#pragma once

#include <string>
#include <vector>
#include <variant>
#include <optional>
#include <memory>

// for clangd
#include "utils.hpp"

namespace interpreter::tokens {

struct BaseNode {
  std::pair<size_t, size_t> start_position;
  std::pair<size_t, size_t> end_position;

  std::optional<utils::IdType> type_;
};

// ----------------- Declarations -----------------

using AnyIdentifier = std::string;
using NameOrOperatorIdentifier = std::string;
using NameIdentifier = std::string;
using AnyTypeIdentifier = std::string;
using TypeIdentifier = std::string;
using AbstractTypeIdentifier = std::string;
using OperatorIdentifier = std::string;
using TypeclassIdentifier = std::string;

// Sources -----------------

struct SourceFile;

// Namespaces, partitions -----------------

struct Namespace;
struct NamespaceSources;

// Definitions -----------------

struct ImportStatement;
struct AliasDefinitionStatement;
struct VariableDefinitionStatement;
struct FunctionDeclaration;
struct FunctionDefinitionStatement;
struct TypeDefinitionStatement;
struct AbstractTypeDefinitionStatement;
struct TypeclassDefinitionStatement;
struct PartitionStatement;

//
using NamespaceStatement = std::variant<
  std::unique_ptr<AliasDefinitionStatement>,
  std::unique_ptr<FunctionDeclaration>,
  std::unique_ptr<FunctionDefinitionStatement>,
  std::unique_ptr<TypeDefinitionStatement>,
  std::unique_ptr<PartitionStatement>,
  std::unique_ptr<Namespace>>;
//
using SourceStatement = std::variant<
  std::unique_ptr<ImportStatement>,
  std::unique_ptr<AbstractTypeDefinitionStatement>,
  std::unique_ptr<TypeclassDefinitionStatement>,
  std::unique_ptr<NamespaceStatement>>;
//

// Definition parts

using ImportSymbol = AnyIdentifier; // can be extended name

struct FunctionDefinition;
struct TypeDefinition;
struct AnyAnnotatedType;

// TypeIdentifier <-> AbstractTypeIdentifier <-> std::string
using AnnotatedType = AnyAnnotatedType;

using AnnotatedAbstractType = AnyAnnotatedType;

// Flow control -----------------

struct TypeConstructorPatternParameter;
struct TypeConstructorPattern;

struct Match;
struct Condition;
struct DoWhileLoop;
struct WhileLoop;
struct ForLoop;
struct LoopLoop;

using FlowControl = std::variant<
  std::unique_ptr<Match>,
  std::unique_ptr<Condition>,
  std::unique_ptr<DoWhileLoop>,
  std::unique_ptr<WhileLoop>,
  std::unique_ptr<ForLoop>,
  std::unique_ptr<LoopLoop>>;

// Statements, expressions, blocks, etc. -----------------

struct Block;

struct FloatNumberLiteral;
struct NumberLiteral;
struct StringLiteral;
struct CharLiteral;
struct UnitLiteral;

using Literal = std::variant<
  std::unique_ptr<FloatNumberLiteral>,
  std::unique_ptr<NumberLiteral>,
  std::unique_ptr<StringLiteral>,
  std::unique_ptr<CharLiteral>,
  std::unique_ptr<UnitLiteral>>;

