#!/bin/sh

_EXEC="$(realpath "${0%/*}")"
. "$_EXEC/cgilite/cgilite.sh"
. "$_EXEC/cgilite/storage.sh"

debug(){
  if [ $# = 0 ]; then
    tee /dev/stderr
  else
    printf %s\\n "$*" >/dev/stderr
  fi
}

timeid(){
  # generate time based ID
  # Fixme: Unix time stamps assumed to be 32bit always
  d=$(date +%s)
  { printf $(
      while [ "$d" -gt 0 ]; do
        printf \\%o\\n $((d % 256))
        d=$((d / 256))
      done |tac |tr -d \\n
    )
    head -c5 /dev/urandom
  } \
  | uuencode -m - \
  | sed -n '2{y;+/;:_;;p}'
}

checkid(){
  grep -m 1 -xE '[0-9a-zA-Z:_]{12}';
}

yield_page(){
printf 'Content-Type: text/html; charset=utf-8\r\n\r\n'
./cgilite/html-sh.sed <<EOF
[html [head
  [meta name="viewport" content="width=device-width"]
  [link rel="stylesheet" type="text/css" href="/invoices.css"]
  [title Invoices]
] [body class="$1"
  [div #menu
    [a "/invoices/" Invoices]
    [a "/clients/" Clients]
    [a "/senders/" Senders]
  ]
  $(cat)
] ]
EOF
}

edit_client(){
  id="$1"
  if [ -f "clients/$id" ]; then
    read -r address hourly <"clients/$id"
  fi
  [ "$address" ] || address="address="
  [  "$hourly" ] ||  hourly="hourly="
  printf '
    [form method="POST" action="/update_client"
      [hidden "id" "%s"]
      <textarea name="address" placeholder="address">
%s</textarea>
      [label for=hourly Hourly Rate:]
      [input #hourly type=number name=hourly value="%s"]
      [submit "update" "update" Update]
    ]' \
    "$(HTML $id)" \
    "$(UNSTRING "${address#address=}" |HTML)" \
    "$(UNSTRING "${hourly#hourly=}" |grep -xE '[0-9]+')"
}

edit_sender(){
  id="$1"
  if [ -f "senders/$id" ]; then
    address="$(cat "senders/$id")"
  fi
  [ "$address" ] || address="Name
Street
City

Phone:
000 000000

Tax no.
xxx / 000 / ###
"
  printf '
    [form method="POST" action="/update_sender"
      [hidden "id" "%s"]
      <textarea name="address" placeholder="address">%s</textarea>
      [submit "update" "update" Update]
    ]' \
    "$(HTML $id)" \
    "$(HTML "${address}")"
}

list_clients(){
  [ -d clients/ ] && for c in clients/*; do
    read -r address hourly <"$c"
    address="$(UNSTRING "${address#address=}")"
    [ "$address" ] || address="(no address)"
    printf '[div .client .address <!--
      -->%s

[label Hourly Rate:] %s€
    [a href="/clients/%s" Edit]]
    ' "$(HTML "$address")" \
      "$(HTML "${hourly#hourly=}")" \
      "$(HTML "${c#clients/}")"
  done
}

list_senders(){
  [ -d senders/ ] && for s in senders/*; do
    address=$(cat "$s")
    [ "$address" ] || address="(no address)"
    printf '[div .sender .address <!--
      -->%s[a href="/senders/%s" Edit]]
    ' "$(HTML "$address")" "$(HTML "${s#senders/}")"
  done
}

sender_list(){
  local select="$1" n name
  [ -d senders/ ] && for n in '' senders/*; do
    [ "$n" ] && name="$(sed q "$n" |HTML)"
    [ "${n#senders/}" = "$select" ] \
    && printf '<option value="%s" selected=selected>%s</option>' "${n#senders/}" "$name" \
    || printf '<option value="%s">%s</option>' "${n#senders/}" "$name"
  done
}

client_list(){
  local select="$1" n address hourly name
  [ -d clients/ ] && for n in '' clients/*; do
    [ "$n" ] && read -r address hourly <"$n"
    name="$(UNSTRING "${address#address=}" |sed q |HTML)"
    [ "${n#clients/}" = "$select" ] \
    && printf '<option value="%s" selected=selected>%s</option>' "${n#clients/}" "$name" \
    || printf '<option value="%s">%s</option>' "${n#clients/}" "$name"
  done
}

list_invoices(){
  [ -d invoices/ ] && for i in invoices/*; do
    read -r sender client date number vat<<-EOF
	$(sed q "$i")
	EOF
    [ -f "senders/${sender#sender=}" ] \
    && sender="$(sed q "senders/${sender#sender=}")" \
    || sender="(unset)"
    [ ! -f "clients/${client#client=}" ] \
    && client="(unset)" \
    || read -r client hourly <"clients/${client#client=}"
    [ "${date#date=}" -ge 0 ] 2>&- \
    && date="$(date -d "@${date#date=}" +%x)" \
    || date="(unset)"

