/* -*- c++ -*- */
/*
 * Copyright 2015 Free Software Foundation, Inc.
 *
 * This file is part of GNU Radio
 *
 * SPDX-License-Identifier: GPL-3.0-or-later
 *
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "flat_flowgraph.h"
#include <gnuradio/block_detail.h>
#include <gnuradio/buffer.h>
#include <gnuradio/logger.h>
#include <gnuradio/prefs.h>
#include <volk/volk.h>
#include <boost/format.hpp>
#include <iostream>
#include <map>

namespace gr {

// 32Kbyte buffer size between blocks
#define GR_FIXED_BUFFER_SIZE (32 * (1L << 10))

static const unsigned int s_fixed_buffer_size =
    prefs::singleton()->get_long("DEFAULT", "buffer_size", GR_FIXED_BUFFER_SIZE);

flat_flowgraph_sptr make_flat_flowgraph()
{
    return flat_flowgraph_sptr(new flat_flowgraph());
}

flat_flowgraph::flat_flowgraph()
{
    configure_default_loggers(d_logger, d_debug_logger, "flat_flowgraph");
}

flat_flowgraph::~flat_flowgraph() {}

void flat_flowgraph::setup_connections()
{
    basic_block_vector_t blocks = calc_used_blocks();

    // Assign block details to blocks
    for (basic_block_viter_t p = blocks.begin(); p != blocks.end(); p++)
        cast_to_block_sptr(*p)->set_detail(allocate_block_detail(*p));

    // Connect inputs to outputs for each block
    for (basic_block_viter_t p = blocks.begin(); p != blocks.end(); p++) {
        connect_block_inputs(*p);

        block_sptr block = cast_to_block_sptr(*p);
        block->set_unaligned(0);
        block->set_is_unaligned(false);
    }

    // Connect message ports connetions
    for (msg_edge_viter_t i = d_msg_edges.begin(); i != d_msg_edges.end(); i++) {
        GR_LOG_DEBUG(
            d_debug_logger,
            boost::format("flat_fg connecting msg primitives: (%s, %s)->(%s, %s)\n") %
                i->src().block() % i->src().port() % i->dst().block() % i->dst().port());
        i->src().block()->message_port_sub(
            i->src().port(), pmt::cons(i->dst().block()->alias_pmt(), i->dst().port()));
    }
}

block_detail_sptr flat_flowgraph::allocate_block_detail(basic_block_sptr block)
{
    int ninputs = calc_used_ports(block, true).size();
    int noutputs = calc_used_ports(block, false).size();
    block_detail_sptr detail = make_block_detail(ninputs, noutputs);

    block_sptr grblock = cast_to_block_sptr(block);
    if (!grblock)
        throw std::runtime_error(
            (boost::format("allocate_block_detail found non-gr::block (%s)") %
             block->alias())
                .str());

    GR_LOG_DEBUG(d_debug_logger, "Creating block detail for " + block->identifier());

    for (int i = 0; i < noutputs; i++) {
        grblock->expand_minmax_buffer(i);

        buffer_sptr buffer = allocate_buffer(block, i);
        GR_LOG_DEBUG(d_debug_logger,
                     "Allocated buffer for output " + block->identifier() + " " +
                         std::to_string(i));
        detail->set_output(i, buffer);

        // Update the block's max_output_buffer based on what was actually allocated.
        if ((grblock->max_output_buffer(i) != buffer->bufsize()) &&
            (grblock->max_output_buffer(i) != -1))
            GR_LOG_WARN(d_logger,
                        boost::format("Block (%1%) max output buffer set to %2%"
                                      " instead of requested %3%") %
                            grblock->alias() % buffer->bufsize() %
                            grblock->max_output_buffer(i));
        grblock->set_max_output_buffer(i, buffer->bufsize());
    }

    return detail;
}

buffer_sptr flat_flowgraph::allocate_buffer(basic_block_sptr block, int port)
{
    block_sptr grblock = cast_to_block_sptr(block);
    if (!grblock)
        throw std::runtime_error("allocate_buffer found non-gr::block");
    int item_size = block->output_signature()->sizeof_stream_item(port);

    // *2 because we're now only filling them 1/2 way in order to
    // increase the available parallelism when using the TPB scheduler.
    // (We're double buffering, where we used to single buffer)
    int nitems = s_fixed_buffer_size * 2 / item_size;

    // Make sure there are at least twice the output_multiple no. of items
    if (nitems < 2 * grblock->output_multiple()) // Note: this means output_multiple()
        nitems = 2 * grblock->output_multiple(); // can't be changed by block dynamically

