1 files changed, 82 insertions, 22 deletions

diff --git a/services/docker/mail-server/aws-sendmail/mail.ts b/services/docker/mail-server/aws-sendmail/mail.ts
index d4bcf75..98afcaa 100644
--- a/services/docker/mail-server/aws-sendmail/mail.ts
+++ b/services/docker/mail-server/aws-sendmail/mail.ts
@@ -1,5 +1,6 @@
 import { encodeBase64 } from "@std/encoding/base64";
 import { getLogger } from "./logger.ts";
+import { generateTimeStringForFileName } from "./util.ts";
 
 export type MailDeliverStateNotSent = { kind: "not-sent" };
 export type MailDeliverStateDelivered = {
@@ -21,8 +22,10 @@ class MailParseError extends Error {
   constructor(
     message: string,
     public readonly mail: Mail,
+    public readonly lineNumber?: number,
     options?: ErrorOptions,
   ) {
+    if (lineNumber != null) message += `(at line ${lineNumber})`;
     super(message, options);
   }
 }
@@ -44,9 +47,14 @@ const eolNames = new Map([
 ]);
 
 interface ParsedMail {
-  headerStr: string;
-  bodyStr: string;
-  sepStr: string;
+  sections: {
+    header: string;
+    body: string;
+  };
+  /**
+   * The empty line between headers and body.
+   */
+  sep: string;
   eol: string;
 }
 
@@ -89,48 +97,100 @@ export class Mail {
     // "\r\n" is a false positive.
     if (twoEolMatch == null || twoEolMatch[0] === "\r\n") {
       throw new MailParseError(
-        "No header/body separator (2 successive EOLs) found. Cannot append headers.",
+        "No header/body section separator (2 successive EOLs) found.",
         this,
       );
     }
 
-    const [eol, sepStr] = [twoEolMatch[1], twoEolMatch[2]];
+    const [eol, sep] = [twoEolMatch[1], twoEolMatch[2]];
 
-    if (eol !== sepStr) {
+    if (eol !== sep) {
       getLogger().warn(
-        `Different EOLs (${eolNames.get(eol)} \
-        and ${eolNames.get(sepStr)}) found in mail.`,
+        `Different EOLs (${eolNames.get(eol)} and ${eolNames.get(sep)}) found.`,
       );
     }
 
     return {
-      headerStr: this.raw.slice(0, twoEolMatch.index! + eol.length),
-      bodyStr: this.raw.slice(twoEolMatch.index! + eol.length + sepStr.length),
-      sepStr,
+      sections: {
+        header: this.raw.slice(0, twoEolMatch.index! + eol.length),
+        body: this.raw.slice(twoEolMatch.index! + eol.length + sep.length),
+      },
+      sep,
       eol,
     };
   }
 
   simpleParseHeaders(): [key: string, value: string][] {
-    const { headerStr } = this.simpleParse();
-    const lines: string[] = [];
-    for (const line of headerStr.split(/\r?\n|\r/)) {
+    const { sections } = this.simpleParse();
+    const headers: [string, string][] = [];
+
+    let field: string | null = null;
+    let lineNumber = 1;
+
+    const handleField = () => {
+      if (field == null) return;
+      const sepPos = field.indexOf(":");
+      if (sepPos === -1) {
+        throw new MailParseError(
+          "No ':' in the header field.",
+          this,
+          lineNumber,
+        );
+      }
+      headers.push([field.slice(0, sepPos).trim(), field.slice(sepPos + 1)]);
+      field = null;
+    };
+
+    for (const line of sections.header.trimEnd().split(/\r?\n|\r/)) {
       if (line.match(/^\s/)) {
-        if (lines.length === 0) {
-          throw new MailParseError("Header part starts with a space.", this);
+        if (field == null) {
+          throw new MailParseError(
+            "Header field starts with a space.",
+            this,
+            lineNumber,
+          );
+        }
+        field += line;
+      } else {
+        handleField();
+        field = line;
+      }
+      lineNumber += 1;
+    }
+
+    handleField();
+
+    return headers;
+  }
+
+  simpleGetDate(): Date | null {
+    const headers = this.simpleParseHeaders();
+    for (const [key, value] of headers) {
+      if (key.toLowerCase() === "date") {
+        const date = new Date(value);
+        if (isNaN(date.getTime())) {
+          getLogger().warn(`Invalid date string (${value}) found in header.`);
+          return null;
         }
-        lines[lines.length - 1] += line;
+        return date;
       }
     }
+    return null;
+  }
 
-    // TODO: Continue here.
+  simpleGetDateString<T>(fallback: T): string | T {
+    const date = this.simpleGetDate();
+    if (date == null) return fallback;
+    return generateTimeStringForFileName(date, true);
   }
 
+  // TODO: Add folding.
   appendHeaders(headers: [key: string, value: string][]) {
-    const { headerStr, bodyStr, sepStr, eol } = this.simpleParse();
-    const newHeaderStr = headerStr +
-      headers.map(([k, v]) => `${k}: ${v}${eol}`).join("");
-    this.raw = newHeaderStr + sepStr + bodyStr;
+    const { sections, sep, eol } = this.simpleParse();
+
+    this.raw = sections.header +
+      headers.map(([k, v]) => `${k}: ${v}`).join(eol) + eol + sep +
+      sections.body;
   }
 }