add script for listing and adding parts

1 files changed, 191 insertions, 0 deletions

diff --git a/scripts/parts b/scripts/parts
new file mode 100755
index 0000000..ae73c2f
--- /dev/null
+++ b/scripts/parts
@@ -0,0 +1,191 @@
+#! /bin/sh
+# usage: parts list
+# usage: parts add PATH [NAME [DESCRIPTION]]
+set -efu
+
+
+list_parts() {
+  jq -r '
+    def replicate(n; x):
+      if n == 0 then "" else n * x end
+      ;
+    def flattenMap(inner):
+      def addDepth(depth):
+        if type == "array" then
+          map(addDepth(depth + 1))
+        else
+          { depth: depth, value: . }
+        end
+        ;
+      def addIndex:
+        to_entries | map(.value + { index: .key })
+        ;
+      def getPrefix:
+        match("( *).*").captures[0].string
+        ;
+      def stripPrefix:
+        match(" *(.*)").captures[0].string
+        ;
+      def shiftPrefix:
+        match("( *[^ ]+)( *)( .*)").captures|map(.string)|.[1]+.[0]+.[2]
+        ;
+      addDepth(0) | flatten | addIndex | map(inner) | map(shiftPrefix)
+      ;
+    def parseContentType:
+      if . != null then . else "text/plain; charset=UTF-8" end |
+      split(";\\s*";"") |
+      (.[0] | split("/")) as $compoundType |
+      $compoundType[0] as $type |
+      $compoundType[1] as $subtype |
+      (.[1:] | map(split("=") | { key: .[0], value: .[1] }) | from_entries)
+        as $params |
+      {
+        $type, $subtype, $params,
+      }
+      ;
+    def formatPart:
+      .body as $body |
+      ((.headers // []) | from_entries) as $headers |
+      ($headers["content-type"] | parseContentType) as $ct |
+      "\($ct.type)/\($ct.subtype)" as $compoundType |
+      $ct.params.name as $name |
+      [ "\($compoundType) \($name | tojson) \($body | length)" ] +
+      if $ct.type == "multipart" then .body | map(formatPart) else [] end
+      ;
+
+    formatPart |
+    flattenMap("\(replicate(.depth - 1; "  "))part#\(.index + 1) \(.value)")[]
+  '
+}
+
+add_part() {(
+  filepath=$1
+  filename=${2-$(basename "$filepath")}
+  description=${3-$filename}
+
+  contentType="$(file -Lib "$filepath"); name=$filename"
+  case $contentType in
+    text/plain|text/plain\;*)
+      contentTransferEncoding=8bit
+      content() {
+        cat "$filepath"
+      }
+      ;;
+    *)
+      contentTransferEncoding=base64
+      content() {
+        base64 "$filepath"
+      }
+      ;;
+  esac
+  contentDisposition="attachment; filename=$filename"
+  contentDescription=$description
+
+  boundary=$(date -Ins | sha1sum | cut -d\  -f1)
+
+  {
+    jq '{ mail: . }'
+    content | jq -Rs '{ content: . }'
+  } |
+  jq -sr \
+    --arg boundary "$boundary" \
+    --arg contentType "$contentType" \
+    --arg contentTransferEncoding "$contentTransferEncoding" \
+    --arg contentDisposition "$contentDisposition" \
+    --arg contentDescription "$contentDescription" \
+  '
+    add |
+
+    .mail as $mail |
+    .content as $content |
+
+    def parseContentType:
+      if . == null then null else
+        split(";\\s*";"") |
+        (.[0] | split("/")) as $type |
+        (.[1:] | map(split("=") | { key: .[0], value: .[1] }) | from_entries)
+          as $parameters |
+        {
+          type: $type[0],
+          subtype: $type[1],
+          parameters: $parameters,
+        }
+      end;
+
+    ($mail.headers | from_entries) as $headers |
+    ($headers["content-type"] | if . == null then
+      {
+        type: "text",
+        subtype: "plain",
+        parameters: {
+          charset: "UTF-8",
+        },
+      }
+    else parseContentType
+    end)
+      as $ct |
+
+
+    def add_part:
+      {
+        headers: ({
+          "content-type": $contentType,
+          "content-transfer-encoding": $contentTransferEncoding,
+          "content-disposition": $contentDisposition,
+          "content-description": $contentDescription,
+        } | to_entries),
+        body: $content,
+      }
+        as $part |
+      { headers: .headers
+      , body: (.body + [$part])
+      };
+
+    ($mail.headers | from_entries) as $headers |
+
+    def is_multipart_mixed:
+      $headers["content-type"] // "" | test("^multipart/mixed\\b.*");
+
+    if is_multipart_mixed then
+      $mail | add_part
+    else
+      { headers: (
+          $mail.headers |
+          map(select(.key != "mime-version")) |
+          map(select(.key != "content-type")) |
+          map(select(.key != "content-transfer-encoding")) |
+          .  + ({
+            "mime-version": "1.0",
+            "Content-Type": "multipart/mixed; boundary=\"----=\($boundary)\"",
+          } | to_entries)
+        )
+      , body: [{
+          headers: ({
+            "content-type":
+              ($headers["content-type"] // "text/plain; charset=UTF-8"),
+            "content-transfer-encoding":
+              ($headers["content-transfer-encoding"] // "8bit"),
+          } | to_entries),
+          body: $mail.body,
+        }]
+      } |
+      add_part
+    end
+  '
+)}
+
+
+
+command=$1; shift
+case $command in
+  list)
+    mailaid | list_parts
+    ;;
+  add)
+    mailaid | add_part "$@" | mailaid -d
+    ;;
+  *)
+    echo "$0: error: unknown command: $command" >&2
+    exit 1
+    ;;
+esac