/*
 * 	User defined function for MySQL.
*/
#include <stdio.h>
#include <string.h>
#include <mysql/mysql.h>
#include <string>
#include <map>
#include <boost/date_time/gregorian/gregorian_types.hpp>
#include <boost/date_time/gregorian/parsers.hpp>
#include <boost/date_time/gregorian/formatters.hpp>

using namespace boost::gregorian;
using namespace std;

static void udf_init(UDF_INIT *initid)
{
	initid->maybe_null = false;	/* 1 if function can return NULL */
	initid->const_item = false;
	initid->decimals = 0;		/* for real functions */
	initid->max_length = 0;
	//initid->ptr = NULL;
	//initid->extension = NULL;
}

extern "C" my_bool CF_convert_init(UDF_INIT *initid, UDF_ARGS *args, char *message)
{
	udf_init (initid);
	initid->max_length = 26;
	initid->maybe_null = true;
	if (args->arg_count != 5){
		strcpy(message,"Wrong argument count to CF_convert, expect 5");
		return 1;
	}else if (args->arg_type[0] != STRING_RESULT
		|| args->arg_type[1] != INT_RESULT
		|| args->arg_type[2] != INT_RESULT
		|| args->arg_type[4] != INT_RESULT){
		strcpy(message,"Wrong arguments type to CF_convert, expect \"type\",number,number, string or number, number");
		return 1;
	}
	return false;
}
extern "C" void CF_convert_deinit(UDF_INIT *initid)
{
}
extern "C" char *CF_convert(
	UDF_INIT *initid,
	UDF_ARGS *args,
	char *result,
	unsigned long *length,
	char *is_null,
	char *error)
{
	char *ret = NULL;
	memset(result,0,initid->max_length);
	if (args->arg_count == 5){
		const char *type = args->args[0];
		int size = *(int*)(args->args[1]);
		int format = *(int*)(args->args[4]);
		bool is_datetime = strcasecmp(type,"datetime")==0;
		if (strcasecmp(type,"int")==0){
			if (args->args[3] == NULL){
				*error = 1;
				return NULL;
			}else{
				if (size == 0) size = 10;
				int val = 0;
				if(args->arg_type[3] == STRING_RESULT){
					val = atoi(args->args[3]);
				}else if(args->arg_type[3] == DECIMAL_RESULT){
					val = atoi(args->args[3]);
				}
				size = snprintf (result,size+1,"%d",val);
			}
		}else if (strcasecmp(type,"numeric")==0
			|| strcasecmp(type,"float")==0){
			if (args->args[3] == NULL){
				*error = 1;
				return NULL;
			}else{
				if (size == 0) size = 10;
				double val = 0;
				if(args->arg_type[3] == STRING_RESULT){
					val = atof(args->args[3]);
				}else if(args->arg_type[3] == DECIMAL_RESULT){
					val = atof(args->args[3]);
				}
				int size2 = *(int*)(args->args[2]);
				size = snprintf (result,size+1,"%*.*lf",size,size2,val);
			}
		}else if ((strcasecmp(type,"char")==0
			|| strcasecmp(type,"varchar")==0
			|| is_datetime)
				&& args->arg_type[3] == STRING_RESULT){
			if (args->args[3] == NULL){
				*error = 1;
				return NULL;
			}else{
				if (is_datetime) size=20;
				if (size == 0) size = 1;
				const char *val = args->args[3];
				int lenval = strlen(val);
				if (format == 109){
					if (lenval == 10 || lenval == 19){
						int year = atoi(val);
						int month = atoi(val+5);
						int day = atoi(val+8);
						const char *hour = "12:00:00:000AM";
						char tmphour[8+4+2+1];
						if (lenval == 19){
							hour = val+11;
							if (strlen(hour)==8){
								int n = atoi(hour);
								const char *suffix = ":000AM";
								if (n > 12){
									suffix = ":000PM";
									n -= 12;
								}else if (n == 0){
									n = 12;
								}
								snprintf (tmphour,sizeof(tmphour),"%2d%s%s",n,hour+2,suffix);
								hour = tmphour;
							}
						}
						static const char *tbmonth[]={
							"Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec"
						};
						size = snprintf (result,size+1,"%s %2d %d %s",tbmonth[month-1],day,year,hour);
					}else{
						*error = 1;
						size = sprintf (result,"%*.*s",size,size,"Invalid date");
					}
				}else if (format == 101){
					if (lenval == 10 || lenval == 19){
						int year = atoi(val);
						int month = atoi(val+5);
						int day = atoi(val+8);
						size = snprintf (result,size-1,"%02d/%02d/%04d",month,day,year);
					}else{
						*error = 1;
						size = sprintf (result,"%*.*s",size,size,"Invalid date");
					}
				}else if (format == 102){
					if (lenval == 10 || lenval == 19){
						int year = atoi(val);
						int month = atoi(val+5);
						int day = atoi(val+8);
						size = snprintf (result,size-1,"%04d.%02d.%02d",year,month,day);
					}else{
						*error = 1;
						size = sprintf (result,"%*.*s",size,size,"Invalid date");
					}
				}else if (format == 103){
					if (lenval == 10 || lenval == 19){
						int year = atoi(val);
						int month = atoi(val+5);
						int day = atoi(val+8);
						size = snprintf (result,size-1,"%02d/%02d/%04d",day,month,year);
					}else{
						*error = 1;
						size = sprintf (result,"%*.*s",size,size,"Invalid date");
					}
				}else if (format == 104){
					if (lenval == 10 || lenval == 19){
						int year = atoi(val);
						int month = atoi(val+5);
						int day = atoi(val+8);
						size = snprintf (result,size-1,"%02d.%02d.%04d",day,month,year);
					}else{
						*error = 1;
						size = sprintf (result,"%*.*s",size,size,"Invalid date");
					}
				}else if (format == 105){
					if (lenval == 10 || lenval == 19){
						int year = atoi(val);
						int month = atoi(val+5);
						int day = atoi(val+8);
						size = snprintf (result,size-1,"%02d-%02d-%04d",day,month,year);
					}else{
						*error = 1;
						size = sprintf (result,"%*.*s",size,size,"Invalid date");
					}
				}else{
					size = sprintf (result,"ERROR convert ??? format %d",format);
					*error = 1;
					size = 0;
				}
			}
		}else{
			size = sprintf (result,"ERROR convert ??? type %s",type);
			*error = 1;
		}
		*length=size;
		ret = result;
	}
	return ret;
}