    // If any downstream blocks are decimators and/or have a large output_multiple,
    // ensure we have a buffer at least twice their decimation factor*output_multiple
    basic_block_vector_t blocks = calc_downstream_blocks(block, port);

    // limit buffer size if indicated
    if (grblock->max_output_buffer(port) > 0) {
        // std::cout << "constraining output items to " << block->max_output_buffer(port)
        // << "\n";
        nitems = std::min((long)nitems, (long)grblock->max_output_buffer(port));
        nitems -= nitems % grblock->output_multiple();
        if (nitems < 1)
            throw std::runtime_error("problems allocating a buffer with the given max "
                                     "output buffer constraint!");
    } else if (grblock->min_output_buffer(port) > 0) {
        nitems = std::max((long)nitems, (long)grblock->min_output_buffer(port));
        nitems -= nitems % grblock->output_multiple();
        if (nitems < 1)
            throw std::runtime_error("problems allocating a buffer with the given min "
                                     "output buffer constraint!");
    }

    for (basic_block_viter_t p = blocks.begin(); p != blocks.end(); p++) {
        block_sptr dgrblock = cast_to_block_sptr(*p);
        if (!dgrblock)
            throw std::runtime_error("allocate_buffer found non-gr::block");

        double decimation = (1.0 / dgrblock->relative_rate());
        int multiple = dgrblock->output_multiple();
        int history = dgrblock->history();
        nitems =
            std::max(nitems, static_cast<int>(2 * (decimation * multiple + history)));
    }

    //  std::cout << "make_buffer(" << nitems << ", " << item_size << ", " << grblock <<
    //  "\n";
    // We're going to let this fail once and retry. If that fails,
    // throw and exit.
    buffer_sptr b;
    try {
        b = make_buffer(nitems, item_size, grblock);
    } catch (std::bad_alloc&) {
        b = make_buffer(nitems, item_size, grblock);
    }

    // Set the max noutput items size here to make sure it's always
    // set in the block and available in the start() method.
    // But don't overwrite if the user has set this externally.
    if (!grblock->is_set_max_noutput_items())
        grblock->set_max_noutput_items(nitems);

    return b;
}

void flat_flowgraph::connect_block_inputs(basic_block_sptr block)
{
    block_sptr grblock = cast_to_block_sptr(block);
    if (!grblock)
        throw std::runtime_error("connect_block_inputs found non-gr::block");

    // Get its detail and edges that feed into it
    block_detail_sptr detail = grblock->detail();
    edge_vector_t in_edges = calc_upstream_edges(block);

    // For each edge that feeds into it
    for (edge_viter_t e = in_edges.begin(); e != in_edges.end(); e++) {
        // Set the buffer reader on the destination port to the output
        // buffer on the source port
        int dst_port = e->dst().port();
        int src_port = e->src().port();
        basic_block_sptr src_block = e->src().block();
        block_sptr src_grblock = cast_to_block_sptr(src_block);
        if (!src_grblock)
            throw std::runtime_error("connect_block_inputs found non-gr::block");
        buffer_sptr src_buffer = src_grblock->detail()->output(src_port);


        GR_LOG_DEBUG(d_debug_logger,
                     "Setting input " + std::to_string(dst_port) + " from edge " +
                         (*e).identifier());

        detail->set_input(dst_port,
                          buffer_add_reader(src_buffer,
                                            grblock->history() - 1,
                                            grblock,
                                            grblock->sample_delay(src_port)));
    }
}

void flat_flowgraph::merge_connections(flat_flowgraph_sptr old_ffg)
{
    // Allocate block details if needed.  Only new blocks that aren't pruned out
    // by flattening will need one; existing blocks still in the new flowgraph will
    // already have one.
    for (basic_block_viter_t p = d_blocks.begin(); p != d_blocks.end(); p++) {
        block_sptr block = cast_to_block_sptr(*p);

        if (!block->detail()) {
            GR_LOG_DEBUG(d_debug_logger,
                         "merge: allocating new detail for block " + block->identifier());
            block->set_detail(allocate_block_detail(block));
        } else {
            GR_LOG_DEBUG(d_debug_logger,
                         "merge: reusing original detail for block " +
                             block->identifier());
        }
    }

