#pragma once

#include "stdafx.h"

class CPUThread;

namespace vm
{
	extern void* const g_base_addr; // base address of ps3/psv virtual memory for common access
	extern void* g_priv_addr; // base address of ps3/psv virtual memory for privileged access

	enum memory_location_t : uint
	{
		main,
		user_space,
		video,
		stack,
		
		memory_location_max,
		any = 0xffffffff,
	};

	enum page_info_t : u8
	{
		page_readable           = (1 << 0),
		page_writable           = (1 << 1),
		page_executable         = (1 << 2),

		page_fault_notification = (1 << 3),
		page_no_reservations    = (1 << 4),

		page_allocated          = (1 << 7),
	};

	// This flag is changed by various reservation functions and may have different meaning.
	// reservation_break() - true if the reservation was successfully broken.
	// reservation_acquire() - true if another existing reservation was broken.
	// reservation_free() - true if this thread's reservation was successfully removed.
	// reservation_op() - false if reservation_update() would succeed if called instead.
	// Write access to reserved memory - only set to true if the reservation was broken.
	extern thread_local bool g_tls_did_break_reservation;

	// Unconditionally break the reservation at specified address
	void reservation_break(u32 addr);

	// Reserve memory at the specified address for further atomic update
	void reservation_acquire(void* data, u32 addr, u32 size);

	// Attempt to atomically update previously reserved memory
	bool reservation_update(u32 addr, const void* data, u32 size);

	// Process a memory access error if it's caused by the reservation
	bool reservation_query(u32 addr, u32 size, bool is_writing, std::function<bool()> callback);

	// Returns true if the current thread owns reservation
	bool reservation_test();

	// Break all reservations created by the current thread
	void reservation_free();

	// Perform atomic operation unconditionally
	void reservation_op(u32 addr, u32 size, std::function<void()> proc);

	// Change memory protection of specified memory region
	bool page_protect(u32 addr, u32 size, u8 flags_test = 0, u8 flags_set = 0, u8 flags_clear = 0);

	// Check if existing memory range is allocated. Checking address before using it is very unsafe.
	// Return value may be wrong. Even if it's true and correct, actual memory protection may be read-only and no-access.
	bool check_addr(u32 addr, u32 size = 1);

	// Search and map memory in specified memory location (don't pass alignment smaller than 4096)
	u32 alloc(u32 size, memory_location_t location, u32 align = 4096);

	// Map memory at specified address (in optionally specified memory location)
	u32 falloc(u32 addr, u32 size, memory_location_t location = any);

	// Unmap memory at specified address (in optionally specified memory location)
	bool dealloc(u32 addr, memory_location_t location = any);

	// Object that handles memory allocations inside specific constant bounds ("location"), currently non-virtual
	class block_t final
	{
		std::map<u32, u32> m_map; // addr -> size mapping of mapped locations
		std::mutex m_mutex;

		bool try_alloc(u32 addr, u32 size);

	public:
		block_t() = delete;

		block_t(u32 addr, u32 size, u64 flags = 0)
			: addr(addr)
			, size(size)
			, flags(flags)
		{
		}

		~block_t();

	public:
		const u32 addr; // start address
		const u32 size; // total size
		const u64 flags; // currently unused

		atomic_t<u32> used{}; // amount of memory used, may be increased manually prevent some memory from allocating

		// Search and map memory (don't pass alignment smaller than 4096)
		u32 alloc(u32 size, u32 align = 4096);

		// Try to map memory at fixed location
		u32 falloc(u32 addr, u32 size);

		// Unmap memory at specified location previously returned by alloc()
		bool dealloc(u32 addr);
	};

	// create new memory block with specified parameters and return it
	std::shared_ptr<block_t> map(u32 addr, u32 size, u64 flags = 0);

	// delete existing memory block with specified start address
	std::shared_ptr<block_t> unmap(u32 addr);

	// get memory block associated with optionally specified memory location or optionally specified address
	std::shared_ptr<block_t> get(memory_location_t location, u32 addr = 0);
	
	template<typename T = void> T* get_ptr(u32 addr)
	{
		return reinterpret_cast<T*>(static_cast<u8*>(g_base_addr) + addr);
	}

	template<typename T> T& get_ref(u32 addr)
	{
		return *get_ptr<T>(addr);
	}

	template<typename T = void> T* priv_ptr(u32 addr)
	{
		return reinterpret_cast<T*>(static_cast<u8*>(g_priv_addr) + addr);
	}

	template<typename T> T& priv_ref(u32 addr)
	{
		return *priv_ptr<T>(addr);
	}

	inline u32 get_addr(const void* real_pointer)
	{
		const std::uintptr_t diff = reinterpret_cast<std::uintptr_t>(real_pointer) - reinterpret_cast<std::uintptr_t>(g_base_addr);
		const u32 res = static_cast<u32>(diff);

		if (res == diff)
		{
			return res;
		}

		if (real_pointer)
		{
			throw EXCEPTION("Not a virtual memory pointer (%p)", real_pointer);
		}

