Implement support for replies

src/threads/id.ts

@@ -15,8 +15,21 @@ export function buildThreadAddressMatcher(): RegExp {
     // In the config, the thread ID is represented with the placeholder: %ID%
 
     const idPrefix = escapeRexString(config.mail.threads.idPrefix)
-    const idCapture = `(${idPrefix}[^@]+)`  // first rule of email: don't be as strict as the RFC
+    const idCapture = `(${idPrefix}[^@.]+)`  // first rule of email: don't be as strict as the RFC (special case: IDs after the prefix cannot contain a period)
+
+    const replyPrefix = escapeRexString(config.mail.threads.replyPrefix)
+    const replyCapture = `(${replyPrefix}[^@.]+)?`
+
+    const template = escapeRexString(config.mail.threads.template)
+        .replace('%ID%', idCapture)
+        .replace('%REPLY%', replyCapture)
 
-    const template = escapeRexString(config.mail.threads.template).replace('%ID%', idCapture)
     return new RegExp(`^${template}$`)
 }
+
+export function formatThreadAddress(thread: string, replyToHash?: string): string {
+    let reply = replyToHash ? `${config.mail.threads.replyPrefix}${replyToHash}` : ''
+    return config.mail.threads.template
+        .replace('%ID%', thread)
+        .replace('%REPLY%', reply)
+}

src/threads/refresh.ts

@@ -1,11 +1,12 @@
 import {getMailboxesToSearch, MailboxIterable} from "../mail/read.ts";
 import {withClient} from "../mail/client.ts";
-import type {Message, RootData, ThreadData} from "../types.ts";
+import type {Message, RootData, ThreadComment, ThreadData} from "../types.ts";
 import {AsyncCollection} from "../bones/collection/AsyncCollection.ts";
 import {sha256} from "../bones/crypto.ts";
 import {config} from "../config.ts";
 import { marked } from "marked";
 import {sanitizeHtml} from "../mail/sanitize.ts";
+import {formatThreadAddress} from "./id.ts";
 
 export async function refreshThreadsEntirely(): Promise<void> {
     await withClient(async client => {
@@ -41,6 +42,9 @@ export async function refreshThreadsEntirely(): Promise<void> {
                 comments: [],
             }
 
+            // 3 passes required to make this work (works because objects are by-reference)
+            // Pass 1: create all the ThreadComment instances and make a map by their ID
+            const commentsByHash: {[hash: string]: ThreadComment} = {}
             const messages = messagesByThread[threadId]
             for ( const message of messages ) {
                 if (
@@ -50,7 +54,10 @@ export async function refreshThreadsEntirely(): Promise<void> {
                     threadData.refresh.markers[message.mailbox] = message.modseq
                 }
 
-                threadData.comments.push({
+                commentsByHash[message.idHash] = {
+                    idHash: message.idHash,
+                    replyToHash: message.replyToHash,
+                    replyAddress: formatThreadAddress(threadId, message.idHash),
                     user: {
                         name: message.from.name || '(anonymous)',
                         mailId: sha256(message.from.address!.toLowerCase()),
@@ -60,7 +67,30 @@ export async function refreshThreadsEntirely(): Promise<void> {
                     subject: message.subject,
                     text: message.content,
                     rendered: message.html || sanitizeHtml(await marked(message.content)),
-                })
+                }
+            }
+
+            // Pass 2: Push replies into the replies array of their immediate parent
+            for ( const message of messages ) {
+                if ( !message.replyToHash ) {
+                    continue
+                }
+
+                if ( !commentsByHash[message.replyToHash].replies ) {
+                    commentsByHash[message.replyToHash].replies = []
+                }
+
+                commentsByHash[message.replyToHash].replies!.push(commentsByHash[message.idHash])
+            }
+
+            // Pass 3: push all top-level comments into the ThreadData
+            for ( const idHash of Object.keys(commentsByHash) ) {
+                const comment = commentsByHash[idHash]
+                if ( comment.replyToHash ) {
+                    continue
+                }
+
+                threadData.comments.push(comment)
             }
 
             const json = JSON.stringify(