work_instruction_creator.py

# Import libraries
import streamlit as st
import json
from json import JSONEncoder
import base64
import os
import glob
import filetype
from PIL import Image
from streamlit_drawable_canvas import st_canvas
import io
import time
import datetime
import random
from paho.mqtt import client as mqtt_client
import streamlit_authenticator as stauth
from threading import current_thread
from streamlit.runtime.scriptrunner.script_run_context import add_script_run_ctx
from streamlit_server_state import server_state #is similar to the built-in SessionState but it allows the app to re-run when its value is changed
import mysql.connector


# Adjust page configurations
st.set_page_config(page_title="Work Instruction Manager",layout="wide")

# Initialize connection with MySQL Database.
# Uses st.experimental_singleton to only run once.
# @st.experimental_singleton
def init_connection():
    return mysql.connector.connect(**st.secrets["mysql"])

conn = init_connection()

# Perform query.
# Uses st.experimental_memo to only rerun when the query changes or after 10 min.
# @st.experimental_memo(ttl=10) 
def run_query(query):
    with conn.cursor() as cur:
        cur.execute(query)
        return cur.fetchall()

# #User Authentication
users = run_query("SELECT * from users;") # Fetch users credentials from mysql database
usernames = [user[0] for user in users]
names = [user[1] for user in users]
hashed_passwords = [user[2] for user in users]

credentials = {"usernames":{}}

for un, name, pw in zip(usernames, names, hashed_passwords):
	user_dict = {"name":name,"password":pw}
	credentials["usernames"].update({un:user_dict})

# Creating a login widget
authenticator = stauth.Authenticate(credentials, "cookies_here", "edcba", cookie_expiry_days = 30)

name, authentication_status, username = authenticator.login('Login', 'main')

# Authenticating users
if authentication_status == False:
    st.error('Username/password is incorrect')

if authentication_status == None:
    st.warning('Please enter your username and password')

if authentication_status:
	st.sidebar.image('multimedia/MSF-LogoNobg.gif')
	st.sidebar.subheader("Digital Work Instruction Manager")
	st.sidebar.write(f'Welcome *{name}*')
	authenticator.logout('Logout', 'sidebar')
	col_s= st.columns([10, 2])
	col_s[1].image('multimedia/MSF-LogoNobg.gif')

	# mqtt broker
	broker = 'broker.emqx.io'
	port = 1883
	topic = "python/mytest/mqtt"
	topic2 = "wi/mqtt/button"
	client_id = f'python-mqtt-{random.randint(0, 1000)}' # generate client ID with pub prefix randomly

	if 'step_array' not in st.session_state:	# Initialize an array to store the WI step timers
		st.session_state.step_array = []

	if 'msg_count' not in st.session_state:		# Initialize msg_count for counting the number of messages received from the subscribed topic
		st.session_state.msg_count = 1
	
	KEY_CONTEXT = st.runtime.scriptrunner.script_run_context.SCRIPT_RUN_CONTEXT_ATTR_NAME
	main_context = getattr(current_thread(), KEY_CONTEXT)


	# Class declarations
	class WorkInstruction:			# Class for a work instruction that is initialized when a new WI is created
		def __init__(self, wi_name, wi_desc, wi_id, wi_stid, wi_steps):
			self.wi_name = wi_name
			self.wi_desc = wi_desc
			self.wi_id = wi_id
			self.wi_stid = wi_stid
			self.wi_steps = wi_steps

	class AnotherWorkInstruction:	# Class for a work instruction when reading and decoding from the JSON file
		def __init__(self, dict):
			self.__dict__.update(dict)

	class Step:						# Class for a step in the work instruction when a new step is created
		def __init__(self, step_name, step_desc, step_visual, step_inputs):
			self.step_name = step_name
			self.step_desc = step_desc
			self.step_visual = step_visual
			self.step_inputs = step_inputs
			self.step_inputs_no = len(step_inputs)

	class AnotherStep:				# Class for a step in the work instruction when reading and decoding from the JSON file
		def __init__(self, dict):
			self.__dict__.update(dict)

	class Input:					# Class for an input field in the step
		def __init__(self, input_name, input_type):
			self.input_name = input_name
			self.input_type = input_type

	class TextField(Input):			# Subclass of text filed type Input() objects
		def __init__(self, input_name, destination):
			self.destination = destination
			super().__init__(input_name,'text input')

	class Button(Input):			# Subclass of button type Input() objects
		def __init__(self, input_name, function):
			self.function = function
			super().__init__(input_name,'button')

	class WIEncoder(JSONEncoder):	# Custom JSON encoder for the step, work instruction and input field class objects that otherwise cannot be encoded
		def default(self,obj):
			if type(obj).__name__ == "Step" or type(obj).__name__ == "AnotherStep" or type(obj).__name__ == "WorkInstruction" or type(obj).__name__ == "AnotherWorkInstruction"or type(obj).__name__ == "TextField" or type(obj).__name__ == "Button":
				return obj.__dict__	# Encode the above class objects using their __dict__ attribute
				# Not recommended to use built-in Python methods/attributes, try to see if it is possible to optimize and fina another alternative
			else:
				return json.JSONEncoder.default(self,obj)	# Encode all other data types normally


