import React, { useState, useEffect, useReducer, useRef } from "react";

import { isSameDay, parseISO, format } from "date-fns";
import openSocket from "socket.io-client";
import clsx from "clsx";

import { green } from "@material-ui/core/colors";
import {
  Button,
  CircularProgress,
  Divider,
  IconButton,
  makeStyles,
} from "@material-ui/core";
import {
  AccessTime,
  Block,
  Done,
  DoneAll,
  ExpandMore,
  GetApp,
} from "@material-ui/icons";

import MarkdownWrapper from "../MarkdownWrapper";
import ModalImageCors from "../ModalImageCors";
import MessageOptionsMenu from "../MessageOptionsMenu";
import whatsBackground from "../../assets/wa-background.png";

import api from "../../services/api";
import toastError from "../../errors/toastError";

const useStyles = makeStyles((theme) => ({
  messagesListWrapper: {
    overflow: "hidden",
    position: "relative",
    display: "flex",
    flexDirection: "column",
    flexGrow: 1,
  },

  messagesList: {
    backgroundImage: `url(${whatsBackground})`,
    display: "flex",
    flexDirection: "column",
    flexGrow: 1,
    padding: "20px 20px 20px 20px",
    overflowY: "scroll",
    [theme.breakpoints.down("sm")]: {
      paddingBottom: "90px",
    },
    ...theme.scrollbarStyles,
  },

  circleLoading: {
    color: green[500],
    position: "absolute",
    opacity: "70%",
    top: 0,
    left: "50%",
    marginTop: 12,
  },

  messageLeft: {
    marginRight: 20,
    marginTop: 2,
    minWidth: 100,
    maxWidth: 600,
    height: "auto",
    display: "block",
    position: "relative",
    "&:hover #messageActionsButton": {
      display: "flex",
      position: "absolute",
      top: 0,
      right: 0,
    },

    whiteSpace: "pre-wrap",
    backgroundColor: "#ffffff",
    color: "#303030",
    alignSelf: "flex-start",
    borderTopLeftRadius: 0,
    borderTopRightRadius: 8,
    borderBottomLeftRadius: 8,
    borderBottomRightRadius: 8,
    paddingLeft: 5,
    paddingRight: 5,
    paddingTop: 5,
    paddingBottom: 0,
    boxShadow: "0 1px 1px #b3b3b3",
  },

  quotedContainerLeft: {
    margin: "-3px -80px 6px -6px",
    overflow: "hidden",
    backgroundColor: "#f0f0f0",
    borderRadius: "7.5px",
    display: "flex",
    position: "relative",
  },

  quotedMsg: {
    padding: 10,
    maxWidth: 300,
    height: "auto",
    display: "block",
    whiteSpace: "pre-wrap",
    overflow: "hidden",
  },

  quotedSideColorLeft: {
    flex: "none",
    width: "4px",
    backgroundColor: "#6bcbef",
  },

  messageRight: {
    marginLeft: 20,
    marginTop: 2,
    minWidth: 100,
    maxWidth: 600,
    height: "auto",
    display: "block",
    position: "relative",
    "&:hover #messageActionsButton": {
      display: "flex",
      position: "absolute",
      top: 0,
      right: 0,
    },

    whiteSpace: "pre-wrap",
    backgroundColor: "#dcf8c6",
    color: "#303030",
    alignSelf: "flex-end",
    borderTopLeftRadius: 8,
    borderTopRightRadius: 8,
    borderBottomLeftRadius: 8,
    borderBottomRightRadius: 0,
    paddingLeft: 5,
    paddingRight: 5,
    paddingTop: 5,
    paddingBottom: 0,
    boxShadow: "0 1px 1px #b3b3b3",
  },

  quotedContainerRight: {
    margin: "-3px -80px 6px -6px",
    overflowY: "hidden",
    backgroundColor: "#cfe9ba",
    borderRadius: "7.5px",
    display: "flex",
    position: "relative",
  },

  quotedMsgRight: {
    padding: 10,
    maxWidth: 300,
    height: "auto",
    whiteSpace: "pre-wrap",
  },

  quotedSideColorRight: {
    flex: "none",
    width: "4px",
    backgroundColor: "#35cd96",
  },

  messageActionsButton: {
    display: "none",
    position: "relative",
    color: "#999",
    zIndex: 1,
    backgroundColor: "inherit",
    opacity: "90%",
    "&:hover, &.Mui-focusVisible": { backgroundColor: "inherit" },
  },

