// vim: set sts=2 ts=8 sw=2 tw=99 et:
// 
// Copyright (C) 2006-2015 AlliedModders LLC
// 
// This file is part of SourcePawn. SourcePawn is free software: you can
// redistribute it and/or modify it under the terms of the GNU General Public
// License as published by the Free Software Foundation, either version 3 of
// the License, or (at your option) any later version.
//
// You should have received a copy of the GNU General Public License along with
// SourcePawn. If not, see http://www.gnu.org/licenses/.
//
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include "plugin-runtime.h"
#include "x86/jit_x86.h"
#include "plugin-context.h"
#include "environment.h"

#include "md5/md5.h"

using namespace sp;
using namespace SourcePawn;

static inline bool
IsPointerCellAligned(void *p)
{
  return uintptr_t(p) % 4 == 0;
}

PluginRuntime::PluginRuntime(LegacyImage *image)
 : image_(image),
   paused_(false),
   computed_code_hash_(false),
   computed_data_hash_(false)
{
  code_ = image_->DescribeCode();
  data_ = image_->DescribeData();
  memset(code_hash_, 0, sizeof(code_hash_));
  memset(data_hash_, 0, sizeof(data_hash_));

  ke::AutoLock lock(Environment::get()->lock());
  Environment::get()->RegisterRuntime(this);
}

PluginRuntime::~PluginRuntime()
{
  // The watchdog thread takes the global JIT lock while it patches all
  // runtimes. It is not enough to ensure that the unlinking of the runtime is
  // protected; we cannot delete functions or code while the watchdog might be
  // executing. Therefore, the entire destructor is guarded.
  ke::AutoLock lock(Environment::get()->lock());

  Environment::get()->DeregisterRuntime(this);

  for (uint32_t i = 0; i < image_->NumPublics(); i++)
    delete entrypoints_[i];

  for (size_t i = 0; i < m_JitFunctions.length(); i++)
    delete m_JitFunctions[i];
}

bool
PluginRuntime::Initialize()
{
  if (!ke::IsAligned(code_.bytes, sizeof(cell_t))) {
    // Align the code section.
    aligned_code_ = new uint8_t[code_.length];
    if (!aligned_code_)
      return false;

    memcpy(aligned_code_, code_.bytes, code_.length);
    code_.bytes = aligned_code_;
  }

  natives_ = new sp_native_t[image_->NumNatives()];
  if (!natives_)
    return false;
  memset(natives_, 0, sizeof(sp_native_t) * image_->NumNatives());

  publics_ = new sp_public_t[image_->NumPublics()];
  if (!publics_)
    return false;
  memset(publics_, 0, sizeof(sp_public_t) * image_->NumPublics());

  pubvars_ = new sp_pubvar_t[image_->NumPubvars()];
  if (!pubvars_)
    return false;
  memset(pubvars_, 0, sizeof(sp_pubvar_t) * image_->NumPubvars());

  entrypoints_ = new ScriptedInvoker *[image_->NumPublics()];
  if (!entrypoints_)
    return false;
  memset(entrypoints_, 0, sizeof(ScriptedInvoker *) * image_->NumPublics());

  context_ = new PluginContext(this);
  if (!context_->Initialize())
    return false;

  SetupFloatNativeRemapping();

  if (!function_map_.init(32))
    return false;

  return true;
}

struct NativeMapping {
  const char *name;
  unsigned opcode;
};

static const NativeMapping sNativeMap[] = {
  { "FloatAbs",       OP_FABS },
  { "FloatAdd",       OP_FLOATADD },
  { "FloatSub",       OP_FLOATSUB },
  { "FloatMul",       OP_FLOATMUL },
  { "FloatDiv",       OP_FLOATDIV },
  { "float",          OP_FLOAT },
  { "FloatCompare",   OP_FLOATCMP },
  { "RoundToCeil",    OP_RND_TO_CEIL },
  { "RoundToZero",    OP_RND_TO_ZERO },
  { "RoundToFloor",   OP_RND_TO_FLOOR },
  { "RoundToNearest", OP_RND_TO_NEAREST },
  { "__FLOAT_GT__",   OP_FLOAT_GT },
  { "__FLOAT_GE__",   OP_FLOAT_GE },
  { "__FLOAT_LT__",   OP_FLOAT_LT },
  { "__FLOAT_LE__",   OP_FLOAT_LE },
  { "__FLOAT_EQ__",   OP_FLOAT_EQ },
  { "__FLOAT_NE__",   OP_FLOAT_NE },
  { "__FLOAT_NOT__",  OP_FLOAT_NOT },
  { NULL,             0 },
};

