/*
 * C TemplateS : template expander
 * Based on the original libctemplate by Stephen C. Losen
 * 
 * Version 0.1
 *
 * Copyright (c) 2017-2019 Alexander M. Pickering (alex@cogarr.net)
 *
 * Distributed under GPL V3, see COPYING for more information.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as publish by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public Liscense for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 *
 */

#include <string.h>
#include <ctype.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include <sys/stat.h>
#include <stdarg.h>
#include <ctemplates.h>

struct TMPL_varitem*         TMPL_alloc_varitem(void);
void                         TMPL_free_varitem(struct TMPL_varitem* vi);
int                          TMPL_add_var_to_varlist(
                                                     struct TMPL_varlist* t,
                                                     const char* varname,
                                                     const char* var
                                                    );
void                         print_ast_helper(
                                              struct TMPL_templates* t,
                                              struct TMPL_tagnode* cursor,
                                              int level
                                             );
void                         print_ast(struct TMPL_templates* root);
struct TMPL_token*           TMPL_tokenize(const char* tmplstr, size_t strlen);
struct TMPL_tagnode*         alloc_tagnode(void);
size_t                       get_quoted_string(const char* start, size_t len);
int                          is_whitespace(char c);
struct TMPL_tagnode*         parse_text(
                                        struct TMPL_token* head,
                                        struct TMPL_buf* errbuf
                                       );
struct TMPL_tagnode*         parse_else(
                                        struct TMPL_token* head,
                                        struct TMPL_buf* errbuf
                                       );
struct TMPL_tagnode*         parse_elseif(
                                          struct TMPL_token* head,
                                          struct TMPL_buf* errbuf
                                         );
struct TMPL_tagnode*         parse_if(
                                      struct TMPL_token* head,
                                      struct TMPL_buf* errbuf
                                     );
struct TMPL_tagnode*         parse_loop(
                                        struct TMPL_token* head,
                                        struct TMPL_buf* errbuf
                                       );
struct TMPL_tagnode*         parse_variable(
                                            struct TMPL_token* head,
                                            struct TMPL_buf* errbuf
                                           );
struct TMPL_tagnode*         parse_continue(
                                            struct TMPL_token* head,
                                            struct TMPL_buf* errbuf
                                           );
struct TMPL_tagnode*         parse_break(
                                         struct TMPL_token* head,
                                         struct TMPL_buf* errbuf
                                        );
struct TMPL_tagnode*         parse_end(
                                       struct TMPL_token* head,
                                       struct TMPL_buf* errbuf
                                      );
struct TMPL_varlist*         TMPL_alloc_varlist(void);
int                          TMPL_free_hashmapitems(any_t a, any_t b);
void                         TMPL_free_varlist(struct TMPL_varlist* vl);
struct TMPL_loop*            TMPL_alloc_loop(void);
void                         TMPL_free_loop(struct TMPL_loop* tl);
int                          TMPL_add_varlist_to_loop(
                                                      struct TMPL_loop* tl,
                                                      struct TMPL_varlist* vl
                                                     );
int                          TMPL_add_loop_to_varlist(
                                                      struct TMPL_varlist* vl,
                                                      const char* name,
                                                      struct TMPL_loop* l
                                                     );
struct TMPL_tagnode*         parse(
                                   struct TMPL_token* head,
                                   struct TMPL_buf* errbuf
                                  );
struct TMPL_templates*       alloc_templates(void);
struct TMPL_templates*       compile(const char* tmplstr);
int                          render_variable(
                                             struct TMPL_templates* t,
                                             struct TMPL_varlist* varlist
                                            );
int                          render_text(
                                         struct TMPL_templates* t,
                                         struct TMPL_varlist* varlist
                                        );
int                          print_pair(any_t indent, any_t b);
int                          render_if(
                                       struct TMPL_templates* t,
                                       struct TMPL_varlist* varlist
                                      );
int                          render_elseif(
                                           struct TMPL_templates* t,
                                           struct TMPL_varlist* varlist
                                          );
int                          render_loop(
                                         struct TMPL_templates* t,
                                         struct TMPL_varlist* varlist
                                        );
int                          render_continue(
                                         struct TMPL_templates* t,
                                         struct TMPL_varlist* varlist
                                        );
int                          render_break(
                                         struct TMPL_templates* t,
                                         struct TMPL_varlist* varlist
                                        );
int                          render_any(
                                        struct TMPL_templates* t,
                                        struct TMPL_varlist* varlist
                                       );
int                          TMPL_render_helper(
                                                struct TMPL_templates* t,
                                                struct TMPL_varlist* varlist
                                               );
char*                        TMPL_render(
                                         struct TMPL_templates* t,
                                         struct TMPL_varlist* varlist,
					 size_t* size_p
                                        );
int                          TMPL_alloc_template(
                                                 const char* tmplstr,
                                                 struct TMPL_templates **t
                                                );
void                         TMPL_free_template(struct TMPL_templates* t);
void                         TMPL_free_tagnode(struct TMPL_tagnode* tn);
char*                        TMPL_get_error(struct TMPL_templates* t);
void                         print_varlist_helper(
                                                  struct TMPL_varlist* vl,
                                                  int indent
                                                 );

struct TMPL_varitem*
TMPL_alloc_varitem(){
	struct TMPL_varitem* ret = (struct TMPL_varitem*)malloc(sizeof(struct TMPL_varitem));
	return ret;
}

void
TMPL_free_varitem(struct TMPL_varitem* vi){
	if(vi->type == vartype_var){
		free(vi->item.s);
	}else{
		TMPL_free_loop(vi->item.l);
	}
	free(vi);
}

