import { invoke } from './tauri'
import { EventCallback, emit, listen, once } from './helpers/event'

interface WindowDef {
  label: string
}

declare global {
  interface Window {
    __TAURI__: {
      __windows: WindowDef[]
      __currentWindow: WindowDef
    }
  }
}

function getCurrent(): WebviewWindowHandle {
  return new WebviewWindowHandle(window.__TAURI__.__currentWindow.label)
}

function getAll(): WindowDef[] {
  return window.__TAURI__.__windows
}

// events that are emitted right here instead of by the created webview
const localTauriEvents = ['tauri://created', 'tauri://error']

class WebviewWindowHandle {
  label: string
  listeners: { [key: string]: Array<EventCallback<any>> }

  constructor(label: string) {
    this.label = label
    this.listeners = {}
  }

  /**
   * Listen to an event emitted by the webview
   *
   * @param event the event name
   * @param handler the event handler callback
   */
  async listen<T>(event: string, handler: EventCallback<T>): Promise<void> {
    if (this._handleTauriEvent(event, handler)) {
      return Promise.resolve()
    }
    return listen(event, handler)
  }

  /**
   * Listen to an one-off event emitted by the webview
   *
   * @param event the event name
   * @param handler the event handler callback
   */
  async once<T>(event: string, handler: EventCallback<T>): Promise<void> {
    if (this._handleTauriEvent(event, handler)) {
      return Promise.resolve()
    }
    return once(event, handler)
  }

  /**
   * emits an event to the webview
   *
   * @param event the event name
   * @param [payload] the event payload
   */
  async emit(event: string, payload?: string): Promise<void> {
    if (localTauriEvents.includes(event)) {
      // eslint-disable-next-line
      for (const handler of this.listeners[event] || []) {
        handler({ type: event, payload })
      }
      return Promise.resolve()
    }
    return emit(event, this.label, payload)
  }

  _handleTauriEvent<T>(event: string, handler: EventCallback<T>): boolean {
    if (localTauriEvents.includes(event)) {
      if (!(event in this.listeners)) {
        // eslint-disable-next-line
        this.listeners[event] = [handler]
      } else {
        // eslint-disable-next-line
        this.listeners[event].push(handler)
      }
      return true
    }
    return false
  }

  _emitTauriEvent(event: string): void {}
}

class WebviewWindow extends WebviewWindowHandle {
  constructor(label: string, options: WindowOptions = {}) {
    super(label)
    invoke({
      __tauriModule: 'Window',
      message: {
        cmd: 'createWebview',
        options: {
          label,
          ...options
        }
      }
    })
      .then(async () => this.emit('tauri://created'))
      .catch(async (e) => this.emit('tauri://error', e))
  }

  /**
   * Gets the WebviewWindow handle for the webview associated with the given label.
   *
   * @param {string} label the webview window label.
   *
   * @return {WebviewWindowHandle} the handle to communicate with the webview or null if the webview doesn't exist
   */
  static getByLabel(label: string): WebviewWindowHandle | null {
    if (getAll().some((w) => w.label === label)) {
      return new WebviewWindowHandle(label)
    }
    return null
  }
}

class WindowManager {
  /**
   * Updates the window resizable flag.
   */
  async setResizable(resizable: boolean): Promise<void> {
    return invoke({
      __tauriModule: 'Window',
      message: {
        cmd: 'setResizable',
        resizable
      }
    })
  }

  /**
   * sets the window title
   *
   * @param title the new title
   */
  async setTitle(title: string): Promise<void> {
    return invoke({
      __tauriModule: 'Window',
      message: {
        cmd: 'setTitle',
        title
      }
    })
  }

  /**
   * Maximizes the window.
   */
  async maximize(): Promise<void> {
    return invoke({
      __tauriModule: 'Window',
      message: {
        cmd: 'maximize'
      }
    })
  }

  /**
   * Unmaximizes the window.
   */
  async unmaximize(): Promise<void> {
    return invoke({
      __tauriModule: 'Window',
      message: {
        cmd: 'unmaximize'
      }
    })
  }

  /**
   * Minimizes the window.
   */
  async minimize(): Promise<void> {
    return invoke({
      __tauriModule: 'Window',
      message: {
        cmd: 'minimize'
      }
    })
  }

  /**
   * Unminimizes the window.
   */
  async unminimize(): Promise<void> {
    return invoke({
      __tauriModule: 'Window',
      message: {
        cmd: 'unminimize'
      }
    })
  }

  /**
   * Sets the window visibility to true.
   */
  async show(): Promise<void> {
    return invoke({
      __tauriModule: 'Window',
      message: {
        cmd: 'show'
      }
    })
  }