		return 0;
	}

	template<typename T> struct cast_ptr
	{
		static_assert(std::is_same<T, u32>::value, "Unsupported VM_CAST() type");

		force_inline static u32 cast(const T& addr, const char* file, int line, const char* func)
		{
			return 0;
		}
	};

	template<> struct cast_ptr<u32>
	{
		force_inline static u32 cast(const u32 addr, const char* file, int line, const char* func)
		{
			return addr;
		}
	};

	template<> struct cast_ptr<u64>
	{
		force_inline static u32 cast(const u64 addr, const char* file, int line, const char* func)
		{
			const u32 res = static_cast<u32>(addr);

			if (res != addr)
			{
				throw fmt::exception(file, line, func, "VM_CAST failed (addr=0x%llx)", addr);
			}

			return res;
		}
	};

	template<typename T> struct cast_ptr<be_t<T>>
	{
		force_inline static u32 cast(const be_t<T>& addr, const char* file, int line, const char* func)
		{
			return cast_ptr<T>::cast(addr.value(), file, line, func);
		}
	};

	template<typename T> struct cast_ptr<le_t<T>>
	{
		force_inline static u32 cast(const le_t<T>& addr, const char* file, int line, const char* func)
		{
			return cast_ptr<T>::cast(addr.value(), file, line, func);
		}
	};

	// function for VM_CAST
	template<typename T> force_inline static u32 impl_cast(const T& addr, const char* file, int line, const char* func)
	{
		return cast_ptr<T>::cast(addr, file, line, func);
	}

	static const u8& read8(u32 addr)
	{
		return get_ref<const u8>(addr);
	}

	static void write8(u32 addr, u8 value)
	{
		get_ref<u8>(addr) = value;
	}

	namespace ps3
	{
		void init();

		inline const be_t<u16>& read16(u32 addr)
		{
			return get_ref<const be_t<u16>>(addr);
		}

		inline void write16(u32 addr, be_t<u16> value)
		{
			get_ref<be_t<u16>>(addr) = value;
		}

		inline const be_t<u32>& read32(u32 addr)
		{
			return get_ref<const be_t<u32>>(addr);
		}

		inline void write32(u32 addr, be_t<u32> value)
		{
			get_ref<be_t<u32>>(addr) = value;
		}

		inline const be_t<u64>& read64(u32 addr)
		{
			return get_ref<const be_t<u64>>(addr);
		}

		inline void write64(u32 addr, be_t<u64> value)
		{
			get_ref<be_t<u64>>(addr) = value;
		}

		inline const be_t<u128>& read128(u32 addr)
		{
			return get_ref<const be_t<u128>>(addr);
		}

		inline void write128(u32 addr, be_t<u128> value)
		{
			get_ref<be_t<u128>>(addr) = value;
		}
	}
	
	namespace psv
	{
		void init();

		inline const le_t<u16>& read16(u32 addr)
		{
			return get_ref<const le_t<u16>>(addr);
		}

		inline void write16(u32 addr, le_t<u16> value)
		{
			get_ref<le_t<u16>>(addr) = value;
		}

		inline const le_t<u32>& read32(u32 addr)
		{
			return get_ref<const le_t<u32>>(addr);
		}

		inline void write32(u32 addr, le_t<u32> value)
		{
			get_ref<le_t<u32>>(addr) = value;
		}

		inline const le_t<u64>& read64(u32 addr)
		{
			return get_ref<const le_t<u64>>(addr);
		}

		inline void write64(u32 addr, le_t<u64> value)
		{
			get_ref<le_t<u64>>(addr) = value;
		}

		inline const le_t<u128>& read128(u32 addr)
		{
			return get_ref<const le_t<u128>>(addr);
		}

		inline void write128(u32 addr, le_t<u128> value)
		{
			get_ref<le_t<u128>>(addr) = value;
		}
	}

	namespace psp
	{
		using namespace psv;

		void init();
	}

	void close();

	u32 stack_push(CPUThread& CPU, u32 size, u32 align, u32& old_pos);
	void stack_pop(CPUThread& CPU, u32 addr, u32 old_pos);
}

#include "vm_ref.h"
#include "vm_ptr.h"
#include "vm_var.h"

namespace vm
{
	class stack
	{
		u32 m_begin;
		u32 m_size;
		int m_page_size;
		int m_position;
		u8 m_align;

	public:
		void init(u32 begin, u32 size, u32 page_size = 180, u8 align = 0x10)
		{
			m_begin = begin;
			m_size = size;
			m_page_size = page_size;
			m_position = 0;
			m_align = align;
		}

		u32 alloc_new_page()
		{
			assert(m_position + m_page_size < (int)m_size);
			m_position += (int)m_page_size;
			return m_begin + m_position;
		}

		u32 dealloc_new_page()
		{
			assert(m_position - m_page_size > 0);
			m_position -= (int)m_page_size;
			return m_begin + m_position;
		}
	};
}