/* Adds a variable to the variable list, returns -1 on error*/
int
TMPL_add_var_to_varlist(struct TMPL_varlist* t, const char* varname, const char* var){
	struct TMPL_varitem* vi = TMPL_alloc_varitem();
	vi->type = vartype_var;
	size_t slen = strlen(var);/*strlen dosn't count \0*/
	vi->item.s = (char*)malloc(sizeof(char)*(slen + 1));/*+1 for \0*/
	vi->item.s[slen] = '\0';
	memcpy(vi->item.s,var,slen);
	int succ = hashmap_put(t->map,(char*)varname,(char*)vi);
	if(succ != MAP_OK) return 0;
	return -1;
}

void
print_ast_helper(struct TMPL_templates* t, struct TMPL_tagnode* cursor, int level){
	/*printf("Helper called, level %d\n",level);*/
	int i;
	/*printf("Cursor is: %p\n", (void*)cursor);*/
	if(t->cursor == cursor){
		printf("> ");
	}else{
		printf("  ");
	}
	for(i = 0; i < level; i++){
		printf("|");
	}
	/*printf("type is %d\n",cursor->type);*/
	printf("} %d ->",(int)cursor->type);
	switch(cursor->type){
		case tag_null:
			printf("TAG NULL");
			break;
		case tag_text:
			printf("TAG Text \"");
			if(cursor->TMPL_tag.text.len < 10){
				size_t i;
				for(i = 0; i < cursor->TMPL_tag.text.len; i++)
					putchar(*(cursor->TMPL_tag.text.start + i));
				printf("\"\n");
			}else{
				int i;
				for(i = 0; i < 7; i++)
					putchar(*(cursor->TMPL_tag.text.start + i));
				printf("...\"\n");
			}
			break;
		case tag_var:
			printf("TAG var(%s)",cursor->TMPL_tag.var.varname);
			if(cursor->TMPL_tag.var.defaultval != NULL){
				printf(" +default:%d",(int)cursor->TMPL_tag.var.default_len);
			}
			printf("\n");
			break;
		case tag_if:
		case tag_elseif:
			printf("TAG If/elseif,(%s) == (%s)\n",cursor->TMPL_tag.ifelse.varname,cursor->TMPL_tag.ifelse.testval);
			level++;
			printf("  ");
			for(i=0;i<level;i++){
				printf("|");
			}
			printf("True:\n");
			print_ast_helper(t,cursor->TMPL_tag.ifelse.tbranch,level);
			if(cursor->TMPL_tag.ifelse.fbranch != NULL){
				printf("  ");
				for(i=0;i<level;i++){
					printf("|");
				}
				printf("False:\n");
				print_ast_helper(t,cursor->TMPL_tag.ifelse.fbranch,level);
			}
			level--;
			break;
		case tag_else:
			printf("TAG Else\n");
			break;
		case tag_end:
			printf("TAG End\n");
			break;
		case tag_loop:
			printf("TAG Loop (%s)(%p), body:\n",cursor->TMPL_tag.loop.loopname, (void*)cursor);
			print_ast_helper(t,cursor->TMPL_tag.loop.body,level+1);
			break;
		case tag_break:
			printf("TAG Break (%d) -> (%p)\n",cursor->TMPL_tag.breakcont.level, (void*)cursor->TMPL_tag.breakcont.into);
			break;
		case tag_continue:
			printf("TAG Continue (%d)\n",cursor->TMPL_tag.breakcont.level);
			break;
	}
	if(cursor->next != NULL){
		print_ast_helper(t,cursor->next,level);
	}
}
void
print_ast(struct TMPL_templates* t){
	printf("continues: %5d | breaks: %5d | jumping: %5d\n",t->continues, t->breaks, t->jumping);
	printf("-----------------------------\n");
	print_ast_helper(t,t->roottag,0);
}

struct TMPL_token*
TMPL_tokenize(const char* tmplstr, size_t m_strlen){
	if(m_strlen == 0) return NULL;
	struct TMPL_token* first;
	const char* textcursor = tmplstr;
	size_t newlength;
	enum TMPL_tagtype ttype;
	ttype = starts_with_token(tmplstr+1,m_strlen);
	if(*tmplstr == '<' && ttype != tag_null){
		first = scan_tag(textcursor,m_strlen,&newlength);
		first->type = ttype;
	}else{
		first = scan_text(textcursor,m_strlen,&newlength);
		first->type = tag_text;
	}
	textcursor += newlength;
	first->end = textcursor;
	first->length = newlength;
	m_strlen -= newlength;
	struct TMPL_token* tokencursor = first;
	struct TMPL_token* newnode;
	while(*textcursor != '\0'){
		ttype = starts_with_token(textcursor+1,m_strlen);
		if(ttype == tag_null){
			newnode = scan_text(textcursor,m_strlen,&newlength);
			newnode->type = tag_text;
		}else{
			newnode = scan_tag(textcursor,m_strlen,&newlength);
			newnode->type = ttype;
		}
		newnode->last = tokencursor;
		tokencursor->next = newnode;
		textcursor += newlength;
		m_strlen -= newlength;
		tokencursor = newnode;
	}
	return first;
}

struct TMPL_tagnode*
alloc_tagnode(){
	struct TMPL_tagnode* t = malloc(sizeof(struct TMPL_tagnode));
	return t;
}

