#!/bin/bash
# PAPERWEB - GPLv3 licence
# Copyright 2016 Yves Gablin
#  This program is free software: you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by
#  the Free Software Foundation, either version 3 of the License, or
#  (at your option) any later version.
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#  You should have received a copy of the GNU General Public License
#  along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
#   -h This help.
#
# Query:
#   -Q [-d <pipe-separated list of YYYYMMDD/YYYYMM/YYYY prefixes to search>]
#      [-l <pipe-separated list of labels to match (all must be found)>]
#      [-k <pipe-separated list of keywords to match (all must be found)>]
#      [-i] : case-insensitive search
#   At least -d, -l, or -k must be used.
#   Result (WSN):
#     OUTPUT   = "[" [ DOC_LIST ] "]" .
#     DOC_LIST = DOC { "," DOC } .
#     DOC      = "{""folder"":" FOLDER ",""labels"":[" [ LABELS ]
#                "],""count"":" COUNT ",""type"":" TYPE ",""etag"":" ETAG "}" .
#     FOLDER   = json_string .
#     LABELS   = json_string { "," json_string } .
#     COUNT    = json_number .
#     TYPE     = """pdf""" | """pages""" .
#     ETAG     = json_string .
#
# Retrieve a single document's metadata:
#   -M <date>
#   Result (WSN):
#     OUTPUT   = DOC .
#
# Retrieve a document's thumbnails:
#   -T <date> : the folder-name of the document
#   Result (WSN):
#     OUTPUT   = "[" THUMBS "]" .
#     THUMBS   = CONTENTS { "," CONTENTS } .
#     CONTENTS = "{""mime"":" MIME ",""data"":" B64_DATA ",""width"":"
#                WIDTH ",""height"":" HEIGHT ",""etag"":" ETAG "}" .
#     MIME     = json_string .
#     B64_DATA = json_string .
#     WIDTH    = json_number .
#     HEIGHT   = json_number .
#
# Retrieve a document's page/PDF and metadata:
#   -D <date> -p <page number>
#   Result (WSN):
#     OUTPUT   = CONTENTS .
#   The "data" field contains the wanted page in JPEG format, except if the
#   document is a PDF file: then the whole PDF file is encoded.
#   Width and height should be ignored for PDF contents.
#
# Retrieve a document page's metadata without the actual page:
#   -M <date> -p <page number>
#   Result (WSN):
#     OUTPUT   = "{""mime"":" MIME ",""width"":" WIDTH ",""height"":"
#                HEIGHT ",""etag"":" ETAG "}" .
#   Width and height should be ignored for PDF contents.
#
# Retrieve a raw document's page/PDF without metadata:
#   -R <date> -p <page number>
#   Result: page contents.
#   The returned data is the raw page in JPEG format, except if the document is
#   a PDF file: then the whole PDF file is returned.
#
# The behaviour exposed above changes if the commands "pdfinfo" and "pdftoppm"
# are both available. In this case, pages from PDF documents are treated the
# same way as pages from image-based documents.

##########  CONFIGURATION ########## 

BASE='/PATH/TO/PAPERWORK/BASE/DIRECTORY'
PDF_DPI=90

##### NO CHANGE PAST THIS LINE #####

# INIT
mode=
dates=()
labels=()
words=()
q_ci=
doc=
page=
{ type pdfinfo && type pdftoppm; } &>/dev/null && pdfasjpg=true

# READ COMMAND LINE PARAMETERS
while getopts hQd:l:k:iT:D:p:M:R: opt; do case "$opt" in
h) sed -n '2,/^$/s/.//p' "$0"; exit 0 ;;
Q) mode=Q ;;
d) IFS='|' read -a dates < <(tr -dc '|[:digit:]' <<<"$OPTARG") ;;
l) IFS='|' read -a labels < <(tr -d ',"[:cntrl:]' <<<"$OPTARG") ;;
k) IFS='|' read -a words < <(tr -d ',"[:cntrl:]' <<<"$OPTARG") ;;
i) q_ci=true ;;
T|D|M|R)
   mode=$opt; doc=$(tr -dc '[:digit:]_' <<<"$OPTARG") ;;
p) page=$(tr -dc '[:digit:]' <<<"$OPTARG") ;;
esac; done

# CHECK COMMAND LINE PARAMETERS
case "$mode" in
Q) for ((i=${#dates[*]}-1;i>=0;i--)); do [ ${#dates[i]} -ge 4 ] || unset dates[i]; done
   [ -n "${dates[*]}${labels[*]}${words[*]}" ] || exit 2 ;;
T) [ -n "$doc" -a -d "$BASE/$doc" ] || exit 3 ;;
D|M|R)
   [ -n "$doc" -a -d "$BASE/$doc" ] || exit 3
   if [ $mode != M -o -n "$page" ]; then
     if [ -f "$BASE/$doc/doc.pdf" ]; then
       if [ -n "$pdfasjpg" ]; then
         maxp=$(pdfinfo "$BASE/$doc/doc.pdf" | awk '/^Pages:/{print $2}')
         [ -n "$maxp" -a -n "$page" -a $page -gt 0 -a $page -le $maxp ] || exit 3
       fi
     else
       [ -f "$BASE/$doc/paper.$page.jpg" ] || exit 3
     fi
   fi ;;
*) exit 1 ;;
esac

# RUN

# &0: image data
# &1: "<width> <height>"
function image_wh() {
  file -b - | sed -r 's/.*, ([0-9]+)x([0-9]+),[^,]*$/\1 \2/'
}