//
struct NameExpression;
struct ScopedStatement;
struct AccessExpression;
using SubExpressionToken = std::variant<
  std::unique_ptr<NameExpression>,
  std::unique_ptr<ScopedStatement>,
  std::unique_ptr<AccessExpression>,
  std::unique_ptr<Literal>>;
//
struct FunctionCallExpression;
struct BinaryOperatorExpression;
struct ArrayExpression;
struct ReferenceExpression;
using SubExpression = std::variant<
  std::unique_ptr<FunctionCallExpression>,
  std::unique_ptr<BinaryOperatorExpression>,
  std::unique_ptr<SubExpressionToken>,
  std::unique_ptr<ReferenceExpression>>;
//
enum class LoopControlExpression {
    Break,
    Continue,
};
//
struct ReturnExpression;
using PrefixedExpression = std::variant<
  std::unique_ptr<ReturnExpression>,
  std::unique_ptr<LoopControlExpression>,
  std::unique_ptr<Block>>;
//
struct LambdaFunction;
struct TypeConstructor;
struct UnaryOperatorExpression;
using Expression = std::variant<
  std::unique_ptr<LambdaFunction>,
  std::unique_ptr<TypeConstructor>,
  std::unique_ptr<PrefixedExpression>,
  std::unique_ptr<UnaryOperatorExpression>,
  std::unique_ptr<SubExpression>>;
//
struct TupleExpression;
struct VariantExpression;
using SuperExpression = std::variant<
  std::unique_ptr<FlowControl>,
  std::unique_ptr<TupleExpression>,
  std::unique_ptr<VariantExpression>,
  std::unique_ptr<ArrayExpression>,
  std::unique_ptr<Expression>>;
//

struct ScopedStatement;

// Operators

struct BinaryOperatorExpression;
struct UnaryOperatorExpression;
struct ReferenceExpression;

// Other expressions

struct FunctionCallExpression;

struct TupleExpression;
struct VariantExpression;
struct ReturnExpression;
struct TypeConstructorParameter;
struct TypeConstructor;
struct LambdaFunction;
struct ArrayExpression;

// Name

struct PartitionName {
  BaseNode base;

  std::vector<TypeIdentifier> path;
  NameIdentifier name;
};

struct NameExpression;
struct TupleName;
struct VariantName;
struct AnnotatedName;

// // ScopedAnyName <-> AnyName
using AnyName = std::variant<
  std::unique_ptr<AnnotatedName>,
  std::unique_ptr<TupleName>,
  std::unique_ptr<VariantName>>;

using ScopedAnyName = AnyName;

// Type, typeclass, etc. -----------------

// Type

struct FunctionType;
struct TupleType;
struct VariantType;
struct TypeExpression;
struct TypeExpression;

using Constructor = std::string;

// // ScopedAnyType <-> AnyType
using AnyType = std::variant<
  std::unique_ptr<TypeExpression>,
  std::unique_ptr<TupleType>,
  std::unique_ptr<VariantType>,
  std::unique_ptr<FunctionType>>;

using ScopedAnyType = AnyType;

struct ExtendedScopedAnyType;

// Typeclass

struct ParametrizedTypeclass;

// TypeclassSubExpression -> ParametrizedTypeclass

// Typeclass & Type

struct ParametrizedType;

// Comments [IGNORE] -----------------
// Identifiers, constants, etc. -----------------

struct ExtendedName {
  BaseNode base;

  std::string name;
};

using Pattern = std::variant<
  std::unique_ptr<ExtendedName>,
  std::unique_ptr<Literal>,
  std::unique_ptr<TypeConstructorPattern>>;


using ScopedPattern = Pattern;

////////////////////////////////////////////////////////////////////////////////////////////

// ----------------- Sources -----------------

struct SourceFile {
  BaseNode base;

  std::vector<SourceStatement> statements;
};

// ----------------- Namespaces, partittions -----------------

struct NamespaceSources {
  BaseNode base;

  std::vector<NamespaceStatement> statements;
};

struct Namespace {
  BaseNode base;

  std::optional<utils::IsConstModifier> modifier; // modifier => variable namespace
  TypeIdentifier type;
  NamespaceSources scope;

  std::optional<utils::IdType> link_type_id_;
  std::optional<utils::IdType> link_typeclass_id_;
};

