const fs = require('fs')
const {CompositeDisposable, Disposable} = require('atom')
const {dontSaveIf, shouldSave} = require('./controls')

module.exports = {
  subscriptions: null,

  provideService () {
    return {dontSaveIf}
  },

  activate () {
    this.subscriptions = new CompositeDisposable()

    const handleBlur = event => {
      if (event.target === window) {
        this.autosaveAllPaneItems()
      } else if (event.target.matches('atom-text-editor:not(mini)')) {
        return this.autosavePaneItem(event.target.getModel())
      }
    }

    window.addEventListener('blur', handleBlur, true)
    this.subscriptions.add(new Disposable(() => window.removeEventListener('blur', handleBlur, true)))

    this.subscriptions.add(atom.workspace.onDidAddPaneItem(({item}) => this.autosavePaneItem(item, true)))
    this.subscriptions.add(atom.workspace.onWillDestroyPaneItem(({item}) => this.autosavePaneItem(item)))
  },

  deactivate () {
    this.subscriptions.dispose()
    return this.autosaveAllPaneItems()
  },

  autosavePaneItem (paneItem, create = false) {
    if (!atom.config.get('autosave.enabled')) return
    if (!paneItem) return
    if (typeof paneItem.getURI !== 'function' || !paneItem.getURI()) return
    if (typeof paneItem.isModified !== 'function' || !paneItem.isModified()) return
    if (typeof paneItem.getPath !== 'function' || !paneItem.getPath()) return
    if (!shouldSave(paneItem)) return

    try {
      const stats = fs.statSync(paneItem.getPath())
      if (!stats.isFile()) return
    } catch (e) {
      if (e.code !== 'ENOENT') return
      if (!create) return
    }

    const pane = atom.workspace.paneForItem(paneItem)
    let promise = Promise.resolve()
    if (pane) {
      promise = pane.saveItem(paneItem)
    } else if (typeof paneItem.save === 'function') {
      promise = paneItem.save()
    }
    return promise
  },

  autosaveAllPaneItems () {
    return Promise.all(
      atom.workspace.getPaneItems().map((paneItem) => this.autosavePaneItem(paneItem))
    )
  }
}