#!/usr/bin/env python

# The Edge sign in system, RESTful/json backend, v.0.7

# Copyright Byron Crowe, 2016.
# This program is distributed under the terms of the GNU General Public License

import os
import sys
import nfc
import time
import json
import web
import threading
import hashlib

#parent_id = linked card

##
## Load user database in. Returns a dict. Currenly loads JSON
##
def loadusers():
  print "Loading database:",
  with open("cards.json","r") as f:
    userdict=json.load(f)
    print "  Loaded:",len(userdict.keys())  

  return userdict

##
## Save user database. Expects a dict. Currenly saves as JSON
##
def saveusers(userdict):

  print "Cleaning database:",
  for test in userdict:
#    print "Loaded:",test,"  >",userdict[test].get('flags')
#    userdict[test]['flags']="novalid,noexpire"
    for cleanup in userdict[test].keys():
      if userdict[test].get(cleanup)==None:
        print "Already cleared:"+test+" key:"+cleanup,
      elif userdict[test].get(cleanup)=="":
        print "Deleing:"+test+" key:"+cleanup,
        del userdict[test][cleanup]
  print "."
  print "Saving database",
#  return      # Uncomment to disable saving
  with open("cards.json","w") as f:
    json.dump(cardusers,f,sort_keys = True, indent = 4, ensure_ascii = False)
  print "." 

##
## Update card/tag data. Do validity checks and only update passed data.
## Also create new card/tag if none exists
##
def updatecarddata(updatedata):
  global cardusers
  returnvalue = "Tag updated."   # Default message, we'll pike otherwise
  
  # Handle things that will cause an update to fail
  if currentcard==None:
    return "Error: No tag!"
  if updatedata.get('cardid') != currentcard:
    return "Error: Tag removed, data not updated!"
  if cardusers.get(currentcard)==None:
    print "Adding tag:"+currentcard
    returnvalue="New tag! Adding to database."
    cardusers[currentcard] = { 'name': '-none-', 'last_seen': '' }
  else:
    print "Updating tag:"+currentcard

  del updatedata['cardid']  # This should not end up in the database
  for updatekey in updatedata:
    if cardusers[currentcard].get(updatekey)!=None:
       print "Updating>"+updatekey+"<>"+updatedata[updatekey]+"<  ",
       cardusers[currentcard][updatekey]=updatedata[updatekey]
    else:
      if updatedata[updatekey]:
        print "Adding>"+updatekey+"<>"+updatedata[updatekey]+"<  ",
        cardusers[currentcard][updatekey]=updatedata[updatekey]
      else:
        print "Not using>"+updatekey+"<  ",
  print
 
  saveusers(cardusers)
  return returnvalue

##
## Sign in user, save data to both main log and emergancy log.
## Then if the card is still on the reader, trigger an update
##
def signinuser(updatedata):
  signincard = updatedata['cardid']
  signinfile = 'signindata.csv'
  # This file should be unique for any one date/day.
  emergfile = hashlib.md5(`time.strftime("%a, %d %b %Y")+'Salt'`).hexdigest()[:10]+".txt"

#  if not cardusers.get('emergfile'):
#    cardusers['emergfile']=

  # String for signin 'sheet'
  s=`time.strftime("%a, %d %b %Y %H:%M:%S")`+',"'
  s=s+updatedata['name']+'","'+updatedata['email']+'","'+updatedata.get('visit_use',"None")+'",'
  # Update vists if user has a tag, othersise give a '-'
  if(cardusers.get(signincard)):
    cardusers[signincard]['visits'] = cardusers[signincard].get('visits',0) + 1
    s=s+`cardusers[signincard]['visits']`+"\n"
  else:
    s=s+"-\n"

  #String for emergancy log
  e='Signed in:'+`time.strftime("%H:%M:%S")`+'  Name:'+updatedata['name']+'  Phone:'+updatedata['phone']+'  Visit reason:'+updatedata.get('visit_use',"None")
  e=e+'\nEmergancy details. Name:'+updatedata['e_name']+'  Phone:'+updatedata['e_phone']+'  Relation/notes:'+updatedata['e_relation']
  e=e+'\n\n'

  # Make sure we have a file, if not, give us some headers.
  if(os.path.isfile(signinfile) != True):
    sf = open(emergfile, 'w')
    sf.write("Time,name,email,reasion,vists\n")
    sf.close()

  # Same for emergancy sheet, title with today's date.
  if(os.path.isfile(emergfile) != True):
    ef = open(emergfile, 'w')
    ef.write(" Emergancy details file for:"+`time.strftime("%a, %d %b %Y")`+"\n\n")
    ef.close()

  # Open, write out and close signin/emerg files.
  sf = open(signinfile, 'a')
  ef = open(emergfile, 'a')
  print "Logged data:"+s
  sf.write(s)
  ef.write(e)
  sf.close()
  ef.close()

  # User didn't put a card on the reader or removed it before this call
  if currentcard==None:
    return "Signed in!\n(No tag/update)"

  # Ok! Save any changes.
  return 'Signed in!\n'+updatecarddata(updatedata)

##
## Delete a tag/card, do finial checks first.
##
def deletecarddata(updatedata):
  # User didn't put a card on the reader or removed it before this call
  if currentcard==None:
    return "Error: No Tag!"
  if updatedata.get('cardid') != currentcard:
    return "Error: Tag Changed!"  

