create wrapmime module and simplify some mailmime code

src/wrapmime.rs

@@ -0,0 +1,119 @@
+use std::ffi::CString;
+
+use crate::dc_tools::*;
+use crate::error::Error;
+use mmime::clist::*;
+use mmime::mailimf_types::*;
+use mmime::mailimf_types_helper::*;
+use mmime::mailmime_disposition::*;
+use mmime::mailmime_types::*;
+use mmime::mailmime_types_helper::*;
+use mmime::other::*;
+
+#[macro_export]
+macro_rules! clist_append {
+    ($clist:expr,  $item:expr) => {
+        if clist_insert_after(
+            $clist as *mut clist,
+            (*$clist).last,
+            $item as *mut libc::c_void,
+        ) != 0
+        {
+            bail!("could not allocate or append list item");
+        }
+    };
+}
+
+pub fn add_filename_part(
+    message: *mut mailmime,
+    basename: &str,
+    mime_type: &str,
+    file_content: &str,
+) -> Result<(), Error> {
+    let mime_type_c = CString::new(mime_type.to_string()).expect("failed to create CString");
+    unsafe {
+        let content_type = mailmime_content_new_with_str(mime_type_c.as_ptr());
+        let mime_fields = mailmime_fields_new_filename(
+            MAILMIME_DISPOSITION_TYPE_ATTACHMENT as libc::c_int,
+            basename.strdup(),
+            MAILMIME_MECHANISM_8BIT as libc::c_int,
+        );
+        let file_mime_part = mailmime_new_empty(content_type, mime_fields);
+        set_body_text(file_mime_part, file_content)?;
+        mailmime_smart_add_part(message, file_mime_part);
+    }
+    Ok(())
+}
+
+pub fn new_custom_field(fields: *mut mailimf_fields, name: &str, value: &str) {
+    unsafe {
+        let field = mailimf_field_new_custom(name.strdup(), value.strdup());
+        let res = mailimf_fields_add(fields, field);
+        assert!(
+            res as u32 == MAILIMF_NO_ERROR,
+            "could not create mailimf field"
+        );
+    }
+}
+
+
+pub fn build_body_text(text: &str) -> Result<*mut mailmime, Error> {
+    let mime_fields: *mut mailmime_fields;
+    let message_part: *mut mailmime;
+
+    let content = new_mailmime_content_type("text/plain");
+    append_ct_param(content, "charset", "utf-8")?;
+
+    unsafe {
+        mime_fields = mailmime_fields_new_encoding(MAILMIME_MECHANISM_8BIT as libc::c_int);
+        message_part = mailmime_new_empty(content, mime_fields);
+    }
+    set_body_text(message_part, text)?;
+
+    Ok(message_part)
+}
+
+pub fn append_ct_param(
+    content: *mut mailmime_content,
+    name: &str,
+    value: &str,
+) -> Result<(), Error> {
+    unsafe {
+        let name_c = CString::new(name).unwrap().as_ptr();
+        let value_c = CString::new(value).unwrap().as_ptr();
+
+        clist_append!(
+            (*content).ct_parameters,
+            mailmime_param_new_with_data(
+                name_c as *const u8 as *const libc::c_char as *mut libc::c_char,
+                value_c as *const u8 as *const libc::c_char as *mut libc::c_char
+            )
+        );
+    }
+    Ok(())
+}
+
+pub fn new_mailmime_content_type(content_type: &str) -> *mut mailmime_content {
+    let ct = CString::new(content_type).unwrap();
+    let content: *mut mailmime_content;
+    // mailmime_content_new_with_str only parses but does not retain/own ct
+    //
+    unsafe {
+        content = mailmime_content_new_with_str(ct.as_ptr());
+    }
+    if content.is_null() {
+        panic!("mailimf failed to allocate");
+    }
+    content
+}
+
+pub fn set_body_text(part: *mut mailmime, text: &str) -> Result<(), Error> {
+    use libc::strlen;
+    unsafe {
+        let text_c = text.strdup();
+        if 0 != mailmime_set_body_text(part, text_c, strlen(text_c)) {
+            bail!("could not set body text on mime-structure");
+        }
+    }
+    Ok(())
+}