/*Finds a quoted string, allows for \"*/
size_t
get_quoted_string(const char* start, size_t len){
	size_t i;
	int setup = 0;
	for(i = 0; i < len; i++){
		if(*(start+i) == '\\'){
			setup = 1;
		}else if(*(start+i) == '"'){
			if(setup == 1){
				/*Do nothing, this is \"*/
			}else{
				return i;
			}
		}else{
			setup = 0;
		}
	}
	return i;
}

int
is_whitespace(char c){
	return (c == ' ' || c == '\t' || c == '\n') ? 1 : 0;
}

const char* tokentype_to_str(struct TMPL_token *head){
	switch(head->type){
		case tag_null:
			return "NULL";
		case tag_text:
			return "TEXT";
		case tag_var:
			return "VAR";
		case tag_if:
			return "IF";
		case tag_elseif:
			return "ELSEIF";
		case tag_else:
			return "ELSE";
		case tag_end:
			return "END";
		case tag_loop:
			return "LOOP";
		case tag_break:
			return "BREAK";
		case tag_continue:
			return "CONTINUE";
		default:
			return "UNKNOWN";
	}
}

struct TMPL_tagnode*
parse_text(struct TMPL_token* head, struct TMPL_buf* errbuf){
	struct TMPL_tagnode* t = alloc_tagnode();
	head->into = t;
	t->TMPL_tag.text.start = head->start;
	t->TMPL_tag.text.len = head->length;
	t->type = head->type;
	struct TMPL_tagnode* n = parse(head->next, errbuf);
	t->next = n;
	return t;
}

struct TMPL_tagnode*
parse_else(struct TMPL_token* head, struct TMPL_buf* errbuf){
	struct TMPL_tagnode* branch = parse(head->next,errbuf);
	return branch;
}

struct TMPL_tagnode*
parse_elseif(struct TMPL_token* head, struct TMPL_buf* errbuf){
	struct TMPL_tagnode* t = alloc_tagnode();
	head->into = t;
	const char* start_of_attribs = head->start + TAG_ELSEIF_LENGTH;
	int name_offset = kmp(start_of_attribs,head->length, ATTRIBUTE_VARNAME,ATTRIBUTE_VARNAME_LENGTH);
	const char* start_of_name = start_of_attribs + name_offset + ATTRIBUTE_VARNAME_LENGTH;
	while(is_whitespace(*start_of_name))
		start_of_name++;
	if(*start_of_name != '='){
		bputs(errbuf,"Parsing error: Expected \"=\" in <TMPL_ELSEIF ...> after name near ");
		bputsn(errbuf,head->start, ERR_MSG_LEN);
		bputs(errbuf,"\n");
	}else{
		start_of_name++;
	}
	while(is_whitespace(*start_of_name))
		start_of_name++;
	start_of_name++;//consume "
	size_t name_length = get_quoted_string(start_of_name,head->length);
	char* name = (char*)malloc(sizeof(char)*name_length);
	memcpy(name,start_of_name,name_length);
	name[name_length] = '\0';
	t->TMPL_tag.ifelse.varname = name;

	int testval_offset = kmp(start_of_attribs,head->length, ATTRIBUTE_VALUE,ATTRIBUTE_VALUE_LENGTH);
	if(testval_offset == -1){
		t->TMPL_tag.ifelse.testval = NULL;
	}else{
		const char* start_of_value = start_of_attribs + testval_offset + ATTRIBUTE_VALUE_LENGTH;
		while(is_whitespace(*start_of_value))
			start_of_value++;
		if(*start_of_value != '='){
			bputs(errbuf,"Parsing error: Expected \"=\" in <TMPL_ELSEIF ...> after value near ");
			bputsn(errbuf,head->start,ERR_MSG_LEN);
			bputs(errbuf,"\n");
		}else{
			start_of_value++;//consume =
		}
		while(is_whitespace(*start_of_value))
			start_of_value++;
		start_of_value++;//consume "
		size_t value_length = get_quoted_string(start_of_value,head->length);
		char* value = (char*)malloc(sizeof(char)*value_length);
		memcpy(value,start_of_value,value_length);
		value[value_length] = '\0';
		t->TMPL_tag.ifelse.testval = value;
	}
	struct TMPL_token* cursor = head->next;
	int nest_level = 0;
	struct TMPL_token* fstart = NULL;
	while(nest_level > 0 || cursor->type != tag_end){
		if(fstart == NULL){
			if(cursor->type == tag_elseif){
				fstart = cursor;
			}else if(cursor->type == tag_else){
				fstart = cursor;
			}
		}
		if(cursor->type == tag_if || cursor->type == tag_loop){
			nest_level++;
		}else if(cursor->type == tag_end){
			nest_level--;
		}
		cursor = cursor->next;
	}
	if(fstart != NULL){
		if(fstart->type == tag_elseif){
			t->TMPL_tag.ifelse.fbranch = parse_elseif(fstart,errbuf);
		}else if(fstart->type == tag_else){
			t->TMPL_tag.ifelse.fbranch = parse_else(fstart,errbuf);
		}else{
			t->TMPL_tag.ifelse.fbranch = parse(fstart,errbuf);
		}
	}else{
		t->TMPL_tag.ifelse.fbranch = NULL;
	}

	t->TMPL_tag.ifelse.tbranch = parse(head->next,errbuf);
	t->next = parse(cursor->next,errbuf);
	t->type = tag_elseif;
	return t;

