ChWebsiteApp/CHDataManagement/Generator/PageContentGenerator.swift
2024-12-13 11:26:34 +01:00

542 lines
19 KiB
Swift

import Foundation
import Ink
import Splash
typealias VideoSource = (url: String, type: VideoFileType)
final class PageContentParser {
private let pageLinkMarker = "page:"
private let tagLinkMarker = "tag:"
private static let codeHighlightFooter = "<script>hljs.highlightAll();</script>"
private let swift = SyntaxHighlighter(format: HTMLOutputFormat())
let results = PageGenerationResults()
private let content: Content
let language: ContentLanguage
var largeImageWidth: Int {
content.settings.pages.largeImageWidth
}
var thumbnailWidth: Int {
content.settings.pages.contentWidth
}
init(content: Content, language: ContentLanguage) {
self.content = content
self.language = language
}
func requestImages(_ generator: ImageGenerator) {
for request in results.imagesToGenerate {
generator.generateImageSet(
for: request.image.id,
maxWidth: CGFloat(request.size),
maxHeight: CGFloat(request.size))
}
}
func reset() {
results.reset()
}
func generatePage(from content: String) -> String {
reset()
let parser = MarkdownParser(modifiers: [
Modifier(target: .images, closure: processMarkdownImage),
Modifier(target: .codeBlocks, closure: handleCode),
Modifier(target: .links, closure: handleLink),
Modifier(target: .html, closure: handleHTML),
Modifier(target: .headings, closure: handleHeadlines)
])
return parser.html(from: content)
}
private func handleCode(html: String, markdown: Substring) -> String {
guard markdown.starts(with: "```swift") else {
results.requiredHeaders.insert(.codeHightlighting)
results.requiredFooters.insert(PageContentParser.codeHighlightFooter)
return html // Just use normal code highlighting
}
// Highlight swift code using Splash
let code = markdown.between("```swift", and: "```").trimmed
return "<pre><code>" + swift.highlight(code) + "</pre></code>"
}
private func handleLink(html: String, markdown: Substring) -> String {
let file = markdown.between("(", and: ")")
if file.hasPrefix(pageLinkMarker) {
return handlePageLink(file: file, html: html, markdown: markdown)
}
if file.hasPrefix(tagLinkMarker) {
return handleTagLink(file: file, html: html, markdown: markdown)
}
#warning("Check existence of linked file")
return html
}
private func handlePageLink(file: String, html: String, markdown: Substring) -> String {
// Retain links pointing to elements within a page
let textToChange = file.dropAfterFirst("#")
let pageId = textToChange.replacingOccurrences(of: pageLinkMarker, with: "")
guard let page = content.page(pageId) else {
results.missingPages.insert(pageId)
// Remove link since the page can't be found
return markdown.between("[", and: "]")
}
results.linkedPages.insert(page)
let pagePath = content.absoluteUrlToPage(page, language: language)
return html.replacingOccurrences(of: textToChange, with: pagePath)
}
private func handleTagLink(file: String, html: String, markdown: Substring) -> String {
// Retain links pointing to elements within a page
let textToChange = file.dropAfterFirst("#")
let tagId = textToChange.replacingOccurrences(of: tagLinkMarker, with: "")
guard let tag = content.tag(tagId) else {
results.missingTags.insert(tagId)
// Remove link since the tag can't be found
return markdown.between("[", and: "]")
}
results.linkedTags.insert(tag)
let tagPath = content.absoluteUrlToTag(tag, language: language)
return html.replacingOccurrences(of: textToChange, with: tagPath)
}
private func handleHTML(html: String, markdown: Substring) -> String {
#warning("Check HTML code in markdown for required resources")
// Things to check: <img src= <a href= <source>
return html
}
/**
Modify headlines by extracting an id from the headline and adding it into the html element
Format: ##<title>#<id>
The id is created by lowercasing the string, removing all special characters, and replacing spaces with scores
*/
private func handleHeadlines(html: String, markdown: Substring) -> String {
let id = markdown
.last(after: "#")
.trimmed
.filter { $0.isNumber || $0.isLetter || $0 == " " }
.lowercased()
.components(separatedBy: " ")
.filter { $0 != "" }
.joined(separator: "-")
let parts = html.components(separatedBy: ">")
return parts[0] + " id=\"\(id)\">" + parts.dropFirst().joined(separator: ">")
}
private func percentDecoded(_ string: String) -> String {
guard let decoded = string.removingPercentEncoding else {
print("Invalid string: \(string)")
return string
}
return decoded
}
private func processMarkdownImage(html: String, markdown: Substring) -> String {
//
let argumentList = percentDecoded(markdown.between(first: "](", andLast: ")"))
let arguments = argumentList.components(separatedBy: ";")
let rawCommand = percentDecoded(markdown.between("![", and: "]").trimmed)
guard rawCommand != "" else {
return handleImage(arguments)
}
guard let command = ShorthandMarkdownKey(rawValue: rawCommand) else {
// Treat unknown commands as normal links
results.unknownCommands.append(rawCommand)
return html
}
switch command {
case .image:
return handleImage(arguments)
