"use strict";

import { BrowserWindow, ipcMain } from "electron";
import { createProtocol } from "vue-cli-plugin-electron-builder/lib";
import { backgroundMitt } from './emitter';
import { RenderMessage } from "@/types/message/index";
import * as path from "path";
import fs from 'fs';

interface IpcRendererPayload {
  endpoint: string;
  message: RenderMessage | null;
}

let win: BrowserWindow | null;

// Called when a NavBar button is pressed.
const onNavBar = (_event: any, action: string): void => {
  if (win) {
    if (action === "close") {
      win.close()
    } else {
      win.minimize()
    }
  }
}

// Util function to render message on ipc-renderer event.
const renderMessage = (payload: IpcRendererPayload): void => {
    if (win) {
        win.webContents.send(payload.endpoint, {
            message: payload.message
        });
    }
}

// Write a json with position and size of window.
const saveWindowState = () => {
    if (win) {
       const bounds = win.getBounds();
       const position = win.getPosition();

       const state = JSON.stringify(
         {
           w: bounds.width, 
           h: bounds.height,
           x: position[0],
           y: position[1]
         }
       );

       fs.writeFile('windowState.json', state, (err) => {
          if (err) throw err;      
          return;
       });
    }
}

// Do this on window mount.
const onWindowMount = (): void => {
    console.log("BW:Adding window listeners. ")

    // Must tell initApp that window exists.
    backgroundMitt.emit('window-active', true);

    // Handle win nav-bar event.
    ipcMain.removeHandler("nav-bar") // avoid setting duplicate handlers
    ipcMain.handle("nav-bar", onNavBar);
    
    // Gateway for messages to the frontend.
    backgroundMitt.removeAllListeners('ipc-renderer')
    backgroundMitt.on('ipc-renderer', renderMessage);

    console.log("BW:Listeners created.")
}

// Do this on window dismount (close).
const onWindowDismount = (): void => {
    console.log("BW:Window closed.")
    win = null;
    backgroundMitt.emit('window-active', false);
}

// function used by run.ts to create the main window.
export async function createWindow(): Promise<void> {
  return new Promise((resolve, _reject) => {
    console.log("BW:Creating browser window. ")

    // avoid creating duplicate windows.
    if (win) resolve();

    // Load the saved window state.
    const state = JSON.parse(fs.readFileSync('windowState.json').toString());

    // Define the browser window.
    win = new BrowserWindow({
      width: state.w,
      height: state.h,
      x: state.x,
      y: state.y,
      resizable: true,
      backgroundColor: '#EBEBEB',
      frame: false,
      minWidth: 350,
      minHeight: 500,
      webPreferences: {
        nodeIntegration: (process.env.ELECTRON_NODE_INTEGRATION as unknown) as boolean, preload: path.join(__dirname, "preload.js")
      }
    });

    // Load the URL.
    if (process.env.WEBPACK_DEV_SERVER_URL) {
      win.loadURL(process.env.WEBPACK_DEV_SERVER_URL as string); // dev
    } 

    else {
      createProtocol("app");
      win.loadURL("app://./index.html"); // prod
    }

    // Handle window close.
    win.on("closed", onWindowDismount);

    // Save window state on resize and move.
    win.on("moved", saveWindowState);
    win.on("resize", saveWindowState);

    win.once('ready-to-show', () => {
      if (win) win.show()
    })

    // For showing/hiding the splash screen.
    win.webContents.on('did-finish-load', () => {
      if (win) win.webContents.send('window-ready', {
          message: true
      });

      onWindowMount();
      resolve();
    });

  });
}