import Header from './Header/Header.jsx';
import Sidebar from './Sidebar/Sidebar.jsx';
import Canvas from './Canvas/Canvas.jsx';
import { Grid, GridItem, useRecipe, useDialog } from '@chakra-ui/react';
import { useState } from 'react';
import DialogPopup from './Canvas/CanvasComponents/DialogPopup.jsx';

export default function Dashboard() {
  const recipe = useRecipe({ key: "dashboard" });
  const styles = recipe();
  const dialog = useDialog();
  const [darkMode, setDarkMode] = useState(false);

  const [view, setView] = useState("mydashboard");

  const emptyDash = () => ({
    layout: [], 
    widgetArray: [],
    originalLayout: [],
    originalWidgets: [],
    isEditable: false,  
    isDelete: false,
  })

  // Add views as needed to initialize widget canvas views 
  const CANVAS_VIEWS = new Set([ "mydashboard", "gas" ]); 

  // Widget dashboard state
  const [dashboards, setDashboards] = useState(() => ({
    mydashboard: emptyDash(),
    gas: emptyDash(),
  }));

  const isCanvasView = CANVAS_VIEWS.has(view);
  const dash = dashboards[view] ?? emptyDash();

  const updateDash = (key, updater) => {
    setDashboards(prev => ({
      ...prev,
      [key]: updater(prev[key] ?? emptyDash()),
    }));
  };

  // Widget setter functions
  const setLayout = (fnOrValue) => {
    if (!isCanvasView) return; 
    updateDash(view, s => ({
      ...s,
      layout: typeof fnOrValue === "function" ? fnOrValue( s.layout ) : fnOrValue,
    }));
  };

  const setWidgetArray = (fnOrValue) => {
    if (!isCanvasView) return;
    updateDash(view, s => ({
      ...s, 
      widgetArray: typeof fnOrValue === "function" ? fnOrValue(s.widgetArray) : fnOrValue,
    }));
  };

  const setIsEditable = (value) => {
    if (!isCanvasView) return;
    updateDash(view, s => ({ ...s, isEditable: value }));
  };

  const setIsDelete = (value) => { 
    if (!isCanvasView) return;
    updateDash(view, s => ({ ...s, isDelete: value }));
  };
 
  const beginEditIfNeeded = () => {
    if (!isCanvasView) return;
    updateDash(view, s => {
      if(s.isEditable) return s; // already editing
      return {
        ...s,
        originalLayout: s.layout,
        originalWidgets: s.widgetArray,
      };
    });
  };

  const onCancel = () => {
    if (!isCanvasView) return;
    
    updateDash(view, s => ({
      ...s,
      layout: (s.originalLayout?.length ? s.originalLayout : s.layout).map(it => ({
        ...it,
        static: true,
      })),
      widgetArray: s.originalWidgets ?? s.widgetArray,
      isEditable: false,
      isDelete: false, 
      originalLayout: [],
      originalWidgets: [],
    }));
  };

  const onLayoutChange = (newLayout) => {
    setLayout(newLayout);
  };

  const handleViewChange = (nextView) => {
    // prevent nav only when current view is a widget canvas AND you're editing 
    if (CANVAS_VIEWS.has(view) && dash.isEditable) {
      dialog.setOpen(true);
      return;
    }
    setView(nextView);
  };

  // Prop Forwarding
  const canvasProps = { 
    view, 
    onChangeView: handleViewChange, 
    
    // active canvas props 
    layout: dash.layout, 
    widgetArray: dash.widgetArray, 
    isEditable: dash.isEditable, 
    isDelete: dash.isDelete, 
    
    // handler functions
    setLayout, 
    setWidgetArray, 
    setIsEditable, 
    setIsDelete, 
    beginEditIfNeeded,
    onCancel,
    onLayoutChange, 
  };
  const sidebarProps = { view, onChangeView: handleViewChange, darkMode, setDarkMode };
  const headerProps = { onChangeView: handleViewChange };
  
  return (
    <> 
      <DialogPopup dialog={dialog} />
      <Grid css={styles}
        templateRows="1fr 11fr"
        // templateColumns="1fr 20fr"
        templateColumns="auto 1fr"
        height="100vh"
        width="100vw"
      >
        <GridItem rowSpan={1} colSpan={2}>
          <Header {...headerProps}/>
        </GridItem>
        <GridItem colSpan={1}>
          <Sidebar {...sidebarProps}/>
        </GridItem>
        <GridItem colSpan={1} width="100%" overflow="auto">
          <Canvas {...canvasProps}/>
        </GridItem>
      </Grid>
    </>
  );
}