg -d "$NOTE" > "$TARGET"
}
function create(){
    if [ -e "$NOTE" ]; then
       printf "\nERROR: Note already exists\nHint: use -e to edit the note.\n"
       exit
    else
        mkdir -p "$NOTE_DIR"
    fi

    if [ -z "$ENCRYPTION" ]; then
        echo "TITLE: $NAME" > "$NOTE"
        echo "DATE: $(date)" >> "$NOTE"
    elif [ "$ENCRYPTION" == "TRUE" ]; then
        TARGET="$TMP_DIR"/"$SESSION_ID"
        p_header > "$TARGET"
        encrypt
    fi

    if [ -e "$NOTE" ]; then
        echo "Created note: $NOTEBOOK/$SECTION/$NAME."
    fi

}
function delete(){
    if [ "$DELETE" == "TRUE" ]; then
        if [ -e "$NOTE" ]; then
            rm "$NOTE"
            echo ""
            echo "Deleted note: $NOTEBOOK/$SECTION/$NAME."
            exit
        else
            echo ""
            echo "ERROR: Note $NOTEBOOK/$SECTION/$NAME does not exist."
            exit
        fi
    fi
}
function edit(){
if [ ! -r "$NOTE" ]; then
    echo "ERROR: Note cannot be opened for editing."
    exit 40;
fi

if [ "$ENCRYPTION" == "TRUE" ]; then
    cp "$NOTE" "$NOTE".bk
    decrypt
else TARGET="$NOTE"; fi


if [ -z "$CREATE" ]; then printf "\nEDIT %s" "$(date)" >> "$TARGET"; fi

"$EDITOR" "$TARGET"

if [ "$ENCRYPTION" == "TRUE" ]; then
    rm "$NOTE"
    encrypt;
    if [ -r "$NOTE" ]; then rm "$NOTE".bk;  fi
fi



}
function print(){
    if [ "$PRINT" == "TRUE" ]; then
        if [ -r "$NOTE" ] || [ -r "${NOTE%.*}" ]; then
            if [ -z "$CREATE" ]; then
                if [ "$ENCRYPTION" == "TRUE" ]; then
                    openssl enc -d -aes-256-cbc -in "${NOTE%.*}" -pass pass:"$ENC_KEY"
                else
                cat "$NOTE"
                echo "" >> "$NOTE"
                fi
            else
                echo ""
                echo "ERROR: Note cannot be found."
                echo ""

            fi
        fi
    fi
}
function list(){
    if [ -d "$BASE_DIR"/"$NOTEBOOK" ]; then
        printf "\nNotes in %s:\n" "$(basename "$NOTEBOOK")"

        NOTES=(
            $(find "$BASE_DIR"/"$NOTEBOOK" -name "*.$EXT" -print0 |\
                sed s:"$BASE_DIR"/"$NOTEBOOK"/: "    " :g |\
                sed -e s:".$EXT"::g | tr "/" " ")
        )
        let i=0
        for NOTE in "${NOTES[@]}"; do
            if [ -d "$BASE_DIR"/"$NOTEBOOK"/"$NOTE" ]; then
                if [ "$LAST_SECTION" != "$NOTE" ]; then
                    printf "  Section: %s\n" "$NOTE"
                fi
                LAST_SECTION="$NOTE"
            else
                #if [ $(($i % 1)) -eq 0 ]; then
                #    printf "\n     "
                #fi
                printf "    %s\n" "$NOTE"
            fi
            let i++
        done
        printf "\n"
    else
        echo ""
        echo "ERROR: Notebook $NOTEBOOK does not exist."
        echo ""
    fi
}
# End Section: Functions




###############################################################################
#==============================================================================
# Begin Main Program
#==============================================================================
###############################################################################

#==============================================================================
# Section: Configuration / Stage 1
#==============================================================================
if [ -r "$CONFIG_FILE" ]; then
    source "$CONFIG_FILE"
else
    create_sns_root
    source "$CONFIG_FILE"
fi

if [ "$ENCRYPTION" == "TRUE" ]; then
    if [ -z "$PUBKEY" ]; then
        ERR_NO_KEY="TRUE"
        ENCRYPTION="FALSE"
    fi

    command -v gpg >/dev/null 2>&1 ||\
        { ERR_NO_GPG="TRUE"; ENCRYPTION="FALSE"; }
fi

if [ "$ENCRYPTION" == "TRUE" ]; then
    PROD_STR="Simple Note System (Encryption Enabled)"
    if [ ! -d "$BASE_DIR"/tmp ]; then
        mkdir -p "$BASE_DIR"/tmp
    fi
fi

echo "$PROD_STR, $VER_STR"

if [ -z "$EDITOR" ]; then
   >&2 echo "Error no editor specified in environment."