  messageContactName: {
    display: "flex",
    color: "#6bcbef",
    fontWeight: 500,
  },

  textContentItem: {
    overflowWrap: "break-word",
    padding: "3px 80px 6px 6px",
  },

  textContentItemDeleted: {
    fontStyle: "italic",
    color: "rgba(0, 0, 0, 0.36)",
    overflowWrap: "break-word",
    padding: "3px 80px 6px 6px",
  },

  messageMedia: {
    objectFit: "cover",
    width: 250,
    height: 200,
    borderTopLeftRadius: 8,
    borderTopRightRadius: 8,
    borderBottomLeftRadius: 8,
    borderBottomRightRadius: 8,
  },

  timestamp: {
    fontSize: 11,
    position: "absolute",
    bottom: 0,
    right: 5,
    color: "#999",
  },

  dailyTimestamp: {
    alignItems: "center",
    textAlign: "center",
    alignSelf: "center",
    width: "110px",
    backgroundColor: "#e1f3fb",
    margin: "10px",
    borderRadius: "10px",
    boxShadow: "0 1px 1px #b3b3b3",
  },

  dailyTimestampText: {
    color: "#808888",
    padding: 8,
    alignSelf: "center",
    marginLeft: "0px",
  },

  ackIcons: {
    fontSize: 18,
    verticalAlign: "middle",
    marginLeft: 4,
  },

  deletedIcon: {
    fontSize: 18,
    verticalAlign: "middle",
    marginRight: 4,
  },

  ackDoneAllIcon: {
    color: green[500],
    fontSize: 18,
    verticalAlign: "middle",
    marginLeft: 4,
  },

  downloadMedia: {
    display: "flex",
    alignItems: "center",
    justifyContent: "center",
    backgroundColor: "inherit",
    padding: 10,
  },
}));

const reducer = (state, action) => {
  if (action.type === "LOAD_MESSAGES") {
    const messages = action.payload;
    const newMessages = [];

    messages.forEach((message) => {
      const messageIndex = state.findIndex((m) => m.id === message.id);
      if (messageIndex !== -1) {
        state[messageIndex] = message;
      } else {
        newMessages.push(message);
      }
    });

    return [...newMessages, ...state];
  }

  if (action.type === "ADD_MESSAGE") {
    const newMessage = action.payload;
    const messageIndex = state.findIndex((m) => m.id === newMessage.id);

    if (messageIndex !== -1) {
      state[messageIndex] = newMessage;
    } else {
      state.push(newMessage);

    }

    return [...state];
  }

  if (action.type === "UPDATE_MESSAGE") {
    const messageToUpdate = action.payload;
    const messageIndex = state.findIndex((m) => m.id === messageToUpdate.id);

    if (messageIndex !== -1) {
      state[messageIndex] = messageToUpdate;
    }

    return [...state];
  }

  if (action.type === "RESET") {
    return [];
  }
};

const MessagesList = ({ ticketId, isGroup }) => {
  const classes = useStyles();

  const [messagesList, dispatch] = useReducer(reducer, []);
  const [pageNumber, setPageNumber] = useState(1);
  const [hasMore, setHasMore] = useState(false);
  const [loading, setLoading] = useState(false);
  const lastMessageRef = useRef();

  const [selectedMessage, setSelectedMessage] = useState({});
  const [anchorEl, setAnchorEl] = useState(null);
  const messageOptionsMenuOpen = Boolean(anchorEl);
  const currentTicketId = useRef(ticketId);

  useEffect(() => {
    dispatch({ type: "RESET" });
    setPageNumber(1);

    currentTicketId.current = ticketId;
  }, [ticketId]);

  useEffect(() => {
    setLoading(true);
    const delayDebounceFn = setTimeout(() => {
      const fetchMessages = async () => {
        try {
          const { data } = await api.get("/messages/" + ticketId, {
            params: { pageNumber },
          });  

          if (currentTicketId.current === ticketId) {
            dispatch({ type: "LOAD_MESSAGES", payload: data.messages });
            setHasMore(data.hasMore);
            setLoading(false);
          }