void
PluginRuntime::SetupFloatNativeRemapping()
{
  float_table_ = new floattbl_t[image_->NumNatives()];
  for (size_t i = 0; i < image_->NumNatives(); i++) {
    const char *name = image_->GetNative(i);
    const NativeMapping *iter = sNativeMap;
    while (iter->name) {
      if (strcmp(name, iter->name) == 0) {
        float_table_[i].found = true;
        float_table_[i].index = iter->opcode;
        break;
      }
      iter++;
    }
  }
}

unsigned
PluginRuntime::GetNativeReplacement(size_t index)
{
  if (!float_table_[index].found)
    return OP_NOP;
  return float_table_[index].index;
}

void
PluginRuntime::SetName(const char *name)
{
  size_t len = strlen(name);
  name_ = new char[len + 1];
  strcpy(name_, name);
}

static cell_t
InvalidNative(IPluginContext *pCtx, const cell_t *params)
{
  return pCtx->ThrowNativeErrorEx(SP_ERROR_INVALID_NATIVE, "Invalid native");
}

void
PluginRuntime::AddJittedFunction(CompiledFunction *fn)
{
  m_JitFunctions.append(fn);

  ucell_t pcode_offset = fn->GetCodeOffset();
  FunctionMap::Insert p = function_map_.findForAdd(pcode_offset);
  assert(!p.found());

  function_map_.add(p, pcode_offset, fn);
}

CompiledFunction *
PluginRuntime::GetJittedFunctionByOffset(cell_t pcode_offset)
{
  FunctionMap::Result r = function_map_.find(pcode_offset);
  if (r.found())
    return r->value;
  return nullptr;
}

int
PluginRuntime::FindNativeByName(const char *name, uint32_t *index)
{
  size_t idx;
  if (!image_->FindNative(name, &idx))
    return SP_ERROR_NOT_FOUND;

  if (index)
    *index = idx;

  return SP_ERROR_NONE;
}

int
PluginRuntime::GetNativeByIndex(uint32_t index, sp_native_t **native)
{
  return SP_ERROR_PARAM;
}

int
PluginRuntime::UpdateNativeBinding(uint32_t index, SPVM_NATIVE_FUNC pfn, uint32_t flags, void *data)
{
  if (index >= image_->NumNatives())
    return SP_ERROR_INDEX;

  sp_native_t *native = &natives_[index];

  native->pfn = pfn;
  native->status = pfn
                   ? SP_NATIVE_BOUND
                   : SP_NATIVE_UNBOUND;
  native->flags = flags;
  native->user = data;
  return SP_ERROR_NONE;
}

const sp_native_t *
PluginRuntime::GetNative(uint32_t index)
{
  if (index >= image_->NumNatives())
    return nullptr;

  if (!natives_[index].name)
    natives_[index].name = image_->GetNative(index);

  return &natives_[index];
}

uint32_t
PluginRuntime::GetNativesNum()
{
  return image_->NumNatives();
}

int
PluginRuntime::FindPublicByName(const char *name, uint32_t *index)
{
  size_t idx;
  if (!image_->FindPublic(name, &idx))
    return SP_ERROR_NOT_FOUND;

  if (index)
    *index = idx;
  return SP_ERROR_NONE;
}

int
PluginRuntime::GetPublicByIndex(uint32_t index, sp_public_t **out)
{
  if (index >= image_->NumPublics())
    return SP_ERROR_INDEX;

  sp_public_t &entry = publics_[index];
  if (!entry.name) {
    uint32_t offset;
    image_->GetPublic(index, &offset, &entry.name);
    entry.code_offs = offset;
    entry.funcid = (index << 1) | 1;
  }

  if (out)
    *out = &entry;
  return SP_ERROR_NONE;
}

uint32_t
PluginRuntime::GetPublicsNum()
{
  return image_->NumPublics();
}

int
PluginRuntime::GetPubvarByIndex(uint32_t index, sp_pubvar_t **out)
{
  if (index >= image_->NumPubvars())
    return SP_ERROR_INDEX;

  sp_pubvar_t *pubvar = &pubvars_[index];
  if (!pubvar->name) {
    uint32_t offset;
    image_->GetPubvar(index, &offset, &pubvar->name);
    if (int err = context_->LocalToPhysAddr(offset, &pubvar->offs))
      return err;
  }

