#include <malloc.h>

#include <string.h>

#include "sp_file_headers.h"

#include "sp_vm_types.h"

#include "sp_vm_engine.h"

#include "zlib/zlib.h"

#include "sp_vm_basecontext.h"

using namespace SourcePawn;

void *SourcePawnEngine::BaseAlloc(size_t size)

{

	return malloc(size);

}

void SourcePawnEngine::BaseFree(void *memory)

{

	free(memory);

}

IPluginContext *SourcePawnEngine::CreateBaseContext(sp_context_t *ctx)

{

	return new BaseContext(ctx);

}

void SourcePawnEngine::FreeBaseContext(IPluginContext *ctx)

{

	sp_context_t *_ctx = ctx->GetContext();

	IVirtualMachine *vm = ctx->GetVirtualMachine();

	vm->FreeContextVars(_ctx);

	delete ctx;

}

sp_plugin_t *_ReadPlugin(sp_file_hdr_t *hdr, uint8_t *base, sp_plugin_t *plugin, int *err)

{

	char *nameptr;

	uint8_t sectnum = 0;

	sp_file_section_t *secptr = (sp_file_section_t *)(base + sizeof(sp_file_hdr_t));

	memset(plugin, 0, sizeof(sp_plugin_t));

	plugin->base = base;

	while (sectnum < hdr->sections)

	{

		nameptr = (char *)(base + hdr->stringtab + secptr->nameoffs);

		if (!(plugin->pcode) && !strcmp(nameptr, ".code"))

		{

			sp_file_code_t *cod = (sp_file_code_t *)(base + secptr->dataoffs);

			plugin->pcode = base + secptr->dataoffs + cod->code;

			plugin->pcode_size = cod->codesize;

			plugin->flags = cod->flags;

		}

		else if (!(plugin->data) && !strcmp(nameptr, ".data"))

		{

			sp_file_data_t *dat = (sp_file_data_t *)(base + secptr->dataoffs);

			plugin->data = base + secptr->dataoffs + dat->data;

			plugin->data_size = dat->datasize;

			plugin->memory = dat->memsize;

		}

		else if (!(plugin->info.publics) && !strcmp(nameptr, ".publics"))

		{

			plugin->info.publics_num = secptr->size / sizeof(sp_file_publics_t);

			plugin->info.publics = (sp_file_publics_t *)(base + secptr->dataoffs);

		}

		else if (!(plugin->info.pubvars) && !strcmp(nameptr, ".pubvars"))

		{

			plugin->info.pubvars_num = secptr->size / sizeof(sp_file_pubvars_t);

			plugin->info.pubvars = (sp_file_pubvars_t *)(base + secptr->dataoffs);

		}

		else if (!(plugin->info.natives) && !strcmp(nameptr, ".natives"))

		{

			plugin->info.natives_num = secptr->size / sizeof(sp_file_natives_t);

			plugin->info.natives = (sp_file_natives_t *)(base + secptr->dataoffs);

		}

		else if (!(plugin->info.stringbase) && !strcmp(nameptr, ".names"))

		{

			plugin->info.stringbase = (const char *)(base + secptr->dataoffs);

		}

		else if (!(plugin->debug.files) && !strcmp(nameptr, ".dbg.files"))

		{

			plugin->debug.files = (sp_fdbg_file_t *)(base + secptr->dataoffs);

		}

		else if (!(plugin->debug.lines) && !strcmp(nameptr, ".dbg.lines"))

		{

			plugin->debug.lines = (sp_fdbg_line_t *)(base + secptr->dataoffs);

		}

		else if (!(plugin->debug.symbols) && !strcmp(nameptr, ".dbg.symbols"))

		{

			plugin->debug.symbols = (sp_fdbg_symbol_t *)(base + secptr->dataoffs);

		}

		else if (!(plugin->debug.lines_num) && !strcmp(nameptr, ".dbg.info"))

		{

			sp_fdbg_info_t *inf = (sp_fdbg_info_t *)(base + secptr->dataoffs);

			plugin->debug.files_num = inf->num_files;

			plugin->debug.lines_num = inf->num_lines;

			plugin->debug.syms_num = inf->num_syms;

		}

		else if (!(plugin->debug.stringbase) && !strcmp(nameptr, ".dbg.strings"))

		{

			plugin->debug.stringbase = (const char *)(base + secptr->dataoffs);

		}

		secptr++;

		sectnum++;