          if (pageNumber === 1 && data.messages.length > 1) {
            scrollToBottom();
          }
        } catch (err) {
          setLoading(false);
          toastError(err);
        }
      };
      fetchMessages();
    }, 500);
    return () => {
      clearTimeout(delayDebounceFn);
    };
  }, [pageNumber, ticketId]);

  useEffect(() => {
    const socket = openSocket(process.env.REACT_APP_BACKEND_URL);

    socket.on("connect", () => socket.emit("joinChatBox", ticketId));

    socket.on("appMessage", (data) => {

      if (data.action === "create") {

        console.log('ADD_MESSAGE: ', data.message)

        dispatch({ type: "ADD_MESSAGE", payload: data.message });

        scrollToBottom();
      }

      if (data.action === "update") {

        dispatch({ type: "UPDATE_MESSAGE", payload: data.message });
      }
    });

    return () => {
      socket.disconnect();
    };
  }, [ticketId]);

  const loadMore = () => {
    setPageNumber((prevPageNumber) => prevPageNumber + 1);
  };

  const scrollToBottom = () => {
    if (lastMessageRef.current) {
      lastMessageRef.current.scrollIntoView({});
    }
  };

  const handleScroll = (e) => {
    if (!hasMore) return;
    const { scrollTop } = e.currentTarget;

    if (scrollTop === 0) {
      document.getElementById("messagesList").scrollTop = 1;
    }

    if (loading) {
      return;
    }

    if (scrollTop < 50) {
      loadMore();
    }
  };

  const handleOpenMessageOptionsMenu = (e, message) => {
    setAnchorEl(e.currentTarget);
    setSelectedMessage(message);
  };

  const handleCloseMessageOptionsMenu = (e) => {
    setAnchorEl(null);
  };

  const checkMessageMedia = (message) => {
    if (message.mediaType === "image") {
      return <ModalImageCors imageUrl={message.mediaUrl} />;
    }
    if (message.mediaType === "audio") {

      return (
        <audio controls>
          <source src={message.mediaUrl} type="audio/ogg"></source>
        </audio>
      );
    }

    if (message.mediaType === "video") {
      return (
        <video
          className={classes.messageMedia}
          src={message.mediaUrl}
          controls
        />
      );
    } else {
      return (
        <>
          <div className={classes.downloadMedia}>
            <Button
              startIcon={<GetApp />}
              color="primary"
              variant="outlined"
              target="_blank"
              href={message.mediaUrl}
            >
              Download
            </Button>
          </div>
          <Divider />
        </>
      );
    }
  };

  const renderMessageAck = (message) => {
    if (message.ack === 0) {
      return <AccessTime fontSize="small" className={classes.ackIcons} />;
    }
    if (message.ack === 1) {
      return <Done fontSize="small" className={classes.ackIcons} />;
    }
    if (message.ack === 2) {
      return <DoneAll fontSize="small" className={classes.ackIcons} />;
    }
    if (message.ack === 3 || message.ack === 4) {
      return <DoneAll fontSize="small" className={classes.ackDoneAllIcon} />;
    }
  };

  const renderDailyTimestamps = (message, index) => {
    if (index === 0) {
      return (
        <span
          className={classes.dailyTimestamp}
          key={`timestamp-${message.id}`}
        >
          <div className={classes.dailyTimestampText}>
            {format(parseISO(messagesList[index].createdAt), "dd/MM/yyyy")}
          </div>
        </span>
      );
    }

    if (index < messagesList.length - 1) {
      let messageDay = parseISO(messagesList[index].createdAt);
      let previousMessageDay = parseISO(messagesList[index - 1].createdAt);

      if (!isSameDay(messageDay, previousMessageDay)) {

        return (
          <span
            className={classes.dailyTimestamp}
            key={`timestamp-${message.id}`}
          >
            <div className={classes.dailyTimestampText}>
              {format(parseISO(messagesList[index].createdAt), "dd/MM/yyyy")}
            </div>
          </span>
        );
      }
    }

    if (index === messagesList.length - 1) {

      let messageDay = parseISO(messagesList[index].createdAt);
      let previousMessageDay = parseISO(messagesList[index - 1].createdAt); 

      return (
        <>
          {!isSameDay(messageDay, previousMessageDay) &&
            <span
              className={classes.dailyTimestamp}
              key={`timestamp-${message.id}`}
            >
              <div className={classes.dailyTimestampText}>
                {format(parseISO(messagesList[index].createdAt), "dd/MM/yyyy")}
              </div>
            </span>
          }
          <div
            key={`ref-${message.createdAt}`}
            ref={lastMessageRef}
            style={{ float: "left", clear: "both" }}
          />
        </>
      );
    }
  };