	# Function and variable declarations
	def edit_wi(file_path):			# Function to change to editor mode upon selecting the work instruction to edit
		st.session_state.page_mode = "edit"
		st.session_state.wi_file_path = file_path
		load_wi(file_path)

	def deploy_wi(file_path):		# Function to change to deploy mode upon selecting the work instruction to deploy
		st.session_state.page_mode = "deploy"
		load_wi(file_path)
		t = time.time()
		st.session_state.step_array.append(t)
		client = connect_mqtt()
		client.on_message = on_message
		client.loop_start()
		
	def create_new_wi():			# Function to create a new work instruction object and JSON file path
		st.session_state.page_mode = "new_wi"

	def delete_wi(file_path):	# Function to delete a new work instruction object and JSON file path
		if os.path.exists(file_path):
			os.remove(file_path)
		else:
			print("The file does not exist")

	def add_visual_guide():			# Function to add a media file from the file_uploader widget to the list of visual guide files
		if visual_guide_upload is not None:
			st.session_state.step_visual_list[st.session_state.step_index].append(visual_guide_upload.read())	# Copy IOBytes file from camera_input and append it to list of visual guides
		if visual_guide_upload1 is not None:
			st.session_state.step_visual_list[st.session_state.step_index].append(visual_guide_upload1.read())  # Copy IOBytes file from file_uploader and append it to list of visual guides
		
	def save_photo():			# Function to add the edited media file to the list of visual guide files
		if canvas_image is not None:
			st.session_state.step_visual_list[st.session_state.step_index].append(canvas_image)

	def load_wi(read_directory):	# Function to load a work instruction from JSON file, called through callback from edit button
		st.session_state.step_list = []			# Create empty lists in st.session_state to store the loaded data
		st.session_state.step_visual_list = []
		with open(read_directory,"r") as load_file_test:	# Open file in file directory to read
			load_file_content = json.loads(load_file_test.read(),object_hook = AnotherWorkInstruction)	# Create work instruction object to save data from JSON file
			st.session_state.wi_name = load_file_content.wi_name	# Load variables from file session state variables
			st.session_state.wi_desc = load_file_content.wi_desc
			st.session_state.wi_id = load_file_content.wi_id
			st.session_state.wi_stid = load_file_content.wi_stid

			for step in load_file_content.wi_steps:		# Load each step in st.session_state to persist between changes
				st.session_state.step_list.append(step)
				temp_visual_list = []	# Declare empty list to compile
				for media_file in step.step_visual:
					temp_visual_list.append(base64.b64decode(bytes(media_file,'utf-8')))	# Decode media files saved in JSON file from utf-8 string->base64 bytes->binary file type
				st.session_state.step_visual_list.append(temp_visual_list)	# Append the list of visual guide files for each step

	def save_wi(write_directory):	# Function to save a work instruction to JSON file, called through callback from save work instruction button
		if step_select != "--Choose a step to edit--":
			st.session_state.step_list[st.session_state.step_index].step_name = step_title	# Save changes in step title and description to st.session_state before exporting to JSON file
			st.session_state.step_list[st.session_state.step_index].step_desc = step_desc
			st.session_state.step_select_dropdown = st.session_state.step_list[st.session_state.step_index].step_name	# Save the current step title into the dropdown list options

		step_index = range(len(st.session_state.step_visual_list))
		for index in step_index:	# Loop through each step to write into JSON file
			temp_visual_list = []
			for file in st.session_state.step_visual_list[index]:
				temp_visual_list.append(base64.b64encode(file).decode('utf-8'))	# Encode the media files for visual guides from binary data type->base64 bytes->utf-8 string
			st.session_state.step_list[index].step_visual = temp_visual_list	# Save media files into JSON file for each step
		temp_wi_object = WorkInstruction(wi_name,wi_desc,wi_id,wi_stid,st.session_state.step_list)	# Create WorkInstruction class object to write to JSON
		with open(write_directory,"w") as save_file_test:	# Open file in file directory to write
			save_file_test.write(json.dumps(temp_wi_object,indent = 2,cls=WIEncoder))	# Convert WorkInstruction class object to JSON string using dumps, using the custom encoder WIEncoder