// ----------------- Definitions -----------------

struct ImportStatement {
  BaseNode base;

  std::optional<TypeIdentifier> name;
  std::string module_name;
  std::vector<ImportSymbol> symbols;
};

struct AliasDefinitionStatement {
  BaseNode base;

  utils::AliasModifier modifier;
  TypeIdentifier type;
  std::vector<AbstractTypeIdentifier> parameters;
  std::unique_ptr<TypeExpression> value;

  utils::IdType type_id_;
};

struct VariableDefinitionStatement {
  BaseNode base;

  utils::IsConstModifier modifier;
  utils::AssignmentModifier assignment_modifier;
  AnyName name;
  SuperExpression value;
};

struct FunctionDeclaration {
  BaseNode base;

  bool is_in_interface = false;
  ExtendedName name;
  std::vector<std::unique_ptr<AnnotatedAbstractType>> parameters;
  std::unique_ptr<FunctionType> type;

  utils::IdType function_id_;
};

struct FunctionDefinitionStatement {
  BaseNode base;

  std::unique_ptr<FunctionDefinition> definition;
  SuperExpression value;

  utils::IdType function_id_;
};

struct TypeDefinitionStatement {
  BaseNode base;

  bool is_in_interface = false;
  utils::ClassModifier modifier;
  std::unique_ptr<TypeDefinition> definition;
  AnyType value;

  utils::IdType type_id_;
};

struct AbstractTypeDefinitionStatement {
  BaseNode base;

  utils::AbstractTypeModifier modifier;
  std::unique_ptr<AnnotatedType> type;

  utils::IdType type_graph_id_;
  utils::IdType type_id_;
};

struct TypeclassDefinitionStatement {
  BaseNode base;

  std::unique_ptr<TypeDefinition> definition;
  std::vector<std::unique_ptr<FunctionDeclaration>> requirements;

  utils::IdType typeclass_id_;
};

struct PartitionStatement {
  BaseNode base;

  utils::PartitionModifier modifier;
  PartitionName name;
  SuperExpression value;

  utils::IdType executable_id_;
};

// Definition parts -----------------

struct FunctionDefinition {
  BaseNode base;

  utils::FunctionTypeModifier modifier;
  ExtendedName name;
  std::vector<ExtendedName> arguments;
};

struct TypeDefinition {
  BaseNode base;

  std::unique_ptr<AnnotatedType> type;
  std::vector<std::unique_ptr<AnnotatedAbstractType>> parameters;
};

struct AnyAnnotatedType {
  BaseNode base;

  AnyTypeIdentifier type;
  std::vector<std::unique_ptr<ParametrizedTypeclass>> typeclasses;
};

// ----------------- Flow control -----------------

struct TypeConstructorPatternParameter {
  BaseNode base;

  std::optional<ExtendedName> name;
  ScopedPattern value;
};

struct TypeConstructorPattern {
  BaseNode base;

  std::unique_ptr<TypeExpression> constructor;
  std::vector<TypeConstructorPatternParameter> parameters;
};

struct MatchCase {
  BaseNode base;

  Pattern value;
  std::optional<Expression> condition;
  std::optional<Expression> statement;
};

struct Match {
  BaseNode base;

  Expression value;
  std::vector<MatchCase> matches;
};

struct Condition {
  BaseNode base;

  std::vector<Expression> conditions; // if, elif
  std::vector<Expression> statements; // if, elif, else
};

struct DoWhileLoop {
  BaseNode base;

  Expression condition;
  Expression statement;
};

struct WhileLoop {
  BaseNode base;

  Expression condition;
  Expression statement;
};

struct ForLoop {
  BaseNode base;

  utils::IsConstModifier variable_modifier;
  AnyName variable;
  Expression interval;
  Expression statement;
};

struct LoopLoop {
  BaseNode base;

  Expression statement;
};

// ----------------- Statements, expressions, blocks, etc. -----------------

using BlockStatement = std::variant<
  std::unique_ptr<Expression>,
  std::unique_ptr<VariableDefinitionStatement>,
  std::unique_ptr<FlowControl>,
  std::unique_ptr<PrefixedExpression>>;

struct Block {
  BaseNode base;

  std::vector<BlockStatement> statements;
};

struct ScopedStatement {
  BaseNode base;

  SuperExpression statement;
};

// Operators -----------------

struct BinaryOperatorExpression {
  BaseNode base;

  OperatorIdentifier operator_name;
  SubExpression left_expression;
  SubExpression right_expression;
};

struct UnaryOperatorExpression {
  BaseNode base;