case .hikingStatistics:
return handleHikingStatistics(arguments)
case .downloadButtons:
return handleDownloadButtons(arguments)
case .video:
return handleVideo(arguments)
case .externalLink:
return handleExternalButtons(arguments)
case .gitLink:
return handleGitButtons(arguments)
case .pageLink:
return handlePageLink(arguments)
case .includedHtml:
return handleExternalHtml(arguments)
case .box:
return handleSimpleBox(arguments)
case .model:
return handleModel(arguments)
case .svg:
return handleSvg(arguments)
default:
results.unknownCommands.append(command.rawValue)
return ""
}
}
/**
Format: `[image](<imageId>;<caption?>]`
*/
private func handleImage(_ arguments: [String]) -> String {
guard (1...2).contains(arguments.count) else {
results.invalidCommandArguments.append((.image , arguments))
return ""
}
let imageId = arguments[0]
guard let image = content.image(imageId) else {
results.missingFiles.insert(imageId)
return ""
}
results.files.insert(image)
let caption = arguments.count == 2 ? arguments[1] : nil
let altText = image.getDescription(for: language)
let path = content.absoluteUrlToFile(image)
guard !image.type.isSvg else {
return SvgImage(imagePath: path, altText: altText).content
}
let thumbnail = FeedEntryData.Image(
rawImagePath: path,
width: thumbnailWidth,
height: thumbnailWidth,
altText: altText)
results.imagesToGenerate.insert(.init(size: thumbnailWidth, image: image))
let largeImage = FeedEntryData.Image(
rawImagePath: path,
width: largeImageWidth,
height: largeImageWidth,
altText: altText)
results.imagesToGenerate.insert(.init(size: largeImageWidth, image: image))
return PageImage(
imageId: imageId.replacingOccurrences(of: ".", with: "-"),
thumbnail: thumbnail,
largeImage: largeImage,
caption: caption).content
}
/**
Format: `![hiking-stats](<time>;<elevation-up>;<elevation-down>;<distance>;<calories>)`
*/
private func handleHikingStatistics(_ arguments: [String]) -> String {
#warning("Make statistics more generic using key-value pairs")
guard (1...5).contains(arguments.count) else {
results.invalidCommandArguments.append((.hikingStatistics, arguments))
return ""
}
let time = arguments[0].trimmed
let elevationUp = arguments.count > 1 ? arguments[1].trimmed : nil
let elevationDown = arguments.count > 2 ? arguments[2].trimmed : nil
let distance = arguments.count > 3 ? arguments[3].trimmed : nil
let calories = arguments.count > 4 ? arguments[4].trimmed : nil
return HikingStatistics(
time: time,
elevationUp: elevationUp,
elevationDown: elevationDown,
distance: distance,
calories: calories)
.content
}
/**
Format: `![download](<<fileId>,<text>,<download-filename?>;...)`
*/
private func handleDownloadButtons(_ arguments: [String]) -> String {
let buttons = arguments.compactMap(convertButton)
return ContentButtons(items: buttons).content
}
private func convertButton(definition button: String) -> ContentButtons.Item? {
let parts = button.components(separatedBy: ",")
guard (2...3).contains(parts.count) else {
results.invalidCommandArguments.append((.downloadButtons, parts))
return nil
}
let fileId = parts[0].trimmed
let title = parts[1].trimmed
let downloadName = parts.count > 2 ? parts[2].trimmed : nil
guard let file = content.file(id: fileId) else {
results.missingFiles.insert(fileId)
return nil
}
results.files.insert(file)
let filePath = content.absoluteUrlToFile(file)
return ContentButtons.Item(icon: .download, filePath: filePath, text: title, downloadFileName: downloadName)
}
/**
Format: `![video](<fileId>;<option1...>]`
*/
private func handleVideo(_ arguments: [String]) -> String {
guard arguments.count >= 1 else {
results.invalidCommandArguments.append((.video, arguments))
return ""
}
let fileId = arguments[0].trimmed
let options = arguments.dropFirst().compactMap(convertVideoOption)
guard let file = content.file(id: fileId) else {
results.missingFiles.insert(fileId)
return ""
}
results.files.insert(file)
guard let videoType = file.type.videoType?.htmlType else {
results.invalidCommandArguments.append((.video, arguments))
return ""
}
let filePath = content.absoluteUrlToFile(file)
return ContentPageVideo(
filePath: filePath,
videoType: videoType,
options: options)
.content
}
private func convertVideoOption(_ videoOption: String) -> VideoOption? {
guard let optionText = videoOption.trimmed.nonEmpty else {
return nil
}
guard let option = VideoOption(rawValue: optionText) else {
results.invalidCommandArguments.append((.video, [optionText]))
return nil
}
if case let .poster(imageId) = option {
if let image = content.image(imageId) {
results.files.insert(image)
let link = content.absoluteUrlToFile(image)
let width = 2*thumbnailWidth
let fullLink = WebsiteImage.imagePath(source: link, width: width, height: width)
return .poster(image: fullLink)
} else {
results.missingFiles.insert(imageId)
return nil // Image file not present, so skip the option
}
}
if case let .src(videoId) = option {
if let video = content.video(videoId) {
results.files.insert(video)
let link = content.absoluteUrlToFile(video)
// TODO: Set correct video path?