}

struct TMPL_tagnode*
parse_if(struct TMPL_token* head, struct TMPL_buf* errbuf){
	struct TMPL_tagnode* t = alloc_tagnode();
	head->into = t;
	const char* start_of_attribs = head->start + TAG_IF_LENGTH;
	/*Find the name of the varialbe*/	
	int name_offset = kmp(start_of_attribs,head->length,ATTRIBUTE_VARNAME,ATTRIBUTE_VARNAME_LENGTH);
	const char* start_of_name = start_of_attribs + name_offset + ATTRIBUTE_VARNAME_LENGTH;
	while(is_whitespace(*start_of_name))
		start_of_name++;
	if(*start_of_name != '='){
		bputs(errbuf,"Parsing error: Expected \"=\" in <TMPL_IF ...> after name near ");
		bputsn(errbuf, head->start, ERR_MSG_LEN);
		bputs(errbuf,"\n");
	}else{
		start_of_name++;
	}
	while(is_whitespace(*start_of_name))
		start_of_name++;
	start_of_name++;//consume "
	size_t name_length = get_quoted_string(start_of_name,head->length);
	char* name = (char*)malloc(sizeof(char)*name_length);
	memcpy(name,start_of_name,name_length);
	name[name_length] = '\0';
	t->TMPL_tag.ifelse.varname = name;
	/*Find the name to check against*/
	int testval_offset = kmp(start_of_attribs,head->length, ATTRIBUTE_VALUE,ATTRIBUTE_VALUE_LENGTH);
	if(testval_offset == -1){
		t->TMPL_tag.ifelse.testval = NULL;
	}else{
		const char* start_of_value = start_of_attribs + testval_offset + ATTRIBUTE_VALUE_LENGTH;
		while(is_whitespace(*start_of_value))
			start_of_value++;
		if(*start_of_value != '='){
			bputs(errbuf,"Parsing error: Expected \"=\" in <TMPL_IF/TMPL_ELSEIF ...> after value near ");
			bputsn(errbuf,head->start,ERR_MSG_LEN);
			bputs(errbuf,"\n");
		}else{
			start_of_value++;
		}
		while(is_whitespace(*start_of_value))
			start_of_value++;
		start_of_value++;//consume "
		size_t value_length = get_quoted_string(start_of_value,head->length);
		char* value = (char*)malloc(sizeof(char)*value_length);
		memcpy(value,start_of_value,value_length);
		value[value_length] = '\0';
		t->TMPL_tag.ifelse.testval = value;
	}
	/*Find the true branch*/
	struct TMPL_token* cursor = head->next;
	int nest_level = 0;
	struct TMPL_token* fstart = NULL;
	while(nest_level > 0 || cursor->type != tag_end){
		if(fstart == NULL){
			if(cursor->type == tag_elseif){
				fstart = cursor;
			}else if(cursor->type == tag_else){
				fstart = cursor;
			}
		}
		if(cursor->type == tag_if || cursor->type == tag_loop){
			nest_level++;
		}else if(cursor->type == tag_end){
			nest_level--;
		}
		cursor = cursor->next;
	}
	if(fstart != NULL){
		if(fstart->type == tag_elseif){
			t->TMPL_tag.ifelse.fbranch = parse_elseif(fstart,errbuf);
		}else if(fstart->type == tag_else){
			t->TMPL_tag.ifelse.fbranch = parse_else(fstart,errbuf);
		}else{
			t->TMPL_tag.ifelse.fbranch = parse(fstart,errbuf);
		}
	}else{
		t->TMPL_tag.ifelse.fbranch = NULL;
	}

	t->TMPL_tag.ifelse.tbranch = parse(head->next,errbuf);
	/*Walk the tbranch and try to find if we have elseifs*/
	t->next = parse(cursor->next,errbuf);
	t->type = tag_if;
	return t;
}


struct TMPL_tagnode*
parse_loop(struct TMPL_token* head, struct TMPL_buf* errbuf){
	struct TMPL_tagnode* t = alloc_tagnode();
	head->into = t;
	const char* loop_start = head->start + TAG_LOOP_LENGTH;
	int loop_length = head->length - TAG_LOOP_LENGTH;
	int name_offset = kmp(loop_start,loop_length, ATTRIBUTE_VARNAME, ATTRIBUTE_VARNAME_LENGTH);
	if(name_offset == -1 && DEBUGGING){
		bputs(errbuf,"Parsing error: Could not find name attribute for loop near\n");
		bputsn(errbuf,head->start, ERRBUF_HINTLEN);
		return NULL;
	}
	if(name_offset >= 0){
		const char* start_of_name = loop_start + name_offset + ATTRIBUTE_VARNAME_LENGTH;
		while(is_whitespace(*start_of_name))
			start_of_name++;
		if(*start_of_name != '='){
			bputs(errbuf,"Parsing error: Expected \"=\" in <TMPL_LOOP ...> after name near ");
			bputsn(errbuf, head->start, ERR_MSG_LEN);
			bputs(errbuf,"\n");
		}else{
			start_of_name++;//consume '='
		}
		while(is_whitespace(*start_of_name))
			start_of_name++;
		start_of_name++;//consume "
		size_t name_size = get_quoted_string(start_of_name,head->length);
		char* loopname = (char*)malloc(sizeof(char)*(name_size + 1));
		memcpy(loopname,start_of_name,name_size);
		loopname[name_size] = '\0';
		t->TMPL_tag.loop.loopname = loopname;

	}
	t->type = tag_loop;
	int nest_level = 0;
	struct TMPL_token* cursor = head->next;
	while(cursor != NULL && (nest_level > 0 || cursor->type != tag_end)){
		if(cursor == NULL){
			bputs(errbuf,"Parse error : tried parsing loop and hit end of stream near\n");
			bputsn(errbuf,head->start,ERRBUF_HINTLEN);
			return NULL;
		}
		if(cursor->type == tag_if ||
		   cursor->type == tag_loop){
			nest_level++;
		}else if(cursor->type == tag_end){
			nest_level--;
		}
		cursor = cursor->next;
	}
	if(cursor == NULL){
		bputs(errbuf,"Parse error: Tried parsing loop and hit end of stream near\n");
		bputsn(errbuf,head->start,ERRBUF_HINTLEN);
		return NULL;
	}
	t->next = parse(cursor->next,errbuf);
	t->TMPL_tag.loop.body = parse(head->next,errbuf);
	return t;
}

const char end_str[] = "";
struct TMPL_tagnode* parse_end(struct TMPL_token* head, struct TMPL_buf* errbuf){
	struct TMPL_tagnode* t = alloc_tagnode();
	if(t == NULL){
		bputs(errbuf,"Parse error: Failed to create a tag node");
		return NULL;
	}
	head->into = t;
	t->TMPL_tag.text.start = end_str;
	t->TMPL_tag.text.len = 0;
	t->type = tag_text;
	t->next = NULL;
	return t;
}

