/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */

/* Cherokee
 *
 * Authors:
 *      Alvaro Lopez Ortega <alvaro@alobbs.com>
 *
 * Copyright (C) 2001-2014 Alvaro Lopez Ortega
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU General Public
 * License as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 */

#include "common-internal.h"
#include "template.h"

/* Template Replacements
 */

typedef struct {
	cherokee_list_t            listed;
	cuint_t                    pos;
	cherokee_template_token_t *token;
	struct {
		ssize_t            begin;
		ssize_t            end;
	} slice;
} cherokee_template_replacement_t;

#define TEMPLATE_REPL(x) ((cherokee_template_replacement_t *)(x))

static ret_t
replacement_new (cherokee_template_replacement_t **repl)
{
	CHEROKEE_NEW_STRUCT (n, template_replacement);

	n->pos         = 0;
	n->token       = NULL;
	n->slice.begin = -1;
	n->slice.end   = -1;
	INIT_LIST_HEAD (&n->listed);

	*repl = n;
	return ret_ok;
}

static ret_t
replacement_free (cherokee_template_replacement_t *repl)
{
	free (repl);
	return ret_ok;
}


/* Template Tokens
 */

static ret_t
token_new (cherokee_template_token_t **token)
{
	CHEROKEE_NEW_STRUCT (n, template_token);

	INIT_LIST_HEAD (&n->listed);
	cherokee_buffer_init (&n->key);

	n->func  = NULL;
	n->param = NULL;

	*token = n;
	return ret_ok;
}

static ret_t
token_free (cherokee_template_token_t *token)
{
	cherokee_buffer_mrproper (&token->key);

	free (token);
	return ret_ok;
}


/* Template
 */

ret_t
cherokee_template_init (cherokee_template_t *tem)
{
	cherokee_buffer_init (&tem->text);
	INIT_LIST_HEAD (&tem->tokens);
	INIT_LIST_HEAD (&tem->replacements);

	return ret_ok;
}


ret_t
cherokee_template_mrproper (cherokee_template_t *tem)
{
	cherokee_list_t *i, *tmp;

	list_for_each_safe (i, tmp, &tem->tokens) {
		token_free (TEMPLATE_TOKEN(i));
	}

	list_for_each_safe (i, tmp, &tem->replacements) {
		replacement_free (TEMPLATE_REPL(i));
	}

	cherokee_buffer_mrproper (&tem->text);
	return ret_ok;
}


ret_t
cherokee_template_new_token (cherokee_template_t        *tem,
                             cherokee_template_token_t **token)
{
	ret_t ret;

	ret = token_new (token);
	if (unlikely (ret != ret_ok))
		return ret;

	cherokee_list_add (&(*token)->listed, &tem->tokens);
	return ret_ok;
}


ret_t
cherokee_template_set_token  (cherokee_template_t        *tem,
                              const char                 *name,
                              cherokee_tem_repl_func_t    func,
                              void                       *param,
                              cherokee_template_token_t **token)
{
	ret_t                      ret;
	cherokee_template_token_t *n;

	ret = cherokee_template_new_token (tem, &n);
	if (unlikely (ret != ret_ok))
		return ret;

	cherokee_buffer_add (&n->key, name, strlen(name));
	n->func  = func;
	n->param = param;

	if (token) {
		*token = n;
	}

	return ret_ok;
}


ret_t
cherokee_template_parse (cherokee_template_t *tem,
                         cherokee_buffer_t   *incoming)
{
	char              *token1;
	char              *token2;
	char              *slice1;
	char              *slice2;
	char              *s;
	cherokee_list_t   *i;
	ssize_t            slice_begin;
	ssize_t            slice_end;
	ret_t              ret          = ret_ok;
	char              *p            = incoming->buf;
	char              *end          = incoming->buf + incoming->len;
	cherokee_buffer_t  token        = CHEROKEE_BUF_INIT;

	while (p < end) {
		cherokee_template_replacement_t *repl;

		/* Find the next token
		 */
		token1 = strstr (p, "${");
		if (token1 == NULL) {
			cherokee_buffer_add (&tem->text, p, end-p);
			ret = ret_ok;
			goto out;
		}

		token2 = strchr (token1, '}');
		if (token2 == NULL) {
			cherokee_buffer_add (&tem->text, p, end-p);
			ret = ret_ok;
			goto out;
		}

		/* Text slices support
		 */
		s           = NULL;
		slice_begin = CHEROKEE_BUF_SLIDE_NONE;
		slice_end   = CHEROKEE_BUF_SLIDE_NONE;

		if ((token2 < end) && (token2[1] == '[')) {
			s = slice1 = token2+2;

