111 lines
3.2 KiB
Swift
111 lines
3.2 KiB
Swift
import Foundation
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import Models
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/// Builds RFC 5322 formatted email messages.
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public enum MessageFormatter: Sendable {
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/// Format an OutgoingMessage into a complete RFC 5322 message string with CRLF line endings.
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public static func format(_ message: OutgoingMessage) -> String {
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var headers: [(String, String)] = []
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headers.append(("From", formatAddress(message.from)))
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headers.append(("To", message.to.map(formatAddress).joined(separator: ", ")))
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if !message.cc.isEmpty {
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headers.append(("Cc", message.cc.map(formatAddress).joined(separator: ", ")))
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}
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// BCC intentionally omitted from headers per RFC 5322
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headers.append(("Subject", message.subject))
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headers.append(("Date", formatRFC2822Date(Date())))
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headers.append(("Message-ID", "<\(message.messageId)>"))
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if let inReplyTo = message.inReplyTo {
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headers.append(("In-Reply-To", "<\(inReplyTo)>"))
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}
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if let references = message.references {
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headers.append(("References", references))
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}
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headers.append(("MIME-Version", "1.0"))
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headers.append(("Content-Type", "text/plain; charset=utf-8"))
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headers.append(("Content-Transfer-Encoding", "quoted-printable"))
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var result = ""
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for (name, value) in headers {
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result += "\(name): \(value)\r\n"
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}
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result += "\r\n"
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result += quotedPrintableEncode(message.bodyText)
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return result
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}
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/// Generate a unique Message-ID for the given domain.
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public static func generateMessageId(domain: String) -> String {
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"\(UUID().uuidString)@\(domain)"
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}
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/// Extract the domain part from an email address.
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public static func domainFromEmail(_ email: String) -> String {
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guard let atIndex = email.lastIndex(of: "@") else { return email }
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return String(email[email.index(after: atIndex)...])
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}
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/// Format an EmailAddress as RFC 5322 address: `"Name" <addr>` or bare `addr`.
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public static func formatAddress(_ addr: EmailAddress) -> String {
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if let name = addr.name, !name.isEmpty {
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return "\"\(name)\" <\(addr.address)>"
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}
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return addr.address
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}
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/// Format a Date as RFC 2822 date string.
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public static func formatRFC2822Date(_ date: Date) -> String {
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let formatter = DateFormatter()
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formatter.locale = Locale(identifier: "en_US_POSIX")
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formatter.dateFormat = "EEE, dd MMM yyyy HH:mm:ss Z"
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formatter.timeZone = TimeZone.current
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return formatter.string(from: date)
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}
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/// Encode a string using quoted-printable encoding (RFC 2045).
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public static func quotedPrintableEncode(_ text: String) -> String {
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var result = ""
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let data = Array(text.utf8)
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var lineLength = 0
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for byte in data {
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let encoded: String
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if byte == 0x0A {
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// LF → CRLF
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encoded = "\r\n"
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result += encoded
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lineLength = 0
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continue
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} else if byte == 0x0D {
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// CR — skip, we handle LF → CRLF above
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continue
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} else if byte == 0x09 || (byte >= 0x20 && byte <= 0x7E && byte != 0x3D) {
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// Printable ASCII (except =) and tab: literal
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encoded = String(UnicodeScalar(byte))
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} else {
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// Everything else: =XX hex encoding
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encoded = String(format: "=%02X", byte)
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}
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// Soft line break if line would exceed 76 chars
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if lineLength + encoded.count > 76 {
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result += "=\r\n"
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lineLength = 0
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}
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result += encoded
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lineLength += encoded.count
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}
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return result
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}
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}
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