#ifndef LISP_H
#define LISP_H

#include "nob.h"

typedef enum e_TokenKind {
    TOKEN_KIND_PAR_LEFT,
    TOKEN_KIND_PAR_RIGHT,
    TOKEN_KIND_NUMBER,
    TOKEN_KIND_SYMBOL,
} TokenKind;

typedef struct s_Token {
    TokenKind kind;
    Nob_String_View data;
} Token;

typedef struct s_Tokens {
    Token *items;
    size_t count;
    size_t capacity;
} Tokens;

typedef enum e_NodeKind {
    NODE_KIND_SYMBOL,
    NODE_KIND_LIST,
    NODE_KIND_NUMBER,
    NODE_KIND_FUNCTION,
} NodeKind;

typedef struct s_Node Node;
typedef struct s_Nodes Nodes;
typedef struct s_Scopes Scopes;

typedef Node *(*LispFunction)(Nodes *args, Scopes *scopes);

struct s_Node {
    NodeKind kind;
    union {
        Nob_String_View as_symbol;
        Nodes *as_list;
        long long as_number;
        struct {
            Nob_String_View name;
            LispFunction apply;
        } as_function;
    };
};

struct s_Nodes {
    Node *items;
    size_t count;
    size_t capacity;
};

typedef struct s_ScopeObject {
    Nob_String_View name;
    Node node;
} ScopeObject;

// TODO: use hashtable
typedef struct s_Scope {
    ScopeObject *items;
    size_t count;
    size_t capacity;
} Scope;

struct s_Scopes {
    Scope *items;
    size_t count;
    size_t capacity;
};

const char *token_kind_name(TokenKind kind);
void node_print(Node node);

void build_scopes(Scopes *scopes);
void tokenize(Nob_String_View content, Tokens *tokens);
Node *parse(Tokens *tokens);
Node *eval(Node *node, Scopes *scopes);

// builtins
Node *lisp_function_addition(Nodes *args, Scopes *scopes);
Node *lisp_function_println(Nodes *args, Scopes *scopes);
Node *lisp_function_list(Nodes *args, Scopes *scopes);
Node *lisp_function_append(Nodes *args, Scopes *scopes);
Node *lisp_function_length(Nodes *args, Scopes *scopes);
Node *lisp_function_isnull(Nodes *args, Scopes *scopes);

#endif // LISP_H