teest

-- Custom Bit Library for ComputerCraft
local bit = {}

function bit.band(a, b)
    local result = 0
    local bitval = 1
    while a > 0 and b > 0 do
        if a % 2 == 1 and b % 2 == 1 then result = result + bitval end
        bitval = bitval * 2
        a = math.floor(a / 2)
        b = math.floor(b / 2)
    end
    return result
end

function bit.bor(a, b)
    local result = 0
    local bitval = 1
    while a > 0 or b > 0 do
        if a % 2 == 1 or b % 2 == 1 then result = result + bitval end
        bitval = bitval * 2
        a = math.floor(a / 2)
        b = math.floor(b / 2)
    end
    return result
end

function bit.bxor(a, b)
    local result = 0
    local bitval = 1
    while a > 0 or b > 0 do
        if a % 2 ~= b % 2 then result = result + bitval end
        bitval = bitval * 2
        a = math.floor(a / 2)
        b = math.floor(b / 2)
    end
    return result
end

function bit.bnot(n)
    return (-n) - 1
end

function bit.blshift(n, bits)
    return n * (2 ^ bits)
end

function bit.brshift(n, bits)
    return math.floor(n / (2 ^ bits))
end

function bit.blogic_rshift(n, bits)
    if n >= 0 then
        return bit.brshift(n, bits)
    else
        return bit.brshift((n + 0x100000000), bits)
    end
end

-- Z-machine implementation
local memory = {}
local pc = 1
local stack = {}
local sp = 1
local locals = {}
local globals = {}
local version = 0

-- Initialize memory
for i = 1, 65536 do
    memory[i] = 0
end

-- Helper functions
local function readByte(addr)
    return memory[addr]
end

local function readWord(addr)
    return (memory[addr] * 256) + memory[addr + 1]
end

local function writeByte(addr, value)
    memory[addr] = value % 256
end

local function writeWord(addr, value)
    memory[addr] = math.floor(value / 256)
    memory[addr + 1] = value % 256
end

local function pushStack(value)
    stack[sp] = value
    sp = sp + 1
end

local function popStack()
    sp = sp - 1
    return stack[sp]
end

-- ZSCII decoding (simplified)
local function decodeZSCII(addr)
    local result = ""
    local i = addr
    while true do
        local word = readWord(i)
        for j = 1, 3 do
            local char = bit.band(bit.brshift(word, (3-j)*5), 0x1F)
            if char ~= 0 then
                result = result .. string.char(char + 96)
            end
        end
        if bit.band(word, 0x8000) ~= 0 then break end
        i = i + 2
    end
    return result
end

-- Operand types
local OP_LARGE = 0
local OP_SMALL = 1
local OP_VAR = 2
local OP_OMITTED = 3

-- Fetch and decode operands
local function fetchOperands(opcode)
    local operandTypes = {}
    local operands = {}

    if opcode < 0x80 then -- 2OP
        operandTypes[1] = bit.band(bit.brshift(opcode, 6), 0x03)
        operandTypes[2] = bit.band(bit.brshift(opcode, 4), 0x03)
    elseif opcode < 0xB0 then -- 1OP
        operandTypes[1] = bit.band(bit.brshift(opcode, 4), 0x03)
    elseif opcode < 0xC0 then -- 0OP
        -- No operands
    else -- VAR
        local specifier = readByte(pc)
        pc = pc + 1
        for i = 1, 4 do
            local type = bit.band(bit.brshift(specifier, (4-i)*2), 0x03)
            if type ~= OP_OMITTED then
                table.insert(operandTypes, type)
            end
        end
    end

    for _, type in ipairs(operandTypes) do
        if type == OP_LARGE then
            table.insert(operands, readWord(pc))
            pc = pc + 2
        elseif type == OP_SMALL then
            table.insert(operands, readByte(pc))
            pc = pc + 1
        elseif type == OP_VAR then
            local var = readByte(pc)
            pc = pc + 1
            if var == 0 then
                table.insert(operands, popStack())
            elseif var < 16 then
                table.insert(operands, locals[var])
            else
                table.insert(operands, globals[var - 16])
            end
        end
    end

