#include <stdlib.h>
#include <string.h>
#include <cassert>
#include <iostream>
#include <algorithm>

#include "i40e_bm.h"

#include "i40e_base_wrapper.h"

using namespace i40e;

extern nicbm::Runner *runner;

queue_base::queue_base(const std::string &qname_, uint32_t &reg_head_,
        uint32_t &reg_tail_)
    : qname(qname_), log(qname_), active_first_pos(0), active_first_idx(0), active_cnt(0),
    base(0), len(0), reg_head(reg_head_), reg_tail(reg_tail_),
    enabled(false), desc_len(0)
{
    for (size_t i = 0; i < MAX_ACTIVE_DESCS; i++) {
        desc_ctxs[i] = nullptr;
    }
}

void queue_base::ctxs_init()
{
    for (size_t i = 0; i < MAX_ACTIVE_DESCS; i++) {
        desc_ctxs[i] = &desc_ctx_create();
    }
}

void queue_base::trigger_fetch()
{
    if (!enabled)
        return;

    // calculate how many we can fetch
    uint32_t next_idx = (active_first_idx + active_cnt) % len;
    uint32_t desc_avail = (reg_tail - next_idx) % len;
    uint32_t fetch_cnt = desc_avail;
    fetch_cnt = std::min(fetch_cnt, MAX_ACTIVE_DESCS - active_cnt);
    if (max_active_capacity() <= active_cnt)
        fetch_cnt = std::min(fetch_cnt, max_active_capacity() - active_cnt);
    fetch_cnt = std::min(fetch_cnt, max_fetch_capacity());

    if (next_idx + fetch_cnt > len)
        fetch_cnt = len - next_idx;

#ifdef DEBUG_QUEUES
    log << "fetching avail=" << desc_avail << " cnt=" << fetch_cnt << " idx=" <<
        next_idx << logger::endl;
#endif

    // abort if nothign to fetch
    if (fetch_cnt == 0)
        return;

    // mark descriptor contexts as fetching
    uint32_t first_pos = (active_first_pos + active_cnt) % MAX_ACTIVE_DESCS;
    for (uint32_t i = 0; i < fetch_cnt; i++) {
        desc_ctx &ctx = *desc_ctxs[(first_pos + i) % MAX_ACTIVE_DESCS];
        assert(ctx.state == desc_ctx::DESC_EMPTY);

        ctx.state = desc_ctx::DESC_FETCHING;
        ctx.index = (next_idx + i) % len;
    }
    active_cnt += fetch_cnt;

    // prepare & issue dma
    dma_fetch *dma = new dma_fetch(*this, desc_len * fetch_cnt);
    dma->write = false;
    dma->dma_addr = base + next_idx * desc_len;
    dma->pos = first_pos;
#ifdef DEBUG_QUEUES
    log << "    dma = " << dma << logger::endl;
#endif
    runner->issue_dma(*dma);
}

void queue_base::trigger_process()
{
    if (!enabled)
        return;

    // first skip over descriptors that are already done processing
    uint32_t i;
    for (i = 0; i < active_cnt; i++)
        if (desc_ctxs[(active_first_pos + i) % MAX_ACTIVE_DESCS]->state
                <= desc_ctx::DESC_PREPARED)
            break;

    // then run all prepared contexts
    uint32_t j;
    for (j = 0; i + j < active_cnt; j++) {
        desc_ctx &ctx = *desc_ctxs[(active_first_pos + i + j)
            % MAX_ACTIVE_DESCS];
        if (ctx.state != desc_ctx::DESC_PREPARED)
            break;

        ctx.state = desc_ctx::DESC_PROCESSING;
#ifdef DEBUG_QUEUES
        log << "processing desc " << ctx.index << logger::endl;
#endif
        ctx.process();
    }
}

void queue_base::trigger_writeback()
{
    if (!enabled)
        return;

    // from first pos count number of processed descriptors
    uint32_t avail;
    for (avail = 0; avail < active_cnt; avail++)
        if (desc_ctxs[(active_first_pos + avail) % MAX_ACTIVE_DESCS]->state
                != desc_ctx::DESC_PROCESSED)
            break;

    uint32_t cnt = std::min(avail, max_writeback_capacity());
    if (active_first_idx + cnt > len)
        cnt = len - active_first_idx;

#ifdef DEBUG_QUEUES
    log << "writing back avail=" << avail << " cnt=" << cnt <<
        " idx=" << active_first_idx << logger::endl;
#endif

    if (cnt == 0)
        return;

