const { app, BrowserWindow, dialog, ipcMain, Menu, shell } = require("electron");
const fs = require("node:fs/promises");
const path = require("node:path");

const isDev = !app.isPackaged;
const applicationModes = {
  word: {
    title: "QWord",
    windowTitle: "Документ1 - QWord",
    route: "/qword"
  },
  sheets: {
    title: "QExcell",
    windowTitle: "Книга1 - QExcell",
    route: "/qexcell"
  },
  slides: {
    title: "QPowerPoint",
    windowTitle: "Презентация1 - QPowerPoint",
    route: "/qpowerpoint"
  },
  mail: {
    title: "QOutlook",
    windowTitle: "Почта - QOutlook",
    route: "/qoutlook"
  }
};
const applicationAliases = {
  word: "word",
  qword: "word",
  docx: "word",
  sheets: "sheets",
  sheet: "sheets",
  excel: "sheets",
  excell: "sheets",
  qexcell: "sheets",
  xlsx: "sheets",
  slides: "slides",
  slide: "slides",
  powerpoint: "slides",
  qpowerpoint: "slides",
  pptx: "slides",
  mail: "mail",
  outlook: "mail",
  qoutlook: "mail",
  eml: "mail",
  msg: "mail"
};
const fileKinds = {
  docx: {
    title: "Открыть документ Word",
    saveTitle: "Сохранить документ Word",
    defaultName: "Документ QWord.docx",
    filters: [{ name: "Документы Word (.docx)", extensions: ["docx"] }]
  },
  xlsx: {
    title: "Открыть книгу Excel",
    saveTitle: "Сохранить книгу Excel",
    defaultName: "Книга QExcell.xlsx",
    filters: [{ name: "Книги Excel (.xlsx)", extensions: ["xlsx"] }]
  },
  pptx: {
    title: "Открыть презентацию PowerPoint",
    saveTitle: "Сохранить презентацию PowerPoint",
    defaultName: "Презентация QPowerPoint.pptx",
    filters: [{ name: "Презентации PowerPoint (.pptx)", extensions: ["pptx"] }]
  },
  eml: {
    title: "Открыть письмо EML",
    saveTitle: "Сохранить письмо EML",
    defaultName: "Письмо.eml",
    filters: [{ name: "Письма EML (.eml)", extensions: ["eml"] }]
  },
  mail: {
    title: "Открыть письмо Outlook",
    saveTitle: "Сохранить письмо EML",
    defaultName: "Письмо.eml",
    filters: [{ name: "Письма Outlook (.eml, .msg)", extensions: ["eml", "msg"] }]
  }
};

function validatedKind(kind) {
  if (typeof kind !== "string" || !Object.hasOwn(fileKinds, kind)) {
    throw new Error("Неподдерживаемый тип файла QOffice.");
  }

  return fileKinds[kind];
}

function safeDefaultName(kind, defaultFileName) {
  const config = validatedKind(kind);
  const extension = config.filters[0].extensions[0];
  return safeFileNameWithExtension(defaultFileName, extension, config.defaultName);
}

function safeFileNameWithExtension(defaultFileName, extension, fallbackName) {
  const candidate = typeof defaultFileName === "string" && defaultFileName.trim() ? path.basename(defaultFileName.trim()) : fallbackName;
  return candidate.toLowerCase().endsWith(`.${extension}`) ? candidate : `${candidate}.${extension}`;
}

function ownerWindow(event) {
  return BrowserWindow.fromWebContents(event.sender) ?? BrowserWindow.getFocusedWindow() ?? undefined;
}

function sendFocusedCommand(command) {
  const focusedWindow = BrowserWindow.getFocusedWindow();
  if (focusedWindow && !focusedWindow.isDestroyed()) {
    focusedWindow.webContents.send("qoffice:command", command);
  }
}

function applicationModeFromArgs(argv = process.argv, env = process.env) {
  const explicitArg = argv.find((argument) => argument.startsWith("--qoffice-app=") || argument.startsWith("--app="));
  const rawMode = explicitArg?.split("=")[1] ?? env.QOFFICE_APP ?? "";
  const mode = applicationAliases[String(rawMode).trim().toLowerCase()] ?? "word";
  return applicationModes[mode];
}

