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// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
import Foundation
protocol FaviconURLHandler {
func getFaviconURL(model: SiteImageModel) async throws -> URL
func cacheFaviconURL(cacheKey: String, faviconURL: URL)
func clearCache()
}
struct DefaultFaviconURLHandler: FaviconURLHandler {
private let urlFetcher: FaviconURLFetcher
private let urlCache: FaviconURLCache
init(urlFetcher: FaviconURLFetcher = DefaultFaviconURLFetcher(),
urlCache: FaviconURLCache = DefaultFaviconURLCache.shared) {
self.urlFetcher = urlFetcher
self.urlCache = urlCache
}
/// Attempts to get the favicon URL associated with this site. First checks the URL cache. If the URL can't be obtained
/// from the cache, then a network request is made to hopefully scrape the favicon URL from a webpage's metadata.
/// **Note**: This is a slow call when the URL is not cached.
func getFaviconURL(model: SiteImageModel) async throws -> URL {
guard model.siteURL.scheme != "internal" else {
// For internal URLs, skip trying to fetch a faviconURL (result in `"unsupported URL"` network errors)
throw SiteImageError.noFaviconFound
}
do {
let url = try await urlCache.getURLFromCache(cacheKey: model.cacheKey)
return url
} catch {
do {
let url = try await urlFetcher.fetchFaviconURL(siteURL: model.siteURL) // Slow call
await urlCache.cacheURL(cacheKey: model.cacheKey, faviconURL: url)
return url
} catch {
throw SiteImageError.noFaviconURLFound
}
}
}
func cacheFaviconURL(cacheKey: String, faviconURL: URL) {
Task {
await urlCache.cacheURL(cacheKey: cacheKey, faviconURL: faviconURL)
}
}
func clearCache() {
Task {
await urlCache.clearCache()
}
}
}