	def create_new_step():			# Function to create a new step and add to the work instruction
		del st.session_state["step_select_dropdown"]	# Delete the current dropdown widget to replace with the updated list of steps
		new_step = Step("Step " + str(len(st.session_state.step_list)+1),"",[],[])	# Create a new step as a Step() class object
		st.session_state.step_list.append(new_step)		# Add new step to list in st.session_state
		st.session_state.step_visual_list.append([])	# Declare blank list for media files for the visual guides of the new step

	def switch_step_edit():			# Function to update the list of step titles, called through callback when switching to another step to edit
		if step_select != "--Choose a step to edit--":
			st.session_state.step_list[st.session_state.step_index].step_name = step_title
			st.session_state.step_list[st.session_state.step_index].step_desc = step_desc

	def delete_step_edit():			# Function to delete a step from the work instruction
		st.session_state.step_list.pop(st.session_state.step_index)
		st.session_state.step_visual_list.pop(st.session_state.step_index)
		st.session_state.step_select_dropdown = "--Choose a step to edit--"

	def switch_step_deploy():		# Function to change the current step when a step is selected through the radio options
		st.session_state.display_state = 0		# Display state 0 will show the instructions for the step for the deployed work instruction
		st.session_state.step_index = step_select_list.index(st.session_state.step_select_radio)	# Update the step index to the current selected step

	def switch_next_step_deploy():	# Function to change to the next step in the work instruction, called through callback function when next step button is clicked
		st.session_state.step_index += 1		# Increase the step index by 1. That's- that's it. Yea.
		st.session_state.step_select_radio = step_select_list[st.session_state.step_index]		# Update the radio option selection to the current step

	def finish_steps_deploy():		# Function to change the display to the finish page when all steps in the work instructions are completed
		st.session_state.display_state = 1		# Display state 1 will show the finish page with summary for the deployed work instruction

	def return_to_directory():		# Function to return to the directory of work instructions in the device
		st.session_state.page_mode = "directory"
		for key in st.session_state.keys():			# Clear all st.session_state variables and widget keys except the authentication keys to start from default state
			if key=="name" or key=="authentication_status" or key=="username":
				pass
			else:
				del st.session_state[key]

	def connect_mqtt():				# Function to create an MQTT client and connect to an MQTT broker
		def on_connect(client, userdata, flags, rc):
			if rc == 0:
				print("Connected to MQTT Broker!!!!")
			else:
				print("Failed to connect, return code %d\n", rc)
			client.subscribe(topic2)
		client = mqtt_client.Client(client_id)
		client.on_connect = on_connect
		client.connect(broker, port)
		return client

	def publish(client):	# Function to Publish WI step's timers to the topic
		t = time.time()
		st.session_state.step_array.insert(st.session_state.msg_count, t)
		msg = f"step {st.session_state.msg_count} of {st.session_state.wi_name} finished in: {int((st.session_state.step_array[st.session_state.msg_count] - st.session_state.step_array[st.session_state.msg_count-1])/60)}min {int((st.session_state.step_array[st.session_state.msg_count] - st.session_state.step_array[st.session_state.msg_count-1])%60)}s"
		result = client.publish(topic, msg)
		status = result[0]
		if status == 0:
			print(f"Send `{msg}` to topic `{topic}`")
		else:
			print(f"Failed to send message to topic {topic}")
		st.session_state.msg_count += 1

	def summ(arr, client):		# Function to Publish the sum of WI step's timers to the topic
		sum = arr[-1] - arr[0]
		def publish(client):
			msg = f"{st.session_state.wi_name} Instructions finished in: {int(sum/60)}min {int(sum%60)}s"
			result = client.publish(topic, msg)
			status = result[0]
			if status == 0:
				print(f"All Steps finished in: {int(sum/60)}min {int(sum%60)}s")
		publish(client)

	def next_publish():		# Function to switch step and publish
		switch_next_step_deploy()
		client = connect_mqtt()
		publish(client)

	def finish_publish():		# Function to switch to the finish page and publish
		finish_steps_deploy()
		client = connect_mqtt()
		publish(client)
		summ(st.session_state.step_array, client)
		client.loop_stop()

	def on_message(client, userdata, msg):		# Function to Receive Messages from a subscribed topic
		print(f"Received `{msg.payload.decode()}` from `{msg.topic}` topic")
		thread = current_thread()
		if getattr(thread, KEY_CONTEXT, None) is None:
			setattr(thread, KEY_CONTEXT, main_context)
		server_state.tttt = True