			/* First number */
			if ((s < end) && (*s == '-')) s++;
			while ((s < end) && ((*s >= '0') && (*s <= '9'))) s++;

			/* Check of colon */
			if (*s != ':') {
				slice1 = NULL;
			} else {
				*s = '\0';
				slice_begin = strtol (slice1, NULL, 10);
				*s = ':';
				slice1 = slice2 = ++s;

				/* Look for the end */
				if ((s < end) && (*s == '-')) s++;
				while ((s < end) && ((*s >= '0') && (*s <= '9'))) s++;

				if (*s != ']') {
					slice_begin = CHEROKEE_BUF_SLIDE_NONE;
				} else {
					*s = '\0';
					slice_end = strtol (slice1, NULL, 10);
					*s = ']';
				}
			}
		}

		/* Copy the text before the token
		 */
		cherokee_buffer_add (&tem->text, p, token1 - p);

		cherokee_buffer_clean (&token);
		cherokee_buffer_add   (&token, token1+2, (token2-token1)-2);

		/* Create the replacement object
		 */
		ret = replacement_new (&repl);
		if (ret != ret_ok) {
			goto out;
		}

		repl->pos         = tem->text.len;
		repl->slice.begin = slice_begin;
		repl->slice.end   = slice_end;

		cherokee_list_add_tail (&repl->listed, &tem->replacements);

		/* Assign the token object
		 */
		list_for_each (i, &tem->tokens) {
			cherokee_template_token_t *token_i = TEMPLATE_TOKEN(i);

			if (cherokee_buffer_cmp_buf (&token, &token_i->key) == 0) {
				repl->token = token_i;
				break;
			}
		}

		if (unlikely (repl->token == NULL)) {
			LOG_ERROR (CHEROKEE_ERROR_TEMPLATE_NO_TOKEN, token.buf);
			ret = ret_error;
			goto out;
		}

		/* Get ready for the next iteration
		 */
		if (s != NULL) {
			p = s + 1;
			s = NULL;
		} else  {
			p = token2+1;
		}
	}

out:
	cherokee_buffer_mrproper (&token);
	return ret;
}

ret_t
cherokee_template_parse_file (cherokee_template_t *tem,
                              const char          *file)
{
	ret_t             ret;
	cherokee_buffer_t tmp = CHEROKEE_BUF_INIT;

	ret = cherokee_buffer_read_file (&tmp, (char *)file);
	if (ret != ret_ok)
		return ret;

	ret = cherokee_template_parse (tem, &tmp);
	if (ret != ret_ok) {
		ret = ret_error;
		goto out;
	}

	ret = ret_ok;

out:
	cherokee_buffer_mrproper (&tmp);
	return ret;
}


ret_t
cherokee_template_render (cherokee_template_t *tem,
                          cherokee_buffer_t   *output,
                          void                *param)
{
	ret_t                            ret;
	cherokee_list_t                 *i;
	cherokee_template_replacement_t *repl;
	cuint_t                          pos   = 0;

	list_for_each (i, &tem->replacements) {
		repl = TEMPLATE_REPL(i);

		/* Copy the string preceding the token
		 */
		if (repl->pos > 0) {
			cherokee_buffer_add (output,
			                     tem->text.buf + pos,
			                     repl->pos - pos);
		}

		/* Add the token (slide)
		 */
		if ((repl->slice.begin != CHEROKEE_BUF_SLIDE_NONE) ||
		    (repl->slice.end   != CHEROKEE_BUF_SLIDE_NONE))
		{
			cherokee_buffer_t tmp = CHEROKEE_BUF_INIT;

			ret = repl->token->func (tem, repl->token, &tmp, param);
			if (unlikely (ret != ret_ok)) {
				cherokee_buffer_mrproper (&tmp);
				return ret;
			}

			ret = cherokee_buffer_add_buffer_slice (output, &tmp, repl->slice.begin, repl->slice.end);
			if (unlikely (ret != ret_ok)) {
				cherokee_buffer_mrproper (&tmp);
				return ret;
			}

			cherokee_buffer_mrproper (&tmp);

		/* Add the token (regular)
		 */
		} else {
			ret = repl->token->func (tem, repl->token, output, param);
			if (unlikely (ret != ret_ok)) {
				return ret;
			}
		}

		pos = repl->pos;
	}

	/* Copy the last chunk
	 */
	cherokee_buffer_add (output,
	                     tem->text.buf + pos,
	                     tem->text.len - pos);

	return ret_ok;
}