// symtab.c
#include "../../frontend.h"
#include "scope.h"
#include "symtab.h"

typedef symtab_t symtab_t;
typedef struct Scope Scope;

void init_symtab(symtab_t* symtab) {
    symtab->global_scope = scope_create(NULL);
    symtab->cur_scope = symtab->global_scope;
}

void del_symtab(symtab_t* symtab) {
    scope_destroy(symtab->global_scope);
}

void symtab_enter_scope(symtab_t* symtab) {
    struct Scope* scope = scope_create(symtab->cur_scope);
    scope->base_offset = symtab->cur_scope->base_offset + symtab->cur_scope->cur_offset;
    symtab->cur_scope = scope;
}

void symtab_leave_scope(symtab_t* symtab) {
    Scope * scope = symtab->cur_scope;
    if (scope == NULL) {
        error("cannot leave NULL scope or global scope");
    }
    symtab->cur_scope = symtab->cur_scope->parent;
    scope_destroy(scope);
}

void* symtab_add_symbol(symtab_t* symtab, const char* name, void* ast_node, int can_duplicate) {
    struct Scope* scope = symtab->cur_scope;
    void* node = scope_lookup_current(scope, name);
    if (node != NULL) {
        if (!can_duplicate) {
            error("duplicate symbol %s", name);
        }
        return node;
    }

    scope_insert(scope, name, ast_node);
    return node;
}

void* symtab_lookup_symbol(symtab_t* symtab, const char* name) {
    return scope_lookup(symtab->cur_scope, name);
}