	def id_update():		# Function to update the station ID in the database
		a = str(st.session_state.id); aa = str(a)
		run_query(f"UPDATE station SET id = '{aa}';")
		conn.commit()

	def startdate_update():		# Function to update the start date in the database
		a = st.session_state.startdate.strftime("%m/%d/%Y")
		run_query(f"UPDATE access SET start_date = '{a}';")
		conn.commit()

	def starttime_update():		# Function to update the start time in the database
		a = st.session_state.starttime.strftime("%H:%M:%S")
		run_query(f"UPDATE access SET start_time = '{a}';")
		conn.commit()
	
	def enddate_update():		# Function to update the end date in the database
		a = st.session_state.enddate.strftime("%m/%d/%Y")
		run_query(f"UPDATE access SET end_date = '{a}';")
		conn.commit()
	
	def endtime_update():		# Function to update the end time in the database
		a = st.session_state.endtime.strftime("%H:%M:%S")
		run_query(f"UPDATE access SET end_time = '{a}';")
		conn.commit()

	def server_update():		# Function to update the MQTT broker server in the database
		x = st.session_state.ti1
		run_query(f"UPDATE broker SET server = '{x}';")
		conn.commit()

	def port_update():		# Function to update the MQTT broker server port in the database
		x = st.session_state.ti2
		run_query(f"UPDATE broker SET port = '{x}';")
		conn.commit()

	def topic_update():		# Function to update the MQTT broker server topic in the database
		x = st.session_state.ti3
		run_query(f"UPDATE broker SET topic = '{x}';")
		conn.commit()


	if "tttt" not in server_state:
		server_state.tttt = False

	if "retunr" not in server_state:
		server_state.retunr = False	



	if 'page_mode' not in st.session_state:
		st.session_state.page_mode = "directory"

	if st.session_state.page_mode == "directory":	# Directory mode: display the list of work instructions
		directory_path = "work_instruction_files/*.json"	# Declare folder path

		st.title("Work Instruction Manager")
		st.header("List of work instructions")

		# Create pseudo-table using st.columns to display the list of work instructions
		header_cols = st.columns([2,1,2,4,1,1,1])	# Declare headers of "table"
		header_cols[0].markdown("**Barcode ID**")
		header_cols[1].markdown("**Station ID**")
		header_cols[2].markdown("**WI Document Name**")
		header_cols[3].markdown("**WI Document Description**")
		
		directory_table = st.container()	# Content of tables are inserted here

		bottom_cols = st.columns(2)			# Just for aesthetics
		id_field = bottom_cols[0].text_input("Search for work instruction by ID or scan barcode")	# Input field to filter WI by ID/barcode

		if st.session_state["username"] == "admin" or st.session_state["username"] == "instructor":
			new_wi = bottom_cols[0].button("Create new work instruction", on_click=create_new_wi)	# Button to create a new work instruction for the admin and the instructor

		wi_file_list = glob.glob(directory_path)	# Find all the files in the directory path folder, return as file paths
		file_index = 0
		for path in wi_file_list:		# Each iteration of for loop is a new row in the "table"
			wi_content = json.loads(open(path).read())

			if st.session_state["username"] == "admin" or st.session_state["username"] == "instructor":
				if wi_content['wi_id'].startswith(id_field):	# Filter the work instruction based on the starting digits of the ID
				# if id_field in wi_content['wi_id']:			# Alternative option: Filter based on digits in any segment of the ID
					table_cols = directory_table.columns([2,1,2,4,1,1,1])
					table_cols[0].markdown(wi_content['wi_id'])
					table_cols[1].markdown(wi_content['wi_stid'])
					table_cols[2].markdown(wi_content['wi_name'])
					table_cols[3].markdown(wi_content['wi_desc'])
					table_cols[4].button("Edit",key=("edit"+str(file_index)),on_click=edit_wi,args=(path,))		# Button to switch to editing page of the selected work instruction
					table_cols[5].button("Delete",key=("delete"+str(file_index)),on_click=delete_wi,args=(path,))	# Button to delete the selected work instruction
					table_cols[6].button("Deploy",key=("deploy"+str(file_index)),on_click=deploy_wi,args=(path,))	# Button to switch to deployment page of the selected work instruction
				file_index+=1

				if id_field == wi_content['wi_id']:	# Deploy the WI if the id input in the Search field correspond to a WI ID
					server_state.retunr = True  # set a value to 'retunr' in the server state
					deploy_wi(path)
					server_state.retunr = False		# change the value of the 'retunr' in the server state to re-run the app
			
