#include <dlfcn.h>
#include <dirent.h>
#include "helpers.h"
#include "callback.h"
#include "plugin.h"

/////////////////////////////////////////////////////////////////////////////
// {75ed2211-0a25-4a55-962b-31d3b0e6123a}
DEFINE_UUID(UUID_REST_PLUGIN,
	0x75ed2211, 0x0a25, 0x4a55, 0x96, 0x2b, 0x31, 0xd3, 0xb0, 0xe6, 0x12, 0x3a);

/////////////////////////////////////////////////////////////////////////////

typedef struct _PLUGIN
{
	std::string sName;
	std::string sLibPath;
	void *hLib;
}PLUGIN;

typedef int (*PFN_REST_REQUEST_HANDLER)(const struct _u_request*, struct _u_response*, void*);

/////////////////////////////////////////////////////////////////////////////

static std::vector<FILEREQUEST> g_afr;
static std::vector<PLUGIN> g_aPlugins;

/////////////////////////////////////////////////////////////////////////////

static bool _IsSharedLib(const char *pszFilename)
{
	char *pSave = nullptr, szFilename[PATH_MAX], *pszTok;
	strcpy(szFilename, pszFilename);
	
	if((pszTok = strtok_r(szFilename, ".", &pSave)))
	{
		while((pszTok = strtok_r(nullptr, ".", &pSave)))
		{
			if(!strcmp(pszTok, "so"))
				return true;
		}
	}

	return false;
}

/////////////////////////////////////////////////////////////////////////////

int LoadPlugins(const char *pszRootDir, struct _u_instance *pInst, json_error_t &rJerr, PCREST_PLUGIN_REQUEST_CONTEXT prc)
{
	DIR *d;
	int nLoaded = 0;
	struct dirent *dir;
	char szPluginDir[PATH_MAX + 32];
	char szPluginLib[PATH_MAX + 32 + 256];
    sprintf(szPluginDir, "%s/plugin", pszRootDir);

	if((d = opendir(szPluginDir)))
	{
		while((dir = readdir(d)))
		{
			if((dir->d_type == DT_REG) &&
				_IsSharedLib(dir->d_name))
			{
			    sprintf(szPluginLib, "%s/plugin/%s", pszRootDir, dir->d_name);
				void *hLib = dlopen(szPluginLib, RTLD_NOW);	

				if(hLib)
				{
					PFN_GETPLUGININFO GetPluginInfo = (PFN_GETPLUGININFO)dlsym(hLib, "GetPluginInfo");
					
					if(GetPluginInfo)
					{
						const REST_PLUGIN_INFO *ppi = nullptr;

						if((ppi = GetPluginInfo()))
						{
							if(!_uuid_compare(&UUID_REST_PLUGIN, &ppi->signature))
							{
								PLUGIN plugin;
								plugin.sName = ppi->pszPluginName;
								plugin.sLibPath = szPluginLib;
								plugin.hLib = hLib;
								g_aPlugins.push_back(plugin);
								
								for(size_t i = 0; i < ppi->nHandlerCnt; ++i)
								{
									const REST_REQUEST_HANDLER &rh = ppi->handler[i];
									PFN_REST_REQUEST_HANDLER RequestHandler = (PFN_REST_REQUEST_HANDLER)dlsym(hLib, rh.pszFunctionName);
									
									if(RequestHandler)
									{
										if(ulfius_add_endpoint_by_val(pInst, rh.pszHttpMethod, rh.pszVirtPath, nullptr, 0, RequestHandler, (void*)prc) == U_OK)
											++nLoaded;
									}
								}
							}
							else
							{
								dlclose(hLib);
							}
						}
						else
						{
							dlclose(hLib);
						}
					}
					else
					{
						dlclose(hLib);
					}
				}
			}
		}

		closedir(d);
	}

	return nLoaded;
}

/////////////////////////////////////////////////////////////////////////////

void UnloadPlugins(void)
{
	for(PLUGIN &p : g_aPlugins)
	{
		if(p.hLib)
			dlclose(p.hLib);
	}
	
	g_aPlugins.clear();
}

/////////////////////////////////////////////////////////////////////////////

int InitializeStaticFiles(const char *pszRootDir, struct _u_instance *pInst, json_error_t &rJerr)
{
	int nRet = 0;
	char szFilename[PATH_MAX + 32];
    sprintf(szFilename, "%s/staticfiles.json", pszRootDir);

    if(FileExist(szFilename))
    {
		CJson_t jtRoot(json_load_file(szFilename, JSON_REJECT_DUPLICATES, &rJerr)); // new reference!

		if(jtRoot.IsValid())
		{
			const char *pszVal;
			bool bVal;

			if(!jtRoot.IsArray())
			{
				ETRACE("staticfiles.json contains no array!\n");
				return -1;
			}

			for(size_t i = 0; i < json_array_size(jtRoot); i++)
			{
				FILEREQUEST fr;
				CJson_t jtArr(json_array_get(jtRoot, i), false); // borrowed reference!

				if(jtArr.IsValid())
				{
					if(!jtArr.IsObject())
					{
						ETRACE("staticfiles.json: element %zu is no object!\n", i);
						return -1;
					}

					json_t *pjtMethod = json_object_get(jtArr, "method");
					pszVal = json_string_value(pjtMethod);
					fr.strMethod = pszVal;

					json_t *pjtUrl = json_object_get(jtArr, "URL");
					pszVal = json_string_value(pjtUrl);
					fr.strURL = pszVal;

					json_t *pjtFilename = json_object_get(jtArr, "fileName");
					pszVal = json_string_value(pjtFilename);
					sprintf(szFilename, "%s/%s", pszRootDir, pszVal);
					fr.strFilename = szFilename;

					json_t *pjtContentType = json_object_get(jtArr, "contentType");
					pszVal = json_string_value(pjtContentType);
					fr.strContentType = pszVal;

					json_t *pjtIsString = json_object_get(jtArr, "isString");
					bVal = json_boolean_value(pjtIsString);
					fr.bString = bVal;

					fr.pfnCallback = &FileBodyResponseCallback;

					g_afr.push_back(fr);
				}
				else
				{
					ETRACE("Error!\n");
					return -1;
				}
			}
		}
		else
		{
			if(rJerr.column == -1 || rJerr.line == -1)
			{
				TRACE("staticfiles.json: no static files configured.\n");
				return 0;
			}
			else
			{
				ETRACE("%s: line %d, column %d: %s.\n", szFilename, rJerr.line, rJerr.column, rJerr.text);
				return -1;
			}
		}
    }
    else
    {
//		TRACE("No static files found.\n");
		return 0;
    }

	// Endpoint list declaration
	for(auto it = g_afr.begin(); it != g_afr.end(); it++)
	{
		FILEREQUEST &rfr = *it;

		if(ulfius_add_endpoint_by_val(pInst, rfr.strMethod.c_str(), rfr.strURL.c_str(), nullptr, 0, rfr.pfnCallback, &rfr) != U_OK)
		{
			ETRACE("Error adding endpoint for URL '%s'!\n", rfr.strURL.c_str());
			return -1;
		}
		else
		{
			nRet++;
		}
	}

    return nRet;
}