  # Delete tag
  print "Deleting tag:"+currentcard
  del cardusers[currentcard]		# Actual delete
  saveusers(cardusers)

  return "Tag deleted from database."

##
##  ---   Web servery stuff --
##
class MyWebserver(threading.Thread):

  # Start the web server.
  def run (self):
    urls = (
      '/card/id', 'web_get_id',
      '/card/data', 'web_get_carduser',
      '/card/update', 'web_card_update'
    )
    app = web.application(urls, globals())
    print "Starting:",
    app.run()
    print "Started."

  def stop(self):
    print "Stopping web server"
    os._exit(0)    
#    self.process.terminate()
#    self.process = None

# Return just if there is a card on the reader and card id.
class web_get_id:
  def GET(self):
    web.header('Access-Control-Allow-Origin', '*')
    web.header('Access-Control-Allow-Method', '*')
    web.header('Access-Control-Allow-Credentials', 'true')
    return json.dumps({
      'cardid': currentcard
    })

# Return full user data for current card
# This will eventually involve a database lookup and other things so is a diffrent call to just 'tag on reader'.
class web_get_carduser:
  def GET(self):
    web.header('Access-Control-Allow-Origin', '*')
    web.header('Access-Control-Allow-Method', '*')
    web.header('Access-Control-Allow-Credentials', 'true')
    # If current card on the reader is an emergancy card, give the current emergfilename.
    if cardusers.get(currentcard):
      if cardusers[currentcard].get('to_use')=='emerg,emerg,emerg':
        cardusers[currentcard]['notes']=hashlib.md5(`time.strftime("%a, %d %b %Y")+'Salt'`).hexdigest()[:10]+".txt"

    return json.dumps({
      'cardid': currentcard,
      "Data":cardusers.get(currentcard, 'No User')
    })

# Main return/update/signin function. Looks after: Normal and advanced 'update's, 'signin' and 'delete'
# Most actions result in a 'return' before the end of the function.
class web_card_update:
  def POST(self):
    web.header('Access-Control-Allow-Origin', '*')
    web.header('Access-Control-Allow-Method', '*')
    web.header('Access-Control-Allow-Credentials', 'true')
#    data = web.data()
#    print "Post got ->",data,"<-"
    webdata=web.input();
    #dvanced_="false",submitmode_=""

    # Clean up import data. Put in a new dict for later as web.import dosen't surport .get()
    # All returned fields without data get a "", maybe they should be not added to the dict?
    safedata={}
    for webkeys in webdata:
      toclean=web.input(webkeys="")[webkeys]
      toclean=toclean[:60]		    # Limit fields to 60 chars. Need exception for 'notes'
      toclean = toclean.replace('"',"'");   # Any other 'replace' cleanups need to be here.
#      print "webkey>"+webkeys+"<	Data>"+toclean+"<"
      safedata[webkeys[:-1]]=toclean        # Remove trailing _ from returned names to create actual keys.

    # Return 
#    updatedata=validandtranslate(safedata)

    # Sign in user. Do first checks, then call function.
    if(safedata.get("submitmode")=="signin"):
      updatedata=validandtranslate(safedata,("cardid","name","email","phone","e_name","e_phone","e_relation","notes","visit_use"))
      print "Log user in!"
      if not safedata.get('flags').find("novalid"):	 # We don't want test tags signing in.
        print "  'novalid' found.."
        return "Not valid user."
      if updatedata['visit_use'] == "":			# Allow for to_use to overwrite visit_use
       print "To Use Override:"+updatedata['to_use']	# Might not be needed due to web interface updates.
       updatedata['visit_use']=updatedata['to_use'] 
      return signinuser(updatedata)

    # Advanced mode, update 'invalid' cards and enables delete
    # Also allows update of aditonal fields
    elif(safedata.get("advanced")=="true"):
      updatedata=validandtranslate(safedata,("cardid","name","email","phone","to_use","e_name","e_phone","e_relation","notes","visit_use","flags"))
      print "Advanced mode: Submit:",safedata.get("submitmode"),"  CardID:",safedata.get("cardid"),"  Parent:",safedata.get("parentid"),"  Name:",safedata.get("name")

      if(safedata.get("submitmode")=="update"):		# Update but not signin, some checks disabled
#        updatedata['parentid']=webdata.parentid_
        return updatecarddata(updatedata)         # Advanced update function

      elif(safedata.get("submitmode")=="delete"):	# Delete a card, throw to function for final checks.
        if(safedata.get("delete_sure")=="true"):
#          print "Delete tag:"+updatedata['cardid']
          return deletecarddata(updatedata)
        else:
          return "Error: No confirm for delete."