extern "C" my_bool CF_textptr_init(UDF_INIT *initid, UDF_ARGS *args, char *message)
{
	udf_init (initid);
	initid->max_length = 26;
	return false;
}
extern "C" void CF_textptr_deinit(UDF_INIT *initid)
{
}
extern "C" char *CF_textptr(
	UDF_INIT *initid,
	UDF_ARGS *args,
	char *result,
	unsigned long *length,
	char *is_null,
	char *error)
{
	#if 0
		strcpy (result,"0xabc");
		*length = strlen(result);
	#else
		result[0] = 0xab;
		result[1] = 0xcd;
		*length = 2;
	#endif
	return result;
}

static map<int,string> id2name;
static map<string,int> name2id;

extern "C" my_bool CF_object_name_init(UDF_INIT *initid, UDF_ARGS *args, char *message)
{
	static bool is_init = false;
	if (!is_init){
		#include "id2name.h"
		is_init = true;
	}
	udf_init (initid);
	initid->max_length = 255;
	initid->maybe_null = true;
	if (args->arg_count != 1){
		strcpy(message,"Wrong arguments to CF_object_name, expect 1");
		return 1;
	}else if (args->arg_type[0] != INT_RESULT){
		strcpy(message,"Wrong arguments to CF_object_name, expect numeric");
		return 1;
	}
	return false;
}
extern "C" void CF_object_name_deinit(UDF_INIT *initid)
{
}
extern "C" char *CF_object_name(
	UDF_INIT *initid,
	UDF_ARGS *args,
	char *result,
	unsigned long *length,
	char *is_null,
	char *error)
{
	char *ret = NULL;
	if (args->arg_count == 1 && args->args[0] != NULL){
		int id = *(int*)(args->args[0]);
		map<int,string>::iterator it = id2name.find(id);
		if (it != id2name.end()){
			string &x = it->second;
			*length = x.size();
			strcpy (result,x.c_str());
			ret = result;
		}
	}
	return ret;
}

