/*
 * 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)
 *
 * Copyright 2017 Alexander M. Pickering  Distributed under the terms
 * of the GNU General Public License (GPL)
 */

#ifndef _CTEMPLATE_H
#define _CTEMPLATE_H

#define MAX_TEMPLATE_LENGTH 2147384647

#define ERRBUF_HINTLEN 50

//Length of error messages
#define ERR_MSG_LEN 500

/* A variable list, holds key-value pairs as (string -> (string | loop)) */
struct TMPL_varlist;

/* A list structure, holds an array of varlists to be looped over*/
struct TMPL_loop;

/* Holdes all the data needed for a template*/
struct TMPL_templates;

/* Adds a variable to a variable list under a certain name */
void TMPL_add_var_to_varlist(struct TMPL_varlist* vl, const char* name, const char* value);

/* Adds a loop to a variable list under a certain name */
void TMPL_add_loop_to_varlist(struct TMPL_varlist* vl, const char* name, struct TMPL_loop* loop);

/* Adds a variable list as one of the varlists in a loop */
void TMPL_add_varlist_to_loop(struct TMPL_loop* l, struct TMPL_varlist* vl);

/* Create a new varlist. If allocation fails, the struct retuned will be NULL */
struct TMPL_varlist* TMPL_alloc_varlist(void);
/* Frees a varlist (and recursively, any loops under it, any varlists under those loops, ect.) */
void TMPL_free_varlist(struct TMPL_varlist* t);

/* Allocate a new template. If allocation fails, the retunred value will be non-zero*/
int TMPL_alloc_template(const char* tmplstr, struct TMPL_templates **t);
/* Free a template. Do not use the string returned by TMPL_render() the template is freed */
void TMPL_free_template(struct TMPL_templates* t);

/* Create a new loop. If allocation fails, the struct returned will be NULL */
struct TMPL_loop* TMPL_alloc_loop(void);
/* Free a loop. If the loop is added to a varlist, just call free on the varlist
and any loops that have been added to it will automatically be freed.*/
void TMPL_free_loop(struct TMPL_loop* tl);

/* Takes a template and varlist, and collapses it into a string. 
If size_p is non-null, the size of the resulting string will be placed in it.
If any errors happened the t->error will be non-zero and the error can be
retreived with TMPL_err(t,&size)*/
char* TMPL_render(struct TMPL_templates* t, struct TMPL_varlist* varlist, size_t* size_p);
/*Returns a string error that might give more information*/
const char* TMPL_err(struct TMPL_templates* t,size_t* size);

/* A debug functions */
void print_varlist(struct TMPL_varlist* vl);
void print_ast(struct TMPL_templates* root);

#endif