			if st.session_state["username"] == "operator":
				bk = run_query("SELECT * from broker;")
				# If the user is the operator, then replace the broker details with the data from the database
				for bkk in bk:
					broker = bkk[0]
					port = int(bkk[1])
					topic2 = bkk[2]
				x = run_query("SELECT * from access;")
				for xk in x:
					x1 = xk[0]; x2 = xk[1]; x3 = xk[2]; x4 = xk[3]
				sd = datetime.datetime.strptime(x1, "%m/%d/%Y").date()
				stt = datetime.datetime.strptime(x2, "%H:%M:%S").time()
				ed = datetime.datetime.strptime(x3, "%m/%d/%Y").date()
				et = datetime.datetime.strptime(x4, "%H:%M:%S").time()
				at = datetime.datetime.now().time()
				ad = datetime.date.today()
				if sd <= ad and ad <= ed and stt < at and at < et:	# Retrieve the dates and times from the database and check if the current date and time is in the valid interval before displaying the contents
					b = run_query("SELECT * from station;")
					for bk in b:
						sid = bk[0]
					if sid in wi_content['wi_stid']:
						table_cols = directory_table.columns([2,1,2,4,1,1,1])
						table_cols[0].markdown(wi_content['wi_id'])
						table_cols[1].markdown(wi_content['wi_stid'])
						table_cols[2].markdown(wi_content['wi_name'])
						table_cols[3].markdown(wi_content['wi_desc'])
						table_cols[5].button("Deploy",key=("deploy"+str(file_index)),on_click=deploy_wi,args=(path,))	# Button to switch to deployment page of the selected work instruction
					file_index+=1
					if id_field == wi_content['wi_id']:	# Deploy the WI if the id input in the Search field correspond to a WI ID
						server_state.retunr = True # set a value to 'retunr' in the server state
						deploy_wi(path)
						server_state.retunr = False # change the value of the 'retunr' in the server state to re-run the app
				
		# Add a dashboard to the admin page
		if st.session_state["username"] == "admin":
			st.markdown("***"); st.write("")
			st.header("Operator Settings")
			st.subheader("Operator Station ID")
			cols1 = st.columns([2.5,2.5,2.5,2.5]); st.subheader("")
			st.subheader("Operator Access Control")
			cols2 = st.columns([2.5,2.5,2.5,2.5])
			cols2[0].markdown("**Start Date**"); cols2[1].markdown("**Start Time**"); cols2[2].markdown("**End Date**"); cols2[3].markdown("**End Time**"); st.subheader("")
			st.subheader("Operator Broker")
			cols3 = st.columns([2.5,2.5,2.5,2.5])
			cols3[0].markdown("**Server**"); cols3[1].markdown("**Port**"); cols3[2].markdown("**Topic**")			
			b = run_query("SELECT * from station;")
			for bk in b:
				sid = bk[0]
			x = run_query("SELECT * from access;")
			for xk in x:
				x1 = xk[0]; x2 = xk[1]; x3 = xk[2]; x4 = xk[3]
			sd = datetime.datetime.strptime(x1, "%m/%d/%Y").date()
			stt = datetime.datetime.strptime(x2, "%H:%M:%S").time()
			ed = datetime.datetime.strptime(x3, "%m/%d/%Y").date()
			et = datetime.datetime.strptime(x4, "%H:%M:%S").time()
			bk = run_query("SELECT * from broker;")
			for bkk in bk:
				bk0 = bkk[0]; bk1 = bkk[1]; bk2 = bkk[2]
			cols1[0].number_input("id", 1, 3, int(sid), label_visibility='collapsed', on_change=id_update, key="id")
			cols2[0].date_input("startdate", sd, label_visibility='collapsed', on_change=startdate_update, key='startdate')
			cols2[1].time_input('starttime', stt,label_visibility='collapsed', on_change=starttime_update, key='starttime')
			cols2[2].date_input("enddate", ed, label_visibility='collapsed', on_change=enddate_update, key='enddate')
			cols2[3].time_input('endtime', et, label_visibility='collapsed', on_change=endtime_update, key='endtime')
			cols3[0].text_input('server', bk0, label_visibility='collapsed', on_change=server_update, key='ti1')
			cols3[1].text_input('port', bk1, label_visibility='collapsed', on_change=port_update, key='ti2')
			cols3[2].text_input('topic', bk2, label_visibility='collapsed', on_change=topic_update, key='ti3')



