(Objective-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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#import <CkoImap.h>
#import <CkoJsonObject.h>
#import <CkoJsonArray.h>

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

CkoImap *imap = [[CkoImap alloc] init];

// Connect to your IMAP server and authenticate..
imap.Ssl = YES;
imap.Port = [NSNumber numberWithInt:993];
BOOL success = [imap Connect: @"imap.mail.us-west-2.awsapps.com"];
if (success != YES) {
    NSLog(@"%@",imap.LastErrorText);
    return;
}

success = [imap Login: @"myLogin" password: @"myPassword"];
if (success != YES) {
    NSLog(@"%@",imap.LastErrorText);
    return;
}

// Select a mailbox
success = [imap SelectMailbox: @"Inbox"];
if (success != YES) {
    NSLog(@"%@",imap.LastErrorText);
    return;
}

// Search for all message having the letter 'a' somewhere in the Subject,
// and return the messages as JSON.
CkoJsonObject *json = [imap ThreadCmd: @"REFERENCES" charset: @"UTF-8" searchCriteria: @"SUBJECT a" bUid: YES];
if (imap.LastMethodSuccess == NO) {
    NSLog(@"%@",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"] intValue];
NSLog(@"%@%d",@"The total number of top-level threads is ",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.
NSLog(@"%@",@"Following the 2nd top level thread...");
CkoJsonArray *arr = [json ArrayOf: @"threads[1]"];
int threadSize = [arr.Size intValue];
int i = 0;
while (i < threadSize) {
    // Do we have an array or integer at this position?
    if ([[arr TypeAt: [NSNumber numberWithInt: i]] intValue] == 4) {
        // This is a sub-array.
        CkoJsonArray *subArr = [arr ArrayAt: [NSNumber numberWithInt: i]];

        // Follow the sub-array starting at the 1st position..
        arr = subArr;
        i = 0;
        threadSize = [arr.Size intValue];
    }
    else {
        // Must be a single integer.
        NSLog(@"%d",[[arr IntAt: [NSNumber numberWithInt: i]] intValue]);
        i = i + 1;
    }

}

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