#include <string>
#include <mutex>
#include <regex>
#include <functional>
#include <algorithm>
#include <sstream>
#include <memory>
#include "triton/codegen/analysis/axes.h"
#include "triton/codegen/analysis/allocation.h"
#include "triton/codegen/analysis/liveness.h"
#include "triton/codegen/analysis/align.h"
#include "triton/codegen/analysis/swizzle.h"
#include "triton/codegen/transform/coalesce.h"
#include "triton/codegen/transform/dce.h"
#include "triton/codegen/transform/peephole.h"
#include "triton/codegen/transform/membar.h"
#include "triton/codegen/transform/reassociate.h"
#include "triton/codegen/transform/reorder.h"
#include "triton/codegen/transform/cts.h"
#include "triton/codegen/transform/disassociate.h"
#include "triton/codegen/selection/generator.h"
#include "triton/runtime/function.h"
#include "triton/lang/cpp.h"
#include "triton/lang/parser.h"
#include "triton/lang/code_gen.h"
#include "triton/driver/device.h"
#include "triton/driver/stream.h"
#include "triton/driver/kernel.h"
#include "triton/driver/module.h"
#include "triton/driver/error.h"
#include "triton/ir/module.h"
#include "triton/ir/function.h"
#include "triton/ir/print.h"
#include "triton/runtime/error.h"
#include "triton/tools/bench.hpp"
#include "triton/tools/sha1.hpp"
#include "triton/tools/sys/getenv.hpp"
#include "triton/tools/sys/mkdir.hpp"
#include "llvm/IR/Module.h"
#include <mutex>
#include <fstream>

std::mutex mut;

namespace triton{
namespace runtime {

/* --------------------- */
/*    HELPERS            */
/* --------------------- */

void _loop_nest(std::vector<size_t> const & ranges,
                       std::function<void(std::vector<size_t> const &)> const & f){
  size_t D = ranges.size();
  std::vector<size_t> values(D, 0);
  size_t i = D - 1;
  while(true){
    f(values);
    while(values[i]++ == ranges[i] - 1){
      if(i == 0)
        return;
      values[i--] = 0;
    }
    i = D - 1;
  }
}


/* --------------------- */
/*    OPTIONS            */
/* --------------------- */

std::string options_t::to_str() const{
  std::string ret = "nw-" + std::to_string(num_warps);
  for(const auto& x : defines){
    ret += '-';
    ret += x.first;
    ret += '-';
    ret += x.second;
  }
  // legalize
  for(char& x: ret){
    if(x == ' ' || x == '^' || x == ',' || x == ':')
      x = '_';
  }
  return ret;
}


/* --------------------- */
/*     CALLER OBJECT     */
/* --------------------- */

arg_type convert(ir::type *ty) {
  if(ty->is_integer_ty(1))
    return INT1_T;
  if(ty->is_integer_ty(8))
    return INT8_T;
  if(ty->is_integer_ty(16))
    return INT16_T;
  if(ty->is_integer_ty(32))
    return INT32_T;
  if(ty->is_integer_ty(64))
    return INT64_T;
  if(ty->is_half_ty())
    return HALF_T;
  if(ty->is_float_ty())
    return FLOAT_T;
  if(ty->is_double_ty())
    return DOUBLE_T;
  if(ty->is_pointer_ty())
    return BUFFER_T;
  throw std::runtime_error("unknown type");
}

//void function::caller::write(std::ofstream &ofs) {
//  // write name
//  ofs << name_ << std::endl;
//  // write signature
//  for(size_t i = 0; i < param_tys_.size(); i++)
//    ofs << param_tys_[i] << " ";
//  ofs << std::endl;
//  // write module
//  std::string source = ((driver::cu_module*)(&*parent_))->ptx();
//  ofs << source;
//}

//void function::caller::read(driver::context* ctx, std::ifstream &ifs) {
//  // read name
//  std::getline(ifs, name_);
//  // read signature
//  std::string line;
//  std::getline(ifs, line);
//  std::istringstream current(line);
//  int param;
//  param_tys_.clear();
//  while(current >> param)
//    param_tys_.push_back((arg_type)param);
//  // read module
//  std::string src((std::istreambuf_iterator<char>(ifs)),
//                   std::istreambuf_iterator<char>());
//  parent_.reset(new driver::cu_module(ctx, src));
//  bin_.reset(driver::kernel::create(&*parent_, name_.c_str()));