	if st.session_state.page_mode == "new_wi":
		# Create new WI object here/declare variables in session_state
		st.session_state.step_list = []
		st.session_state.step_visual_list = []
		# Create a JSON file for the new WI
		with st.form("my_form"):
			wi_name = st.text_input("Enter the work instruction title 👇", placeholder="work instruction name")
			wi_id = st.text_input("Enter the work instruction id 👇", placeholder="work instruction id")
			wi_desc = st.text_area("Enter the work instruction description 👇", placeholder="work instruction description")
			wi_stid = st.text_input("Enter the work instruction Station id 👇", placeholder="Station id")
			submitted = st.form_submit_button("Create")
			if submitted:
				f = open(f"work_instruction_files/{wi_name}.json", "a")
				f.write('{')
				f.write(f'"wi_name": "{wi_name}", "wi_desc": "{wi_desc}","wi_id": "{wi_id}","wi_stid": "{wi_stid}","wi_steps": [ ]')
				f.write('}')
				f.close()
				path = f"work_instruction_files/{wi_name}.json"
				edit_wi(path)



	if st.session_state.page_mode == "edit":	# Edit mode: edit the selected work instruction
		step_name_list = []
		for step in st.session_state.step_list:
			step_name_list.append(step.step_name)	# Create list of step names used to create the dropdown list to select the step to edit

		wi_id = st.text_input("Id of work instruction",key="wi_id")			# Text input field to enter the name of the work instruction
		wi_stid = st.text_input("Id of work instruction",key="wi_stid")
		wi_name = st.text_input("Name of work instruction",key="wi_name")			# Text input field to enter the name of the work instruction
		wi_desc = st.text_area("Description of work instruction",key="wi_desc")		# Text area field to enter the description of the work instruction

		# Step selector to choose step to edit
		step_select_container = st.container()		# Dropdown list to select step will appear here
		step_select_list = ["--Choose a step to edit--"] + step_name_list	# Add a placeholder string to the front of the list

		col1,col2,col3,col4,col5 = st.columns(5)
		with col5:
			new_step_button = st.button("Create new step", on_click=create_new_step)	# Button to add a new step
		if new_step_button:
			st.session_state.step_select_dropdown = step_select_list[-1]				# Step index moves to the new step (last index)

		if 'step_select_dropdown' in st.session_state and st.session_state.step_select_dropdown != "--Choose a step to edit--":	# Only triggers after step select dropdown list has been initialized previously
			new_step_index = step_name_list.index(st.session_state.step_select_dropdown)	# Find index of the selected step in the list of step names
			st.session_state.step_select_dropdown = step_name_list[new_step_index]		# Update the step name in the dropdown options, if there were any changes

		step_select = step_select_container.selectbox("Step to edit",step_select_list,key="step_select_dropdown",on_change=switch_step_edit)	# Initialization of dropdown widget
		if step_select != "--Choose a step to edit--":
			st.session_state.step_index = step_name_list.index(st.session_state.step_select_dropdown)	# Find the index of the current step
			st.header("Currently editing: Step " + str(st.session_state.step_index+1))		# Display the current step number
			step_title = st.text_input("Step title",value=st.session_state.step_list[st.session_state.step_index].step_name,key="step_title")	# Input field for the step title
			step_desc = st.text_area("Enter description of step (detailed instructions, materials, etc.)",value=st.session_state.step_list[st.session_state.step_index].step_desc,key="step_description")	# Input field for the step description
			st.markdown("**(Optional) Add a visual guide as a video or image**")
			visual_guide_upload1 = st.file_uploader("Upload video or image guide here", type=['png','jpg','jpeg','mp4','wmv'])	# Media file uploader widget for the visual guides
			visual_guide_upload = st.camera_input("Take a photo for visual guide", key ="visual_guide_upload")
			canvas_image = None # Declare the variable canvas_image

			if st.checkbox('Edit photo'): # Display canvas to edit photo
				# Specify canvas parameters in application
				drawing_mode = st.sidebar.selectbox("Drawing tool:", ("freedraw", "point", "line", "rect", "circle", "transform"))
				stroke_width = st.sidebar.slider("Stroke width: ", 1, 25, 3)
				if drawing_mode == 'point':
					point_display_radius = st.sidebar.slider("Point display radius: ", 1, 25, 3)
				stroke_color = st.sidebar.color_picker("Stroke color hex: ")
				bg_color = st.sidebar.color_picker("Background color hex: ", "#eee")
				realtime_update = st.sidebar.checkbox("Update in realtime", True)
				# get the visual_guide_upload photo size
				if visual_guide_upload:
					img = Image.open(visual_guide_upload)
					w, h = img.size 
				else:
					w, h = 700, 300	
				
