/*
 * This file is part of the Zorin Taskbar extension for Zorin OS.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * Credits:
 * This file is based on code from the Dash to Panel extension
 * Ideas for recursing child actors and assigning inline styles
 * are based on code from the StatusAreaHorizontalSpacing extension
 * https://bitbucket.org/mathematicalcoffee/status-area-horizontal-spacing-gnome-shell-extension
 * mathematical.coffee@gmail.com
 */

import * as Utils from './utils.js'

export const PanelStyle = class {
  enable(panel) {
    this.panel = panel

    this._applyStyles()
  }

  disable() {
    this._removeStyles()
  }

  _applyStyles() {
    this._rightBoxOperations = []

    // center box has been moved next to the right box and will be treated the same
    this._centerBoxOperations = this._rightBoxOperations

    this._leftBoxOperations = []

    this._applyStylesRecursively()

    /* connect signal */
    this._rightBoxActorAddedID = this.panel._rightBox.connect(
      'child-added',
      (container, actor) => {
        if (this._rightBoxOperations.length && !this._ignoreAddedChild)
          this._recursiveApply(actor, this._rightBoxOperations)

        this._ignoreAddedChild = 0
      },
    )
    this._centerBoxActorAddedID = this.panel._centerBox.connect(
      'child-added',
      (container, actor) => {
        if (this._centerBoxOperations.length && !this._ignoreAddedChild)
          this._recursiveApply(actor, this._centerBoxOperations)

        this._ignoreAddedChild = 0
      },
    )
    this._leftBoxActorAddedID = this.panel._leftBox.connect(
      'child-added',
      (container, actor) => {
        if (this._leftBoxOperations.length)
          this._recursiveApply(actor, this._leftBoxOperations)
      },
    )
  }

  _removeStyles() {
    /* disconnect signal */
    if (this._rightBoxActorAddedID)
      this.panel._rightBox.disconnect(this._rightBoxActorAddedID)
    if (this._centerBoxActorAddedID)
      this.panel._centerBox.disconnect(this._centerBoxActorAddedID)
    if (this._leftBoxActorAddedID)
      this.panel._leftBox.disconnect(this._leftBoxActorAddedID)

    this._restoreOriginalStyle(this.panel._rightBox)
    this._restoreOriginalStyle(this.panel._centerBox)
    this._restoreOriginalStyle(this.panel._leftBox)

    this._applyStylesRecursively(true)
  }

  _applyStylesRecursively(restore) {
    /*recurse actors */
    if (this._rightBoxOperations.length) {
      // add the system menu as we move it from the rightbox to the panel to position it independently
      let children = this.panel._rightBox
        .get_children()
        .concat([
          this.panel.statusArea[Utils.getSystemMenuInfo().name].container,
        ])
      for (let i in children)
        this._recursiveApply(children[i], this._rightBoxOperations, restore)
    }

    if (this._centerBoxOperations.length) {
      // add the date menu as we move it from the centerbox to the panel to position it independently
      let children = this.panel._centerBox
        .get_children()
        .concat([this.panel.statusArea.dateMenu.container])
      for (let i in children)
        this._recursiveApply(children[i], this._centerBoxOperations, restore)
    }

    if (this._leftBoxOperations.length) {
      let children = this.panel._leftBox.get_children()
      for (let i in children)
        this._recursiveApply(children[i], this._leftBoxOperations, restore)
    }
  }

  _recursiveApply(actor, operations, restore) {
    for (let i in operations) {
      let o = operations[i]
      if (o.compareFn(actor))
        if (restore)
          o.restoreFn ? o.restoreFn(actor) : this._restoreOriginalStyle(actor)
        else o.applyFn(actor, i)
    }

    if (actor.get_children) {
      let children = actor.get_children()
      for (let i in children) {
        this._recursiveApply(children[i], operations, restore)
      }
    }
  }

  _restoreOriginalStyle(actor) {
    if (actor._dtp_original_inline_style !== undefined) {
      actor.set_style(actor._dtp_original_inline_style)
      delete actor._dtp_original_inline_style
      delete actor._dtp_style_overrides
    }

    if (actor.has_style_class_name('panel-button')) {
      this._refreshPanelButton(actor)
    }
  }

  _refreshPanelButton(actor) {
    if (actor.visible) {
      //force gnome 3.34+ to refresh (having problem with the -natural-hpadding)
      let parent = actor.get_parent()
      let children = parent.get_children()
      let actorIndex = 0

      if (children.length > 1) {
        actorIndex = children.indexOf(actor)
      }

      this._ignoreAddedChild =
        [this.panel._centerBox, this.panel._rightBox].indexOf(parent) >= 0

      parent.remove_child(actor)
      parent.insert_child_at_index(actor, actorIndex)
    }
  }
}