	}

	if (!(plugin->pcode) || !(plugin->data) || !(plugin->info.stringbase))

	{

		goto return_error;

	}

	if ((plugin->flags & SP_FLAG_DEBUG) && (!(plugin->debug.files) || !(plugin->debug.lines) || !(plugin->debug.symbols)))

	{

		goto return_error;

	}

	if (err)

	{

		*err = SP_ERR_NONE;

	}

	return plugin;

return_error:

	if (err)

	{

		*err = SP_ERR_FILE_FORMAT;

	}

	return NULL;

}

sp_plugin_t *SourcePawnEngine::LoadFromFilePointer(FILE *fp, int *err)

{

	sp_file_hdr_t hdr;

	sp_plugin_t *plugin;

	uint8_t *base;

	int z_result;

	int error;

	if (!fp)

	{

		error = SP_ERR_NOT_FOUND;

		goto return_error;

	}

	/* Rewind for safety */

	rewind(fp);

	fread(&hdr, sizeof(sp_file_hdr_t), 1, fp);

	if (hdr.magic != SPFILE_MAGIC)

	{

		error = SP_ERR_FILE_FORMAT;

		goto return_error;

	}

	switch (hdr.compression)

	{

	case SPFILE_COMPRESSION_GZ:

		{

			uint32_t uncompsize = hdr.imagesize - hdr.dataoffs;

			uint32_t compsize = hdr.disksize - hdr.dataoffs;

			uint32_t sectsize = hdr.dataoffs - sizeof(sp_file_hdr_t);

			uLongf destlen = uncompsize;

			char *tempbuf = (char *)malloc(compsize);

			void *uncompdata = malloc(uncompsize);

			void *sectheader = malloc(sectsize);

			fread(sectheader, sectsize, 1, fp);

			fread(tempbuf, compsize, 1, fp);

			z_result = uncompress((Bytef *)uncompdata, &destlen, (Bytef *)tempbuf, compsize);

			free(tempbuf);

			if (z_result != Z_OK)

			{

				free(sectheader);

				free(uncompdata);

				error = SP_ERR_DECOMPRESSOR;

				goto return_error;

			}

			base = (uint8_t *)malloc(hdr.imagesize);

			memcpy(base, &hdr, sizeof(sp_file_hdr_t));

			memcpy(base + sizeof(sp_file_hdr_t), sectheader, sectsize);

			free(sectheader);

			memcpy(base + hdr.dataoffs, uncompdata, uncompsize);

			free(uncompdata);

			break;

		}

	case SPFILE_COMPRESSION_NONE:

		{

			base = (uint8_t *)malloc(hdr.imagesize);

			rewind(fp);

			fread(base, hdr.imagesize, 1, fp);

			break;

		}

	default:

		{

			error = SP_ERR_DECOMPRESSOR;

			goto return_error;

		}

	}

	plugin = (sp_plugin_t *)malloc(sizeof(sp_plugin_t));

	if (!_ReadPlugin(&hdr, base, plugin, err))

	{

		free(plugin);

		free(base);

		return NULL;

	}

	plugin->allocflags = 0;

	return plugin;

return_error:

	if (err)

	{

		*err = error;

	}

	return NULL;

}

sp_plugin_t *SourcePawnEngine::LoadFromMemory(void *base, sp_plugin_t *plugin, int *err)

{

	sp_file_hdr_t hdr;

	uint8_t noptr = 0;

	memcpy(&hdr, base, sizeof(sp_file_hdr_t));

	if (!plugin)

	{

		plugin = (sp_plugin_t *)malloc(sizeof(sp_plugin_t));

		noptr = 1;

	}

	if (!_ReadPlugin(&hdr, (uint8_t *)base, plugin, err))

	{

		if (noptr)

		{

			free(plugin);

		}

		return NULL;

	}

	if (!noptr)

	{

		plugin->allocflags |= SP_FA_SELF_EXTERNAL;

	}

	plugin->allocflags |= SP_FA_BASE_EXTERNAL;

	return plugin;

}

int SourcePawnEngine::FreeFromMemory(sp_plugin_t *plugin)

{

	if (!(plugin->allocflags & SP_FA_BASE_EXTERNAL))

	{

		free(plugin->base);

		plugin->base = NULL;

	}

	if (!(plugin->allocflags & SP_FA_SELF_EXTERNAL))

	{

		free(plugin);

	}

	return SP_ERR_NONE;

}