/* Copyright 2005-2006 Garrett Rooney.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef TMPL_COMMON_H
#define TMPL_COMMON_H

#include "etl_template.h"
#include "etl_variables.h"

#include "lexer.h"

typedef enum {
  ETL_NODE_PRINT,
  ETL_NODE_IF,
  ETL_NODE_UNLESS,
  ETL_NODE_FOR,
  ETL_NODE_MACRO,
  ETL_NODE_DEFMACRO,
  ETL_NODE_LITERAL,
  ETL_NODE_FILTER,
  ETL_NODE_INCLUDE
} etl_template_node_type_t;

typedef struct etl_template_node_t etl_template_node_t;

typedef enum {
  ETL_EXPRESSION_VAR,
  ETL_EXPRESSION_NODE,
  ETL_EXPRESSION_INDEX,
  ETL_EXPRESSION_METHOD,
  ETL_EXPRESSION_LITERAL
} etl_expression_type_t;

typedef enum {
  ETL_EXPRESSION_OP_EQ,    /* == */
  ETL_EXPRESSION_OP_NEQ,   /* != */
  ETL_EXPRESSION_OP_LT,    /* < */
  ETL_EXPRESSION_OP_GT,    /* > */
  ETL_EXPRESSION_OP_LTEQ,  /* <= */ 
  ETL_EXPRESSION_OP_GTEQ,  /* >= */
  ETL_EXPRESSION_OP_MOD,   /* % */
  ETL_EXPRESSION_OP_PLUS,  /* + */
  ETL_EXPRESSION_OP_MINUS, /* - */
  ETL_EXPRESSION_OP_TIMES, /* * */
  ETL_EXPRESSION_OP_DIV    /* / */
} etl_expression_op_t;

typedef struct etl_expression_t {
  etl_expression_type_t type;

  union {
    /* literal variable name */
    char *v;

    /* a node in an expression tree */
    struct {
      etl_expression_op_t op;
      struct etl_expression_t *left;
      struct etl_expression_t *right;
    } *n;

    /* first[second] */
    struct {
      struct etl_expression_t *first;
      struct etl_expression_t *second;
    } *idx;

    etl_variable_t *lit;

    struct {
      struct etl_expression_t *invocant;
      char *name;
      etl_array_t *args;
    } method;
  } contents;
} etl_expression_t;

typedef struct {
  etl_expression_t *var;
  etl_template_node_t *yes_task;
  etl_template_node_t *no_task;
} etl_if_contents_t;

typedef enum {
  ETL_FOR_VAR,
  ETL_FOR_RANGE
} etl_for_type_t;

typedef struct {
  etl_for_type_t type;

  char *var;
  char *var2; /* For the value when looping over k,v in a hash. */
  union {
    etl_expression_t *arr;
    struct {
      etl_expression_t *from;
      etl_expression_t *to;
    } range;
  } over;
  etl_template_node_t *task;
} etl_for_contents_t;

typedef struct {
  etl_expression_t *var;
} etl_print_contents_t;

typedef struct {
  char *data;
} etl_literal_contents_t;

typedef enum {
  etl_template_filter_html = 0,
  etl_template_filter_xml  = 1,
  etl_template_filter_url  = 2
} etl_template_filter_type_t;

typedef struct {
  etl_expression_t *var;
  etl_template_filter_type_t filter;
} etl_filter_contents_t;

typedef struct {
  etl_expression_t *file;
} etl_include_contents_t;

typedef struct {
  char *name;
  etl_array_t *arg_names;
  etl_array_t *arg_values;
  etl_template_node_t *body;
  int refcount;
} etl_macro_contents_t;

struct etl_template_node_t {
  etl_template_node_type_t type;

  /* note: contents with a size == sizeof (void *) are stored inline,
   *       others get stored as a pointer so we can minimize the size
   *       of the contents union. */
  union {
    etl_if_contents_t *i;
    etl_for_contents_t *f;
    etl_print_contents_t p;
    etl_literal_contents_t l;
    etl_filter_contents_t *flt;
    etl_include_contents_t inc;
    etl_macro_contents_t *macro;
  } contents;

  etl_template_node_t *next;
};

struct etl_template_t {
  etl_template_node_t *tree;
  etl_hash_t *macros;
};

typedef struct list_entry_t {
  void *data;
  struct list_entry_t *next; 
} list_entry_t;

typedef struct {
  etl_template_t *tmpl;
  etl_error_t *err;
  etl_hash_t *macros;
  struct list_entry_t *spare;
} etl_template_parser_state_t;

void *etl_template_parser_alloc(void *(*alloc_func)(size_t));

void etl_template_parser_parse(void *parser,
                               int token,
                               etl_token_t *data,
                               etl_template_parser_state_t *state);

void etl_template_parser_free(void *parser, void (*free_func)(void *));

/* Force Lemon to produce the kind of symbols I want... */
#define etl_template_parser_parseAlloc etl_template_parser_alloc
#define etl_template_parser_parseFree etl_template_parser_free
#define etl_template_parser_parseTokenName etl_template_parser_token_name
#define etl_template_parser_parseTrace etl_template_parser_trace

#endif /* TMPL_COMMON_H */