#include "expression_builders.hpp"

#include "basic_builders.hpp"
#include "basic_nodes.hpp"
#include "error_handling.hpp"
#include "expression_nodes.hpp"
#include "tokens.hpp"
#include "type_builders.hpp"
#include "type_nodes.hpp"

namespace builders {

nodes::ExpressionProxy
build_expression(parser::ParseTree::Node parser_node,
                 nodes::ExpressionStorage &expression_storage,
                 nodes::TypeStorage &type_storage) {
  tokens::Type type = tokens::string_to_type(parser_node.get_type());

  switch (type) {
  // --- flow control
  case tokens::Type::MATCH:
    return expression_storage.add_expression(nodes::Expression(
        build_match(parser_node, expression_storage, type_storage)));
  case tokens::Type::CONDITION:
    return expression_storage.add_expression(nodes::Expression(
        build_condition(parser_node, expression_storage, type_storage)));
  case tokens::Type::LOOP:
    return expression_storage.add_expression(nodes::Expression(
        build_loop(parser_node, expression_storage, type_storage)));
  // --- operators
  case tokens::Type::COMMA_EXPRESSION:
    return expression_storage.add_expression(nodes::Expression(
        build_comma_expression(parser_node, expression_storage, type_storage)));
  case tokens::Type::OPERATOR_EXPRESSION:
    return expression_storage.add_expression(
        nodes::Expression(build_operator_expression(
            parser_node, expression_storage, type_storage)));
  // --- containers
  case tokens::Type::BLOCK:
    return expression_storage.add_expression(nodes::Expression(
        build_block(parser_node, expression_storage, type_storage)));
  case tokens::Type::ARRAY:
    return expression_storage.add_expression(nodes::Expression(
        build_array(parser_node, expression_storage, type_storage)));
  // --- modifiers
  case tokens::Type::RETURN:
    return expression_storage.add_expression(nodes::Expression(
        build_return(parser_node, expression_storage, type_storage)));
  case tokens::Type::NAME_DEFINITION:
    return expression_storage.add_expression(
        nodes::Expression(build_name_definition(parser_node)));
  case tokens::Type::ARRAY_ACCESS:
    return expression_storage.add_expression(nodes::Expression(
        build_array_access(parser_node, expression_storage, type_storage)));
  case tokens::Type::TUPLE_ACCESS:
    return expression_storage.add_expression(nodes::Expression(
        build_tuple_access(parser_node, expression_storage, type_storage)));
  case tokens::Type::LOOP_CONTROL:
    return expression_storage.add_expression(
        nodes::Expression(build_loop_control(parser_node)));
  case tokens::Type::REFERENCE_EXPRESSION:
    return expression_storage.add_expression(
        nodes::Expression(build_reference_expression(
            parser_node, expression_storage, type_storage)));
  case tokens::Type::SUFFIX_EXPRESSION:
    return expression_storage.add_expression(
        nodes::Expression(build_suffix_expression(
            parser_node, expression_storage, type_storage)));
  // --- other
  case tokens::Type::NAME_EXPRESSION:
    return expression_storage.add_expression(nodes::Expression(
        build_name_expression(parser_node, expression_storage, type_storage)));
  case tokens::Type::ARGUMENT_NAME_IDENTIFIER:
  case tokens::Type::SIMPLE_NAME_IDENTIFIER:
  case tokens::Type::PLACEHOLDER:
    return expression_storage.add_expression(
        nodes::Expression(nodes::NameExpression(
            build_node(parser_node), build_identifier(parser_node))));
  case tokens::Type::CONSTRUCTOR:
    return expression_storage.add_expression(nodes::Expression(
        build_constructor(parser_node, expression_storage, type_storage)));
  case tokens::Type::LAMBDA:
    return expression_storage.add_expression(nodes::Expression(
        build_lambda(parser_node, expression_storage, type_storage)));
  // --- literals
  case tokens::Type::FLOAT_NUMBER_LITERAL:
    return expression_storage.add_expression(
        nodes::Expression(build_float_number_literal(parser_node)));
  case tokens::Type::NUMBER_LITERAL:
    return expression_storage.add_expression(
        nodes::Expression(build_number_literal(parser_node)));
  case tokens::Type::STRING_LITERAL:
    return expression_storage.add_expression(
        nodes::Expression(build_string_literal(parser_node)));
  case tokens::Type::CHAR_LITERAL:
    return expression_storage.add_expression(
        nodes::Expression(build_char_literal(parser_node)));
  case tokens::Type::BOOL_LITERAL:
    return expression_storage.add_expression(
        nodes::Expression(build_bool_literal(parser_node)));
  case tokens::Type::UNIT_LITERAL:
    return expression_storage.add_expression(
        nodes::Expression(build_unit_literal(parser_node)));
  case tokens::Type::NULL_LITERAL:
    return expression_storage.add_expression(
        nodes::Expression(build_null_literal(parser_node)));
  default:
    error_handling::handle_parsing_error("Unexprected expression node type",
                                         parser_node);
  }
  error_handling::handle_general_error("Unreachable");
  exit(1); // unreachable
}

