const { promises: fs } = require('fs')
const { until, error: webdriverError } = require('selenium-webdriver')
const { strict: assert } = require('assert')

class Driver {
  /**
   * @param {!ThenableWebDriver} driver - A {@code WebDriver} instance
   * @param {string} browser - The type of browser this driver is controlling
   * @param {number} timeout
   */
  constructor (driver, browser, extensionUrl, timeout = 10000) {
    this.driver = driver
    this.browser = browser
    this.extensionUrl = extensionUrl
    this.timeout = timeout
  }

  async delay (time) {
    await new Promise(resolve => setTimeout(resolve, time))
  }

  async wait (condition, timeout = this.timeout) {
    await this.driver.wait(condition, timeout)
  }

  async quit () {
    await this.driver.quit()
  }

  // Element interactions

  async findElement (locator) {
    return await this.driver.wait(until.elementLocated(locator), this.timeout)
  }

  async findVisibleElement (locator) {
    const element = await this.findElement(locator)
    await this.driver.wait(until.elementIsVisible(element), this.timeout)
    return element
  }

  async findClickableElement (locator) {
    const element = await this.findElement(locator)
    await Promise.all([
      this.driver.wait(until.elementIsVisible(element), this.timeout),
      this.driver.wait(until.elementIsEnabled(element), this.timeout),
    ])
    return element
  }

  async findElements (locator) {
    return await this.driver.wait(until.elementsLocated(locator), this.timeout)
  }

  async findClickableElements (locator) {
    const elements = await this.findElements(locator)
    await Promise.all(elements
      .reduce((acc, element) => {
        acc.push(
          this.driver.wait(until.elementIsVisible(element), this.timeout),
          this.driver.wait(until.elementIsEnabled(element), this.timeout),
        )
        return acc
      }, [])
    )
    return elements
  }

  async clickElement (locator) {
    const element = await this.findClickableElement(locator)
    await element.click()
  }

  async scrollToElement (element) {
    await this.driver.executeScript('arguments[0].scrollIntoView(true)', element)
  }

  async assertElementNotPresent (locator) {
    let dataTab
    try {
      dataTab = await this.findElement(locator)
    } catch (err) {
      assert(err instanceof webdriverError.NoSuchElementError || err instanceof webdriverError.TimeoutError)
    }
    assert.ok(!dataTab, 'Found element that should not be present')
  }

  // Navigation

  async navigate (page = Driver.PAGES.HOME) {
    return await this.driver.get(`${this.extensionUrl}/${page}.html`)
  }

  // Metrics

  async collectMetrics () {
    return await this.driver.executeScript(collectMetrics)
  }

  // Window management

  async openNewPage (url) {
    const newHandle = await this.driver.switchTo().newWindow()
    await this.driver.get(url)
    return newHandle
  }

  async switchToWindow (handle) {
    await this.driver.switchTo().window(handle)
  }

  async getAllWindowHandles () {
    return await this.driver.getAllWindowHandles()
  }

  async waitUntilXWindowHandles (x, delayStep = 1000, timeout = 5000) {
    let timeElapsed = 0
    while (timeElapsed <= timeout) {
      const windowHandles = await this.driver.getAllWindowHandles()
      if (windowHandles.length === x) {
        return
      }
      await this.delay(delayStep)
      timeElapsed += delayStep
    }
    throw new Error('waitUntilXWindowHandles timed out polling window handles')
  }

  async switchToWindowWithTitle (title, windowHandles) {
    if (!windowHandles) {
      windowHandles = await this.driver.getAllWindowHandles()
    }

    for (const handle of windowHandles) {
      await this.driver.switchTo().window(handle)
      const handleTitle = await this.driver.getTitle()
      if (handleTitle === title) {
        return handle
      }
    }

    throw new Error('No window with title: ' + title)
  }

  /**
   * Closes all windows except those in the given list of exceptions
   * @param {Array<string>} exceptions - The list of window handle exceptions
   * @param {Array} [windowHandles] - The full list of window handles
   * @returns {Promise<void>}
   */
  async closeAllWindowHandlesExcept (exceptions, windowHandles) {
    windowHandles = windowHandles || await this.driver.getAllWindowHandles()

    for (const handle of windowHandles) {
      if (!exceptions.includes(handle)) {
        await this.driver.switchTo().window(handle)
        await this.delay(1000)
        await this.driver.close()
        await this.delay(1000)
      }
    }
  }

  // Error handling

  async verboseReportOnFailure (test) {
    const artifactDir = `./test-artifacts/${this.browser}/${test.title}`
    const filepathBase = `${artifactDir}/test-failure`
    await fs.mkdir(artifactDir, { recursive: true })
    const screenshot = await this.driver.takeScreenshot()
    await fs.writeFile(`${filepathBase}-screenshot.png`, screenshot, { encoding: 'base64' })
    const htmlSource = await this.driver.getPageSource()
    await fs.writeFile(`${filepathBase}-dom.html`, htmlSource)
  }

  async checkBrowserForConsoleErrors () {
    const ignoredLogTypes = ['WARNING']
    const ignoredErrorMessages = [
      // Third-party Favicon 404s show up as errors
      'favicon.ico - Failed to load resource: the server responded with a status of 404 (Not Found)',
    ]
    const browserLogs = await this.driver.manage().logs().get('browser')
    const errorEntries = browserLogs.filter(entry => !ignoredLogTypes.includes(entry.level.toString()))
    const errorObjects = errorEntries.map(entry => entry.toJSON())
    return errorObjects.filter(entry => !ignoredErrorMessages.some(message => entry.message.includes(message)))
  }
}

function collectMetrics () {
  const results = {
    paint: {},
    navigation: [],
  }

  performance.getEntriesByType('paint').forEach((paintEntry) => {
    results.paint[paintEntry.name] = paintEntry.startTime
  })

  performance.getEntriesByType('navigation').forEach((navigationEntry) => {
    results.navigation.push({
      domContentLoaded: navigationEntry.domContentLoadedEventEnd,
      load: navigationEntry.loadEventEnd,
      domInteractive: navigationEntry.domInteractive,
      redirectCount: navigationEntry.redirectCount,
      type: navigationEntry.type,
    })
  })

  return results
}

Driver.PAGES = {
  HOME: 'home',
  NOTIFICATION: 'notification',
  POPUP: 'popup',
}

module.exports = Driver