  OperatorIdentifier operator_name;
  Expression expression;
};

struct ReferenceExpression {
  BaseNode base;

  std::vector<utils::ReferenceModifier> references;
  std::unique_ptr<ScopedStatement> expression;
};

struct AccessExpression {
  BaseNode base;

  std::unique_ptr<NameExpression> name;
  SubExpressionToken id;
};

// Other Expressions -----------------

struct FunctionCallExpression {
  BaseNode base;

  std::optional<std::variant<std::unique_ptr<SubExpressionToken>,
                             std::unique_ptr<TypeExpression>>> prefix;
  ExtendedName name;
  std::vector<std::unique_ptr<TypeExpression>> parameters;
  std::vector<SubExpressionToken> arguments;
};

struct TupleExpression {
  BaseNode base;

  std::vector<SubExpression> expressions;
};

struct VariantExpression {
  BaseNode base;

  std::vector<SubExpression> expressions;
};

struct ReturnExpression {
  BaseNode base;

  Expression expression;
};

struct TypeConstructorParameter {
  BaseNode base;

  std::optional<ExtendedName> name;
  std::optional<utils::AssignmentModifier> asignment_modifier;
  SubExpression value;
};

struct TypeConstructor {
  BaseNode base;

  std::unique_ptr<TypeExpression> constructor;
  std::vector<TypeConstructorParameter> parameters;
};

struct LambdaFunction {
  BaseNode base;

  std::vector<std::unique_ptr<AnnotatedAbstractType>> parameters;
  std::vector<ExtendedName> arguments;
  Expression expression;

  std::vector<utils::IdType> argument_graph_ids_;
  utils::IdType return_type_graph_id_;
};

struct ArrayExpression {
  BaseNode base;

  std::vector<SubExpression> elements;
};

// Name -----------------

struct NameExpression {
  BaseNode base;

  std::vector<ExtendedName> names;
};

struct TupleName {
  BaseNode base;

  std::vector<ScopedAnyName> names;
};

struct VariantName {
  BaseNode base;

  std::vector<ScopedAnyName> names;
};

struct AnnotatedName {
  BaseNode base;

  NameIdentifier name;
  std::optional<ScopedAnyType> type;
};

// ----------------- Type, typeclass, etc. -----------------

// Type -----------------

struct FunctionType {
  BaseNode base;

  std::vector<ScopedAnyType> types;
};

struct TupleType {
  BaseNode base;

  std::optional<Constructor> type;
  std::vector<std::pair<std::optional<ExtendedName>, std::unique_ptr<ExtendedScopedAnyType>>> entities;
};

struct VariantType {
  BaseNode base;

  std::optional<Constructor> type;
  std::vector<std::variant<Constructor, std::unique_ptr<TupleType>>> constructors;
};

struct ParametrizedType {
  BaseNode base;

  AnyTypeIdentifier type;
  std::vector<std::unique_ptr<TypeExpression>> parameters;

  std::optional<utils::IdType> type_id_; // std::nullopt, if it is namespace without type
};

struct TypeExpression {
  BaseNode base;

  std::vector<ParametrizedType> path;
  ParametrizedType type;

  std::optional<size_t> array_size; // if array; 0 - dynamic size

  std::optional<utils::IdType> type_id_;
  std::optional<utils::IdType> constructor_id_;
};

struct ExtendedScopedAnyType {
  BaseNode base;

  std::vector<utils::ReferenceModifier> references;
  AnyType type;
};

// Typeclass -----------------

struct ParametrizedTypeclass {
  BaseNode base;

  TypeclassIdentifier typeclass;
  std::vector<std::unique_ptr<TypeExpression>> parameters;

  utils::IdType typeclass_id_;
};

// ----------------- Comments [IGNORE] -----------------
// ----------------- Identifiers, constants, etc. -----------------

struct FloatNumberLiteral {
  BaseNode base;

  double value;
};

struct NumberLiteral {
  BaseNode base;

  int64_t value;
};

struct StringLiteral {
  BaseNode base;

  std::string value;
};

struct CharLiteral {
  BaseNode base;

  char value;
};

struct UnitLiteral {
  BaseNode base;
};

} // namespace interpereter::tokens