// --- flow control

// (':=' | '=:') expression (('??' | 'if') expression)? (_do_ expression)?
nodes::Match::Case build_case(parser::ParseTree::Node parser_node,
                              nodes::ExpressionStorage &expression_storage,
                              nodes::TypeStorage &type_storage) {
  std::string case_type = parser_node.nth_child(0).get_value();

  std::optional<parser::ParseTree::Node> condition_node;
  std::optional<parser::ParseTree::Node> expression_node;

  auto current_node = parser_node.nth_named_child(1);

  if (!current_node.is_null()) {
    if (parser_node.child_by_field_name("condition").is_null()) {
      expression_node = current_node;
    } else {
      condition_node = current_node;
      current_node = current_node.next_named_sibling();
      if (!current_node.is_null()) {
        expression_node = current_node;
      }
    }
  }

  return nodes::Match::Case(
      build_node(parser_node),
      case_type == ":=" ? nodes::Match::Case::PATTERN_VALUE
                        : nodes::Match::Case::VALUE_PATTERN,
      build_expression(parser_node.nth_named_child(0), expression_storage,
                       type_storage),
      condition_node.has_value()
          ? build_expression(condition_node.value(), expression_storage,
                             type_storage)
          : std::optional<nodes::ExpressionProxy>(),
      expression_node.has_value()
          ? build_expression(expression_node.value(), expression_storage,
                             type_storage)
          : std::optional<nodes::ExpressionProxy>());
}

// expression case+
nodes::Match build_match(parser::ParseTree::Node parser_node,
                         nodes::ExpressionStorage &expression_storage,
                         nodes::TypeStorage &type_storage) {
  std::vector<nodes::Match::Case> cases;

  auto current_node = parser_node.nth_named_child(1);
  while (!current_node.is_null()) {
    cases.push_back(build_case(current_node, expression_storage, type_storage));
    current_node = current_node.next_named_sibling();
  }

  return nodes::Match(build_node(parser_node),
                      build_expression(parser_node.nth_named_child(0),
                                       expression_storage, type_storage),
                      std::move(cases));
}

// ('??' | 'if') expression _do_ expression (('!!' | 'elif') expression _do_
// expression)* (('!!=>', 'else') expression)?
nodes::Condition build_condition(parser::ParseTree::Node parser_node,
                                 nodes::ExpressionStorage &expression_storage,
                                 nodes::TypeStorage &type_storage) {
  size_t named_child_count = parser_node.named_child_count();

  std::vector<std::pair<nodes::ExpressionProxy, nodes::ExpressionProxy>> cases;

  auto current_node = parser_node.nth_named_child(0);
  auto next_node = current_node.next_named_sibling();

  while (!current_node.is_null() && !next_node.is_null()) {
    cases.push_back(
        {build_expression(current_node, expression_storage, type_storage),
         build_expression(next_node, expression_storage, type_storage)});
    current_node = next_node.next_named_sibling();
    if (current_node.is_null()) {
      break;
    }
    next_node = current_node.next_named_sibling();
  }

  return nodes::Condition(
      build_node(parser_node), std::move(cases),
      named_child_count % 2 == 1
          ? build_expression(parser_node.nth_named_child(named_child_count - 1),
                             expression_storage, type_storage)
          : std::optional<nodes::ExpressionProxy>());
}