				canvas_width = w; canvas_height = h	# Assign them to new variables
				# Create a canvas component
				canvas_result = st_canvas(
					fill_color="rgba(255, 165, 0, 0.3)",  # Fixed fill color with some opacity
					stroke_width=stroke_width,
					stroke_color=stroke_color,
					background_color=bg_color,
					background_image=Image.open(visual_guide_upload),
					update_streamlit=realtime_update,
					height=canvas_height,
					width=canvas_width,
					drawing_mode=drawing_mode,
					point_display_radius=point_display_radius if drawing_mode == 'point' else 0,
					key="canvas")

				if canvas_result.image_data is not None:
					img2 = Image.fromarray(canvas_result.image_data) # Save the canvas drawing which is an Array as Image
				if visual_guide_upload:
					img1 = Image.open(visual_guide_upload)
					img1.paste(img2, (0,0), mask = img2) # superimpose drawing image img2 on the camera photo img1
					img1.save('canvas_image.png')
					byteImgIO = io.BytesIO()
					byteImg = Image.open("canvas_image.png")
					byteImg.save(byteImgIO, "PNG") # change the png image to IOBytes file
					byteImgIO.seek(0)
					canvas_image = byteImgIO.read()
				
				save_photo = st.button("Save edit",on_click=save_photo) # button to save the edit photo

				visual_guide_upload = st.session_state.visual_guide_upload 

			if canvas_image is not None:
				pass
			else:
				add_visual_button = st.button("Add media file as visual guide",on_click=add_visual_guide)	# Button to add the media file to the list of visual guides (st.file_uploader's on_change callback doesn't work for this unfortunately)

			# Section to create feedback/input fields for the users of the work instruction here
			# TD DO: Integrate with database/external processes (HTTP requests etc.)
			st.markdown("**(Optional) Add a field for user input**")
			input_type = st.selectbox("Type of input", ["--Choose an input type--","Text input","Button"])	# Dropdown list to choose the type of input

			if input_type == "Text input":	# For text input fields
				with st.form(key="input_form"):
					txtfield_name = st.text_input("Input field name")
					txtfield_destination = st.text_input("Destination key")			# Arbitrary placeholder, no function implemented yet
					txtfield_submit = st.form_submit_button("Create input field")	# Confirmation button to create the input field
					if txtfield_submit:
						st.session_state.step_list[st.session_state.step_index].step_inputs.append(TextField(txtfield_name,txtfield_destination))	# Create a Textfield() subclass of the Input() class object
			elif input_type == "Button":	# For buttons to trigger external processes
				with st.form(key="input_form"):
					button_name = st.text_input("Button name")
					button_function = st.selectbox("What does this button do?",["--Choose a function--","Send a message to admin","Trigger a process","Take a measurement"])	# Arbitrary placeholder, no function implemented yet
					button_submit = st.form_submit_button("Create button")			# Confirmation button to create the button
					if button_submit:
						st.session_state.step_list[st.session_state.step_index].step_inputs.append(Button(button_name,button_function))			# Create a Button() subclass of the Input() class object

			st.markdown("""---""") # divider line between editor section and preview section for clarity
			st.header("Preview")
			if step_title:
				st.subheader(str(st.session_state.step_index+1) + ". " + step_title)	# Display step number and step title to preview
			if (st.session_state.step_visual_list[st.session_state.step_index] != []):
				if len(st.session_state.step_visual_list[st.session_state.step_index]) == 1:	# For steps with only 1 visual guide item
					visual_cols = st.columns(2)	# Resize image/video to only half the page for organization
				else:
					visual_cols = st.columns(len(st.session_state.step_visual_list[st.session_state.step_index]))	# Otherwise, arrange all visual guide items in a row
				visual_index = 0
				for item in st.session_state.step_visual_list[st.session_state.step_index]:
					if 'image' in filetype.guess(item).mime:
						visual_cols[visual_index].image(item)	# Image files displayed through st.image widget
					elif 'video' in filetype.guess(item).mime:
						visual_cols[visual_index].video(item)	# Video files displayed through st.video widget
					else:
						visual_cols[visual_index].error("Could not display media file.")	# Error message
					visual_index+=1
			
			st.markdown(step_desc)	# Display description and detailed instructions of step

			input_list_length = len(st.session_state.step_list[st.session_state.step_index].step_inputs)
			input_list_index = range(input_list_length)		# Create list of indexes to select each Input() object
			input_preview_list = []
			if input_list_length > 0:
				for i in input_list_index:	# Create input field/button for each Input() object in the current step
					if st.session_state.step_list[st.session_state.step_index].step_inputs[i].input_type == 'text input':
						input_preview_list.append(st.text_input(st.session_state.step_list[st.session_state.step_index].step_inputs[i].input_name))
					elif st.session_state.step_list[st.session_state.step_index].step_inputs[i].input_type == 'button':
						input_preview_list.append(st.button(st.session_state.step_list[st.session_state.step_index].step_inputs[i].input_name))

