#ifndef NIX_IRC_TYPES_H
#define NIX_IRC_TYPES_H

#include <cstdint>
#include <fstream>
#include <memory>
#include <optional>
#include <sstream>
#include <string>
#include <unordered_map>
#include <utility>
#include <variant>
#include <vector>

namespace nix_irc {

constexpr uint32_t IR_MAGIC = 0x4E495258;
constexpr uint32_t IR_VERSION = 2;

enum class NodeType : uint8_t {
  CONST_INT = 0x01,
  CONST_STRING = 0x02,
  CONST_PATH = 0x03,
  CONST_BOOL = 0x04,
  CONST_NULL = 0x05,
  VAR = 0x10,
  LAMBDA = 0x20,
  APP = 0x21,
  BINARY_OP = 0x22,
  UNARY_OP = 0x23,
  ATTRSET = 0x30,
  SELECT = 0x31,
  HAS_ATTR = 0x34,
  WITH = 0x32,
  IF = 0x40,
  LET = 0x50,
  LETREC = 0x51,
  ASSERT = 0x52,
  THUNK = 0x60,
  FORCE = 0x61,
  ERROR = 0xFF
};

enum class BinaryOp : uint8_t { ADD, SUB, MUL, DIV, CONCAT, EQ, NE, LT, GT, LE, GE, AND, OR, IMPL };

enum class UnaryOp : uint8_t { NEG, NOT };

// Forward declare Node for use in shared_ptr
class Node;

struct ConstIntNode {
  int64_t value;
  uint32_t line = 0;
  ConstIntNode(int64_t v = 0, uint32_t l = 0) : value(v), line(l) {}
};

struct ConstStringNode {
  std::string value;
  uint32_t line = 0;
  ConstStringNode(std::string v = "", uint32_t l = 0) : value(std::move(v)), line(l) {}
};

struct ConstPathNode {
  std::string value;
  uint32_t line = 0;
  ConstPathNode(std::string v = "", uint32_t l = 0) : value(std::move(v)), line(l) {}
};

struct ConstBoolNode {
  bool value;
  uint32_t line = 0;
  ConstBoolNode(bool v = false, uint32_t l = 0) : value(v), line(l) {}
};

struct ConstNullNode {
  uint32_t line = 0;
  ConstNullNode(uint32_t l = 0) : line(l) {}
};

struct VarNode {
  uint32_t index = 0;
  std::optional<std::string> name;
  uint32_t line = 0;
  VarNode(uint32_t idx = 0, std::string n = "", uint32_t l = 0)
      : index(idx), name(n.empty() ? std::nullopt : std::optional<std::string>(n)), line(l) {}
};

struct LambdaNode {
  uint32_t arity = 1;
  std::shared_ptr<Node> body;
  std::optional<std::string> param_name;
  bool strict_pattern = true;
  uint32_t line = 0;
  LambdaNode(uint32_t a, std::shared_ptr<Node> b, uint32_t l = 0);
};

struct AppNode {
  std::shared_ptr<Node> func;
  std::shared_ptr<Node> arg;
  uint32_t line = 0;
  AppNode(std::shared_ptr<Node> f, std::shared_ptr<Node> a, uint32_t l = 0);
};

struct BinaryOpNode {
  BinaryOp op;
  std::shared_ptr<Node> left;
  std::shared_ptr<Node> right;
  uint32_t line = 0;
  BinaryOpNode(BinaryOp o, std::shared_ptr<Node> l, std::shared_ptr<Node> r, uint32_t ln = 0);
};

struct UnaryOpNode {
  UnaryOp op;
  std::shared_ptr<Node> operand;
  uint32_t line = 0;
  UnaryOpNode(UnaryOp o, std::shared_ptr<Node> operand, uint32_t l = 0);
};

struct AttrsetNode {
  std::vector<std::pair<std::string, std::shared_ptr<Node>>> attrs;
  bool recursive = false;
  uint32_t line = 0;
  AttrsetNode(bool rec = false, uint32_t l = 0) : recursive(rec), line(l) {}
};

struct SelectNode {
  std::shared_ptr<Node> expr;
  std::shared_ptr<Node> attr;
  std::optional<std::shared_ptr<Node>> default_expr;
  uint32_t line = 0;
  SelectNode(std::shared_ptr<Node> e, std::shared_ptr<Node> a, uint32_t l = 0);
};

struct HasAttrNode {
  std::shared_ptr<Node> expr;
  std::shared_ptr<Node> attr;
  uint32_t line = 0;
  HasAttrNode(std::shared_ptr<Node> e, std::shared_ptr<Node> a, uint32_t l = 0);
};

struct WithNode {
  std::shared_ptr<Node> attrs;
  std::shared_ptr<Node> body;
  uint32_t line = 0;
  WithNode(std::shared_ptr<Node> a, std::shared_ptr<Node> b, uint32_t l = 0);
};