/*Parses the <TMPL_VAR ...> tokens*/
struct TMPL_tagnode*
parse_variable(struct TMPL_token* head, struct TMPL_buf* errbuf){
	struct TMPL_tagnode* t = alloc_tagnode();
	head->into =t;
	/*<TMPL_VAR name="..." default="...">
	           ^*/
	const char* start_of_attribs = head->start + TAG_VAR_LENGTH;
	/*Find the length of attributes*/
	int attribs_length = head->length - TAG_VAR_LENGTH;
	/*Find where the "name" attribute is*/
	int in_name = kmp(start_of_attribs,attribs_length,ATTRIBUTE_VARNAME,ATTRIBUTE_VARNAME_LENGTH);
	/*Find where the "default" attribute is*/
	int in_default = kmp(start_of_attribs,attribs_length,ATTRIBUTE_DEFAULT,ATTRIBUTE_DEFAULT_LENGTH);
	if(in_name == -1){
		bputs(errbuf,"Parsing error: Could not find \"name\" field in <TMPL_VAR ...> near ");
		bputsn(errbuf,head->start,ERR_MSG_LEN);
		bputs(errbuf,"\n");
	}
	if(in_name >= 0){
		const char* start_of_name = start_of_attribs + in_name + ATTRIBUTE_VARNAME_LENGTH;
		while(is_whitespace(*start_of_name))
			start_of_name++;
		if(*start_of_name != '='){
			bputs(errbuf,"Parsing error: Expected \"=\" in <TMPL_VAR ...> after name near ");
			bputsn(errbuf,head->start, ERR_MSG_LEN);
			bputs(errbuf,"\n");
		}else{
			start_of_name++;//consume =
		}
		while(is_whitespace(*start_of_name))
			start_of_name++;
		start_of_name++; //consume "
		size_t name_size = get_quoted_string(start_of_name,head->length);
		char* name = (char*)malloc(sizeof(char)*(name_size + 1));
		memcpy(name,start_of_name,name_size);
		name[name_size] = '\0';
		t->TMPL_tag.var.varname = name;
		t->TMPL_tag.var.name_len = name_size;
	}
	if(in_default >= 0){
		const char* start_of_default = start_of_attribs + in_default + ATTRIBUTE_DEFAULT_LENGTH;
		while(is_whitespace(*start_of_default))
			start_of_default++;
		if(*start_of_default != '='){
			bputs(errbuf,"Parsing error: Expected \"=\" in <TMPL_VAR ...> after default near ");
			bputsn(errbuf,head->start, ERR_MSG_LEN);
			bputs(errbuf,"\n");
		}else{
			start_of_default++;//consume =
		}
		while(is_whitespace(*start_of_default))
			start_of_default++;
		start_of_default++; //consume "
		size_t default_size = get_quoted_string(start_of_default,head->length);
		char* def = (char*) malloc(sizeof(char)*(default_size + 1));
		def[default_size] = '\0';
		memcpy(def,start_of_default,default_size);
		t->TMPL_tag.var.defaultval = def;
		t->TMPL_tag.var.default_len = default_size;
	}else{
		t->TMPL_tag.var.defaultval = NULL;
		t->TMPL_tag.var.default_len = 0;
	}
	t->type = tag_var;
	t->next = parse(head->next,errbuf);
	return t;
}

struct TMPL_tagnode*
parse_continue(struct TMPL_token* head, struct TMPL_buf* errbuf){
	struct TMPL_tagnode* t = alloc_tagnode();
	head->into = t;
	const char* start_of_attribs = head->start + TAG_CONTINUE_LENGTH;
	unsigned int level = 1; //how many loops to continue
	/*We might have multiple loops to continue through*/
	int level_offset = kmp(start_of_attribs,head->length,ATTRIBUTE_LEVEL, ATTRIBUTE_LEVEL_LENGTH);
	if(level_offset != -1){//level found
		const char* start_of_level = start_of_attribs + level_offset + ATTRIBUTE_LEVEL_LENGTH;
		while(is_whitespace(*start_of_level))
			start_of_level++;
		if(*start_of_level != '='){
			if(*start_of_level == '>'){
				level = 1;
			}else{
				bputs(errbuf,"Parsing error: Expected \"=\" in <TMPL_continue ...> near ");
				bputsn(errbuf,head->start,ERR_MSG_LEN);
				bputs(errbuf,"\n");
			}
		}else{
			start_of_level++;
			while(is_whitespace(*start_of_level)){
				start_of_level++;
			}
			sscanf(start_of_level,"%u",&level);
		}
	}
	int y = level;
	struct TMPL_token* cursor = head;
	while(y > 0){
		//Scan backwards until we find the loop we're in
		while(cursor != NULL && cursor->type != tag_loop){
			cursor = cursor->last;
		}
		y--;
		if(y > 0 && cursor == NULL){
			size_t msglen = snprintf(NULL,0,"Parsing error: Continue was %d levels, but was only nested %d levels deep\n",level, level - y);
			char errmsg[msglen];
			sprintf(errmsg, "Parsing error: Continue was %d levels, but was only nested %d levels deep\n",level, level - y);
			bputs(errbuf,errmsg);
		}
	}
	t->TMPL_tag.breakcont.level = level;
	t->next = parse(head->next,errbuf);
	t->type = tag_continue;
	return t;
}

