function void
tokens_print(Tokens tokens){
  lex_print("\n== Token count = %d\n", (S32)tokens.len);
  for(Token *t = tokens.tokens; t != tokens.tokens + tokens.len; t++){
    lex_print("%s \"%.*s\"\n", token_kind_string[t->kind].str, (S32)t->len, t->str);
  }
}

function void
token_print(Token *token){
  lex_print("%.*s", (S32)token->len, token->str);
}

function void
expr_print(Expr *expr){
  switch(expr->kind) {
    case EK_Atom: {
      token_print(expr->token);
    } break;
    
    case EK_Binary:{
      lex_print("(");
      expr_print(expr->binary.left);
      token_print(expr->token);
      expr_print(expr->binary.right);
      lex_print(")");
    } break;
    case EK_Unary:{
      lex_print("(");
      token_print(expr->token);
      expr_print(expr->unary.expr);
      lex_print(")");
    } break;
    
    case EK_Ternary:{
      lex_print("(");
      expr_print(expr->ternary.cond);
      lex_print("?");
      expr_print(expr->ternary.on_true);
      lex_print(":");
      expr_print(expr->ternary.on_false);
      lex_print(")");
    } break;
    case EK_List:{
      lex_print("(");
      for(Expr *n = expr->list.first; n; n=n->next){
        expr_print(n);
        if(n!=expr->list.last) lex_print(",");
      }
      lex_print(")");
    }break;
    
    case EK_Cast:{
      lex_print("(");
      lex_print("(");
      //type_print(expr->cast.type);
      lex_print(")");
      expr_print(expr->cast.expr);
      lex_print(")");
    } break;
    
    case EK_Index:{
      expr_print(expr->index.atom);
      lex_print("[");
      expr_print(expr->index.index);
      lex_print("]");
    }break;
    
    case EK_Call:{
      expr_print(expr->call.atom);
      expr_print(expr->call.list);
    }break;
    default: {invalid_codepath;} break;
  }
}

function void
print_indent(S64 indent){
  for(S64 i = 0; i < indent; i++){
    lex_print(" ");
  }
}

function AST_Node *
ast_get_basis_type(AST_Node *node){
  switch(node->kind) {
    case AK_Struct: case AK_Union: case AK_Enum: case AK_BaseType:{return node;} break;
    case AK_Function:{return node;} break;
    case AK_Typedef:{return node;} break;
    case AK_Array: case AK_Pointer:{return ast_get_basis_type(node->pointer);} break;
    default: invalid_codepath;
  }
  return 0;
}

function void
ast_print_pointers(AST_Node *node){
  if(node->kind == AK_Pointer){
    lex_print("*");
    ast_print_pointers(node->pointer);
  }
  else if(node->kind == AK_Array){
    ast_print_pointers(node->pointer);
  }
}

function void
ast_print_arrays(AST_Node *node){
  if(node->kind == AK_Pointer){
    ast_print_arrays(node->pointer);
  }
  else if(node->kind == AK_Array){
    lex_print("[");
    expr_print(node->expr);
    lex_print("]");
    ast_print_arrays(node->pointer);
  }
}

function void
ast_print_var(AST_Node *node);
function void
ast_print_func_params(AST_Node *node){
  for(AST_Node *n = node->first_child; n; n=n->next){
    ast_print_var(n);
    if(n != node->last_child) lex_print(", ");
  }
}

function void
ast_print_var(AST_Node *node){
  AST_Node *basis_type = ast_get_basis_type(node->variable_type);
  if(basis_type->kind == AK_Function){
    lex_print("%s (*%s)(", basis_type->func_return_type->name.s.str, node->name.s.str);
    ast_print_func_params(basis_type);
    lex_print(")");
  }
  else{
    lex_print("%s ", basis_type->name.s.str);
    ast_print_pointers(node->variable_type);
    lex_print("%s", node->name.s.str);
    ast_print_arrays(node->variable_type);
  }
  
  if(node->expr){
    lex_print(" = ");
    expr_print(node->expr);
  }
}

function AST_Node *
ast_find_note(AST_Node *node, String string){
  for(AST_Node *n = node->first_note; n; n=n->next){
    if(string_compare(n->name.s, string)){
      return n;
    }
  }
  return 0;
}

function String
ast_find_string(AST_Node *node, String string, String default_val){
  AST_Node *find = ast_find_note(node, string);
  if(find){
    if(find->expr->kind == EK_Atom){
      return find->expr->token->string;
    }
  }
  return default_val;
}