//}

//function::caller::caller(driver::context* ctx, std::ifstream &ifs, const options_t& opt)
//  : opt_(opt) {
//  read(ctx, ifs);
//}

function::caller::caller(ir::function *ir,
                         std::shared_ptr<driver::module> parent, const options_t& opt)
  : parent_(parent), opt_(opt), name_(ir->get_name()) {
  bin_.reset(driver::kernel::create(&*parent, name_.c_str()));
  // extract signature
  ir::function_type* ty = ir->get_fn_type();
  for(size_t i = 0; i < ty->get_num_params(); i++){
    param_tys_.push_back(convert(ty->get_param_ty(i)));
    if(!ir->has_attr(i+1))
      continue;
    for(ir::attribute attr: ir->attrs().at(i + 1))
      if(attr.get_kind() == ir::retune)
        retune_.push_back(i);
  }
}


void function::caller::operator ()(driver::stream *stream, const grid_t& _grid, void** args, size_t args_size, const std::map<std::string, std::vector<char>>& csts) const {
  // copy constants
  for(const auto& cst: csts){
    std::unique_ptr<driver::buffer> buffer = parent()->symbol(cst.first.c_str());
    stream->write(&*buffer, true, 0, cst.second);
  }
  // set grid
  if(_grid.size() > 3)
    throw std::runtime_error("grid size must be no greater than 3");
  std::array<size_t, 3> grid;
  for(size_t i = 0; i < 3; i++)
    grid[i] = (i < _grid.size()) ? _grid[i] : 1;
  // enqueue
  stream->enqueue(&*bin_, grid, {opt_.num_warps * 32, 1, 1}, args, args_size);
}


/* --------------------- */
/*    FUNCTION           */
/* --------------------- */

// create Triton-IR from AST
std::unique_ptr<ir::module> function::make_ir(Parser& parser) {
  ir::module* module = new ir::module("", ctx_);
  Generator gen(&parser);
  gen.Gen(module);
  return std::unique_ptr<ir::module>(module);
}

// create Binary from Triton-IR
std::unique_ptr<driver::module> function::make_bin(ir::module &module, driver::device* device, const options_t& opt) {
  std::unique_ptr<codegen::target> target = device->make_target();
  // generate llvm code
  llvm::LLVMContext ctx;
  std::unique_ptr<llvm::Module> llvm(new llvm::Module(module.get_name(), ctx));
  // optimizations
  bool cts_use_async = target->as_nvidia()->sm() >= 80;
  // create passes
  codegen::analysis::align align;
  codegen::analysis::axes axes;
  codegen::transform::cts cts(cts_use_async);
  codegen::transform::disassociate disassociate;
  codegen::analysis::layouts layouts(&axes, &align, opt.num_warps, target.get());
  codegen::analysis::liveness liveness(&layouts);
  codegen::analysis::swizzle swizzle(&layouts, target.get());
  codegen::analysis::allocation allocation(&liveness);
  codegen::transform::membar barriers(&liveness, &layouts, &allocation);
  codegen::transform::dce dce;
  codegen::transform::peephole peephole(target.get());
  codegen::transform::reassociate reassociate;
  codegen::transform::coalesce coalesce(&align, &layouts);
  codegen::generator isel(&axes, &layouts, &align, &allocation, &swizzle, target.get(), opt.num_warps);
  // run passes
  dce.run(module);
  disassociate.run(module);
  dce.run(module);
  peephole.run(module);
  dce.run(module);
  align.run(module);
  if(target->is_gpu())
    cts.run(module);
  axes.run(module);
  layouts.run(module);
  coalesce.run(module);
  dce.run(module);
  align.run(module);
  dce.run(module);
  if(target->is_gpu()){
    reassociate.run(module);
    cts.run(module);
  }
  peephole.run(module);
  dce.run(module);
  align.run(module);
  axes.run(module);
  layouts.run(module);
  swizzle.run(module);
  liveness.run(module);
  allocation.run(module);
  if(allocation.allocated_size() > device->max_shared_memory())
    throw exception::out_of_shared_memory();
  barriers.run(module);
//  ir::print(module, std::cout);
  isel.visit(module, *llvm);
  std::unique_ptr<driver::module> res(driver::module::create(device, std::move(llvm)));
  if(res->spilled() > 256)
    throw exception::out_of_registers();
  return res;
}