struct TMPL_tagnode*
parse_break(struct TMPL_token* head, struct TMPL_buf* errbuf){
	struct TMPL_tagnode* t = alloc_tagnode();
	head->into = t;
	const char* start_of_attribs = head->start + TAG_BREAK_LENGTH;
	unsigned int level = 1; //how many loops to continue
	/*We might have multiple loops to continue through*/
	int level_offset = kmp(start_of_attribs,head->length,ATTRIBUTE_LEVEL, ATTRIBUTE_LEVEL_LENGTH);
	if(level_offset != -1){ //level found
		const char* start_of_level = start_of_attribs + level_offset + ATTRIBUTE_LEVEL_LENGTH;
		while(is_whitespace(*start_of_level))
			start_of_level++;
		if(*start_of_level != '='){
			bputs(errbuf,"Parsing error: Expected \"=\" in <TMPL_break ...> near ");
			bputsn(errbuf,head->start,ERR_MSG_LEN);
			bputs(errbuf,"\n");
		}else{
			start_of_level++;
			while(is_whitespace(*start_of_level)){
				start_of_level++;
			}
			sscanf(start_of_level,"%u",&level);
		}
	}
	t->TMPL_tag.breakcont.level = level;
	int y = level;
	struct TMPL_token* cursor = head;
	while(y > 0){
		//Scan backwards until we find the loop we're in
		while(cursor != NULL && cursor->type != tag_loop){
			char token_text[cursor->length+1];
			memcpy(token_text, cursor->start, cursor->length);
			token_text[cursor->length] = '\0';
			cursor = cursor->last;
		}
		y--;
		if(y > 0 && cursor == NULL){
			exit(-1);
			size_t msglen = snprintf(NULL,0,"Parsing error: Break was %d levels, but was only nested %d levels deep\n",level,level - y);
			char errmsg[msglen];
			sprintf(errmsg,"Parsing error: Break was %d levels, but was only nested %d levels deep\n",level,level - y);
			bputs(errbuf,errmsg);
		}else if(y > 0){
			cursor = cursor->last; //move back one
		}//else break
	}
	t->next = NULL;
	t->TMPL_tag.breakcont.into = cursor->into;
	t->type = tag_break;
	return t;
}

struct TMPL_varlist*
TMPL_alloc_varlist(){
	struct TMPL_varlist* ret = (struct TMPL_varlist*)malloc(sizeof(struct TMPL_varlist));
	ret->map = hashmap_new();
	ret->parent = NULL;
	return ret;
}


int
TMPL_free_hashmapitems(any_t a, any_t b){
	(void)(a);/*Unused parameter*/
	struct TMPL_varitem* vi = (struct TMPL_varitem*)b;
	TMPL_free_varitem(vi);
	return MAP_OK;
}

void
TMPL_free_varlist(struct TMPL_varlist* vl){
	hashmap_iterate(vl->map,TMPL_free_hashmapitems,NULL);
	hashmap_free(vl->map);
	free(vl);
}

struct TMPL_loop*
TMPL_alloc_loop(){
	struct TMPL_loop* ret = (struct TMPL_loop*)malloc(sizeof(struct TMPL_loop));
	if(ret == NULL) return NULL;
	ret->loop_len = 0;
	ret->varlist = NULL;
	ret->next = NULL;
	ret->tail = NULL;
	return ret;
}

void
TMPL_free_loop(struct TMPL_loop* tl){
	if(tl->next != NULL){
		TMPL_free_loop(tl->next);
	}
	if(tl->varlist != NULL)
		TMPL_free_varlist(tl->varlist);
	free(tl);
}

int TMPL_add_varlist_to_loop(struct TMPL_loop* tl,struct TMPL_varlist* vl){
	vl->parent = tl;
	if(tl->loop_len == 0){/*Add the first node*/
		tl->varlist = vl;
		tl->tail = tl;
		tl->loop_len++;
	}else{
		struct TMPL_loop* new = TMPL_alloc_loop();
		if(new == NULL) return -1;
		new->varlist = vl;
		tl->tail->next = new;
		tl->tail = new;
	}
	return 0;
}

/*Returns 0 for "OK" or -1 for "out of memory"*/
int
TMPL_add_loop_to_varlist(struct TMPL_varlist* vl, const char* name, struct TMPL_loop* l){
	struct TMPL_varitem* vi = TMPL_alloc_varitem();
	vi->type = vartype_loop;
	vi->item.l = l;
	l->parent = vl;
	int err = hashmap_put(vl->map,(char*)name,vi);
	if(err == MAP_OK) return 0;
	return -1;
}



/*Parses tokens into a syntax tree*/
struct TMPL_tagnode*
parse(struct TMPL_token* head, struct TMPL_buf* errbuf){
	struct TMPL_tagnode* root;
	if(head == NULL){
		return NULL;
	}
	switch(head->type){
		case tag_text:
			root = parse_text(head,errbuf);
			break;
		case tag_var:
			root = parse_variable(head,errbuf);
			break;
		case tag_loop:
			root = parse_loop(head,errbuf);
			break;
		case tag_end:
			//A 0-sized string to make break fall out right
			root = parse_end(head,errbuf);
			break;
		case tag_if:
			root = parse_if(head,errbuf);
			break;
		case tag_elseif:
			root = NULL;
			break;
		case tag_else:
			root = NULL;
			break;
		case tag_continue:
			root = parse_continue(head,errbuf);
			break;
		case tag_break:
			root = parse_break(head,errbuf);
			break;
		default:
			exit(-1);
			break;
	}
	if(errbuf->total_len > 0){
		printf("Error parsing %p\n",(void*)head);
		size_t dummy;
		printf("Error: %s\n",bstringify(errbuf,&dummy));
		return NULL;
	}
	return root;
}

struct TMPL_templates*
alloc_templates(){
	struct TMPL_templates* t = malloc(sizeof(struct TMPL_templates));
	return t;
}

struct TMPL_templates*
compile(const char* tmplstr){
	size_t slen = strlen(tmplstr);
	struct TMPL_templates* ret = alloc_templates();
	ret->out = alloc_tmpl_buf();
	ret->errout = alloc_tmpl_buf();
	ret->breaks = 0;
	ret->continues = 0;
	ret->jumping = 0;
	struct TMPL_token* tokens = TMPL_tokenize(tmplstr,slen);
	struct TMPL_tagnode* ast = parse(tokens,ret->errout);
	if(ast == NULL){
	}else{
		ret->roottag = ast;
		ret->cursor = ret->roottag;
	}
	return ret;
}

