// This file is part of Gopher2600.
//
// Gopher2600 is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Gopher2600 is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Gopher2600.  If not, see <https://www.gnu.org/licenses/>.
//
// *** NOTE: all historical versions of this file, as found in any
// git repository, are also covered by the licence, even when this
// notice is not present ***

package disassembly

import (
	"gopher2600/hardware/memory/cartridge"
	"gopher2600/hardware/memory/memorymap"
)

// disasmMemory is a simplified memory model that allows the emulated CPU to
// read cartridge memory.
type disasmMemory struct {
	cart *cartridge.Cartridge
}

func (dismem *disasmMemory) Read(address uint16) (uint8, error) {
	// map address
	if address&memorymap.OriginCart == memorymap.OriginCart {
		address = address & memorymap.MemtopCart
		return dismem.cart.Read(address)
	}

	// address outside of cartidge range return nothing
	return 0, nil
}

func (dismem *disasmMemory) Write(address uint16, data uint8) error {
	// map address
	if address&memorymap.OriginCart == memorymap.OriginCart {
		address = address & memorymap.MemtopCart
		return dismem.cart.Write(address, data)
	}

	// address outside of cartidge range - call Listen() in case cartridge
	// requires it to function correctly (tigervision cartridges bank switch on
	// writes to certain addresses)
	dismem.cart.Listen(address, data)

	return nil
}