(.NET Core C#) IMAP Search with THREAD Semantics

Demonstrates how to search an IMAP mailbox and return message numbers grouped together in parent/child relationships based on which messages are replies to others.

Note: This example requires Chilkat v9.5.0.77 or greater.

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// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

Chilkat.Imap imap = new Chilkat.Imap();

// Connect to your IMAP server and authenticate..
imap.Ssl = true;
imap.Port = 993;
bool success = imap.Connect("imap.mail.us-west-2.awsapps.com");
if (success != true) {
    Debug.WriteLine(imap.LastErrorText);
    return;
}

success = imap.Login("myLogin","myPassword");
if (success != true) {
    Debug.WriteLine(imap.LastErrorText);
    return;
}

// Select a mailbox
success = imap.SelectMailbox("Inbox");
if (success != true) {
    Debug.WriteLine(imap.LastErrorText);
    return;
}

// Search for all message having the letter 'a' somewhere in the Subject,
// and return the messages as JSON.
Chilkat.JsonObject json = imap.ThreadCmd("REFERENCES","UTF-8","SUBJECT a",true);
if (imap.LastMethodSuccess == false) {
    Debug.WriteLine(imap.LastErrorText);
    return;
}

// The IMAP server will return a raw response with a format such as this:  (2)(3 6 (4 23)(44 7 96))

// In tree form, it's like this:
// 
//             -- 2
//             -- 3
//                 \-- 6
//                    |-- 4
//                    |      \-- 23
//                    |
//                    |-- 44
//                               \-- 7
//                                       \-- 96
// 

// It means there are 2 main threads returned, but the 2nd thread splits into two sub-threads.
// In total, we can think of it as 3 threads -- 2 main threads (with no parents) and one sub-thread w/ a parent.
// 
// - The 1st thread contains the message 2, and has no parent thread.
// - The 2nd thread contains the messages 3, 6, 4, 23, and has no parent thread.
// - The 3rd thread contains the messages 44, 7, 96 and the parent thread is message 6.
// 

// (Yes, this is all highly confusing...)

// Chilkat will return the above sample response as JSON that looks like this:

// {
//   "threads": [
//     [2],
//     [3, 6, [4, 23], [44, 7, 96]]
//   ]
// }
// 

// Use this online tool to generate parsing code from sample JSON: 
// Generate Parsing Code from JSON
// In this case, the online tool can help you get a feel for how to write the JSON parsing code..

int numThreads = json.SizeOfArray("threads");
Debug.WriteLine("The total number of top-level threads is " + Convert.ToString(numThreads));

// Let's say we wanted to get the messages in the thread 3, 6, 4, 23.
// We always follow the 1st branch to the bottom, ignoring the other branches.
// For example, if we had  [3, 5, [4, 23, [55, 56, 57], [68, 69]], [44, 7, 96]]
// then the thread would be 3, 5, 4, 43, 55, 56, 57

// For testing, let's substitute the response from the IMAP server with this sample:
json.Load("{\"threads\": [[2], [3, 5, [4, 23, [55, 56, 57], [68, 69]], [44, 7, 96]]]}");

// Begin with the 2nd top-level thread, which is at index 1.
Debug.WriteLine("Following the 2nd top level thread...");
Chilkat.JsonArray arr = json.ArrayOf("threads[1]");
int threadSize = arr.Size;
int i = 0;
while (i < threadSize) {
    // Do we have an array or integer at this position?
    if (arr.TypeAt(i) == 4) {
        // This is a sub-array.
        Chilkat.JsonArray subArr = arr.ArrayAt(i);

        // Follow the sub-array starting at the 1st position..
        arr = subArr;
        i = 0;
        threadSize = arr.Size;
    }
    else {
        // Must be a single integer.
        Debug.WriteLine(Convert.ToString(arr.IntAt(i)));
        i = i + 1;
    }

}

// The output is:
// 
// Following the 2nd top level thread...
// 3
// 5
// 4
// 23
// 55
// 56
// 57