return .src(link)
} else {
results.missingFiles.insert(videoId)
return nil // Video file not present, so skip the option
}
}
return option
}
private func handleExternalButtons(_ arguments: [String]) -> String {
// ![external](<<url>;<text>...>
handleButtons(icon: .externalLink, arguments: arguments)
}
private func handleGitButtons(_ arguments: [String]) -> String {
// ![git](<<url>;<text>...>
handleButtons(icon: .gitLink, arguments: arguments)
}
private func handleButtons(icon: PageIcon, arguments: [String]) -> String {
guard arguments.count >= 1 else {
results.invalidCommandArguments.append((.externalLink, arguments))
return ""
}
let buttons: [ContentButtons.Item] = arguments.compactMap { button in
let parts = button.components(separatedBy: ",")
guard parts.count == 2 else {
results.invalidCommandArguments.append((.externalLink, parts))
return nil
}
let rawUrl = parts[0].trimmed
guard let url = rawUrl.addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed) else {
results.invalidCommandArguments.append((.externalLink, parts))
return nil
}
let title = parts[1].trimmed
return .init(
icon: icon,
filePath: url,
text: title)
}
return ContentButtons(items: buttons).content
}
/**
Format: `![html](<fileId>)`
*/
private func handleExternalHtml(_ arguments: [String]) -> String {
guard arguments.count == 1 else {
results.invalidCommandArguments.append((.includedHtml, arguments))
return ""
}
let fileId = arguments[0]
guard let file = content.file(id: fileId) else {
results.missingFiles.insert(fileId)
return ""
}
return file.textContent()
}
/**
Format: `![box](<title>;<body>)`
*/
private func handleSimpleBox(_ arguments: [String]) -> String {
guard arguments.count > 1 else {
results.invalidCommandArguments.append((.box, arguments))
return ""
}
let title = arguments[0]
let text = arguments.dropFirst().joined(separator: ";")
return ContentBox(title: title, text: text).content
}
/**
Format: `![page](<pageId>)`
*/
private func handlePageLink(_ arguments: [String]) -> String {
guard arguments.count == 1 else {
results.invalidCommandArguments.append((.pageLink, arguments))
return ""
}
let pageId = arguments[0]
guard let page = content.page(pageId) else {
results.missingPages.insert(pageId)
return ""
}
guard !page.isDraft else {
// Prevent linking to unpublished content
return ""
}
let localized = page.localized(in: language)
let url = content.absoluteUrlToPage(page, language: language)
let title = localized.linkPreviewTitle ?? localized.title
let description = localized.linkPreviewDescription ?? ""
let image = localized.linkPreviewImage.map { image in
let size = content.settings.pages.pageLinkImageSize
results.files.insert(image)
results.imagesToGenerate.insert(.init(size: size, image: image))
return RelatedPageLink.Image(
url: content.absoluteUrlToFile(image),
description: image.getDescription(for: language),
size: size)
}
return RelatedPageLink(
title: title,
description: description,
url: url,
image: image)
.content
}
/**
Format: `![model](<file>)`
*/
private func handleModel(_ arguments: [String]) -> String {
guard arguments.count == 1 else {
results.invalidCommandArguments.append((.model, arguments))
return ""
}
let fileId = arguments[0]
guard fileId.hasSuffix(".glb") else {
results.invalidCommandArguments.append((.model, ["\(fileId) is not a .glb file"]))
return ""
}
guard let file = content.file(id: fileId) else {
results.missingFiles.insert(fileId)
return ""
}
results.files.insert(file)
results.requiredHeaders.insert(.modelViewer)
let path = content.absoluteUrlToFile(file)
let description = file.getDescription(for: language)
return ModelViewer(file: path, description: description).content
}
private func handleSvg(_ arguments: [String]) -> String {
guard arguments.count == 5 else {
results.invalidCommandArguments.append((.svg, arguments))
return ""
}
guard let x = Int(arguments[1]),
let y = Int(arguments[2]),
let partWidth = Int(arguments[3]),
let partHeight = Int(arguments[4]) else {
results.invalidCommandArguments.append((.svg, arguments))
return ""
}
let imageId = arguments[0]
guard let image = content.image(imageId) else {
results.missingFiles.insert(imageId)
return ""
}
guard case .image(let imageType) = image.type,
imageType == .svg else {
results.invalidCommandArguments.append((.svg, arguments))
return ""
}
let path = content.absoluteUrlToFile(image)
return PartialSvgImage(
imagePath: path,
altText: image.getDescription(for: language),
x: x,
y: y,
width: partWidth,
height: partHeight)
.content
}
}
/*
private func handleGif(file: String, altText: String) -> String {
let imagePath = page.pathRelativeToRootForContainedInputFile(file)
results.require(file: imagePath, source: page.path)
guard let size = results.getImageSize(atPath: imagePath, source: page.path) else {
return ""
}
let width = Int(size.width)
let height = Int(size.height)
return factory.html.image(file: file, width: width, height: height, altText: altText)
}
*/