// ('@' | 'for') (expression | expression ':' expression)? _do_ expression
nodes::Loop build_loop(parser::ParseTree::Node parser_node,
                       nodes::ExpressionStorage &expression_storage,
                       nodes::TypeStorage &type_storage) {
  size_t named_child_count = parser_node.named_child_count();

  if (named_child_count == 1) { // body
    return nodes::Loop(build_node(parser_node),
                       build_expression(parser_node.nth_named_child(0),
                                        expression_storage, type_storage));
  } else if (named_child_count == 2) { // condition, body
    return nodes::Loop(build_node(parser_node),
                       build_expression(parser_node.nth_named_child(0),
                                        expression_storage, type_storage),
                       build_expression(parser_node.nth_named_child(1),
                                        expression_storage, type_storage));
  } else if (named_child_count == 3) { // variable, interval, body
    return nodes::Loop(build_node(parser_node),
                       build_expression(parser_node.nth_named_child(0),
                                        expression_storage, type_storage),
                       build_expression(parser_node.nth_named_child(1),
                                        expression_storage, type_storage),
                       build_expression(parser_node.nth_named_child(2),
                                        expression_storage, type_storage));
  } else {
    error_handling::handle_parsing_error(
        "Unexprected named expression amount in loop", parser_node);
  }

  error_handling::handle_general_error("Unreachable");
  exit(1); // unreachable
}

// --- operators

// expression ',' expression
nodes::NameExpression
build_comma_expression(parser::ParseTree::Node parser_node,
                       nodes::ExpressionStorage &expression_storage,
                       nodes::TypeStorage &type_storage) {
  std::vector<std::pair<std::optional<std::string>, nodes::ExpressionProxy>>
      arguments;

  arguments.emplace_back(std::nullopt,
                         build_expression(parser_node.nth_named_child(0),
                                          expression_storage, type_storage));

  arguments.emplace_back(std::nullopt,
                         build_expression(parser_node.nth_named_child(1),
                                          expression_storage, type_storage));

  return nodes::NameExpression(
      build_node(parser_node),
      nodes::Identifier(
          build_node(parser_node), // can't find more precise location'
          nodes::Identifier::SIMPLE_NAME, ","),
      std::move(arguments), std::nullopt, false, true);
}

// expression operator expression
nodes::NameExpression
build_operator_expression(parser::ParseTree::Node parser_node,
                          nodes::ExpressionStorage &expression_storage,
                          nodes::TypeStorage &type_storage) {
  auto name_node = parser_node.child_by_field_name("name");

  std::vector<std::pair<std::optional<std::string>, nodes::ExpressionProxy>>
      arguments;

  arguments.emplace_back(std::nullopt,
                         build_expression(name_node.previous_named_sibling(),
                                          expression_storage, type_storage));

  arguments.emplace_back(std::nullopt,
                         build_expression(name_node.next_named_sibling(),
                                          expression_storage, type_storage));

  return nodes::NameExpression(build_node(parser_node),
                               build_operator(name_node), std::move(arguments),
                               std::nullopt, false, true);
}

// --- continers

nodes::Container
build_container(parser::ParseTree::Node parser_node,
                nodes::ExpressionStorage &expression_storage,
                nodes::TypeStorage &type_storage,
                nodes::Container::ContainerType container_type) {
  std::vector<nodes::ExpressionProxy> expressions;

  auto current_node = parser_node.nth_named_child(0).next_named_sibling();

  while (!current_node.is_null()) {
    expressions.push_back(
        build_expression(current_node, expression_storage, type_storage));
    current_node = current_node.next_named_sibling();
  }

  return nodes::Container(build_node(parser_node), container_type,
                          std::move(expressions));
}

