/*
 * FileSaver.js
 * A saveAs() FileSaver implementation.
 *
 * By Eli Grey, http://eligrey.com
 *
 * License : https://github.com/eligrey/FileSaver.js/blob/master/LICENSE.md (MIT)
 * source  : http://purl.eligrey.com/github/FileSaver.js
 */

// The one and only way of getting global scope in all environments
// https://stackoverflow.com/q/3277182/1008999
var _global =
	typeof window === 'object' && window.window === window
		? window
		: typeof self === 'object' && self.self === self
		? self
		: typeof global === 'object' && global.global === global
		? global
		: this

function bom(blob, opts) {
	if (typeof opts === 'undefined') opts = { autoBom: false }
	else if (typeof opts !== 'object') {
		console.warn('Deprecated: Expected third argument to be a object')
		opts = { autoBom: !opts }
	}

	// prepend BOM for UTF-8 XML and text/* types (including HTML)
	// note: your browser will automatically convert UTF-16 U+FEFF to EF BB BF
	if (
		opts.autoBom &&
		/^\s*(?:text\/\S*|application\/xml|\S*\/\S*\+xml)\s*;.*charset\s*=\s*utf-8/i.test(
			blob.type
		)
	) {
		return new Blob([String.fromCharCode(0xfeff), blob], {
			type: blob.type,
		})
	}
	return blob
}

function download(url, name, opts) {
	var xhr = new XMLHttpRequest()
	xhr.open('GET', url)
	xhr.responseType = 'blob'
	xhr.onload = function () {
		saveAs(xhr.response, name, opts)
	}
	xhr.onerror = function () {
		console.error('could not download file')
	}
	xhr.send()
}

function corsEnabled(url) {
	var xhr = new XMLHttpRequest()
	// use sync to avoid popup blocker
	xhr.open('HEAD', url, false)
	try {
		xhr.send()
	} catch (e) {}
	return xhr.status >= 200 && xhr.status <= 299
}

// `a.click()` doesn't work for all browsers (#465)
function click(node) {
	try {
		node.dispatchEvent(new MouseEvent('click'))
	} catch (e) {
		var evt = document.createEvent('MouseEvents')
		evt.initMouseEvent(
			'click',
			true,
			true,
			window,
			0,
			0,
			0,
			80,
			20,
			false,
			false,
			false,
			false,
			0,
			null
		)
		node.dispatchEvent(evt)
	}
}

var saveAs =
	// probably in some web worker
	typeof window !== 'object' || window !== _global
		? function saveAs() {
				/* noop */
		  }
		: // Use download attribute first if possible (#193 Lumia mobile)
		'download' in HTMLAnchorElement.prototype
		? function saveAs(blob, name, opts) {
				var URL = _global.URL || _global.webkitURL
				var a = document.createElement('a')
				name = name || blob.name || 'download'

				a.download = name
				a.rel = 'noopener' // tabnabbing

				// TODO: detect chrome extensions & packaged apps
				// a.target = '_blank'

				if (typeof blob === 'string') {
					// Support regular links
					a.href = blob
					if (a.origin !== location.origin) {
						corsEnabled(a.href)
							? download(blob, name, opts)
							: click(a, (a.target = '_blank'))
					} else {
						click(a)
					}
				} else {
					// Support blobs
					a.href = URL.createObjectURL(blob)
					setTimeout(function () {
						URL.revokeObjectURL(a.href)
					}, 4e4) // 40s
					setTimeout(function () {
						click(a)
					}, 0)
				}
		  }
		: // Use msSaveOrOpenBlob as a second approach
		'msSaveOrOpenBlob' in navigator
		? function saveAs(blob, name, opts) {
				name = name || blob.name || 'download'

				if (typeof blob === 'string') {
					if (corsEnabled(blob)) {
						download(blob, name, opts)
					} else {
						var a = document.createElement('a')
						a.href = blob
						a.target = '_blank'
						setTimeout(function () {
							click(a)
						})
					}
				} else {
					navigator.msSaveOrOpenBlob(bom(blob, opts), name)
				}
		  }
		: // Fallback to using FileReader and a popup
		  function saveAs(blob, name, opts, popup) {
				// Open a popup immediately do go around popup blocker
				// Mostly only available on user interaction and the fileReader is async so...
				popup = popup || open('', '_blank')
				if (popup) {
					popup.document.title = popup.document.body.innerText =
						'downloading...'
				}

				if (typeof blob === 'string') return download(blob, name, opts)

				var force = blob.type === 'application/octet-stream'
				var isSafari =
					/constructor/i.test(_global.HTMLElement) || _global.safari
				var isChromeIOS = /CriOS\/[\d]+/.test(navigator.userAgent)

				if (
					(isChromeIOS || (force && isSafari)) &&
					typeof FileReader === 'object'
				) {
					// Safari doesn't allow downloading of blob URLs
					var reader = new FileReader()
					reader.onloadend = function () {
						var url = reader.result
						url = isChromeIOS
							? url
							: url.replace(
									/^data:[^;]*;/,
									'data:attachment/file;'
							  )
						if (popup) popup.location.href = url
						else location = url
						popup = null // reverse-tabnabbing #460
					}
					reader.readAsDataURL(blob)
				} else {
					var URL = _global.URL || _global.webkitURL
					var url = URL.createObjectURL(blob)
					if (popup) popup.location = url
					else location.href = url
					popup = null // reverse-tabnabbing #460
					setTimeout(function () {
						URL.revokeObjectURL(url)
					}, 4e4) // 40s
				}
		  }

module.exports = saveAs