extern "C" my_bool CF_object_id_init(UDF_INIT *initid, UDF_ARGS *args, char *message)
{
	static bool is_init = false;
	if (!is_init){
		#include "id2name.h"
		is_init = true;
	}
	udf_init (initid);
	initid->max_length = 255;
	initid->maybe_null = true;
	if (args->arg_count != 1){
		strcpy(message,"Wrong arguments to CF_object_id, expect 1");
		return 1;
	}else if (args->arg_type[0] != STRING_RESULT){
		strcpy(message,"Wrong arguments to CF_object_id, expect string");
		return 1;
	}
	return false;
}
extern "C" void CF_object_id_deinit(UDF_INIT *initid)
{
}
static string toupper(const char *s)
{
	string ret;
	while (*s != '\0'){
		ret += toupper(*s);
		s++;
	}
	return ret;
}
extern "C" char *CF_object_id(
	UDF_INIT *initid,
	UDF_ARGS *args,
	char *result,
	unsigned long *length,
	char *is_null,
	char *error)
{
	char *ret = NULL;
	if (args->arg_count == 1){
		string sup = toupper(args->args[0]);
		map<string,int>::iterator it = name2id.find(sup);
		if (it != name2id.end()){
			int id = it->second;
			int n = sprintf (result,"%d",id);
			*length = n;
			ret = result;
		}
	}
	return ret;
}

extern "C" my_bool CF_identity_init(UDF_INIT *initid, UDF_ARGS *args, char *message)
{
	udf_init (initid);
	initid->max_length = 15;
	if (args->arg_count != 1){
		// The identity function requires one argument, but does nothing with it.
		strcpy(message,"Wrong argument number to CF_identity, expect 1");
		return 1;
	}
	if (initid->ptr == NULL){
		initid->ptr = (char*)malloc(sizeof(int));	// This will be the counter for this session
		*(int*)(initid->ptr) = 1;
	}
	return false;
}
extern "C" void CF_identity_deinit(UDF_INIT *initid)
{
	free (initid->ptr);
}
extern "C" long long CF_identity(
	UDF_INIT *initid,
	UDF_ARGS *args,
	char *is_null,
	char *error)
{
	long long ret = -1;
	if (args->arg_count == 1){
		ret = *(int*)(initid->ptr);
		*(int*)(initid->ptr) = ret+1;
	}
	return ret;
}
extern "C" my_bool CF_datediff_init(UDF_INIT *initid, UDF_ARGS *args, char *message)
{
	udf_init (initid);
	initid->max_length = 15;
	initid->maybe_null = true;
	if (args->arg_count != 3){
		strcpy(message,"Wrong argument number to CF_datediff, expect 3");
		return 1;
	}else if (args->arg_type[0] != INT_RESULT
		|| args->arg_type[1] != STRING_RESULT
		|| args->arg_type[2] != STRING_RESULT){
		strcpy(message,"Wrong argument types to CF_datediff, expect number,string,string");
		return 1;
	}
	return false;
}
extern "C" void CF_datediff_deinit(UDF_INIT *initid)
{
}
extern "C" long long CF_datediff(
	UDF_INIT *initid,
	UDF_ARGS *args,
	char *is_null,
	char *error)
{
	long long ret = 0;
	if (args->arg_count == 3){
		int *typep = (int*)args->args[0];
		const char *date1 = args->args[1];
		const char *date2 = args->args[2];
		if (typep == NULL || date1 == NULL || date2 == NULL){
			*is_null = 1;
		}else if (strlen(date1)<10 || strlen(date2)<10){
			*is_null = 1;
		}else{
			int type = *typep;
			int year1 = atoi(date1);
			int month1 = atoi(date1+5);
			int year2 = atoi(date2);
			int month2 = atoi(date2+5);

			if (type == 0){
				// day 
				date d1(from_simple_string(date1));
				date d2(from_simple_string(date2));
				ret = (long long) d2.julian_day()-d1.julian_day();
			}else if (type == 1){
				// Week
				date d1(from_simple_string(date1));
				date d2(from_simple_string(date2));
				ret = (long long)(d2.year()*52+d2.week_number())-(d1.year()*52+d1.week_number());
			}else if (type == 2){
				// Month
				ret = (year2*12+month2)-(year1*12+month1);
			}else if (type == 3){
				// year 
				ret = year2-year1;
			}else{
				*is_null = 1;
			}
		}
	}else{
		*is_null = 1;
	}
	return ret;
}