  /**
   * Sets the window visibility to false.
   */
  async hide(): Promise<void> {
    return invoke({
      __tauriModule: 'Window',
      message: {
        cmd: 'hide'
      }
    })
  }

  /**
   * Sets the window transparent flag.
   *
   * @param {boolean} transparent whether the the window should be transparent or not
   */
  async setTransparent(transparent: boolean): Promise<void> {
    return invoke({
      __tauriModule: 'Window',
      message: {
        cmd: 'setTransparent',
        transparent
      }
    })
  }

  /**
   * Whether the window should have borders and bars.
   *
   * @param {boolean} decorations whether the window should have borders and bars
   */
  async setDecorations(decorations: boolean): Promise<void> {
    return invoke({
      __tauriModule: 'Window',
      message: {
        cmd: 'setDecorations',
        decorations
      }
    })
  }

  /**
   * Whether the window should always be on top of other windows.
   *
   * @param {boolean} alwaysOnTop whether the window should always be on top of other windows or not
   */
  async setAlwaysOnTop(alwaysOnTop: boolean): Promise<void> {
    return invoke({
      __tauriModule: 'Window',
      message: {
        cmd: 'setAlwaysOnTop',
        alwaysOnTop
      }
    })
  }

  /**
   * Sets the window width.
   *
   * @param {number} width the new window width
   */
  async setWidth(width: number): Promise<void> {
    return invoke({
      __tauriModule: 'Window',
      message: {
        cmd: 'setWidth',
        width
      }
    })
  }

  /**
   * Sets the window height.
   *
   * @param {number} height the new window height
   */
  async setHeight(height: number): Promise<void> {
    return invoke({
      __tauriModule: 'Window',
      message: {
        cmd: 'setHeight',
        height
      }
    })
  }

  /**
   * Resizes the window.
   *
   * @param {number} width the new window width
   * @param {number} height the new window height
   */
  async resize(width: number, height: number): Promise<void> {
    return invoke({
      __tauriModule: 'Window',
      message: {
        cmd: 'resize',
        width,
        height
      }
    })
  }

  /**
   * Sets the window min size.
   *
   * @param {number} minWidth the new window min width
   * @param {number} minHeight the new window min height
   */
  async setMinSize(minWidth: number, minHeight: number): Promise<void> {
    return invoke({
      __tauriModule: 'Window',
      message: {
        cmd: 'setMinSize',
        minWidth,
        minHeight
      }
    })
  }

  /**
   * Sets the window max size.
   *
   * @param {number} maxWidth the new window max width
   * @param {number} maxHeight the new window max height
   */
  async setMaxSize(maxWidth: number, maxHeight: number): Promise<void> {
    return invoke({
      __tauriModule: 'Window',
      message: {
        cmd: 'setMaxSize',
        maxWidth,
        maxHeight
      }
    })
  }

  /**
   * Sets the window x position.
   *
   * @param {number} x the new window x position
   */
  async setX(x: number): Promise<void> {
    return invoke({
      __tauriModule: 'Window',
      message: {
        cmd: 'setX',
        x
      }
    })
  }

  /**
   * Sets the window y position.
   *
   * @param {number} y the new window y position
   */
  async setY(y: number): Promise<void> {
    return invoke({
      __tauriModule: 'Window',
      message: {
        cmd: 'setY',
        y
      }
    })
  }

  /**
   * Sets the window position.
   *
   * @param {number} x the new window x position
   * @param {number} y the new window y position
   */
  async setPosition(x: number, y: number): Promise<void> {
    return invoke({
      __tauriModule: 'Window',
      message: {
        cmd: 'setPosition',
        x,
        y
      }
    })
  }

  /**
   * Sets the window fullscreen state.
   *
   * @param {boolean} fullscreen whether the window should go to fullscreen or not
   */
  async setFullscreen(fullscreen: boolean): Promise<void> {
    return invoke({
      __tauriModule: 'Window',
      message: {
        cmd: 'setFullscreen',
        fullscreen
      }
    })
  }

  /**
   * Sets the window icon
   *
   * @param {string | number[]} icon icon bytes or path to the icon file
   */
  async setIcon(icon: 'string' | number[]): Promise<void> {
    return invoke({
      __tauriModule: 'Window',
      message: {
        cmd: 'setIcon',
        icon
      }
    })
  }
}

const manager = new WindowManager()

export interface WindowOptions {
  url?: 'app' | string
  x?: number
  y?: number
  width?: number
  height?: number
  minWidth?: number
  minHeight?: number
  maxWidth?: number
  maxHeight?: number
  resizable?: boolean
  title?: string
  fullscreen?: boolean
  transparent?: boolean
  maximized?: boolean
  visible?: boolean
  decorations?: boolean
  alwaysOnTop?: boolean
}

export { WebviewWindow, getCurrent, getAll, manager }