// Functions that operate on channels

#include <ctype.h>
#include <err.h>
#include <gc.h>
#include <math.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdlib.h>
#include <pthread.h>
#include <sys/param.h>

#include "arrays.h"
#include "metamethods.h"
#include "integers.h"
#include "siphash.h"
#include "text.h"
#include "types.h"
#include "util.h"

public Channel_t *Channel$new(Int_t max_size)
{
    if (Int$compare_value(max_size, I_small(0)) <= 0)
        fail("Cannot create a channel with a size less than one: %ld", max_size);
    Channel_t *channel = new(Channel_t);
    channel->items = (Array_t){};
    channel->mutex = (pthread_mutex_t)PTHREAD_MUTEX_INITIALIZER;
    channel->cond = (pthread_cond_t)PTHREAD_COND_INITIALIZER;
    channel->max_size = Int_to_Int64(max_size, false);
    return channel;
}

public void Channel$give(Channel_t *channel, const void *item, bool front, int64_t padded_item_size)
{
    (void)pthread_mutex_lock(&channel->mutex);
    while (channel->items.length >= channel->max_size)
        pthread_cond_wait(&channel->cond, &channel->mutex);
    Int_t index = front ? I_small(1) : I_small(0);
    Array$insert(&channel->items, item, index, padded_item_size);
    (void)pthread_mutex_unlock(&channel->mutex);
    (void)pthread_cond_signal(&channel->cond);
}

public void Channel$give_all(Channel_t *channel, Array_t to_give, bool front, int64_t padded_item_size)
{
    if (to_give.length == 0) return;
    (void)pthread_mutex_lock(&channel->mutex);
    Int_t index = front ? I_small(1) : I_small(0);
    if (channel->items.length + to_give.length >= channel->max_size) {
        for (int64_t i = 0; i < to_give.length; i++) {
            while (channel->items.length >= channel->max_size)
                pthread_cond_wait(&channel->cond, &channel->mutex);
            Array$insert(&channel->items, to_give.data + i*to_give.stride, index, padded_item_size);
        }
    } else {
        Array$insert_all(&channel->items, to_give, index, padded_item_size);
    }
    (void)pthread_mutex_unlock(&channel->mutex);
    (void)pthread_cond_signal(&channel->cond);
}

public void Channel$get(Channel_t *channel, void *out, bool front, int64_t item_size, int64_t padded_item_size)
{
    (void)pthread_mutex_lock(&channel->mutex);
    while (channel->items.length == 0)
        pthread_cond_wait(&channel->cond, &channel->mutex);
    memcpy(out, channel->items.data + channel->items.stride * (front ? 0 : channel->items.length-1), (size_t)(item_size));
    Int_t index = front ? I_small(1) : Int64_to_Int(channel->items.length);
    Array$remove_at(&channel->items, index, I_small(1), padded_item_size);
    (void)pthread_mutex_unlock(&channel->mutex);
    (void)pthread_cond_signal(&channel->cond);
}

public void Channel$peek(Channel_t *channel, void *out, bool front, int64_t item_size)
{
    (void)pthread_mutex_lock(&channel->mutex);
    while (channel->items.length == 0)
        pthread_cond_wait(&channel->cond, &channel->mutex);
    int64_t index = front ? 0 : channel->items.length-1;
    memcpy(out, channel->items.data + channel->items.stride*index, (size_t)(item_size));
    (void)pthread_mutex_unlock(&channel->mutex);
    (void)pthread_cond_signal(&channel->cond);
}

public Array_t Channel$view(Channel_t *channel)
{
    (void)pthread_mutex_lock(&channel->mutex);
    ARRAY_INCREF(channel->items);
    Array_t ret = channel->items;
    (void)pthread_mutex_unlock(&channel->mutex);
    return ret;
}

public void Channel$clear(Channel_t *channel)
{
    (void)pthread_mutex_lock(&channel->mutex);
    Array$clear(&channel->items);
    (void)pthread_mutex_unlock(&channel->mutex);
    (void)pthread_cond_signal(&channel->cond);
}

PUREFUNC public uint64_t Channel$hash(const void *channel, const TypeInfo_t *type)
{
    (void)type;
    return siphash24(*(void**)channel, sizeof(Channel_t*));
}

PUREFUNC public int32_t Channel$compare(const void *x, const void *y, const TypeInfo_t*)
{
    return (*(Channel_t**)x > *(Channel_t**)y) - (*(Channel_t**)x < *(Channel_t**)y);
}

PUREFUNC public bool Channel$equal(const void *x, const void *y, const TypeInfo_t*)
{
    return (*(void**)x == *(void**)y);
}

public Text_t Channel$as_text(const void *channel, bool colorize, const TypeInfo_t *type)
{
    const TypeInfo_t *item_type = type->ChannelInfo.item;
    if (!channel) {
        Text_t typename = generic_as_text(NULL, false, item_type);
        return Text$concat(colorize ? Text("\x1b[34;1m|:") : Text("|:"), typename, colorize ? Text("|\x1b[m") : Text("|"));
    }
    Text_t typename = generic_as_text(NULL, false, item_type);
    return Text$concat(
        colorize ? Text("\x1b[34;1m|:") : Text("|:"),
        typename,
        Text("|<"),
        Int64$hex(*(int64_t*)channel, I_small(0), true, true),
        colorize ? Text(">\x1b[m") : Text(">")
    );
}

public PUREFUNC bool Channel$is_none(const void *obj, const TypeInfo_t*)
{
    return *(void**)obj == NULL;
}

public void Channel$serialize(const void *obj, FILE *out, Table_t *pointers, const TypeInfo_t *type)
{
    Channel_t *channel = (Channel_t*)obj;
    Array$serialize(&channel->items, out, pointers, Array$info(type->ChannelInfo.item));
    Int64$serialize(&channel->max_size, out, pointers, &Int64$info);
}

public void Channel$deserialize(FILE *in, void *outval, Array_t *pointers, const TypeInfo_t *type)
{
    Channel_t *channel = new(Channel_t);
    channel->mutex = (pthread_mutex_t)PTHREAD_MUTEX_INITIALIZER;
    channel->cond = (pthread_cond_t)PTHREAD_COND_INITIALIZER;
    Array$deserialize(in, &channel->items, pointers, Array$info(type->ChannelInfo.item));
    Int64$deserialize(in, &channel->max_size, pointers, &Int64$info);
    *(Channel_t**)outval = channel;
}

// vim: ts=4 sw=0 et cino=L2,l1,(0,W4,m1,\:0