elif [ -n "$ERR_NO_GPG" ]; then
    >&2 echo  "  Error: Encryption was specified, but GPG is not installed."
    exit 100
elif [ -n "$ERR_NO_KEY" ]; then
    >&2 echo "  Error: No GPG recipient was provided in $CONFIG_FILE. "
    exit 110
fi


#==============================================================================
# End Section: Configuration / Stage 1
#==============================================================================
#==============================================================================
# Section: Argument Parsing / Stage 2
#==============================================================================

NAME=""
NOTEBOOK=""
SECTION=""
if [ -z "$1" ]; then help; exit 20
else
    ARGS=( "$@" )
    for ARG in "${ARGS[@]}"; do
        if     [ "$ARG"  = "-c"  ] || [ "$ARG" = "--create" ]; then CREATE="TRUE"
          elif [ "$ARG"  = "-d"  ] || [ "$ARG" = "--delete" ]; then DELETE="TRUE"
          elif [ "$ARG"  = "-e"  ] || [ "$ARG" = "--edit"   ]; then EDIT="TRUE"
          elif [ "$ARG"  = "-ce" ] || [ "$ARG" = "-ec"      ]; then EDIT="TRUE"; CREATE="TRUE"
          elif [ "$ARG"  = "-p"  ] || [ "$ARG" = "--print"  ]; then PRINT="TRUE"
          elif [ "$ARG"  = "-l"  ] || [ "$ARG" = "--list"   ]; then LIST="TRUE"
          elif [ "$ARG"  = "-h"  ] || [ "$ARG" == "--help"  ]; then help;   exit 0
          elif [ "$ARG"  = "-w"  ] || [ "$ARG" == "--wconf" ]; then create_sns_root; exit 0
        else
            if     [ -z "$NAME"     ] && [ -n "$ARG"  ]; then NAME="$ARG"
              elif [ -z "$NOTEBOOK" ] && [ -n "$ARG"  ]; then NOTEBOOK="$ARG"
              elif [ -z "$SECTION"  ] && [ -n "$ARG"  ]; then SECTION="$ARG"
            fi
        fi
    done
    if [ -n "$NAME" ] && [ -z "$NOTEBOOK" ] && [ -n "$LIST" ]; then
        # If we got a note title above, but no notebook, and the list option
        # was specified, we assume that the detected note title is actually a
        # notebook name.
        NOTEBOOK="$NAME"
        NAME=""
    fi
fi

# Note: w_conf and help have highest priority, as they are the only functions
# that can work without any arguments.

#==============================================================================
# End Section: Argument Parsing / Stage 2
#==============================================================================
#==============================================================================
# Section: Actions / Stage 3
#==============================================================================
# List only requires a notebook, and is exclusive.
if [ -z "$NOTEBOOK" ]; then
    echo "  ERROR: Insufficient arguments:"
    echo "          Notebook not specified"
    exit 30
fi

if [ -n "$LIST" ]; then
    list
    exit 0
fi

#All other functions require a note title and notebook.

if [ -z "$NAME" ]; then
    echo "  ERROR: Insufficient arguments:"
    echo "          Title not specified"
    exit 30
fi

SESSION_ID="$RANDOM"
NOTE_DIR="$BASE_DIR"/"$NOTEBOOK"/"$SECTION"/
NOTE="$NOTE_DIR""$NAME"."$EXT"

if [ "$ENCRYPTION" == "TRUE" ]; then NOTE="$NOTE".gpg; fi
if [ "$PRINT"      == "TRUE" ]; then print; exit 0; fi
if [ "$DELETE"     == "TRUE" ]; then delete; exit 0; fi
if [ "$CREATE"     == "TRUE" ]; then create; fi
if [ "$EDIT"       == "TRUE" ]; then edit; fi

#==============================================================================
# End Section: Actions / Stage 3
#==============================================================================