    // mark these descriptors as writing back
    for (uint32_t i = 0; i < cnt; i++) {
        desc_ctx &ctx = *desc_ctxs[(active_first_pos + i) % MAX_ACTIVE_DESCS];
        ctx.state = desc_ctx::DESC_WRITING_BACK;
    }

    do_writeback(active_first_idx, active_first_pos, cnt);
}

void queue_base::trigger()
{
  trigger_fetch();
  trigger_process();
  trigger_writeback();
}

void queue_base::reset()
{
#ifdef DEBUG_QUEUES
    log << "reset" << logger::endl;
#endif

    enabled = false;
    active_first_pos = 0;
    active_first_idx = 0;
    active_cnt = 0;

    for (size_t i = 0; i < MAX_ACTIVE_DESCS; i++) {
        desc_ctxs[i]->state = desc_ctx::DESC_EMPTY;
    }
}

void queue_base::reg_updated()
{
    if (!enabled)
        return;

    trigger();
}

bool queue_base::is_enabled()
{
    return enabled;
}

uint32_t queue_base::max_fetch_capacity()
{
    return UINT32_MAX;
}

uint32_t queue_base::max_active_capacity()
{
    return UINT32_MAX;
}

uint32_t queue_base::max_writeback_capacity()
{
    return UINT32_MAX;
}

void queue_base::interrupt()
{
}

void queue_base::do_writeback(uint32_t first_idx, uint32_t first_pos,
        uint32_t cnt)
{
    dma_wb *dma = new dma_wb(*this, desc_len * cnt);
    dma->write = true;
    dma->dma_addr = base + first_idx * desc_len;
    dma->pos = first_pos;

    uint8_t *buf = reinterpret_cast<uint8_t *> (dma->data);
    for (uint32_t i = 0; i < cnt; i++) {
        desc_ctx &ctx = *desc_ctxs[(first_pos + i) % MAX_ACTIVE_DESCS];
        assert(ctx.state == desc_ctx::DESC_WRITING_BACK);
        memcpy(buf + i * desc_len, ctx.desc, desc_len);
    }

    runner->issue_dma(*dma);
}

void queue_base::writeback_done(uint32_t first_pos, uint32_t cnt)
{
    if (!enabled)
        return;

    // first mark descriptors as written back
    for (uint32_t i = 0; i < cnt; i++) {
        desc_ctx &ctx = *desc_ctxs[(first_pos + i) % MAX_ACTIVE_DESCS];
        assert(ctx.state == desc_ctx::DESC_WRITING_BACK);
        ctx.state = desc_ctx::DESC_WRITTEN_BACK;
    }

#ifdef DEBUG_QUEUES
    log << "written back afi=" << active_first_idx << " afp=" <<
        active_first_pos << " acnt=" << active_cnt << " pos=" <<
        first_pos << " cnt=" << cnt << logger::endl;
#endif

    // then start at the beginning and check how many are written back and then
    // free those
    uint32_t bump_cnt = 0;
    for (bump_cnt = 0; bump_cnt < active_cnt; bump_cnt++) {
        desc_ctx &ctx = *desc_ctxs[(active_first_pos + bump_cnt) %
            MAX_ACTIVE_DESCS];
        if (ctx.state != desc_ctx::DESC_WRITTEN_BACK)
            break;

        ctx.state = desc_ctx::DESC_EMPTY;
    }
#ifdef DEBUG_QUEUES
    log << "   bump_cnt=" << bump_cnt << logger::endl;
#endif

    active_first_pos = (active_first_pos + bump_cnt) % MAX_ACTIVE_DESCS;
    active_first_idx = (active_first_idx + bump_cnt) % len;
    active_cnt -= bump_cnt;

    reg_head = active_first_idx;
    interrupt();
}

queue_base::desc_ctx::desc_ctx(queue_base &queue_)
    : queue(queue_), state(DESC_EMPTY), index(0), data(nullptr), data_len(0),
    data_capacity(0)
{
    desc = new uint8_t[queue_.desc_len];
}

queue_base::desc_ctx::~desc_ctx()
{
    delete[] ((uint8_t *) desc);
    if (data_capacity > 0)
        delete[] ((uint8_t *) data);
}

void queue_base::desc_ctx::prepare()
{
    prepared();
}

void queue_base::desc_ctx::prepared()
{
#ifdef DEBUG_QUEUES
    queue.log << "prepared desc " << index << logger::endl;
#endif
    assert(state == DESC_PREPARING);
    state = DESC_PREPARED;
}

void queue_base::desc_ctx::processed()
{
#ifdef DEBUG_QUEUES
    queue.log << "processed desc " << index << logger::endl;
#endif
    assert(state == DESC_PROCESSING);
    state = DESC_PROCESSED;
}

