/**************************************************************************/
/*  aethex_compiler.h                                                     */
/**************************************************************************/
/*                         This file is part of:                          */
/*                          AETHEX ENGINE                                 */
/*                     https://aethex.foundation                          */
/**************************************************************************/
/* Copyright (c) 2026-present AeThex Labs.                                */
/**************************************************************************/

#ifndef AETHEX_COMPILER_H
#define AETHEX_COMPILER_H

#include "aethex_parser.h"
#include "core/io/resource.h"
#include "core/object/ref_counted.h"

// ==========================================
// AeThex Cross-Platform Compiler
// ==========================================
// Compiles AeThex AST to:
// - AeThex Bytecode (for engine VM)
// - Roblox Luau
// - UEFN Verse
// - Unity C#
// - JavaScript (Web)
// ==========================================

class AeThexCompiler : public RefCounted {
	GDCLASS(AeThexCompiler, RefCounted);

public:
	// Compilation targets
	enum Target {
		TARGET_BYTECODE,    // Engine VM
		TARGET_LUAU,        // Roblox
		TARGET_VERSE,       // UEFN
		TARGET_CSHARP,      // Unity
		TARGET_JAVASCRIPT,  // Web
		TARGET_MAX
	};

	// Bytecode opcodes
	enum Opcode : uint8_t {
		// Stack
		OP_PUSH_NULL,
		OP_PUSH_BOOL,
		OP_PUSH_INT,
		OP_PUSH_FLOAT,
		OP_PUSH_STRING,
		OP_POP,
		OP_DUP,
		
		// Variables
		OP_LOAD_LOCAL,
		OP_STORE_LOCAL,
		OP_LOAD_GLOBAL,
		OP_STORE_GLOBAL,
		OP_LOAD_MEMBER,
		OP_STORE_MEMBER,
		
		// Arithmetic
		OP_ADD,
		OP_SUB,
		OP_MUL,
		OP_DIV,
		OP_MOD,
		OP_NEG,
		
		// Comparison
		OP_EQ,
		OP_NE,
		OP_LT,
		OP_LE,
		OP_GT,
		OP_GE,
		
		// Logic
		OP_NOT,
		OP_AND,
		OP_OR,
		
		// Control flow
		OP_JUMP,
		OP_JUMP_IF,
		OP_JUMP_IF_NOT,
		OP_LOOP,
		
		// Functions
		OP_CALL,
		OP_CALL_METHOD,
		OP_RETURN,
		
		// Objects
		OP_NEW_ARRAY,
		OP_NEW_DICT,
		OP_INDEX_GET,
		OP_INDEX_SET,
		
		// AeThex specific
		OP_SYNC,          // Sync across platforms
		OP_BEACON_EMIT,   // Emit beacon (signal)
		OP_NOTIFY,        // Console output
		OP_AWAIT,         // Async await
		
		OP_MAX
	};

	// Compiled bytecode chunk
	struct Chunk {
		Vector<uint8_t> code;
		Vector<Variant> constants;
		Vector<String> strings;
		HashMap<String, int> local_indices;
		int line_info = 0;
		
		void write(uint8_t byte) { code.push_back(byte); }
		void write_int(int32_t value);
		void write_float(float value);
		int add_constant(const Variant &value);
		int add_string(const String &str);
	};

	// Compilation result
	struct CompiledScript {
		String source_path;
		Target target = TARGET_BYTECODE;
		
		// For bytecode
		HashMap<String, Chunk> functions;
		Chunk main_chunk;
		Vector<String> beacons;  // Signal declarations
		
		// For cross-platform
		String output_code;
		
		// Metadata
		String reality_name;
		Vector<String> supported_platforms;
	};

private:
	CompiledScript result;
	Target current_target = TARGET_BYTECODE;
	Chunk *current_chunk = nullptr;
	int scope_depth = 0;
	bool had_error = false;
	
	struct Local {
		String name;
		int depth = 0;
		bool is_const = false;
	};
	Vector<Local> locals;

	// Bytecode compilation
	void compile_node(const AeThexParser::ASTNode *node);
	void compile_reality(const AeThexParser::ASTNode *node);
	void compile_journey(const AeThexParser::ASTNode *node);
	void compile_beacon(const AeThexParser::ASTNode *node);
	void compile_statement(const AeThexParser::ASTNode *node);
	void compile_expression(const AeThexParser::ASTNode *node);
	void compile_binary(const AeThexParser::ASTNode *node);
	void compile_unary(const AeThexParser::ASTNode *node);
	void compile_call(const AeThexParser::ASTNode *node);
	void compile_literal(const AeThexParser::ASTNode *node);
	void compile_identifier(const AeThexParser::ASTNode *node);
	void compile_if(const AeThexParser::ASTNode *node);
	void compile_sync(const AeThexParser::ASTNode *node);
	
	void emit_byte(uint8_t byte);
	void emit_bytes(uint8_t b1, uint8_t b2);
	void emit_return();
	int emit_jump(Opcode op);
	void patch_jump(int offset);
	void emit_loop(int loop_start);
	
	void begin_scope();
	void end_scope();
	void declare_local(const String &name, bool is_const);
	int resolve_local(const String &name);
	
	// Cross-platform code generation
	String generate_luau(const AeThexParser::ASTNode *root);
	String generate_verse(const AeThexParser::ASTNode *root);
	String generate_csharp(const AeThexParser::ASTNode *root);
	String generate_javascript(const AeThexParser::ASTNode *root);
	
	String luau_node(const AeThexParser::ASTNode *node, int indent = 0);
	String verse_node(const AeThexParser::ASTNode *node, int indent = 0);
	String csharp_node(const AeThexParser::ASTNode *node, int indent = 0);
	String js_node(const AeThexParser::ASTNode *node, int indent = 0);
	
	String indent_str(int level) const;

protected:
	static void _bind_methods();

public:
	AeThexCompiler();
	~AeThexCompiler();
	
	// Compile AST to target
	Error compile(const AeThexParser::ASTNode *root, Target p_target = TARGET_BYTECODE);
	
	// Get results
	const CompiledScript &get_result() const { return result; }
	String get_output_code() const { return result.output_code; }
	bool has_error() const { return had_error; }
	
	// Cross-platform export
	String export_to_luau(const AeThexParser::ASTNode *root);
	String export_to_verse(const AeThexParser::ASTNode *root);
	String export_to_csharp(const AeThexParser::ASTNode *root);
	String export_to_javascript(const AeThexParser::ASTNode *root);
	
	// Static helpers
	static String target_name(Target t);
	static String opcode_name(Opcode op);
};

VARIANT_ENUM_CAST(AeThexCompiler::Target);

#endif // AETHEX_COMPILER_H