import os
import csv
import gradio as gr
import itertools
import random
from collections import deque

DATA_FILENAME = "data.csv"
DATA_FILE = os.path.join("/data", DATA_FILENAME)

MAX_LINES = 20

def generate_html(me: str) -> str:
    with open(DATA_FILE) as csvfile:
        reader = csv.reader(csvfile)
        rows = deque(reader, maxlen=MAX_LINES)
        if len(rows) == 0:
            return "no messages yet"
        else:
            html = "<div class='chatbot'>"
            for row, _ in itertools.zip_longest(rows, range(MAX_LINES), fillvalue=("", "")):
                username = row[0]
                if username == me:
                    msg_type = "own"
                elif username == "[chatbot]":
                    msg_type = "admin"
                elif username == "":
                    msg_type = "empty"
                else:
                    msg_type = "other"
                html += "<div class='message'>"
                html += f"<span class='nick'>{row[0]}</span>"
                html += f"<span class='{msg_type}'>{row[1]}</span>"
                html += "</div>"
            html += "</div>"
            return html


def store_message(writer: str, message: str, me: str):
    if writer and message:
        with open(DATA_FILE, "a") as csvfile:
            csv.writer(csvfile).writerow([writer, message])

    return generate_html(me)

anons = "alligator, anteater, armadillo, auroch, axolotl, badger, bat, bear, beaver, blobfish, buffalo, camel, chameleon, cheetah, chipmunk, chinchilla, chupacabra, cormorant, coyote, crow, dingo, dinosaur, dog, dolphin, dragon, duck, dumbo octopus, elephant, ferret, fox, frog, giraffe, goose, gopher, grizzly, hamster, hedgehog, hippo, hyena, jackal, jackalope, ibex, ifrit, iguana, kangaroo, kiwi, koala, kraken, lemur, leopard, liger, lion, llama, manatee, mink, monkey, moose, narwhal, nyan cat, orangutan, otter, panda, penguin, platypus, python, pumpkin, quagga, quokka, rabbit, raccoon, rhino, sheep, shrew, skunk, slow loris, squirrel, tiger, turtle, unicorn, walrus, wolf, wolverine, wombat"
anons = anons.split(",")

def login(username, state):
    if username == "":
        username = f"Anonymous {random.choice(anons).strip()}"
    print(username)
    state["username"] = username
    store_message("[chatbot]", f"{username} joins the chat", username)
    return (
        state,
        gr.update(visible=False),
        gr.update(visible=True),
        generate_html(username),
    )

def send_message(message, state):
    username = state["username"]
    store_message(username, message, me=username)
    return (generate_html(username), "")

css = """
.message {height: 28px;}
.nick {font-weight:bold;}
.other {background-color:cornflowerblue;color:white; padding:4px;margin:4px;border-radius:4px; }
.own {background-color:lime;color:white; padding:4px;margin:4px;border-radius:4px; }
.admin {background-color:orange;color:black; padding:4px;margin:4px;border-radius:4px; }
"""
with gr.Blocks(css=css) as demo:
    state = gr.Variable({
        'username': None,
    })

    gr.Markdown(
        """
        <h1><center>Persistent Storage Chat</center></h1>
        <p>This is a simple demo that implements a chatroom using persistent storage.
        All the messages are saved in a file, but only the last 20 ones are displayed.</p>
        """
    )

    with gr.Group():
        with (login_box := gr.Row().style(equal_height=True)):
            username = gr.Textbox(
                label="What's your name? (leave empty for anonymous)", show_label=True, max_lines=1
            )
            login_btn = gr.Button("Enter the chat")

    with (chat_box := gr.Box(visible=False)):
        with gr.Row():
            output = gr.HTML(label="Chat", lines=20)
        with gr.Row():
            message = gr.Textbox(
                label="Your message", show_label=False, max_lines=1
            )

    username.submit(
        login,
        inputs=[username, state],
        outputs=[state, login_box, chat_box, output],
    )
    login_btn.click(
        fn=login,
        inputs=[username, state],
        outputs=[state, login_box, chat_box, output],
    )

    message.submit(
        send_message,
        inputs=[message, state],
        outputs=[output, message],
    )
demo.launch()