import React, { useCallback, useEffect, useState } from 'react';
import styled from "styled-components";
import BrowserNavBar from "../molecules/BrowserNavBar";
import { BrowserWindow } from "./BrowserWindow";
import { useBrowserDimensionsStore } from "../../context/browserDimensions";
import { BrowserTabs } from "../molecules/BrowserTabs";
import { useSocketStore } from "../../context/socket";
import { getCurrentTabs, getCurrentUrl, interpretCurrentRecording } from "../../api/recording";

export const BrowserContent = () => {
 const { width } = useBrowserDimensionsStore();
 const { socket } = useSocketStore();

 const [tabs, setTabs] = useState<string[]>(['current']);
 const [tabIndex, setTabIndex] = React.useState(0);

 const handleChangeIndex = useCallback((index: number) => {
   setTabIndex(index);
 }, [tabIndex])

  const handleCloseTab = useCallback((index: number) => {
    // the tab needs to be closed on the backend
    socket?.emit('closeTab', {
      index,
      isCurrent: tabIndex === index,
    });
    // change the current index as current tab gets closed
    if (tabIndex === index) {
      if (tabs.length > index + 1) {
        handleChangeIndex(index);
      } else {
        handleChangeIndex(index - 1);
      }
    } else {
      handleChangeIndex(tabIndex - 1);
    }
    // update client tabs
    setTabs((prevState) => [
      ...prevState.slice(0, index),
      ...prevState.slice(index + 1)
    ])
  }, [tabs, socket, tabIndex]);

  const handleAddNewTab = useCallback(() => {
    // Adds new tab by pressing the plus button
    socket?.emit('addTab');
    // Adds a new tab to the end of the tabs array and shifts focus
    setTabs((prevState) => [...prevState, 'new tab']);
    handleChangeIndex(tabs.length);
  }, [socket, tabs]);

 const handleNewTab = useCallback((tab: string) => {
   // Adds a new tab to the end of the tabs array and shifts focus
   setTabs((prevState) => [...prevState, tab]);
   // changes focus on the new tab - same happens in the remote browser
   handleChangeIndex(tabs.length);
   handleTabChange(tabs.length);
 }, [tabs]);

  const handleTabChange = useCallback((index: number) => {
    // page screencast and focus needs to be changed on backend
      socket?.emit('changeTab', index);
  }, [socket]);

  const handleUrlChanged = (url: string) => {
    const parsedUrl = new URL(url);
    if (parsedUrl.hostname) {
      const host = parsedUrl.hostname.match(/\b(?!www\.)[a-zA-Z0-9]+/g)?.join('.')
      if (host && host !== tabs[tabIndex]) {
        setTabs((prevState) => [
          ...prevState.slice(0, tabIndex),
          host,
          ...prevState.slice(tabIndex + 1)
        ])
      }
    } else {
      if (tabs[tabIndex] !== 'new tab') {
        setTabs((prevState) => [
          ...prevState.slice(0, tabIndex),
          'new tab',
          ...prevState.slice(tabIndex + 1)
        ])
      }
    }

  };

  const tabHasBeenClosedHandler = useCallback((index: number) => {
    handleCloseTab(index);
  }, [handleCloseTab])

 useEffect(() => {
   if (socket) {
     socket.on('newTab', handleNewTab);
     socket.on('tabHasBeenClosed', tabHasBeenClosedHandler);
   }
   return () => {
     if (socket) {
       socket.off('newTab', handleNewTab);
       socket.off('tabHasBeenClosed', tabHasBeenClosedHandler);
     }
   }
 }, [socket, handleNewTab])

  useEffect(() => {
    getCurrentTabs().then((response) => {
      if (response) {
        setTabs(response);
      }
    }).catch((error) => {
      console.log("Fetching current url failed");
    })
  }, [])

  return (
    <BrowserContentWrapper>
      <BrowserTabs
        tabs={tabs}
        handleTabChange={handleTabChange}
        handleAddNewTab={handleAddNewTab}
        handleCloseTab={handleCloseTab}
        handleChangeIndex={handleChangeIndex}
        tabIndex={tabIndex}
      />
      <BrowserNavBar
        // todo: use width from browser dimension once fixed
        browserWidth={1270}
        handleUrlChanged={handleUrlChanged}
      />
      <BrowserWindow/>
    </BrowserContentWrapper>
  );
}

const BrowserContentWrapper = styled.div`
  grid-area: browser;
`;