    # 
    return "Error: Invalid submit request!"
  def GET(self):
    return "Nope! Your using the wrong update method. Go away."

# Checks and only passes valid keys
# Returns empty data field for no data 
def validandtranslate(indict,validkeys):
  #"parentid",  # Need to enable this
#  validkeys=("cardid","name","email","phone","to_use","e_name","e_phone","e_relation","notes","visit_use","flags")
  outdict={}
  print "Check keys: "+`validkeys`
  for checkkey in validkeys:
    if (indict.get(checkkey,None)):
      print "|"+checkkey+"<>"+indict[checkkey]+"|  ",
      outdict[checkkey]=indict[checkkey]
    else:
      print "|"+checkkey+"<No data  ",
      outdict[checkkey]=""
  print 
  return outdict

## -- end web servery stuff --

# Used by clf. nfc card function. Called on card read.
def process_tag_data(tag):
    inloop=True
    tag_id = tag.identifier.encode('hex').upper()
 #   print 'Tag ID is', tag_id
    global currenttag
    currenttag=tag_id
#    print "Cur:",currenttag
#    time.sleep(1000)


## -- Tidy up function
def shutdown():
  print "Shutting down program."
  saveusers(cardusers)
  os.system("touch loginkill")     # Signial to other scripts that we got killed
  webthread.stop()                 # Web server off
  clf.close()
  exit()                           # Get out of here!

def globalexceptioncatch(exctype, value, traceback):
  print "Caught excption."
  shutdown()

##
## --  Actual program starts here --
##

print 'Starting'

# Our globals, some needed, some not.
inloop=False
currenttag=0
prevtag=1
currentcard = None
tag_data_timeout = 2  # 10 seconds
last_tag_read_time = 0
#thekilltag = '0492DE622B2B80'
thekilltag = '04860072794384'

#Get us our cards!
cardusers=loadusers()

#saveusers(cardusers)
#exit()

# Uncomment these two lines only when there is no users in the database
#from dummydata import loaddummydata
#cardusers=loaddummydata()

#Make sure 'kill' card is in the system, needed to stop and exit program
#This runs after any other database or data load,
if cardusers.get(thekilltag)==None:
  print "Adding kill tag:",thekilltag
  cardusers[thekilltag] = { 'name': 'Ralph', 'email': 'kill@tag.com', 'to_use': 'Gonna,WreckIt!', }

print "DB tests:"
print "  Name:",cardusers['0455B36A714081']['name'],"last_seen",cardusers['0455B36A714081']['last_seen']
if( cardusers[thekilltag]['email'] == 'kill@tag.com' ):
  print "  Kill tag found! Safe to start. Last kill:",cardusers[thekilltag].get('last_seen','Never')
else:
  print "  No kill tag.."
  exit()

# Make sure to catch all exceptions
#sys.excepthook = globalexceptioncatch

#set up card reader
print "Opening reader: ",
try:
  clf = nfc.ContactlessFrontend('usb')
except:
  print "Ccan't start! Shutting down."
  shutdown()
print 'NFC reader', clf, 'opened'

# And RESTful-api
print 'Web server:',
webthread=MyWebserver()
webthread.start()

print 'Entering main loop'

while True:

  currenttag=0
  # Try and read, give up after 1 second.
  after1s = lambda: time.time() - started > 1
  started = time.time();
  clf.connect(rdwr={'on-connect': process_tag_data}, terminate=after1s)

  # Best way to cleanly kill the whole program due to web/nfc blocking
  if currenttag == thekilltag:
    print "Kill tag!("+cardusers[thekilltag]['to_use']+") exiting.."
    cardusers[currenttag]['last_seen']=time.time()   # Save current time of kill 
    shutdown()

#  print "Current:",currenttag,"  Prev:",prevtag
  if prevtag==0 and currenttag==0:
    print "Waiting for next card."
  elif currenttag==prevtag:
    print "Card read, please remove card."
    # keep this if we want to keep info up while card is held on reader
    last_tag_read_time = time.time()
  else:
    prevtag=currenttag
    if currenttag != 0:
      # global declaraion not needed since we're outside a class/function
      currentcard = currenttag
      last_tag_read_time = time.time()
      print 'Tag ID:',currenttag,'User',cardusers.get(currenttag, 'No User')
      if(cardusers.has_key(currenttag)):
        cardusers[currenttag]['last_seen']=time.time()                        # Needs extra bits to handle parent/child cards
      else:
        print "Unknown tag."

  # clear tag data after a timeout
  if last_tag_read_time + tag_data_timeout < time.time():
    last_tag_read_time = time.time()
    currentcard = None
    print "Card timeout."

  if currenttag != 0:  # Bit of a delay if a card is on 
    time.sleep(0.5)  # This blocks, so maybe a problem?