// '{' (expression ';')* '}'
nodes::Container build_block(parser::ParseTree::Node parser_node,
                             nodes::ExpressionStorage &expression_storage,
                             nodes::TypeStorage &type_storage) {
  return build_container(parser_node, expression_storage, type_storage,
                         nodes::Container::BLOCK);
}

// '[[' expression+ ']]'
nodes::Container build_array(parser::ParseTree::Node parser_node,
                             nodes::ExpressionStorage &expression_storage,
                             nodes::TypeStorage &type_storage) {
  return build_container(parser_node, expression_storage, type_storage,
                         nodes::Container::ARRAY);
}

// --- modifiers

// ('return' | 'bring') expression
nodes::Return build_return(parser::ParseTree::Node parser_node,
                           nodes::ExpressionStorage &expression_storage,
                           nodes::TypeStorage &type_storage) {
  std::string modifier = parser_node.nth_child(0).get_value();

  return nodes::Return(build_node(parser_node),
                       modifier == "return" ? nodes::Return::RETURN
                                            : nodes::Return::BRING,
                       build_expression(parser_node.nth_named_child(0),
                                        expression_storage, type_storage));
}

// _var_let_ (simple_name_identifier | placeholder)
nodes::NameDefinition
build_name_definition(parser::ParseTree::Node parser_node) {
  std::string modifier = parser_node.nth_child(0).get_value();

  auto name_node = parser_node.nth_named_child(0);

  return nodes::NameDefinition(build_node(parser_node),
                               (modifier == "%" || modifier == "let")
                                   ? nodes::NameDefinition::LET
                                   : nodes::NameDefinition::VAR,
                               build_identifier(name_node));
} // IN PROGRESS

// expression '[' expression ']'
nodes::Access build_array_access(parser::ParseTree::Node parser_node,
                                 nodes::ExpressionStorage &expression_storage,
                                 nodes::TypeStorage &type_storage) {
  return nodes::Access(build_node(parser_node), nodes::Access::ARRAY,
                       build_expression(parser_node.nth_named_child(0),
                                        expression_storage, type_storage),
                       build_expression(parser_node.nth_named_child(1),
                                        expression_storage, type_storage));
}

// expression '.' number_literal
nodes::Access build_tuple_access(parser::ParseTree::Node parser_node,
                                 nodes::ExpressionStorage &expression_storage,
                                 nodes::TypeStorage &type_storage) {
  return nodes::Access(
      build_node(parser_node), nodes::Access::TUPLE,
      build_expression(parser_node.nth_named_child(0), expression_storage,
                       type_storage),
      expression_storage.add_expression(nodes::Expression(
          build_number_literal(parser_node.nth_named_child(1)))));
}

// 'break' | 'continue'
nodes::LoopControl build_loop_control(parser::ParseTree::Node parser_node) {
  return nodes::LoopControl(build_node(parser_node),
                            parser_node.get_value() == "break"
                                ? nodes::LoopControl::BREAK
                                : nodes::LoopControl::CONTINUE);
}

nodes::ModifierExpression
build_modifier_expression(parser::ParseTree::Node parser_node,
                          nodes::ExpressionStorage &expression_storage,
                          nodes::TypeStorage &type_storage,
                          size_t modifier_position) {

  return nodes::ModifierExpression(
      build_node(parser_node),
      build_modifier(parser_node.nth_child(modifier_position)),
      build_expression(parser_node.nth_named_child(0), expression_storage,
                       type_storage));
}

// _reference_ expression
nodes::ModifierExpression
build_reference_expression(parser::ParseTree::Node parser_node,
                           nodes::ExpressionStorage &expression_storage,
                           nodes::TypeStorage &type_storage) {
  return build_modifier_expression(parser_node, expression_storage,
                                   type_storage, 0);
}