			col1,col2,col3,col4,col5 = st.columns(5)	# Formatting to place button on the right side
			col1.header('')
			delete_step_edit = col1.button("Delete Step", on_click=delete_step_edit)	# Button to delete step

		col1,col2,col3,col4,col5 = st.columns(5)
		with col5:
			st.text('')
			save_step_button = st.button("Save changes", on_click=save_wi,args=(st.session_state.wi_file_path,))	# Button to save work instruction to JSON file
		directory_button = st.button("Return to work instruction directory",on_click=return_to_directory)	# Button to return to main directory of all the work instructions



	if st.session_state.page_mode == "deploy":	# Deploy mode: display the selected work instruction step-by-step for the reader to follow
		step_name_list = []
		step_select_list = []
		counter = 0

		if len(st.session_state.step_list) == 0:
			st.subheader('No Step to display')
			directory_button = st.button("Return to work instruction directory",on_click=return_to_directory)	# Button to return to main directory of all the work instructions

		else:
			for step in st.session_state.step_list:	# Import steps from session_state to deploy
				step_name_list.append(step.step_name)	# Create list of step titles
				counter += 1
				step_select_list.append("Step " + str(counter) + ": " + step.step_name)	# Display title and number of step

			if 'display_state' not in st.session_state:	# Initialize display_state variable which determines whether to show a step or the finish page
				st.session_state.display_state = 0		# In display_state == 0, step will be shown as normal

			if 'step_index' not in st.session_state:	# Initialize step_index variable to find the index of the step
				st.session_state.step_index = 0			# Start with the first step

			display_section = st.container()			# Declare container here to put in the finish page/step content

			if st.session_state.display_state == 1:		# display_state == 1, display finish page
				st.sidebar.markdown("Progress:")
				st.sidebar.progress(100)				# Atuomatically set progress bar to complete
				with display_section:
					st.title("Done!")
					st.markdown("Review the completed steps below:")
					for step_name in step_name_list:	# List the step titles as a summary to the user
						st.markdown("- " + step_name)
					confirm_complete_button = st.button("Confirm and return to main menu",on_click=return_to_directory)	# Button to return to main directory of all the work instructions
					server_state.retunr = True			# set a value to 'retunr' in the server state
					time.sleep(5); return_to_directory()
					server_state.retunr = False			# change the value of the 'retunr' in the server state to re-run the app	
			else:
				st.sidebar.markdown("Progress:")
				st.sidebar.progress(float(st.session_state.step_index/len(step_name_list)))
				if st.session_state.step_index+1 < len(step_select_list):		# Shows next step if there are other steps left; otherwise, go to finish page
					next_step = st.button("Next step",on_click=next_publish)	# Button to go to the next step (increase step_index by 1)
					if server_state.tttt == True:
						next_publish()
						server_state.tttt = False		# change the value of the 'tttt' in the server state to re-run the app
				else:
					finish_steps = st.button("Finish",on_click=finish_publish)		# Button to go to the review of all steps page
					if server_state.tttt == True:
						finish_publish()
						server_state.tttt = False		# change the value of the 'tttt' in the server state to re-run the app

				with display_section:
					st.subheader(str(st.session_state.step_index+1) + ". " + st.session_state.step_list[st.session_state.step_index].step_name)	# Display step number and title				
					if (st.session_state.step_visual_list[st.session_state.step_index] != []):
						if len(st.session_state.step_visual_list[st.session_state.step_index]) == 1:
							visual_cols = st.columns(2)	# Resize image/video to only half the page for organization
						else:
							visual_cols = st.columns(len(st.session_state.step_list[st.session_state.step_index].step_visual))	# Otherwise, arrange all visual guide items in a row
						visual_index = 0
						for item in st.session_state.step_visual_list[st.session_state.step_index]:
							if 'image' in filetype.guess(item).mime:
								visual_cols[visual_index].image(item)	# Image files displayed through st.image widget
							elif 'video' in filetype.guess(item).mime:
								visual_cols[visual_index].video(item)	# Video files displayed through st.video widget
							else:
								visual_cols[visual_index].error("Could not display media file.")	# Error message
							visual_index+=1

					st.markdown(st.session_state.step_list[st.session_state.step_index].step_desc)	# Display descriptions and detailed instructions of step 

			step_select = st.sidebar.radio("Choose a step",step_select_list,on_change=switch_step_deploy,key="step_select_radio")	# Radio widget to switch to another step