    // Calculate the old edges that will be going away, and clear the
    // buffer readers on the RHS.
    for (edge_viter_t old_edge = old_ffg->d_edges.begin();
         old_edge != old_ffg->d_edges.end();
         old_edge++) {
        GR_LOG_DEBUG(d_debug_logger,
                     "merge: testing old edge " + old_edge->identifier() + "...");

        edge_viter_t new_edge;
        for (new_edge = d_edges.begin(); new_edge != d_edges.end(); new_edge++)
            if (new_edge->src() == old_edge->src() && new_edge->dst() == old_edge->dst())
                break;

        if (new_edge == d_edges.end()) { // not found in new edge list
            GR_LOG_DEBUG(d_debug_logger, "not in new edge list");
            // zero the buffer reader on RHS of old edge
            block_sptr block(cast_to_block_sptr(old_edge->dst().block()));
            int port = old_edge->dst().port();
            block->detail()->set_input(port, buffer_reader_sptr());
        } else {
            GR_LOG_DEBUG(d_debug_logger, "found in new edge list");
        }
    }

    // Now connect inputs to outputs, reusing old buffer readers if they exist
    for (basic_block_viter_t p = d_blocks.begin(); p != d_blocks.end(); p++) {
        block_sptr block = cast_to_block_sptr(*p);

        GR_LOG_DEBUG(d_debug_logger, "merge: merging " + block->identifier() + "...");

        if (old_ffg->has_block_p(*p)) {
            // Block exists in old flow graph
            GR_LOG_DEBUG(d_debug_logger, "used in old flow graph")
            block_detail_sptr detail = block->detail();

            // Iterate through the inputs and see what needs to be done
            int ninputs = calc_used_ports(block, true).size(); // Might be different now
            for (int i = 0; i < ninputs; i++) {
                GR_LOG_DEBUG(d_debug_logger,
                             "Checking input " + block->identifier() + ":" +
                                 std::to_string(i) + "...");
                edge edge = calc_upstream_edge(*p, i);

                // Fish out old buffer reader and see if it matches correct buffer from
                // edge list
                block_sptr src_block = cast_to_block_sptr(edge.src().block());
                block_detail_sptr src_detail = src_block->detail();
                buffer_sptr src_buffer = src_detail->output(edge.src().port());
                buffer_reader_sptr old_reader;
                if (i < detail->ninputs()) // Don't exceed what the original detail has
                    old_reader = detail->input(i);

                // If there's a match, use it
                if (old_reader && (src_buffer == old_reader->buffer())) {
                    GR_LOG_DEBUG(d_debug_logger, "matched, reusing");
                } else {
                    GR_LOG_DEBUG(d_debug_logger, "needs a new reader");

                    // Create new buffer reader and assign
                    detail->set_input(
                        i, buffer_add_reader(src_buffer, block->history() - 1, block));
                }
            }
        } else {
            // Block is new, it just needs buffer readers at this point
            GR_LOG_DEBUG(d_debug_logger, "new block");
            connect_block_inputs(block);

            // Make sure all buffers are aligned
            setup_buffer_alignment(block);
        }

        // Connect message ports connetions
        for (msg_edge_viter_t i = d_msg_edges.begin(); i != d_msg_edges.end(); i++) {
            GR_LOG_DEBUG(
                d_debug_logger,
                boost::format("flat_fg connecting msg primitives: (%s, %s)->(%s, %s)\n") %
                    i->src().block() % i->src().port() % i->dst().block() %
                    i->dst().port());
            i->src().block()->message_port_sub(
                i->src().port(),
                pmt::cons(i->dst().block()->alias_pmt(), i->dst().port()));
        }

        // Now deal with the fact that the block details might have
        // changed numbers of inputs and outputs vs. in the old
        // flowgraph.

        block->detail()->reset_nitem_counters();
        block->detail()->clear_tags();
    }
}

void flat_flowgraph::setup_buffer_alignment(block_sptr block)
{
    const int alignment = volk_get_alignment();
    for (int i = 0; i < block->detail()->ninputs(); i++) {
        void* r = (void*)block->detail()->input(i)->read_pointer();
        uintptr_t ri = (uintptr_t)r % alignment;
        // std::cerr << "reader: " << r << "  alignment: " << ri << std::endl;
        if (ri != 0) {
            size_t itemsize = block->detail()->input(i)->get_sizeof_item();
            block->detail()->input(i)->update_read_pointer((alignment - ri) / itemsize);
        }
        block->set_unaligned(0);
        block->set_is_unaligned(false);
    }

    for (int i = 0; i < block->detail()->noutputs(); i++) {
        void* w = (void*)block->detail()->output(i)->write_pointer();
        uintptr_t wi = (uintptr_t)w % alignment;
        // std::cerr << "writer: " << w << "  alignment: " << wi << std::endl;
        if (wi != 0) {
            size_t itemsize = block->detail()->output(i)->get_sizeof_item();
            block->detail()->output(i)->update_write_pointer((alignment - wi) / itemsize);
        }
        block->set_unaligned(0);
        block->set_is_unaligned(false);
    }
}