// expression ('?' | '!')
nodes::ModifierExpression
build_suffix_expression(parser::ParseTree::Node parser_node,
                        nodes::ExpressionStorage &expression_storage,
                        nodes::TypeStorage &type_storage) {
  return build_modifier_expression(parser_node, expression_storage,
                                   type_storage, parser_node.child_count() - 1);
}

// --- other

void build_arguments_until_end(
    parser::ParseTree::Node first_parse_node,
    nodes::ExpressionStorage &expression_storage,
    nodes::TypeStorage &type_storage,
    std::vector<std::pair<std::optional<std::string>, nodes::ExpressionProxy>>
        &arguments) {

  auto current_node = first_parse_node;

  std::optional<std::string> last_annotation;
  while (!current_node.is_null()) {
    if (tokens::string_to_type(current_node.get_type()) ==
        tokens::Type::ANNOTATION_IDENTIFIER) {
      last_annotation = build_annotation(current_node);
    } else {
      arguments.emplace_back(
          std::move(last_annotation),
          build_expression(current_node, expression_storage, type_storage));
      last_annotation = std::nullopt;
    }
    current_node = current_node.next_named_sibling();
  }
}

// (type '.' simple_name | expression '.' simple_name | name | '(' operator
// ')') (annotation? expression)*
nodes::NameExpression
build_name_expression(parser::ParseTree::Node parser_node,
                      nodes::ExpressionStorage &expression_storage,
                      nodes::TypeStorage &type_storage) {
  std::vector<std::pair<std::optional<std::string>, nodes::ExpressionProxy>>
      arguments;

  std::optional<nodes::Type> prefix;

  bool is_point_call = false;

  auto name_node = parser_node.child_by_field_name("name");

  std::optional<parser::ParseTree::Node> prefix_node;

  auto current_node = name_node.previous_named_sibling();
  if (!current_node.is_null()) {
    if (tokens::string_to_type(current_node.get_type()) == tokens::Type::TYPE) {
      prefix_node = current_node;
    } else {
      is_point_call = true;
      arguments.emplace_back(
          std::nullopt,
          build_expression(current_node, expression_storage, type_storage));
    }
  }

  build_arguments_until_end(name_node.next_named_sibling(), expression_storage,
                            type_storage, arguments);

  return nodes::NameExpression(
      build_node(parser_node), build_identifier(name_node),
      std::move(arguments),
      prefix_node.has_value() ? build_type(prefix_node.value(), type_storage)
                              : std::optional<nodes::TypeProxy>(),
      is_point_call, false);
}

// type (annotation? expression)*
nodes::Constructor
build_constructor(parser::ParseTree::Node parser_node,
                  nodes::ExpressionStorage &expression_storage,
                  nodes::TypeStorage &type_storage) {
  std::vector<std::pair<std::optional<std::string>, nodes::ExpressionProxy>>
      arguments;

  build_arguments_until_end(
      parser_node.child_by_field_name("type").next_named_sibling(),
      expression_storage, type_storage, arguments);

  return nodes::Constructor(
      build_node(parser_node),
      build_type(parser_node.child_by_field_name("type"), type_storage),
      std::move(arguments));
}

// '\\' argument_name* _do_ expression
nodes::Lambda build_lambda(parser::ParseTree::Node parser_node,
                           nodes::ExpressionStorage &expression_storage,
                           nodes::TypeStorage &type_storage) {
  std::vector<nodes::Identifier> arguments;

  auto current_node =
      parser_node.nth_child(1); // next to '\\', not null ('=>' should present)

  while (current_node.is_named()) { // until _do_
    arguments.emplace_back(build_identifier(current_node));
    current_node = current_node.next_sibling();
  }

  // skip '=>'
  current_node = current_node.next_named_sibling();

  return nodes::Lambda(
      build_node(parser_node), std::move(arguments),
      build_expression(current_node, expression_storage, type_storage));
}

} // namespace builders