struct IfNode {
  std::shared_ptr<Node> cond;
  std::shared_ptr<Node> then_branch;
  std::shared_ptr<Node> else_branch;
  uint32_t line = 0;
  IfNode(std::shared_ptr<Node> c, std::shared_ptr<Node> t, std::shared_ptr<Node> e, uint32_t l = 0);
};

struct LetNode {
  std::vector<std::pair<std::string, std::shared_ptr<Node>>> bindings;
  std::shared_ptr<Node> body;
  uint32_t line = 0;
  LetNode(std::shared_ptr<Node> b, uint32_t l = 0);
};

struct LetRecNode {
  std::vector<std::pair<std::string, std::shared_ptr<Node>>> bindings;
  std::shared_ptr<Node> body;
  uint32_t line = 0;
  LetRecNode(std::shared_ptr<Node> b, uint32_t l = 0);
};

struct AssertNode {
  std::shared_ptr<Node> cond;
  std::shared_ptr<Node> body;
  uint32_t line = 0;
  AssertNode(std::shared_ptr<Node> c, std::shared_ptr<Node> b, uint32_t l = 0);
};

struct ThunkNode {
  std::shared_ptr<Node> expr;
  uint32_t line = 0;
  ThunkNode(std::shared_ptr<Node> e, uint32_t l = 0);
};

struct ForceNode {
  std::shared_ptr<Node> expr;
  uint32_t line = 0;
  ForceNode(std::shared_ptr<Node> e, uint32_t l = 0);
};

// Node wraps a variant for type-safe AST
class Node {
public:
  using Variant = std::variant<ConstIntNode, ConstStringNode, ConstPathNode, ConstBoolNode,
                               ConstNullNode, VarNode, LambdaNode, AppNode, BinaryOpNode,
                               UnaryOpNode, AttrsetNode, SelectNode, HasAttrNode, WithNode, IfNode,
                               LetNode, LetRecNode, AssertNode, ThunkNode, ForceNode>;

  Variant data;

  template <typename T> Node(T&& value) : data(std::forward<T>(value)) {}

  template <typename T> T* get_if() { return std::get_if<T>(&data); }

  template <typename T> const T* get_if() const { return std::get_if<T>(&data); }

  template <typename T> bool holds() const { return std::holds_alternative<T>(data); }
};

// Constructor implementations
inline LambdaNode::LambdaNode(uint32_t a, std::shared_ptr<Node> b, uint32_t l)
    : arity(a), body(std::move(b)), line(l) {}

inline AppNode::AppNode(std::shared_ptr<Node> f, std::shared_ptr<Node> a, uint32_t l)
    : func(std::move(f)), arg(std::move(a)), line(l) {}

inline BinaryOpNode::BinaryOpNode(BinaryOp o, std::shared_ptr<Node> l, std::shared_ptr<Node> r,
                                  uint32_t ln)
    : op(o), left(std::move(l)), right(std::move(r)), line(ln) {}

inline UnaryOpNode::UnaryOpNode(UnaryOp o, std::shared_ptr<Node> operand, uint32_t l)
    : op(o), operand(std::move(operand)), line(l) {}

inline SelectNode::SelectNode(std::shared_ptr<Node> e, std::shared_ptr<Node> a, uint32_t l)
    : expr(std::move(e)), attr(std::move(a)), line(l) {}

inline HasAttrNode::HasAttrNode(std::shared_ptr<Node> e, std::shared_ptr<Node> a, uint32_t l)
    : expr(std::move(e)), attr(std::move(a)), line(l) {}

inline WithNode::WithNode(std::shared_ptr<Node> a, std::shared_ptr<Node> b, uint32_t l)
    : attrs(std::move(a)), body(std::move(b)), line(l) {}

inline IfNode::IfNode(std::shared_ptr<Node> c, std::shared_ptr<Node> t, std::shared_ptr<Node> e,
                      uint32_t l)
    : cond(std::move(c)), then_branch(std::move(t)), else_branch(std::move(e)), line(l) {}

inline LetNode::LetNode(std::shared_ptr<Node> b, uint32_t l) : body(std::move(b)), line(l) {}

inline LetRecNode::LetRecNode(std::shared_ptr<Node> b, uint32_t l) : body(std::move(b)), line(l) {}

inline AssertNode::AssertNode(std::shared_ptr<Node> c, std::shared_ptr<Node> b, uint32_t l)
    : cond(std::move(c)), body(std::move(b)), line(l) {}

inline ThunkNode::ThunkNode(std::shared_ptr<Node> e, uint32_t l) : expr(std::move(e)), line(l) {}

inline ForceNode::ForceNode(std::shared_ptr<Node> e, uint32_t l) : expr(std::move(e)), line(l) {}

struct SourceFile {
  std::string path;
  std::string content;
  std::shared_ptr<Node> ast;
};

struct IRModule {
  uint32_t version = IR_VERSION;
  std::vector<SourceFile> sources;
  std::vector<std::pair<std::string, std::string>> imports;
  std::shared_ptr<Node> entry;
  std::unordered_map<std::string, uint32_t> string_table;
};

} // namespace nix_irc
#endif