// create Binary from options
void function::make(driver::device *device, options_t opt) {
  if(callers_.find(opt) != callers_.end())
    return;
  // pre-process
  TokenSequence tokens;
  Preprocessor cpp(&src_, true);
  for(auto it: opt.defines)
    cpp.AddMacro(it.first, &it.second);
  cpp.Process(tokens);
  // src -> ast
  Parser parser(tokens);
  parser.Parse();
  // ast -> triton-ir
  auto ir = make_ir(parser);
  // triton-ir -> binary
  std::unique_ptr<driver::module> bin;
  try{
    bin = make_bin(*ir, device, opt);
  }catch(const exception::base&){
    throw;
  }
  // create callable
  ir::function *tmp = ir->get_function_list()[0];
  callers_[opt].reset(new caller(tmp, std::move(bin), opt));
}

// precompile all kernels spanned by given options space
void function::precompile(driver::device* device, const options_space_t& space) {
  // all ranges
  std::vector<size_t> ranges;
  ranges.push_back(space.num_warps.size());
  for(const auto& x: space.defines)
    ranges.push_back(x.second.size());
  // functor for source with given option
  std::map<options_t, std::string> err;
  auto do_make = [&](std::vector<size_t> params) {
    // compilation options
    unsigned i = 0;
    options_t opt;
    opt.num_warps = space.num_warps[params[i++]];
    for(auto D: space.defines)
      opt.defines[D.first] = D.second[params[i++]];
    // compile
    try{
      make(device, opt);
    }catch(const exception::base& e){
      err[opt] = e.what();
    }
  };
  // multi-threaded compilation
  _loop_nest(ranges, do_make);
  if(callers_.empty()){
    std::ostringstream dbg;
    dbg << "Auto-Tuner could not find any valid configuration:" << std::endl;
    for(auto x: err){
      dbg << "[ ";
      dbg << x.first.num_warps << ", ";
      dbg << "{ ";
      for(const auto& y: x.first.defines)
        dbg << '"' << y.first << "\"= \"" << y.second << "\", ";
      dbg << " } ] -> " << x.second << std::endl;
    }
    throw exception::no_valid_configuration(dbg.str());
  }
}

std::string function::get_asm(asm_mode_t mode, driver::device* device, const options_t& opt) {
  make(device, opt);
  const auto& fn = callers_.at(opt);
  if(!fn)
    return "";
  switch(mode){
    case ASM_LLIR:{
      return  fn->parent()->llir();
    }
    case ASM_NV_PTX:
    case ASM_NV_SASS:{
      std::string ptx = ((driver::cu_module*)fn->parent())->ptx();
      // SASS
      std::string input = std::tmpnam(nullptr);
      std::string output = std::tmpnam(nullptr);
      std::ofstream ofs(input);
      ofs << ptx;
      ofs.close();
      if(mode == ASM_NV_PTX)
        return ptx;
      std::string cmd;
      int err;
      // compile ptx
      driver::cu_device* cu_device = (driver::cu_device*)device;
      cmd = "ptxas --gpu-name=sm_" + std::to_string(cu_device->compute_capability()) + " " + input + " -o " + input + ".o";
      err = system(cmd.c_str());
      // disassemble
      cmd = "cuobjdump --dump-sass " + input + ".o >> " + output;
      err = system(cmd.c_str());
      std::regex comment(" *\\/\\* 0x[0-9a-f]+ \\*\\/");
      std::string to_delete = "                                                                                           /*";
      std::ifstream ifs(output);
      std::string line;
      std::string sass;
      while(std::getline(ifs, line))
        if(!std::regex_match(line, comment))
          sass += line + "\n";
      return sass;
    }
    default:
      return "";
  }


}

// returns program with best compilation options for given parameter
function::caller* function::autotune(driver::stream* stream, const grid_fn_ty& grid_fn,
                                     void** args, size_t args_size) {
  // fast path -- no autotuning necessary
  if(callers_.size() == 1)
    return &*callers_.begin()->second;
  // run auto-tuner
  double best_ts = INFINITY;
  caller* ret = nullptr;
  for(auto &x : callers_){
    if(x.second == nullptr)
      throw std::runtime_error("configuration not compiled");
    caller* current = &*x.second;
    double ts = tools::bench([&]() { (*current)(stream, grid_fn(x.first), args, args_size, cst_); },
                                     stream, true);
    ret = (ts < best_ts) ? current : ret;
    best_ts = std::min(ts, best_ts);
  }
  stream->synchronize();
  return ret;
}