function createApplicationMenu(applicationMode) {
  const isMac = process.platform === "darwin";
  const template = [
    ...(isMac
      ? [
          {
            label: applicationMode.title,
            submenu: [
              { role: "about", label: `О ${applicationMode.title}` },
              { type: "separator" },
              { role: "hide", label: `Скрыть ${applicationMode.title}` },
              { role: "hideOthers", label: "Скрыть остальные" },
              { role: "unhide", label: "Показать все" },
              { type: "separator" },
              { role: "quit", label: `Выйти из ${applicationMode.title}` }
            ]
          }
        ]
      : []),
    {
      label: "Файл",
      submenu: [
        { label: "Открыть...", accelerator: "CmdOrCtrl+O", click: () => sendFocusedCommand("open") },
        { label: "Сохранить как...", accelerator: "CmdOrCtrl+S", click: () => sendFocusedCommand("save") },
        { type: "separator" },
        { label: "Экспорт в PDF...", accelerator: "CmdOrCtrl+Shift+E", click: () => sendFocusedCommand("export-pdf") },
        { type: "separator" },
        { label: "Печать...", accelerator: "CmdOrCtrl+P", click: () => sendFocusedCommand("print") },
        { type: "separator" },
        isMac ? { role: "close", label: "Закрыть окно" } : { role: "quit", label: `Выход из ${applicationMode.title}` }
      ]
    },
    {
      label: "Правка",
      submenu: [
        { role: "undo", label: "Отменить" },
        { role: "redo", label: "Повторить" },
        { type: "separator" },
        { role: "cut", label: "Вырезать" },
        { role: "copy", label: "Копировать" },
        { role: "paste", label: "Вставить" },
        { role: "selectAll", label: "Выделить все" }
      ]
    },
    {
      label: "Вид",
      submenu: [
        { role: "resetZoom", label: "Сбросить масштаб" },
        { role: "zoomIn", label: "Увеличить" },
        { role: "zoomOut", label: "Уменьшить" },
        { type: "separator" },
        { role: "togglefullscreen", label: "Во весь экран" }
      ]
    },
    {
      label: "Окно",
      submenu: [
        { role: "minimize", label: "Свернуть" },
        { role: "reload", label: "Перезагрузить" },
        ...(isDev ? [{ role: "toggleDevTools", label: "Инструменты разработчика" }] : [])
      ]
    }
  ];

  Menu.setApplicationMenu(Menu.buildFromTemplate(template));
}

ipcMain.handle("qoffice:open-office-file", async (event, kind) => {
  const config = validatedKind(kind);
  const result = await dialog.showOpenDialog(ownerWindow(event), {
    title: config.title,
    properties: ["openFile"],
    filters: config.filters
  });

  if (result.canceled || result.filePaths.length === 0) {
    return { canceled: true };
  }

  const filePath = result.filePaths[0];
  const bytes = await fs.readFile(filePath);
  return {
    canceled: false,
    fileName: path.basename(filePath),
    filePath,
    base64Data: bytes.toString("base64")
  };
});

ipcMain.handle("qoffice:save-office-file", async (event, payload) => {
  if (!payload || typeof payload !== "object") {
    throw new Error("Некорректный запрос сохранения файла QOffice.");
  }

  const { kind, defaultFileName, base64Data } = payload;
  const config = validatedKind(kind);
  if (typeof base64Data !== "string") {
    throw new Error("Некорректные данные файла QOffice.");
  }

  const result = await dialog.showSaveDialog(ownerWindow(event), {
    title: config.saveTitle,
    defaultPath: safeDefaultName(kind, defaultFileName),
    filters: config.filters
  });

  if (result.canceled || !result.filePath) {
    return { canceled: true };
  }

  await fs.writeFile(result.filePath, Buffer.from(base64Data, "base64"));
  return {
    canceled: false,
    fileName: path.basename(result.filePath),
    filePath: result.filePath
  };
});

ipcMain.handle("qoffice:export-pdf", async (event, defaultFileName) => {
  const sourceWindow = ownerWindow(event);
  if (!sourceWindow) {
    throw new Error("Не удалось найти окно QOffice для экспорта PDF.");
  }

  const result = await dialog.showSaveDialog(sourceWindow, {
    title: "Экспорт PDF",
    defaultPath: safeFileNameWithExtension(defaultFileName, "pdf", "QOffice.pdf"),
    filters: [{ name: "PDF (.pdf)", extensions: ["pdf"] }]
  });

  if (result.canceled || !result.filePath) {
    return { canceled: true };
  }

  const pdf = await event.sender.printToPDF({
    printBackground: true,
    preferCSSPageSize: true
  });

  await fs.writeFile(result.filePath, pdf);
  return {
    canceled: false,
    fileName: path.basename(result.filePath),
    filePath: result.filePath
  };
});

function createWindow(applicationMode) {
  const mainWindow = new BrowserWindow({
    width: 1440,
    height: 920,
    minWidth: 1080,
    minHeight: 720,
    title: applicationMode.windowTitle,
    backgroundColor: "#f6f8fb",
    webPreferences: {
      preload: path.join(__dirname, "preload.cjs"),
      contextIsolation: true,
      nodeIntegration: false
    }
  });

  mainWindow.webContents.setWindowOpenHandler(({ url }) => {
    shell.openExternal(url);
    return { action: "deny" };
  });

  if (isDev) {
    mainWindow.loadURL(new URL(applicationMode.route, "http://127.0.0.1:5173").toString());
  } else {
    mainWindow.loadFile(path.join(__dirname, "../dist/index.html"), { hash: applicationMode.route });
  }
}

const launchApplicationMode = applicationModeFromArgs();
app.setName(launchApplicationMode.title);

app.whenReady().then(() => {
  createApplicationMenu(launchApplicationMode);
  createWindow(launchApplicationMode);

  app.on("activate", () => {
    if (BrowserWindow.getAllWindows().length === 0) {
      createWindow(launchApplicationMode);
    }
  });
});

app.on("window-all-closed", () => {
  if (process.platform !== "darwin") {
    app.quit();
  }
});