#define MAX_DMA_SIZE ((size_t) 0x1000)

void queue_base::desc_ctx::data_fetch(uint64_t addr, size_t data_len)
{
    if (data_capacity < data_len) {
#ifdef DEBUG_QUEUES
        queue.log << "data_fetch allocating" << logger::endl;
#endif
        if (data_capacity != 0)
            delete[] ((uint8_t *) data);

        data = new uint8_t[data_len];
        data_capacity = data_len;
    }

    dma_data_fetch *dma = new dma_data_fetch(*this, std::min(data_len,
                MAX_DMA_SIZE), data);
    dma->part_offset = 0;
    dma->total_len = data_len;
    dma->write = false;
    dma->dma_addr = addr;

#ifdef DEBUG_QUEUES
    queue.log << "fetching data idx=" << index << " addr=" << addr << " len=" <<
        data_len << logger::endl;
    queue.log << "  dma = " << dma << " data=" << data << logger::endl;
#endif
    runner->issue_dma(*dma);

}

void queue_base::desc_ctx::data_fetched(uint64_t addr, size_t len)
{
    prepared();
}

void queue_base::desc_ctx::data_write(uint64_t addr, size_t data_len,
        const void *buf)
{
#ifdef DEBUG_QUEUES
    queue.log << "data_write(addr=" << addr << " datalen=" << data_len << ")" <<
        logger::endl;
#endif
    dma_data_wb *data_dma = new dma_data_wb(*this, data_len);
    data_dma->write = true;
    data_dma->dma_addr = addr;
    memcpy(data_dma->data, buf, data_len);

    runner->issue_dma(*data_dma);
}

void queue_base::desc_ctx::data_written(uint64_t addr, size_t len)
{
#ifdef DEBUG_QUEUES
    queue.log << "data_written(addr=" << addr << " datalen=" << len << ")" <<
        logger::endl;
#endif
    processed();
}

queue_base::dma_fetch::dma_fetch(queue_base &queue_, size_t len_)
    : queue(queue_)
{
    data = new char[len_];
    len = len_;
}

queue_base::dma_fetch::~dma_fetch()
{
    delete[] ((char *) data);
}

void queue_base::dma_fetch::done()
{
    uint8_t *buf = reinterpret_cast <uint8_t *> (data);
    for (uint32_t i = 0; i < len / queue.desc_len; i++) {
        desc_ctx &ctx = *queue.desc_ctxs[(pos + i) % queue.MAX_ACTIVE_DESCS];
        memcpy(ctx.desc, buf + queue.desc_len * i, queue.desc_len);

#ifdef DEBUG_QUEUES
        queue.log << "preparing desc " << ctx.index << logger::endl;
#endif
        ctx.state = desc_ctx::DESC_PREPARING;
        ctx.prepare();
    }
    queue.trigger();
    delete this;
}

queue_base::dma_data_fetch::dma_data_fetch(desc_ctx &ctx_, size_t len_,
        void *buffer)
    : ctx(ctx_)
{
    data = buffer;
    len = len_;
}

queue_base::dma_data_fetch::~dma_data_fetch()
{
}

void queue_base::dma_data_fetch::done()
{
    part_offset += len;
    dma_addr += len;
    data = (uint8_t *) data + len;

    if (part_offset < total_len) {
#ifdef DEBUG_QUEUES
        ctx.queue.log << "  dma_fetch: next part of multi part dma" << logger::endl;
#endif
        len = std::min(total_len - part_offset, MAX_DMA_SIZE);
        runner->issue_dma(*this);
        return;
    }
    ctx.data_fetched(dma_addr - part_offset, total_len);
    ctx.queue.trigger();
    delete this;
}

queue_base::dma_wb::dma_wb(queue_base &queue_, size_t len_)
    : queue(queue_)
{
    data = new char[len_];
    len = len_;
}

queue_base::dma_wb::~dma_wb()
{
    delete[] ((char *) data);
}

void queue_base::dma_wb::done()
{
    queue.writeback_done(pos, len / queue.desc_len);
    queue.trigger();
    delete this;
}


queue_base::dma_data_wb::dma_data_wb(desc_ctx &ctx_, size_t len_)
    : ctx(ctx_)
{
    data = new char[len_];
    len = len_;
}

queue_base::dma_data_wb::~dma_data_wb()
{
    delete[] ((char *) data);
}

void queue_base::dma_data_wb::done()
{
    ctx.data_written(dma_addr, len);
    ctx.queue.trigger();
    delete this;
}