// set copy host buffer "data" into constant memory buffer "name"
void function::set_cst(const char* name, void* data, size_t n_bytes) {
   cst_[std::string(name)] = std::vector<char>((char*)data, (char*)data + n_bytes);
}


std::string function::preheader() {
  return  R"(
#define bool _Bool
#define true 1
#define false 0

#define __readonly      __attribute__((readonly))
#define __writeonly     __attribute__((writeonly))
#define __noalias       __attribute__((noalias))
#define __aligned(A)    __attribute__((aligned(A)))
#define __multipleof(A) __attribute__((multipleof(A)))
#define __retune        __attribute__((retune))

#define F32_INFINITY bitcast<float>(0x7F800000)
#define F16_INFINITY bitcast<half>((int16)0x7C00)

#define min(a,b) (((a)<(b))?(a):(b))
#define max(a,b) (((a)>(b))?(a):(b))

#define PASTER(a, b, _) a ## _ ## b
#define EVALUATOR(a, b, _)  PASTER(a, b, _)
#define atomic_add(TYPE, TM, TN) EVALUATOR(atomic_add, EVALUATOR(TYPE, EVALUATOR(TM, TN, x), _), _)
#define DECLARATION(TYPE, TM, TN) extern void atomic_add(TYPE, TM, TN)(TYPE*[TM, TN], TYPE[TM, TN], bool[TM, TN])

DECLARATION(float, 64, 64);
DECLARATION(float, 64, 128);
DECLARATION(float, 128, 64);
DECLARATION(float, 128, 128);
extern void atomic_add_half_1x1(half*, half, bool);

DECLARATION(half , 64, 64);
DECLARATION(half , 64, 128);
DECLARATION(half , 128, 64);
DECLARATION(half , 128, 128);
extern void atomic_add_float_1x1(float*, float, bool);

extern int atomic_cas(int*, int, int);
extern int atomic_xchg(int*, int);
extern int get_program_id(int);
extern int get_num_programs(int);
extern int select(bool, int, int);
extern char __constant__ * calloc(int);

typedef unsigned char uint8;
typedef unsigned short uint16;
typedef unsigned int uint32;
typedef unsigned long uint64;
typedef char int8;
typedef short int16;
typedef int int32;
typedef long int64;
)";
}

std::string function::get_cache_prefix() {
  //user-specified cache path
  std::string result = tools::getenv("TRITON_CACHE_PATH");
  if(!result.empty()){
    if(tools::mkpath(result)==0)
      return result;
  }
  //create in home
  result = tools::getenv("HOME");
  if(!result.empty())
  {
    result = result + "/.triton/cache/";
    if(tools::mkpath(result)==0)
      return result;
  }
  return "";
}

function::function(const std::string &src,
                   const options_space_t& opt,
                   const std::string &cache_ref):
    src_(src), opt_(opt), cache_ref_(cache_ref) {
  // hash source code
  unsigned char hash[20];
  sha1::calc((void*)src_.data(), src_.size(), hash);
  // create cache path
  char _hex[40];
  sha1::toHexString(hash, _hex);
  std::string hex(_hex, _hex + 40);
  cache_path_ = get_cache_prefix() + hex + "/";
  tools::mkpath(cache_path_);
  // append pre-header to source
  src_ = preheader() + src_;
}

void function::operator()(void** args, size_t args_size, const grid_fn_ty& grid_fn, driver::stream *stream, driver::device *device) {
  // pre-compile kernels
  if(callers_.empty()){
    precompile(device, opt_);
  }
  // re-tuning key
  cache_key_t key;
  key.first = device;
  key.second = callers_.begin()->second->retune();
  // auto-tune if necessary
  auto it = cache_.find(key);
  if(it == cache_.end()){
    auto best = autotune(stream, grid_fn, args, args_size);
    it = cache_.insert({key, best}).first;
  }
  // run
  (*it->second)(stream, grid_fn(it->second->opt()), args, args_size, cst_);
}

void function::operator()(void** args,
                          size_t args_size,
                          const grid_t& grid,
                          driver::stream* stream, driver::device *device) {
  return this->operator()(args, args_size, [&grid](const options_t&){ return grid; }, stream, device);
}



}
}