  const renderMessageDivider = (message, index) => {
    if (index < messagesList.length && index > 0) {
      let messageUser = messagesList[index].fromMe;
      let previousMessageUser = messagesList[index - 1].fromMe;



      if (messageUser !== previousMessageUser) {
        return (
          <span style={{ marginTop: 16 }} key={`divider-${message.id}`}></span>
        );
      }
    }
  };

  const renderQuotedMessage = (message) => {
    return (
      <div
        className={clsx(classes.quotedContainerLeft, {
          [classes.quotedContainerRight]: message.fromMe,
        })}
      >
        <span
          className={clsx(classes.quotedSideColorLeft, {
            [classes.quotedSideColorRight]: message.quotedMsg?.fromMe,
          })}
        ></span>
        <div className={classes.quotedMsg}>
          {!message.quotedMsg?.fromMe && (
            <span className={classes.messageContactName}>
              {message.quotedMsg?.contact?.name}
            </span>
          )}
          {message.quotedMsg?.body}
        </div>
      </div>
    );
  };

  const renderMessages = () => {
    if (messagesList.length > 0) {
      const viewMessagesList = messagesList.map((message, index) => {
        if (!message.fromMe) {
          return (
            <React.Fragment key={message.id}>
              {renderDailyTimestamps(message, index)}
              {renderMessageDivider(message, index)}
              <div className={classes.messageLeft}>
                <IconButton
                  variant="contained"
                  size="small"
                  id="messageActionsButton"
                  disabled={message.isDeleted}
                  className={classes.messageActionsButton}
                  onClick={(e) => handleOpenMessageOptionsMenu(e, message)}
                >
                  <ExpandMore />
                </IconButton>
                {isGroup && (
                  <span className={classes.messageContactName}>
                    {message.contact?.name}
                  </span>
                )}
                {message.mediaUrl && checkMessageMedia(message)}
                <div className={classes.textContentItem}>
                  {message.quotedMsg && renderQuotedMessage(message)}
                  <MarkdownWrapper>{message.body}</MarkdownWrapper>
                  <span className={classes.timestamp}>
                    {format(parseISO(message.createdAt), "HH:mm")}
                  </span>
                </div>
              </div>
            </React.Fragment>
          );
        } else {
          return (
            <React.Fragment key={message.id}>
              {renderDailyTimestamps(message, index)}
              {renderMessageDivider(message, index)}
              <div className={classes.messageRight}>
                <IconButton
                  variant="contained"
                  size="small"
                  id="messageActionsButton"
                  disabled={message.isDeleted}
                  className={classes.messageActionsButton}
                  onClick={(e) => handleOpenMessageOptionsMenu(e, message)}
                >
                  <ExpandMore />
                </IconButton>
                {message.mediaUrl && checkMessageMedia(message)}
                <div
                  className={clsx(classes.textContentItem, {
                    [classes.textContentItemDeleted]: message.isDeleted,
                  })}
                >
                  {message.isDeleted && (
                    <Block
                      color="disabled"
                      fontSize="small"
                      className={classes.deletedIcon}
                    />
                  )}
                  {message.quotedMsg && renderQuotedMessage(message)}
                  <MarkdownWrapper>{message.body}</MarkdownWrapper>
                  <span className={classes.timestamp}>
                    {format(parseISO(message.createdAt), "HH:mm")}
                    {renderMessageAck(message)}
                  </span>
                </div>
              </div>
            </React.Fragment>
          );
        }
      });
      return viewMessagesList;
    } else {
      return <div>Say hello to your new contact!</div>;
    }
  };

  return (
    <div className={classes.messagesListWrapper}>
      <MessageOptionsMenu
        message={selectedMessage}
        anchorEl={anchorEl}
        menuOpen={messageOptionsMenuOpen}
        handleClose={handleCloseMessageOptionsMenu}
      />
      <div
        id="messagesList"
        className={classes.messagesList}
        onScroll={handleScroll}
      >
        {messagesList.length > 0 ? renderMessages() : []}
      </div>
      {loading && (
        <div>
          <CircularProgress className={classes.circleLoading} />
        </div>
      )}
    </div>
  );
};

export default MessagesList;