    printf '[div .invoice
      [h2
          %s]
      [label From:] %s [label To:] %s [label on] %s
      [a href="/invoice/%s" Edit]
    ]' "$(UNSTRING "${number#number=}" |HTML)" \
       "$(HTML "$sender")" \
       "$(UNSTRING "${client#address=}" |sed q |HTML)" "$(HTML "$date")" \
       "$(HTML ${i#invoices/})"
  done
}

edit_invoice(){
  id="$1"
  if [ -f "invoices/$id" ]; then
    read -r sender client date number vat<<-EOF
	$(sed q "invoices/$id")
	EOF
  fi

  [ "${date#date=}" -ge 0 ] 2>&- \
  && date="$(date -d "@${date#date=}" +%F)" \
  || date="$(date +%F)"
  [ "${number#number=}" ] || number="number=$(date +%s)"
  [ "${vat%=*}" = vat -a "${vat#vat=}" -ge 0 ] 2>&- \
  && vatrate="${vat#vat=}" \
  || vatrate=19

  cat <<-EOF 
	[form method="POST" action="/update_invoice"
	  [hidden "id" "$(HTML "$id")"]

	  [label Sender:]
	  [select name=sender
	    $(sender_list "${sender#sender=}")
	  ]

	  [label Client:]
	  [select name=client
	    $(client_list "${client#client=}")
	  ]
	
          [label for=number Invoice Number:]
          [input #number name=number value="$(UNSTRING "${number#number=}" |HTML)"]

          [label for=date Date:]
          [input #date name=date value="${date}" placeholder="YYYY-MM-TT"]

          [radio "vat" "smallbusiness" #vatsb $([ "$vat" = smallbusiness ] && printf checked) ]
          [label for=vatsb Small business exemption from VAT]
          [radio "vat" "allgross" #vatgross $([ "$vat" = allgross ] && printf checked)]
          [label for=vatgross All amounts are gross]
          [radio "vat" "rate" #vatrate $([ "${vat%=*}" = vat ] && printf checked) ]
          [label for=vatrate VAT Rate: [input type=number name="vatrate" value="${vatrate}"]% ]

	  [submit "update" "update" Update]
	]
	EOF
}

info="$(PATH "${PATH_INFO}")"

case $info in
  /invoices.css)
    . "$_EXEC/cgilite/file.sh"
    FILE "$_EXEC/invoices.css"
    ;;
  /clients)
    { list_clients
      printf '[a .new href="/clients/%s" New]' "$(timeid)"
    } | yield_page clients
    ;;
  /clients/*)
    edit_client "${info#/clients/}" |yield_page client
    ;;
  /update_client)
    id="$(POST id |checkid)"
    if [ "$(POST update)" = update -a "$id" ]; then
      mkdir -p clients
      printf 'address=%s	hourly=%s' \
        "$(POST address |STRING)" "$(POST hourly |STRING)" \
        >"clients/$id"
    else
      echo Invalid Data "$(POST id)" "$(POST update)" >&2
    fi
    REDIRECT /clients/
    ;;
  /senders)
    { list_senders
      printf '[a .new href="/senders/%s" New]' "$(timeid)"
    } | yield_page senders
    ;;
  /senders/*)
    edit_sender "${info#/senders/}" |yield_page sender
    ;;
  /update_sender)
    id="$(POST id |checkid)"
    if [ "$(POST update)" = update -a "$id" ]; then
      mkdir -p senders
      POST address >"senders/$id"
    fi
    REDIRECT /senders/
    ;;
  /invoices)
    { list_invoices
      printf '[a .new href="/invoice/%s" New]' "$(timeid)"
    } | yield_page invoices
    ;;
  /invoice/*)
    edit_invoice "${info#/invoice/}" |yield_page invoice
    ;;
  /update_invoice)
    id="$(POST id |checkid)"
    if [ "$(POST update)" = update -a "$id" ]; then
      mkdir -p invoices
      vat="$(POST vat |grep -m1 -xE 'smallbusiness|allgross|rate' )"
      printf 'sender=%s	client=%s	date=%s	number=%s	%s\n' \
        "$(POST sender)" "$(POST client)" \
        "$(date -d "$(POST date)" +%s)" \
        "$(POST number |STRING)" \
        "$([ "$vat" = rate ] && printf 'vat=%i' "$(POST vatrate)" || printf %s "$vat" )" \
      >"invoices/$id"
    fi
    REDIRECT "/invoice/$id"
    ;;
  *) REDIRECT /invoices
    ;;
esac