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const std = @import("std");
const c = @cImport(@cInclude("mosquitto.h"));

var run = true;

fn concat(s1: []const u8, s2: []const u8) anyerror![]const u8 {
    return try std.mem.concat(std.heap.direct_allocator, u8, [_][]const u8{ s1, s2 });
}

fn concat3(s1: []const u8, s2: []const u8, s3: []const u8) anyerror![]const u8 {
    return try std.mem.concat(std.heap.direct_allocator, u8, [_][]const u8{ s1, s2, s3 });
}

extern fn intHandler(sig: i32, info: *std.os.siginfo_t, ctx_ptr: *c_void) void {
    std.debug.warn("\nShutting down...\n");
    run = false;
}

pub fn main() anyerror!void {

// Signal handling
    const act = std.os.Sigaction{
        .sigaction = intHandler,
        .mask = std.os.empty_sigset,
        .flags = 0,
    };
    std.os.sigaction(std.os.SIGINT, &act, null);

// Setup
    var hostnameBuf: [64]u8 = undefined;
    const hostname: []const u8 = try std.os.gethostname(&hostnameBuf);

const statusTopic = try concat3("server/", hostname, "/status");

std.debug.warn("Init status: {}\n", c.mosquitto_lib_init());
    defer std.debug.warn("Deinit: {}\n", c.mosquitto_lib_cleanup());

var mos = c.mosquitto_new(hostname.ptr, false, null);
    defer c.mosquitto_destroy(mos);

// Will
    std.debug.warn("Will: {}\n", c.mosquitto_will_set(mos, statusTopic.ptr, 7, c"offline", 2, true));
    std.debug.warn("Connect: {}\n", c.mosquitto_connect(mos, c"127.0.0.1", 1883, 30));
    defer std.debug.warn("Disconnect: {}\n", c.mosquitto_disconnect(mos));

std.debug.warn("Publish: {}\n", c.mosquitto_publish(mos, null, statusTopic.ptr, 6, c"online", 1, true));

// Loop
    while (run) {
        std.debug.warn("Looping: {}\n", errorCode(c.mosquitto_loop(mos, 10000, 1)));
        std.os.nanosleep(1, 0);
    }

// Set unknown status on exit
    std.debug.warn("Publish: {}\n", c.mosquitto_publish(mos, null, statusTopic.ptr, 17, c"client-disconnect", 1, true));
}

fn errorCode(errcode: c_int) []const u8 {
    const result = switch (@intToEnum(c.mosq_err_t, errcode)) {
        .MOSQ_ERR_AUTH_CONTINUE => "-4",
        .MOSQ_ERR_NO_SUBSCRIBERS => "No subscribers",
        .MOSQ_ERR_SUB_EXISTS => "Subscriber exists",
        .MOSQ_ERR_CONN_PENDING => "Connection pending",
        .MOSQ_ERR_SUCCESS => "OK",
        .MOSQ_ERR_NOMEM => "Out of memory",
        .MOSQ_ERR_PROTOCOL => "Protocol error",
        .MOSQ_ERR_INVAL => "Invalid parameter",
        .MOSQ_ERR_NO_CONN => "No connection",
        .MOSQ_ERR_CONN_REFUSED => "Connection refused",
        .MOSQ_ERR_NOT_FOUND => "Not found",
        .MOSQ_ERR_CONN_LOST => "Connection lost",
        .MOSQ_ERR_TLS => "TLS error",
        .MOSQ_ERR_PAYLOAD_SIZE => "Payload size",
        .MOSQ_ERR_NOT_SUPPORTED => "Not supported",
        .MOSQ_ERR_AUTH => "Auth error",
        .MOSQ_ERR_ACL_DENIED => "Denied by ACL",
        .MOSQ_ERR_UNKNOWN => "Unknown topic",
        .MOSQ_ERR_ERRNO => "ERRNO",
        .MOSQ_ERR_EAI => "15",
        .MOSQ_ERR_PROXY => "16",
        .MOSQ_ERR_PLUGIN_DEFER => "17",
        .MOSQ_ERR_MALFORMED_UTF8 => "Malformed UTF8",
        .MOSQ_ERR_KEEPALIVE => "19",
        .MOSQ_ERR_LOOKUP => "20",
        .MOSQ_ERR_MALFORMED_PACKET => "Malformed packet",
        .MOSQ_ERR_DUPLICATE_PROPERTY => "Duplicate property",
        .MOSQ_ERR_TLS_HANDSHAKE => "TLS handshake error",
        .MOSQ_ERR_QOS_NOT_SUPPORTED => "QOS not supported",
        .MOSQ_ERR_OVERSIZE_PACKET => "Oversize packet",
        .MOSQ_ERR_OCSP => "OSCP error",
        else => "Unknown",
    };
    return result;
}