/*
* Copyright (C) 2023 Johnny Richard
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program.  If not, see <https://www.gnu.org/licenses/>.
*/
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include "ast.h"

void
ast_node_accept_visitor(ast_node_t *node, ast_visitor_t *visitor)
{
  assert(node);
  assert(node->accept_visitor);
  node->accept_visitor(node, visitor);
}

static void
ast_node_function_accept_visitor(ast_node_t *node, ast_visitor_t *visitor)
{
  assert(visitor->visit_function && "unimplemented visit_function");
  visitor->visit_function(visitor, &node->data.function);
}

static void
ast_node_return_stmt_accept_visitor(ast_node_t *node, ast_visitor_t *visitor)
{
  assert(visitor->visit_return_stmt && "unimplemented visit_return_stmt");
  visitor->visit_return_stmt(visitor, &node->data.return_stmt);
}

static void
ast_node_literal_visitor(ast_node_t *node, ast_visitor_t *visitor)
{
  assert(visitor->visit_literal && "unimplemented visit_literal");
  visitor->visit_literal(visitor, &node->data.literal);
}

static void
ast_node_binary_operation_visitor(ast_node_t *node, ast_visitor_t *visitor)
{
  assert(visitor->visit_binary_operation && "unimplemented visit_binary_operation");
  visitor->visit_binary_operation(visitor, &node->data.binary_operation);
}

ast_node_t*
ast_node_new()
{
  ast_node_t *node = (ast_node_t*) malloc(sizeof(ast_node_t));
  if (node == NULL) {
    printf("OOO: could no allocate a node");
    exit(EXIT_FAILURE);
  }
  node->kind = AST_UNKOWN_NODE;
  return node;
}

static void
ast_node_destroy_vector(vector_t *vector)
{
  for (size_t i=0; i < vector->size; i++) {
    ast_node_destroy(vector_at(vector, i));
  }
  vector_destroy(vector);
}

void
ast_node_destroy(ast_node_t *node)
{
  switch (node->kind) {
    case AST_FUNCTION_DECLARATION:
      ast_node_destroy_vector(node->data.function.body);
      break;
    case AST_BINARY_OPERATION:
      ast_node_destroy(node->data.binary_operation.left);
      ast_node_destroy(node->data.binary_operation.right);
      break;
    case AST_VARIABLE_DECLARATION:
      ast_node_destroy(node->data.variable.value);
      break;
    case AST_LITERAL:
      break;
    case AST_RETURN_STMT:
      ast_node_destroy(node->data.return_stmt.argument);
      break;
    case AST_IDENTIFIER:
      break;
    case AST_UNKOWN_NODE:
      break;
    default:
      assert(false && "unmapped free strategy");
  }
  free(node);
}

void
ast_node_init_return_stmt(ast_node_t *node, ast_node_t *argument)
{
  node->accept_visitor = &ast_node_return_stmt_accept_visitor,
  node->kind = AST_RETURN_STMT;
  node->data = (ast_node_data_t) {
    .return_stmt = {
      .argument = argument
    }
  };
}

void
ast_node_init_function_declaration(ast_node_t *node, string_view_t name, type_t return_type, vector_t *body)
{
  node->accept_visitor = &ast_node_function_accept_visitor,
  node->kind = AST_FUNCTION_DECLARATION;
  node->data = (ast_node_data_t) {
    .function = {
      .name = name,
      .return_type = return_type,
      .body = body
    }
  };
}

void
ast_literal_integer_create(ast_node_t *node, uint32_t number)
{
  node->accept_visitor = &ast_node_literal_visitor;
  node->kind = AST_LITERAL;
  node->data = (ast_node_data_t) {
    .literal = {
      .kind = AST_LITERAL_INTEGER,
      .value = {
        .integer = number
      }
    }
  };
}

void
ast_node_init_binary_operation(ast_node_t *node, string_view_t op, ast_node_t *left, ast_node_t *right)
{
  node->accept_visitor = &ast_node_binary_operation_visitor;
  node->kind = AST_BINARY_OPERATION;
  node->data = (ast_node_data_t) {
      .binary_operation = {
        .op = op,
        .left = left,
        .right = right
      }
  };
}

void
ast_node_init_variable_declaration(ast_node_t *node, string_view_t variable_name, type_t type, ast_node_t *value)
{
  // FIXME: define the visitor strategy
  node->kind = AST_VARIABLE_DECLARATION;
  node->data = (ast_node_data_t) {
      .variable = {
        .name = variable_name,
        .type = type,
        .value = value
      }
  };
}

void
ast_node_init_identifier(ast_node_t *node, string_view_t name)
{
  // FIXME: define the visitor strategy
  node->kind = AST_IDENTIFIER;
  node->data = (ast_node_data_t) {
      .variable = {
        .name = name,
      }
  };
}