void
advance_cursor(struct TMPL_templates* t){
	if(t->cursor != NULL && t->cursor->type != tag_end)
		t->cursor = t->cursor->next;
}

int
render_variable(struct TMPL_templates* t, struct TMPL_varlist* varlist){
	struct TMPL_varitem* vi;
	char* varname = t->cursor->TMPL_tag.var.varname;
	int err = hashmap_get(varlist->map,varname,(void**)&vi);
	if(err == MAP_OK){
		bputs(t->out,vi->item.s);
	}else if(err == MAP_MISSING){
		if(t->cursor->TMPL_tag.var.defaultval != NULL){
			bputs(t->out,t->cursor->TMPL_tag.var.defaultval);
		}else{
			printf("Variable not bound, and no default\n");
			/*Error, not bound and no default*/
			return -1;
		}
	}else{
		printf("Not MAP_OK or MAP_MISSING: %d\n", err);
		return -1;
	}
	advance_cursor(t);
	return 0;
}


int
render_text(struct TMPL_templates* t, struct TMPL_varlist* varlist){
	(void)(varlist); /*Unused parameter*/
	struct TMPL_buf* buf = t->out;
	char* text = (char*)t->cursor->TMPL_tag.text.start;
	size_t length = t->cursor->TMPL_tag.text.len;
	bputsn(buf,text,length);
	advance_cursor(t);
	return 0;
}

int
print_pair(any_t indent, any_t b){
	struct TMPL_varitem* vi = (struct TMPL_varitem*)b;
	char *varstring;
	switch(vi->type){
	case 0:
		varstring = "Null";
		break;
	case 1:
		varstring = "Loop";
		break;
	case 2:
		varstring = "Var";
		break;
	default:
		varstring = "Error";
	}
	printf("Print pair, varitem is %p, type is %d (%s)\n",(void*)vi,(int)vi->type, varstring);
	int* ip = (int*)indent;
	int ind = *ip;
	if(vi->type == vartype_var){
		int i;
		for(i = 0; i < ind; i++)
			printf("\t");
		printf("%s\n",vi->item.s);
	}else{
		struct TMPL_loop* cursor;
		printf("{\n");
		ind++;
		/*If the loop doesn't have any varlists added, the cursor's varlist will be null*/
		for(cursor = vi->item.l; cursor != NULL && cursor->varlist != NULL; cursor = cursor->next){
			printf("First iteration though, cursor was %p\n",(void*)cursor);
			print_varlist_helper(cursor->varlist,ind);
		}
		printf("}\n");
	}
	return MAP_OK;
}

void
print_varlist_helper(struct TMPL_varlist* vl, int indent){
	hashmap_iterate(vl->map, print_pair,&indent);
}

void
print_varlist(struct TMPL_varlist* vl){
	print_varlist_helper(vl,0);
}

int
render_if(struct TMPL_templates* t, struct TMPL_varlist* varlist){
	char* varname = t->cursor->TMPL_tag.ifelse.varname;
	char* testval = t->cursor->TMPL_tag.ifelse.testval;
	struct TMPL_varitem* vi;
	int err;
	err = hashmap_get(varlist->map,varname,(void**)&vi);
	struct TMPL_templates* nt = (struct TMPL_templates*)malloc(sizeof(struct TMPL_templates));
	nt->out = t->out;
	nt->errout = t->errout;
	nt->breaks = t->breaks;
	nt->continues = t->continues;
	nt->jumping = 0;
	if(err == MAP_OK){
		//These two if statements can't be combined because of
		//the condition for the elseif
		if(testval == NULL || strcmp(vi->item.s, testval) == 0){
			nt->roottag = t->cursor->TMPL_tag.ifelse.tbranch;
			nt->cursor = nt->roottag;
			err = TMPL_render_helper(nt,varlist);
			if(nt->jumping)
				t->cursor = nt->cursor;
			t->breaks += nt->breaks;
			t->continues = nt->continues;
			t->jumping = nt->jumping;
		}else{

		}

	}else if(t->cursor->TMPL_tag.ifelse.fbranch != NULL){
		nt->roottag = t->cursor->TMPL_tag.ifelse.fbranch;
		nt->cursor = nt->roottag;
		err = TMPL_render_helper(nt,varlist);
		if(nt->jumping)
			t->cursor = nt->cursor;
		t->breaks += nt->breaks;
		t->continues = nt->continues;
		t->jumping = nt->jumping;
	}else{
	}
	advance_cursor(t);
	return err;
}

/*Exactly the same thing as if*/
int
render_elseif(struct TMPL_templates* t, struct TMPL_varlist* varlist){
	return render_if(t,varlist);
}

int
resolve_name(struct TMPL_varlist* varlist, char* name,struct TMPL_varitem** item){
	return hashmap_get(varlist->map,name,(void*)item);
	/*
	struct TMPL_varlist* cursor = varlist;
	int err;
	do{
		err = hashmap_get(cursor->map,name,(void*)item);
		cursor = cursor->parent;
	}while(cursor != NULL && err == MAP_MISSING);
	if(err == MAP_MISSING){
		return MAP_MISSING;
	}
	return MAP_OK;
	*/
}

int
render_break(struct TMPL_templates* t, struct TMPL_varlist* varlist){
	(void)(varlist); /*Unused parameter*/
	t->breaks += t->cursor->TMPL_tag.breakcont.level;
	t->jumping = 1;
	/*t->cursor = t->cursor->TMPL_tag.breakcont.into->next;*/
	t->cursor = t->cursor->TMPL_tag.breakcont.into;
	return 0;
}

