#include <stdbool.h>
#include "io.h"
#include "ipc.h"
#include "child.h"
#include "lamport_time.h"
#include "pa2345.h"


/**
 * 
 * @algo
 *      REQUEST:
 *       *)  Q_i -- queue of P_i;
 *          When P_i needs access to CS, it sends REQUEST(L_i, i)
 *          to all process and adds the message to it's own queue.
 *       *) 
 *
 */
int
request_cs(const void * self) {
    proc_t *p = (proc_t*)self;
    Message msg;
    increase_lamport_time();
    msg.s_header = (MessageHeader) {
        .s_magic = MESSAGE_MAGIC,
        .s_type  = CS_REQUEST,
        .s_local_time = get_lamport_time(),
        .s_payload_len = 0
    };

    send_multicast((void*)p, &msg);

    int request_time = get_lamport_time();
    int wait_reply = p->io->procnum-1;
    while (wait_reply != 0) {
        int id;
        while ((id = receive_any((void*)p, &msg)) < 0);
        set_lamport_time(msg.s_header.s_local_time);
        switch (msg.s_header.s_type) {
            case CS_REQUEST: {
                //fprintf(stderr, "%d: process %d got request from %d\n", get_lamport_time(), p->self_id, id);
                if ((request_time < msg.s_header.s_local_time) ||
                    (request_time == msg.s_header.s_local_time && p->self_id < id))  {
                    p->dr[id] = 1;
                    p->dr_count++;
                } else {
                    increase_lamport_time();
                    msg.s_header.s_type = CS_REPLY;
                    msg.s_header.s_local_time = get_lamport_time();
                    send((void*)p, id, &msg);
                }
                break;
            }
            case CS_REPLY: {
                //fprintf(stderr, "%d: process %d got replay from %d\n", get_lamport_time(), p->self_id, id);
                wait_reply--;
                break;
            }
            case DONE: {
                //fprintf(stderr, "%d: process %d got DONE from %d\n", get_lamport_time(), p->self_id, id);
                p->running_processes--;
                break;
            }
            default: {
                //fprintf(stderr, "%d: process %d got unknown type: %d\n", get_lamport_time(), p->self_id, msg.s_header.s_type);
            }

        }
    }
    return 0;
}

int
release_cs(const void * self) {
    proc_t *p = (proc_t*)self;
    Message msg;
    msg.s_header = (MessageHeader) {
        .s_magic = MESSAGE_MAGIC,
        .s_type  = CS_REPLY,
        .s_payload_len = 0
    };

    for (uint8_t i = 0; i < p->io->procnum || p->dr_count; i++) {
        if (p->dr[i]) {
            increase_lamport_time();
            msg.s_header.s_local_time = get_lamport_time(),
            send((void*)self, i, &msg);
            p->dr[i] = 0;
            p->dr_count--;
        }
    }
    return 0;
}