#ifndef FZL_PARSER_H
#define FZL_PARSER_H

#include <compiler/fzl_reader.h>
#include <compiler/fzl_token.h>
#include <stdbool.h>
#include <stddef.h>

// AST node type
typedef enum
{
  FZL_NODETYPE_TYPEDEF,
  FZL_NODETYPE_HANDLE,
  FZL_NODETYPE_ALIAS,
  FZL_NODETYPE_STRUCT,
  FZL_NODETYPE_REFERENCE,
  FZL_NODETYPE_EXTERN_FN,

  FZL_NODETYPE_EXTERN,
  FZL_NODETYPE_BLOCK,

  FZL_NODETYPE_LITERAL,
  FZL_NODETYPE_FMT_STRING,

  FZL_NODETYPE_IDENTIFIER,

  FZL_NODETYPE_CONDITIONAL,

  FZL_NODETYPE_FUNCTION,
  FZL_NODETYPE_RETURN,
  FZL_NODETYPE_CALL,

  FZL_NODETYPE_CLASS,
  FZL_NODETYPE_FIELD,
  FZL_NODETYPE_CONSTRUCT,

  FZL_NODETYPE_LOOP,
  FZL_NODETYPE_BREAK,

  FZL_NODETYPE_ADD,
  FZL_NODETYPE_SUB,
  FZL_NODETYPE_MUL,
  FZL_NODETYPE_DIV,
  FZL_NODETYPE_POW,
  FZL_NODETYPE_MOD,

  FZL_NODETYPE_UNARY_PLUS,
  FZL_NODETYPE_UNARY_MINUS,

  FZL_NODETYPE_OR,
  FZL_NODETYPE_AND,

  FZL_NODETYPE_EQUAL,
  FZL_NODETYPE_NEQUAL,
  FZL_NODETYPE_LESS,
  FZL_NODETYPE_LESS_EQUAL,
  FZL_NODETYPE_GREATER,
  FZL_NODETYPE_GREATER_EQUAL,

  FZL_NODETYPE_NOT,

  FZL_NODETYPE_DECLARATION,
  FZL_NODETYPE_ASSIGN
} fzl_nodetype_t;

// AST node descriptor
typedef struct fzl_node
{
  fzl_nodetype_t type;
  fzl_token_t *token;
  struct fzl_node *parent;
  struct fzl_node *next;

  union
  {
    // Array of nested nodes (for blocks, etc)
    struct
    {
      struct fzl_node **entries;
      size_t entry_count;
    } list;

    // Call data
    struct
    {
      struct fzl_node *callee;

      struct fzl_node **args;
      size_t args_count;
    } call;

    // Binary operations
    struct
    {
      struct fzl_node *left;
      struct fzl_node *right;
    } binary_op;

    // Unary operations
    struct
    {
      struct fzl_node *operand;
    } unary_op;

    // Variables declaration and initializing
    struct
    {
      fzl_token_t *type;
      struct fzl_node *identifier;
      bool is_out;
    } var;

    // Conditional blocks
    struct
    {
      struct fzl_node *condition;
      struct fzl_node *true_block;
      struct fzl_node *else_block;
    } cond;

    // Function declaration
    struct
    {
      struct fzl_node **args;
      size_t args_count;

      struct fzl_node *body;
      fzl_token_t *name;
      fzl_token_t *type;
    } fn;

    // Return value
    struct
    {
      struct fzl_node *value;
    } ret;

    // Class declaration
    struct
    {
      fzl_token_t *name;

      struct fzl_node **fields;
      size_t fields_count;

      struct fzl_node **methods;
      size_t methods_count;
    } class;

    // Member access
    struct
    {
      struct fzl_node *parent;
      struct fzl_node *field;
    } memb;

    // Object construct
    struct
    {
      struct fzl_node *name;
    } construct;

    // Loop
    struct
    {
      struct fzl_node *init;
      struct fzl_node *cond;
      struct fzl_node *step;

      struct fzl_node *body;
    } loop;

    // Extern library
    struct
    {
      char *libname;

      struct fzl_node **typedefs;
      size_t typedefs_count;

      struct fzl_node **fns;
      size_t fns_count;
    } ext;

    // Type definition
    struct
    {
      char *typename;
      struct fzl_node *type;
    } typedefinition;

    // Structure
    struct
    {
      char *original_name;

      struct fzl_node **entries;
      size_t entries_count;
    } structure;

    // External function
    struct
    {
      char *name;
      char *original_name;

      fzl_token_t *type;

      struct fzl_node **args;
      size_t args_count;
    } ext_fn;
  };
} fzl_node_t;

// Token sequence parser descriptor
typedef struct
{
  fzl_reader_ll_t *first;
  size_t token_count;

  fzl_reader_ll_t *cursor;
  fzl_node_t *root;
} fzl_parser_t;

// Allocate parser
fzl_parser_t *fzl_mkparser(fzl_reader_ll_t *first);

// Allocate new node
fzl_node_t *fzl_mknode(fzl_nodetype_t type, fzl_token_t *tok);

// Parse tokens
int fzl_parse(fzl_parser_t *parser);

// Get last parser error
char *fzl_parser_geterror();

// Free node
void fzl_freenode(fzl_node_t *node);

// Free entire AST going from root node
void fzl_freeast(fzl_node_t *root);

// Free parser
void fzl_freeparser(fzl_parser_t *parser);

#endif // FZL_PARSER_H