# &0: raw string
# &1: json string
function json_string() {
  printf '"%s"' "$(sed 's#[\\/"]#\\&#g;s#\t#\\t#g')"
}

# $1: folder name (relative path)
# &1: json DOC
function json_doc() {
  local type count labs lab nil etag
  [ -f $1/doc.pdf ] && type=pdf || type=pages
  count=$(/bin/ls -1 $1/paper.*.thumb.jpg 2>/dev/null | wc -l)
  labs="$(
    while IFS=, read lab nil; do printf ','; json_string <<<"$lab"; done < <(sort -df $1/labels))"
  etag=$(find $1 -maxdepth 0 -printf '%T@')
  printf '{"folder":%s,"labels":[%s],"count":%d,"type":"%s","etag":%s}' \
    "$(json_string <<<"$1")" "${labs:1}" $count "$type" "$(json_string <<<"$etag")"
}

# $1: file path
#[$2: page number (if it must be extracted from a PDF)]
#[$3: "nodata"]
# &1: json CONTENTS
function json_contents() {
  local mime w=0 h=0 etag
  local -a cmd=(cat $1)
  mime=$(file -bi "$1" | cut -d';' -f1)
  if [ "$mime" != 'application/pdf' ]; then
    read w h < <(image_wh <$1)
  elif [ -n "$2" -a -n "$pdfasjpg" ]; then
    cmd=(pdftoppm -r $PDF_DPI -jpeg -f $2 -l $2 $1)
    mime=image/jpeg
    read w h < <("${cmd[@]}" | image_wh)
  fi
  etag=$(find $1 -printf '%T@')
  if [ -n "$3" ]; then
    printf '{"mime":%s,"width":%d,"height":%d,"etag":%s}' \
      "$(json_string <<<"$mime")" $w $h "$(json_string <<<"$etag")"
  else
    printf '{"mime":%s,"width":%d,"height":%d,"etag":%s,"data":%s}' \
      "$(json_string <<<"$mime")" $w $h "$(json_string <<<"$etag")" \
      "$("${cmd[@]}" | base64 --wrap=0 | json_string)"
  fi
}

cd "$BASE"
case "$mode" in
Q)
  found="$(
    case ${#dates[*]} in
    0) find . -mindepth 1 -maxdepth 1 -type d -printf '%P/|\n' ;;
    1) find ${dates[0]}* -maxdepth 0 -type d -printf '%p/|\n' ;;
    *) eval find {$(IFS=, eval echo '"${dates[*]}"')}\* -maxdepth 0 -type d -printf "'%p/|\\n'" ;;
    esac 2>/dev/null)"
  if [ ${#labels[*]} -gt 0 ]; then
    # This is an AND
    for l in "${labels[@]}"; do
      [ -n "$found" ] && found="$(
        eval grep -lF${q_ci:+i}e "$l" ${found//|/labels} 2>/dev/null \
        | sed 's#labels$#|#')"
    done
    ## That would be an OR (for later, perhaps)
    #found="$(
    #  eval grep -lF${q_ci:+i}f <(printf '%s\n' "${labels[@]}") ${found//|/labels} 2>/dev/null \
    #  | sed 's#labels$#|#')"
  fi
  if [ ${#words[*]} -gt 0 ] && [ -n "$found" ]; then
    # This is an AND
    tmpf="$(
      eval grep -Ho "'>[^<>]*</span'" ${found//|/paper.*.words} 2>/dev/null \
      | sed 's#</span$##;s#&lt;#<#g;s#&gt;#>#g;s#&amp;#\&#g')"
    for w in "${words[@]}"; do
      tmpf="$(grep -hF${q_ci:+i}e "$w" <<<"$tmpf")"
    done
    found="$(cut -d: -f1 <<<"$tmpf" | sed 's#paper\.[0-9]*\.words$#|#' | sort -u)"
    ## That would be an OR (for later, perhaps)
    #found="$(
    #  eval grep -Ho "'>[^<>]*</span'" ${found//|/paper.*.words} 2>/dev/null \
    #  | sed 's#</span$##;s#&lt;#<#g;s#&gt;#>#g;s#&amp;#\&#g' \
    #  | grep -hF${q_ci:+i}f <(printf '%s\n' "${words[@]}") \
    #  | cut -d: -f1 \
    #  | sed 's#paper\.[0-9]*\.words$#|#' \
    #  | sort -u)"
  fi
  printf '['
  while IFS=/ read folder nil; do if [ -n "$folder" ]; then
    printf ',%s' "$(json_doc $folder)"
  fi; done < <(sort -r <<<"$found") | sed 's/^.//'
  printf ']'
  ;;
T)
  printf '['
  /bin/ls -1 $doc/paper.*.thumb.jpg | sort -t. -k2,2n \
  | while read t; do
    printf ',%s' "$(json_contents $t)"
  done | sed 's/^.//'
  printf ']'
  ;;
D|M)
  if [ -z "$page" ]; then
    json_doc $doc
  elif [ -f $doc/doc.pdf ]; then
    json_contents $doc/doc.pdf $page ${mode/D}
  else
    json_contents $doc/paper.$page.jpg '' ${mode/D}
  fi
  ;;
R)
  if [ -f $doc/doc.pdf ]; then
    if [ -n "$pdfasjpg" ]; then
      pdftoppm -r $PDF_DPI -jpeg -f $page -l $page $doc/doc.pdf
    else
      cat $doc/doc.pdf
    fi
  else
    cat $doc/paper.$page.jpg
  fi
  ;;
esac