global Arena todo_arena;

function void
ast__print(AST_Node *node, S64 indent){
  switch(node->kind){
    
    case AK_List:{
      for(AST_Node *n = node->first_child; n; n=n->next){
        ast__print(n, indent);
        lex_print("\n");
      }
    } break;
    
    case AK_Union:
    case AK_Struct:{
      const char *type = node->kind == AK_Struct ? "struct":"union";
      if(indent == 0) lex_print("typedef %s %s %s;\n", type, node->name.s.str, node->name.s.str);
      lex_print("%s %s{\n", type, indent == 0 ? node->name.s.str:(U8 *)"");
      for(AST_Node *n = node->first_child; n; n=n->next){
        AST_Node *using_note = ast_find_note(n, lit("using"));
        AST_Node *array_note = ast_find_note(n, lit("array"));
        AST_Node *sllqueue_note = ast_find_note(n, lit("sllqueue"));
        if(using_note) {
          assert(n->kind == AK_Variable);
          lex_print("union{\n");
          ast__print(n, indent+2);
          lex_print("\n");
          Intern_String name = n->variable_type->name;
          n->variable_type->name = (Intern_String){0};
          assert(n->variable_type->kind == AK_Struct || n->variable_type->kind == AK_Union);
          ast__print(n->variable_type, indent+2);
          n->variable_type->name = name;
          lex_print("\n}");
        }
        else if(array_note){
          AST_Node *cap = ast_find_note(n, lit("cap"));
          AST_Node *len = ast_find_note(n, lit("len"));
          ast__print(n, indent+2);
          lex_print("\nS64 len;\nS64 cap;");
        }
        else if(sllqueue_note){
          lex_print("%s *first_%s;\n", n->variable_type->name.s.str, string_to_lower(&todo_arena, n->name.s).str);
          lex_print("%s *last_%s;\n", n->variable_type->name.s.str, string_to_lower(&todo_arena, n->name.s).str);
        }
        else {
          ast__print(n, indent+2);
        }
        lex_print("\n");
      }
      
      lex_print("}");
      lex_print("%s;", indent == 0 ? (U8 *)"":node->name.s.str?node->name.s.str:(U8*)"");
      if(indent == 0) lex_new_line();
    } break;
    
    case AK_Variable:{
      if(indent == 0) lex_print("global ");
      ast_print_var(node);
      lex_print(";");
    } break;
    
    case AK_Typedef:{
      lex_print("typedef ");
      ast_print_var(node);
      lex_print(";");
    } break;
    
    case AK_Enum:{
      print_indent(indent);
      lex_print("typedef enum %s{\n", node->name.s.str);
      AST_Node *prefix = ast_find_note(node, lit("prefix"));
      
      for(AST_Node *n = node->first_child; n; n=n->next){
        print_indent(indent+2);
        if(prefix){
          expr_print(prefix->expr);
        }
        lex_print("%s", n->name.s.str);
        if(n->expr){
          lex_print(" = ");
          expr_print(n->expr);
        }
        lex_print(",\n");
      }
      
      print_indent(indent); 
      lex_print("}%s;\n", node->name.s.str);
    } break;
    
    default: invalid_codepath;
  }
}

function void
ast_print(AST_Node *node){
  ast__print(node, 0);
}

function B32
intern_is_empty(Intern_String string){
  if(string.s.str == 0) 
    return true;
  return false;
}

typedef struct String_Map{
  String replace;
  String with;
}String_Map;

function B32
token_is_number(Token *token){
  B32 result = token->kind == TK_Int;
  return result;
}

function void
print_string_replaced(String string, String_Map *maps, SizeU count){
  Tokens tokens = lex_stream(string, lit("Replace"));
  for(S64 i = 0; i < tokens.len; i++){
    Token *t = tokens.tokens + i;
    if(t->kind == TK_At) continue;
    for(String_Map *map = maps; map != maps+count; map++){
      if(string_compare(map->replace, t->string)){
        t->string = map->with;
      }
    }
    
    lex_print("%.*s", (S32)t->string.len, t->string.str);
    if(t->kind == TK_Keyword) lex_print(" ");
    if(t->kind == TK_Identifier && 
       (t[1].kind== TK_Identifier || token_is_number(t+1))) lex_print(" ");
    if(t->kind == TK_OpenBrace) lex_print("\n");
    if(t->kind == TK_CloseBrace) lex_print("\n");
    if(t->kind == TK_Semicolon) lex_print("\n");
  }
  free(tokens.tokens);
  
