#!/bin/bash
### everpad_to_zim.sh v0.1
### Copyleft 2013 by alteist@gmail.com
###
### This script exports everpad's Evernote client (https://github.com/nvbn/everpad/) 
### database (Schema v5) to zim wiki file sctructure: 
### Evernote/notebook/note -> zim/notebook/note.txt + notebook/note/attachments.ext
###
### THIS SCRIPT DOES NOT:
### * copy attachments in the right place, but in the end of the note instead. 
###   To fix this, one have to add <en-media> tag to pandoc's source (html 
###   reader + markdown writer) or replace pandoc by some other parser.
### * deal with Evernote's tags and places. To add this feature, one have to
###   convert 'places', 'tags' and 'notetags' tables and relations to zim data. 
###   See: sqlite3 everpad.5.db '.schema tags'.
### * convert zim to everpad back.
###
### KNOWN BUGS:
### * Will break if you use ';' (semicolon) in your notebook or note names/titles.
### * Will strip every symbol that is not in STRIP_REGEXP var (edit if needed).
###
### POSSIBLE BUGS:
### * May break some links and remove some backslash + special character occurences '\[#*_<>~$|:^]'
###
### USAGE:
### 0. Check STRIP_REGEXP if all needed symbols are included.
### 1. packages 'sqlite3' and 'pandoc' required, so run this in Ubuntu/Debian:
### sudo apt-get install sqlite3 pandoc
### 2. chmod +x everpad_to_zim.sh
### 3. ./everpad_to_zim.sh <EXPORT_DIR>

EXPORT_DIR=$1
DB="/home/$USER/.everpad/everpad.5.db"

### FILE NAMES SUPPOSEDLY WILL BE WINDOWS SAFE (DIDN'T CHECK YET):
STRIP_REGEXP='s/[^0-9a-Zа-Я!;,.@()\s\-]/_/g'

if [ "x$1" == "x" ]; then
  cat <<-EOF

	Usage: $0 <EXPORT_DIR>
 
	    Where:
	            <path_to_use_for_export>
	                The path of directory where you want your new zim
                        notebook to be created.
 
EOF
  exit 1;
fi
 
if [ ! -f ${DB} ]; then
  echo "Could not locate everpad's database for user '${USER}'";
  echo "Was searching in $DB, please edit script"
  exit 1;
fi

if ! hash sqlite3; then
  echo "sqlite3 not found or not in PATH, please install or edit script"
  exit 1;
fi

if ! hash pandoc; then
  echo "pandoc not found or not in PATH, please install or edit script"
  exit 1;
fi

echo "WARNING: proceeding will overwrite all files on $EXPORT_DIR. Continue? (y/n)"
read confirm
if ! test $confirm = "y"; then
  exit 0;
fi

echo "everpad -> zim to $EXPORT_DIR started..."

#rm -rf "$EXPORT_DIR"
mkdir -p "$EXPORT_DIR"

### GET NOTEBOOK NAMES
sqlite3 -separator ';' $DB "SELECT id,name from notebooks" |
sed "$STRIP_REGEXP" > /tmp/notebooks
while IFS=';' read nbid nbname; do
  mkdir -p "$EXPORT_DIR/$nbname"

  ### GET TITLE & METADATA OF NOTES IN CURRENT NOTEBOOK
  sqlite3 -separator ';' $DB "SELECT id,title,created,updated FROM notes WHERE notebook_id=$nbid" | 
  sed "$STRIP_REGEXP" > /tmp/notebooks.$nbid
  while IFS=';' read id title created updated; do
    ### ALSO CREATE HTMLFOR DEBUGGING:
    #sqlite3 $DB "SELECT content from notes where id=$id" > "$EXPORT_DIR/$nbname/$title.html"

    ### CONVERT DATES TO UNIXTIMESTAMP
    cdate=`date --date="@$(($created/1000))" +%Y-%m-%dT%T%:z`
    udate=`date --date="@$(($updated/1000))" +%Y%m%d%H%M.%S`

    ### CREATE FILE WITH ZIM HEADERS
    echo -e "Content-Type: text/x-zim-wiki\nWiki-Format: zim 0.4\nCreation-Date: $cdate\n" > "$EXPORT_DIR/$nbname/$title.txt"

    ### EXPORT HTML FROM DB
    sqlite3 $DB "SELECT content from notes where id=$id" | 
    ### THEN CONVERT IT TO MARKDOWN (VERY CLOSE TO ZIM)
    pandoc -f html -t markdown_mmd |
    ### FIX UNWANTED '\' (BACKSLASHES)
    sed 's/\\\([#*_<>~$|:^]\)/\1/g' |
    ### UNESCAPE '\' (DOUBLE BACKSLASHES TO SINGLE)
    sed 's/\\\\/\\/g' |
    ### FIX BROKEN LINKS '[link](link)'->'link' AND ADD TO FILE
    sed 's/\[.*\](\(.*\))/\1/g' >> "$EXPORT_DIR/$nbname/$title.txt"
    #!!!!!!! ^POSSIBLE BUGS IN REGEXPS HERE^ !!!!!!!!#

    ### GET ATTACHMENTS FOR THIS NOTEBOOK
    sqlite3 -separator ';' $DB "SELECT file_name,file_path,guid,mime FROM resources WHERE note_id=$id" > /tmp/notebooks.files.$id
    while IFS=';' read file_name file_path guid mime; do
      mkdir -p "$EXPORT_DIR/$nbname/$title"

      ### IF THERE IS NO HUMAN-READABLE NAME, THEN THERE IS NO EXTENSION
      ### IN THE END OF FILE NAME, SO LET'S ADD IT USING LAST PART OF MIME TYPE
      ### (VERY DUMB BUT WORKS)
      if test $file_name == $guid; then
        file_ext=$(echo $mime | sed 's/^.*\/\(.*\)$/\1/')
        file_name="$file_name.$file_ext"
      fi
      cp $file_path "$EXPORT_DIR/$nbname/$title/$file_name"

      ### INSERT ATTACHMENT TAGS IN THE END OF ZIM TEXT FILE
      echo "[[./$file_name|$file_name]]: {{./$file_name}}" >> "$EXPORT_DIR/$nbname/$title.txt"
    done < /tmp/notebooks.files.$id
    
    ### SET EVERNOTE LAST MODIFY DATE TO FILE LAST MODIFY DATE
    touch "$EXPORT_DIR/$nbname/$title.txt" -t $udate 
  done < /tmp/notebooks.$nbid
done < /tmp/notebooks

zim --index $EXPORT_DIR
zim --gui $EXPORT_DIR
echo "everpad -> zim to $EXPORT_DIR finished, hope everything is ok :)"
exit 0