/*
 *  nextpnr -- Next Generation Place and Route
 *
 *  Copyright (C) 2021-22  gatecat <gatecat@ds0.me>
 *
 *  Permission to use, copy, modify, and/or distribute this software for any
 *  purpose with or without fee is hereby granted, provided that the above
 *  copyright notice and this permission notice appear in all copies.
 *
 *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 */

#include "fasm.h"
#include "log.h"
#include "nextpnr.h"
#include "util.h"

#include <algorithm>
#include <boost/range/adaptor/reversed.hpp>
#include <fstream>

#define VIADUCT_CONSTIDS "viaduct/fabulous/constids.inc"
#include "viaduct_constids.h"

NEXTPNR_NAMESPACE_BEGIN

namespace {
struct FabFasmWriter
{
    FabFasmWriter(const Context *ctx, const FabricConfig &cfg, const std::string &filename)
            : ctx(ctx), cfg(cfg), out(filename)
    {
        if (!out)
            log_error("failed to open fasm file '%s' for writing\n", filename.c_str());
    }
    std::string format_name(IdStringList name)
    {
        std::string result;
        for (IdString entry : name) {
            if (!result.empty())
                result += ".";
            result += entry.str(ctx);
        }
        return result;
    }
    void write_pip(PipId pip)
    {
        auto &data = ctx->pip_info(pip);
        if (data.type.in(id_global_clock, id_O2Q))
            return; // pseudo-pips with no underlying bitstream bits
        // write pip name but with '.' instead of '/' for separator
        out << format_name(data.name) << std::endl;
    }
    void write_routing(const NetInfo *net)
    {
        std::vector<PipId> sorted_pips;
        for (auto &w : net->wires)
            if (w.second.pip != PipId())
                sorted_pips.push_back(w.second.pip);
        std::sort(sorted_pips.begin(), sorted_pips.end());
        out << stringf("# routing for net '%s'\n", ctx->nameOf(net)) << std::endl;
        for (auto pip : sorted_pips)
            write_pip(pip);
        out << std::endl;
    }

    std::string prefix;

    // Write a FASM bitvector; optionally inverting the values in the process
    void write_vector(const std::string &name, const std::vector<bool> &value, bool invert = false)
    {
        out << prefix << name << " = " << int(value.size()) << "'b";
        for (auto bit : boost::adaptors::reverse(value))
            out << ((bit ^ invert) ? '1' : '0');
        out << std::endl;
    }
    // Write a FASM bitvector given an integer value
    void write_int_vector(const std::string &name, uint64_t value, int width, bool invert = false)
    {
        std::vector<bool> bits(width, false);
        for (int i = 0; i < width; i++)
            bits[i] = (value & (1ULL << i)) != 0;
        write_vector(name, bits, invert);
    }
    // Write an int vector param
    void write_int_vector_param(const CellInfo *cell, const std::string &name, uint64_t defval, int width,
                                bool invert = false)
    {
        uint64_t value = int_or_default(cell->params, ctx->id(name), defval);
        std::vector<bool> bits(width, false);
        for (int i = 0; i < width; i++)
            bits[i] = (value & (1ULL << i)) != 0;
        write_vector(stringf("%s[%d:0]", name.c_str(), width - 1), bits, invert);
    }

    void write_bool(const CellInfo *cell, const std::string &name)
    {
        if (bool_or_default(cell->params, ctx->id(name))) {
            out << prefix << name << std::endl;
        }
    }

    void write_logic(const CellInfo *lc)
    {
        prefix = format_name(ctx->getBelName(lc->bel)) + ".";
        if (lc->type.in(id_FABULOUS_LC, id_FABULOUS_COMB)) {
            write_int_vector_param(lc, "INIT", 0U, 1U << cfg.clb.lut_k); // todo lut depermute and thru
        }
        if (lc->type == id_FABULOUS_LC) {
            write_bool(lc, "FF");
        }
        if (lc->type.in(id_FABULOUS_LC, id_FABULOUS_FF)) {
            write_bool(lc, "SET_NORESET");
            write_bool(lc, "NEG_CLK");
            write_bool(lc, "NEG_EN");
            write_bool(lc, "NEG_SR");
            write_bool(lc, "ASYNC_SR");
        }
    }

    void write_io(const CellInfo *io)
    {
        write_bool(io, "INPUT_USED");
        write_bool(io, "OUTPUT_USED");
        write_bool(io, "ENABLE_USED");
    }

    void write_generic_cell(const CellInfo *ci)
    {
        prefix = format_name(ctx->getBelName(ci->bel)) + ".";
        for (auto &param : ci->params) {
            // TODO: better parameter type auto-detection
            if (param.second.is_string) {
                // enum type parameter
                out << prefix << param.first.c_str(ctx) << "." << param.second.str << std::endl;
            } else if (param.second.str.size() == 1) {
                // boolean type parameter
                if (param.second.intval != 0)
                    out << prefix << param.first.c_str(ctx) << std::endl;
            } else {
                // vector type parameter
                int msb = int(param.second.str.size()) - 1;
                out << prefix << param.first.c_str(ctx) << "[" << msb << ":0] = ";
                for (auto bit : boost::adaptors::reverse(param.second.str))
                    out << bit;
                out << std::endl;
            }
        }
    }

    void write_cell(const CellInfo *ci)
    {
        out << stringf("# config for cell '%s'\n", ctx->nameOf(ci)) << std::endl;
        if (ci->type.in(id_FABULOUS_COMB, id_FABULOUS_FF, id_FABULOUS_LC))
            write_logic(ci);
        else if (ci->type == id_IO_1_bidirectional_frame_config_pass)
            write_io(ci);
        else
            write_generic_cell(ci);
        // TODO: other cell types
        out << std::endl;
    }

    void write_fasm()
    {
        for (const auto &net : ctx->nets)
            write_routing(net.second.get());
        for (const auto &cell : ctx->cells)
            write_cell(cell.second.get());
    }

    const Context *ctx;
    const FabricConfig &cfg;
    std::ofstream out;
};
} // namespace

void fabulous_write_fasm(const Context *ctx, const FabricConfig &cfg, const std::string &filename)
{
    FabFasmWriter wr(ctx, cfg, filename);
    wr.write_fasm();
}

NEXTPNR_NAMESPACE_END