}

function void
gen_struct(AST_Node *n, Intern_String shadow_type_name){
  for(AST_Node *member = n->first_child; member; member=member->next){
    AST_Node *using_note = ast_find_note(member, lit("using"));
    AST_Node *array_note = ast_find_note(member, lit("array"));
    AST_Node *sllqueue_note = ast_find_note(member, lit("sllqueue"));
    if(using_note){
      gen_struct(member->variable_type, n->name);
    }
    if(array_note){
      AST_Node *array_type = ast_get_basis_type(member->variable_type);
      
      Intern_String type_name = n->name;
      if(!intern_is_empty(shadow_type_name)) 
        type_name = shadow_type_name;
      
      
      String_Map maps[] = {
        {lit("function"), lit("function\n")},
        {lit("base_type"), type_name.s},
        {lit("base_type_lower"), string_to_lower(&todo_arena, type_name.s)},
        {lit("var_type"), array_type->name.s},
        {lit("var_type_lower"), string_to_lower(&todo_arena, array_type->name.s)},
        {lit("var_name"), member->name.s},
        {lit("var_name_lower"), string_to_lower(&todo_arena, member->name.s)},
        {lit("len"), ast_find_string(array_note, lit("len"), lit("len"))},
        {lit("cap"), ast_find_string(array_note, lit("cap"), lit("cap"))},
        {lit("data"), ast_find_string(array_note, lit("data"), lit("data"))},
      };
      
      
      String a
        = lit("function var_type *base_type@_array_push_empty(base_type *a){"
              "if(a->cap == 0){\n"
              " a->cap = 1024;\n"
              " a->tokens = malloc(sizeof(var_type)*a->cap);\n"
              "}\n"
              "else if(a->len+1 > a->cap){\n"
              " a->cap *= 2;\n"
              " a->tokens = realloc(a->tokens, sizeof(var_type)*a->cap);\n"
              "}\n"
              
              "var_type *result = a->tokens + a->len++;\n"
              "memory_zero(result, sizeof(*result));\n"
              "return result;}");
      print_string_replaced(a, maps, buff_cap(maps));
    }
    if(sllqueue_note){
      String default_first = lit("first");
      String default_last = lit("last");
      String default_next = lit("next");
      if(!string_compare(member->name.s, lit("default"))){
        default_first = string_fmt(&todo_arena, "first_%s", member->name.s.str);
        default_last = string_fmt(&todo_arena, "last_%s", member->name.s.str);
        default_next = string_fmt(&todo_arena, "next_%s", member->name.s.str);
      }
      
      String_Map maps[] = {
        {lit("function"), lit("function\n")},
        {lit("base_type"), n->name.s},
        {lit("base_type_lower"), string_to_lower(&todo_arena, n->name.s)},
        {lit("var_type"), member->variable_type->name.s},
        {lit("var_type_lower"), string_to_lower(&todo_arena, member->variable_type->name.s)},
        {lit("var_name"), member->name.s},
        {lit("var_name_lower"), string_to_lower(&todo_arena, member->name.s)},
        {lit("next"), ast_find_string(sllqueue_note, lit("next"), default_next)},
        {lit("first"), ast_find_string(sllqueue_note, lit("first"), default_first)},
        {lit("last"), ast_find_string(sllqueue_note, lit("last"), default_last)},
      };
      
      String string = 
        lit(
            "function void "
            "base_type_lower@_@var_name_lower@_push(base_type *parent, var_type *child){"
            "if(parent->first == 0){"
            "parent->first = parent->last = child;"
            "}"
            "else{"
            "parent->last = parent->last->next = child;"
            "}"
            "}"
            
            "function var_type * "
            "base_type_lower@_@var_name_lower@_pop_first(base_type *parent){"
            " if(parent->first == parent->last){"
            "  var_type *node = parent->first;" 
            "  parent->first = parent->last = 0;" 
            "  return node;" 
            " }"
            " else if(parent->first){"
            "   var_type *node = parent->first;"
            "   parent->first = parent->first->next;"
            " }"
            "return 0;"
            "}"
            
            
            );
      print_string_replaced(string, maps, buff_cap(maps));
      lex_print("\n");
    }
  }
}