  if (out)
    *out = pubvar;
  return SP_ERROR_NONE;
}

int
PluginRuntime::FindPubvarByName(const char *name, uint32_t *index)
{
  size_t idx;
  if (!image_->FindPubvar(name, &idx))
    return SP_ERROR_NOT_FOUND;

  if (index)
    *index = idx;
  return SP_ERROR_NONE;
}

int
PluginRuntime::GetPubvarAddrs(uint32_t index, cell_t *local_addr, cell_t **phys_addr)
{
  if (index >= image_->NumPubvars())
    return SP_ERROR_INDEX;

  uint32_t offset;
  image_->GetPubvar(index, &offset, nullptr);

  if (int err = context_->LocalToPhysAddr(offset, phys_addr))
    return err;
  *local_addr = offset;
  return SP_ERROR_NONE;
}

uint32_t
PluginRuntime::GetPubVarsNum()
{
  return image_->NumPubvars();
}

IPluginContext *
PluginRuntime::GetDefaultContext()
{
  return context_;
}

IPluginDebugInfo *
PluginRuntime::GetDebugInfo()
{
  return this;
}

IPluginFunction *
PluginRuntime::GetFunctionById(funcid_t func_id)
{
  ScriptedInvoker *pFunc = NULL;

  if (func_id & 1) {
    func_id >>= 1;
    if (func_id >= image_->NumPublics())
      return NULL;
    pFunc = entrypoints_[func_id];
    if (!pFunc) {
      entrypoints_[func_id] = new ScriptedInvoker(this, (func_id << 1) | 1, func_id);
      pFunc = entrypoints_[func_id];
    }
  }

  return pFunc;
}

ScriptedInvoker *
PluginRuntime::GetPublicFunction(size_t index)
{
  assert(index < image_->NumPublics());
  ScriptedInvoker *pFunc = entrypoints_[index];
  if (!pFunc) {
    sp_public_t *pub = NULL;
    GetPublicByIndex(index, &pub);
    if (pub)
      entrypoints_[index] = new ScriptedInvoker(this, (index << 1) | 1, index);
    pFunc = entrypoints_[index];
  }

  return pFunc;
}

IPluginFunction *
PluginRuntime::GetFunctionByName(const char *public_name)
{
  uint32_t index;

  if (FindPublicByName(public_name, &index) != SP_ERROR_NONE)
    return NULL;

  return GetPublicFunction(index);
}

bool
PluginRuntime::IsDebugging()
{
  return true;
}

void
PluginRuntime::SetPauseState(bool paused)
{
  paused_ = paused;
}

bool
PluginRuntime::IsPaused()
{
  return paused_;
}

size_t
PluginRuntime::GetMemUsage()
{
  return sizeof(*this) +
         sizeof(PluginContext) +
         image_->ImageSize() +
         (aligned_code_ ? code_.length : 0) +
         context_->HeapSize();
}

unsigned char *
PluginRuntime::GetCodeHash()
{
  if (!computed_code_hash_) {
    MD5 md5_pcode;
    md5_pcode.update((const unsigned char *)code_.bytes, code_.length);
    md5_pcode.finalize();
    md5_pcode.raw_digest(code_hash_);
    computed_code_hash_ = true;
  }
  return code_hash_;
}

unsigned char *
PluginRuntime::GetDataHash()
{
  if (!computed_data_hash_) {
    MD5 md5_data;
    md5_data.update((const unsigned char *)data_.bytes, data_.length);
    md5_data.finalize();
    md5_data.raw_digest(data_hash_);
    computed_data_hash_ = true;
  }
  return data_hash_;
}

PluginContext *
PluginRuntime::GetBaseContext()
{
  return context_;
}

int
PluginRuntime::ApplyCompilationOptions(ICompilation *co)
{
  return SP_ERROR_NONE;
}

int
PluginRuntime::LookupLine(ucell_t addr, uint32_t *line)
{
  if (!image_->LookupLine(addr, line))
    return SP_ERROR_NOT_FOUND;
  return SP_ERROR_NONE;
}

int
PluginRuntime::LookupFunction(ucell_t addr, const char **out)
{
  const char *name = image_->LookupFunction(addr);
  if (!name)
    return SP_ERROR_NOT_FOUND;
  if (out)
    *out = name;
  return SP_ERROR_NONE;
}

int
PluginRuntime::LookupFile(ucell_t addr, const char **out)
{
  const char *name = image_->LookupFile(addr);
  if (!name)
    return SP_ERROR_NOT_FOUND;
  if (out)
    *out = name;
  return SP_ERROR_NONE;
}