int
render_continue(struct TMPL_templates* t, struct TMPL_varlist* varlist){
	(void)(varlist); /*Unused parameter*/
	t->continues = t->continues + t->cursor->TMPL_tag.breakcont.level;
	t->jumping = 1;
	return 0;
}

int
render_loop(struct TMPL_templates* t, struct TMPL_varlist* varlist){
	char* loopname = t->cursor->TMPL_tag.loop.loopname;
	struct TMPL_tagnode* loopnode = t->cursor;
	struct TMPL_varitem* loop;
	int err;
	err = resolve_name(varlist,loopname,&loop);
	printf("When resolving name, err is %d\n",err);
	/*What should happen when we get to a loop that does not have a name?
	  We follow the precident set for variables, and throw an error.*/
	if(err != MAP_OK){
		bputs(t->errout,"Render error: Variable \"");
		bputs(t->errout,loopname);
		bputs(t->errout,"\" was not bound to a value\n");
		return -1;
	}
	struct TMPL_templates* nt = (struct TMPL_templates*)malloc(sizeof(struct TMPL_templates));
	nt->out = t->out;
	nt->errout = t->errout;
	nt->roottag = t->cursor->TMPL_tag.loop.body;
	nt->cursor = nt->roottag;
	nt->breaks = t->breaks;
	nt->continues = t->continues;
	nt->jumping = 0;
	struct TMPL_loop* cursor;
	/*If the loop has no items, it's varlist will be null*/
	for(cursor = loop->item.l; cursor != NULL && cursor->varlist != NULL; cursor = cursor->next){
		nt->cursor = nt->roottag;
		if(err != 0){
		}
		if(t->jumping){
			if(t->breaks > 0){
				t->breaks--;
				if(t->breaks == 0){
					t->jumping = 0;
				}
				break;
			}
			if(t->continues > 0){
				t->continues--;
				if(t->continues == 0){
					t->jumping = 0;
				}
			}
		}else{
			err = TMPL_render_helper(nt,cursor->varlist);
			t->breaks += nt->breaks;
			t->continues += nt->continues;
			t->jumping += nt->jumping;
			if(nt->jumping){
				t->cursor = nt->cursor;
			}
			nt->breaks = 0;
			nt->continues = 0;
			nt->jumping = 0;
		}
	}
	if(t->jumping > 0){
		t->breaks--;
		if(t->breaks == 0){
			t->jumping = 0;
		}
	}
	if(t->cursor == loopnode)
		advance_cursor(t);
	free(nt);
	return err;
}

int
render_any(struct TMPL_templates* t, struct TMPL_varlist* varlist){
	/*Interpret the template*/
	if(t->jumping) return 0;
	int err;
	switch(t->cursor->type){
		case tag_text:
			err = render_text(t,varlist);
			if(err < 0){
			}
			break;
		case tag_var:
			err = render_variable(t,varlist);
			if(err < 0){
			}
			break;
		case tag_loop:
			err = render_loop(t,varlist);
			if(err < 0){
			}
			break;
		case tag_if:
			err = render_if(t,varlist);
			if(err < 0){
			}
			break;
		case tag_elseif:
			err = render_elseif(t,varlist);
			if(err < 0){
			}
			break;
		case tag_break:
			err = render_break(t,varlist);
			break;
		default:
			exit(-1);
			break;
	}
	return err;
}

int
TMPL_render_helper(struct TMPL_templates* t, struct TMPL_varlist* varlist){
	int err;
	while(t->cursor != NULL && t->jumping == 0 && err == 0){
		err = render_any(t,varlist);
	}
	return err;
}

char*
TMPL_render(struct TMPL_templates* t, struct TMPL_varlist* varlist, size_t* size_p){
	int err;
	if(t->out != NULL){
		free_tmpl_buf(t->out);
	}
	t->out = alloc_tmpl_buf();
	t->cursor = t->roottag;
	err = TMPL_render_helper(t,varlist);
	if(err){
		return NULL;
	}
	char* ret  = bstringify(t->out,size_p);
	return ret;
}

const char*
TMPL_err(struct TMPL_templates* t, size_t* size){
	return bstringify(t->errout,size);
}

int
TMPL_alloc_template(const char* tmplstr, struct TMPL_templates **t){
	struct TMPL_templates* n = compile(tmplstr);

	if(n != NULL){
		*t = n;
		return 0;
	}else{
		TMPL_free_template(n);
		return -1;
	}
}

void
TMPL_free_template(struct TMPL_templates* t){
	free_tmpl_buf(t->out);
	free_tmpl_buf(t->errout);
	TMPL_free_tagnode(t->roottag);
	free(t);
}

void
TMPL_free_tagnode(struct TMPL_tagnode* tn){
	switch(tn->type){
		case tag_text:
			break;
		case tag_var:
			free(tn->TMPL_tag.var.varname);
			if(tn->TMPL_tag.var.defaultval != NULL){
				free(tn->TMPL_tag.var.defaultval);
			}
			break;
		case tag_if:
		case tag_elseif:
		case tag_else:
			free(tn->TMPL_tag.ifelse.varname);
			if(tn->TMPL_tag.ifelse.testval != NULL)
				free(tn->TMPL_tag.ifelse.testval);
			TMPL_free_tagnode(tn->TMPL_tag.ifelse.tbranch);
			if(tn->TMPL_tag.ifelse.fbranch){
				TMPL_free_tagnode(tn->TMPL_tag.ifelse.fbranch);
			}
			break;
		case tag_loop:
			free(tn->TMPL_tag.loop.loopname);
			TMPL_free_tagnode(tn->TMPL_tag.loop.body);
			break;
		case tag_null:
		case tag_break:
		case tag_continue:
		case tag_end:
			break;
	}
	if(tn->next != NULL)
		TMPL_free_tagnode(tn->next);
	free(tn);
}

char*
TMPL_get_error(struct TMPL_templates* t){
	size_t dummy;
	return bstringify(t->errout,&dummy);
}