std::string flat_flowgraph::edge_list()
{
    std::stringstream s;
    for (edge_viter_t e = d_edges.begin(); e != d_edges.end(); e++)
        s << (*e) << std::endl;
    return s.str();
}

std::string flat_flowgraph::msg_edge_list()
{
    std::stringstream s;
    for (msg_edge_viter_t e = d_msg_edges.begin(); e != d_msg_edges.end(); e++)
        s << (*e) << std::endl;
    return s.str();
}

void flat_flowgraph::dump()
{
    for (edge_viter_t e = d_edges.begin(); e != d_edges.end(); e++)
        std::cout << " edge: " << (*e) << std::endl;

    for (basic_block_viter_t p = d_blocks.begin(); p != d_blocks.end(); p++) {
        std::cout << " block: " << (*p) << std::endl;
        block_detail_sptr detail = cast_to_block_sptr(*p)->detail();
        std::cout << "  detail @" << detail << ":" << std::endl;

        int ni = detail->ninputs();
        int no = detail->noutputs();
        for (int i = 0; i < no; i++) {
            buffer_sptr buffer = detail->output(i);
            std::cout << "   output " << i << ": " << buffer << std::endl;
        }

        for (int i = 0; i < ni; i++) {
            buffer_reader_sptr reader = detail->input(i);
            std::cout << "   reader " << i << ": " << reader
                      << " reading from buffer=" << reader->buffer() << std::endl;
        }
    }
}

block_vector_t flat_flowgraph::make_block_vector(basic_block_vector_t& blocks)
{
    block_vector_t result;
    for (basic_block_viter_t p = blocks.begin(); p != blocks.end(); p++) {
        result.push_back(cast_to_block_sptr(*p));
    }

    return result;
}

void flat_flowgraph::clear_endpoint(const msg_endpoint& e, bool is_src)
{
    for (size_t i = 0; i < d_msg_edges.size(); i++) {
        if (is_src) {
            if (d_msg_edges[i].src() == e) {
                d_msg_edges.erase(d_msg_edges.begin() + i);
                i--;
            }
        } else {
            if (d_msg_edges[i].dst() == e) {
                d_msg_edges.erase(d_msg_edges.begin() + i);
                i--;
            }
        }
    }
}

void flat_flowgraph::clear_hier()
{
    GR_LOG_DEBUG(d_debug_logger, "Clear_hier()");
    for (size_t i = 0; i < d_msg_edges.size(); i++) {
        GR_LOG_DEBUG(d_debug_logger,
                     "edge: " + d_msg_edges[i].src().identifier() + "-->" +
                         d_msg_edges[i].dst().identifier());
        if (d_msg_edges[i].src().is_hier() || d_msg_edges[i].dst().is_hier()) {
            GR_LOG_DEBUG(d_debug_logger, "is hier");
            d_msg_edges.erase(d_msg_edges.begin() + i);
            i--;
        }
    }
}

void flat_flowgraph::replace_endpoint(const msg_endpoint& e,
                                      const msg_endpoint& r,
                                      bool is_src)
{
    size_t n_replr(0);
    GR_LOG_DEBUG(d_debug_logger,
                 boost::format("flat_flowgraph::replace_endpoint( %s, %s, %d )\n") %
                     e.block() % r.block() % is_src);
    for (size_t i = 0; i < d_msg_edges.size(); i++) {
        if (is_src) {
            if (d_msg_edges[i].src() == e) {
                GR_LOG_DEBUG(
                    d_debug_logger,
                    boost::format(
                        "flat_flowgraph::replace_endpoint() flattening to ( %s, %s )\n") %
                        r % d_msg_edges[i].dst())
                d_msg_edges.push_back(msg_edge(r, d_msg_edges[i].dst()));
                n_replr++;
            }
        } else {
            if (d_msg_edges[i].dst() == e) {
                GR_LOG_DEBUG(
                    d_debug_logger,
                    boost::format(
                        "flat_flowgraph::replace_endpoint() flattening to ( %s, %s )\n") %
                        r % d_msg_edges[i].src());
                d_msg_edges.push_back(msg_edge(d_msg_edges[i].src(), r));
                n_replr++;
            }
        }
    }
}

void flat_flowgraph::enable_pc_rpc()
{
#ifdef GR_PERFORMANCE_COUNTERS
    if (prefs::singleton()->get_bool("PerfCounters", "on", false)) {
        basic_block_viter_t p;
        for (p = d_blocks.begin(); p != d_blocks.end(); p++) {
            block_sptr block = cast_to_block_sptr(*p);
            if (!block->is_pc_rpc_set())
                block->setup_pc_rpc();
        }
    }
#endif /* GR_PERFORMANCE_COUNTERS */
}

} /* namespace gr */