    return operands
end

-- Opcode implementations
local opcodes = {
    [0x00] = function() return 1 end, -- RTRUE
    [0x01] = function() return 0 end, -- RFALSE
    [0x02] = function(value) return value end, -- PRINT
    [0x03] = function(value) print(value) return 1 end, -- PRINT_RET
    [0x04] = function() end, -- NOP
    [0x05] = function(a) -- SAVE
        local result = saveGame("z_save.dat")
        if version <= 3 then
            pc = a
            return result and 1 or 0
        else
            return result and 1 or 0
        end
    end,
    [0x06] = function(a) -- RESTORE
        local result = restoreGame("z_save.dat")
        if version <= 3 then
            pc = a
            return result and 2 or 0
        else
            return result and 2 or 0
        end
    end,
    [0x07] = function() pc = 1 end, -- RESTART
    [0x08] = function() return popStack() end, -- RET_POPPED
    [0x09] = function() popStack() end, -- POP
    [0x0A] = function() error("QUIT instruction executed") end, -- QUIT
    [0x0B] = function() print() end, -- NEW_LINE
    [0x0C] = function(a) return a end, -- SHOW_STATUS
    [0x0D] = function(a) return a end, -- VERIFY
    [0x0E] = function() -- EXTENDED
        local opcode = readByte(pc)
        pc = pc + 1
        -- Implement extended opcodes here
    end,
    [0x0F] = function(a) -- PIRACY
        if version <= 3 then pc = a end
        return 0
    end,
    -- Add more opcodes here
    [0x80] = function(a, b) if a == b then return 1 else return 0 end end, -- JE
    [0x81] = function(a, b) if a ~= b then return 1 else return 0 end end, -- JL
    [0x82] = function(a, b) if a < b then return 1 else return 0 end end, -- JG
    [0x83] = function(a, b) if a >= b then return 1 else return 0 end end, -- DEC_CHK
    [0x84] = function(a, b) if a <= b then return 1 else return 0 end end, -- INC_CHK
    [0x85] = function(a, b) if a > b then return 1 else return 0 end end, -- JIN
    [0x86] = function(a, b) return math.random(a, b) end, -- TEST
    [0x87] = function(a, b) return bit.bor(a, b) end, -- OR
    [0x88] = function(a, b) return bit.band(a, b) end, -- AND
    [0x89] = function(a, b) if bit.band(a, b) ~= 0 then return 1 else return 0 end end, -- TEST_ATTR
    -- Add more opcodes as needed
}

-- Main execution loop
local function execute()
    while true do
        local opcode = readByte(pc)
        pc = pc + 1
        local operands = fetchOperands(opcode)
        if opcode == 0x0E then -- EXTENDED opcode
            opcode = readByte(pc)
            pc = pc + 1
            operands = fetchOperands(opcode)
            -- Handle extended opcodes here
        end
        if opcodes[opcode] then
            local result = opcodes[opcode](table.unpack(operands))
            if result ~= nil then
                return result
            end
        else
            error("Unknown opcode: " .. opcode)
        end
    end
end

-- Load game file
local function loadGame(filename)
    local file = fs.open(filename, "rb")
    if not file then
        error("Could not open file: " .. filename)
    end
    local content = file.readAll()
    file.close()

    for i = 1, #content do
        memory[i] = string.byte(content, i)
    end

    version = memory[0]
    pc = readWord(0x06)
end

-- Save game state
local function saveGame(filename)
    local file = fs.open(filename, "w")
    if not file then
        return false
    end

    file.write(textutils.serialize(memory))
    file.write(textutils.serialize(stack))

    local state = {
        pc = pc,
        sp = sp,
        locals = locals,
        globals = globals,
        version = version
    }
    file.write(textutils.serialize(state))

    file.close()
    return true
end

-- Restore game state
local function restoreGame(filename)
    local file = fs.open(filename, "r")
    if not file then
        return false
    end

    memory = textutils.unserialize(file.readLine())
    stack = textutils.unserialize(file.readLine())

    local state = textutils.unserialize(file.readLine())
    pc = state.pc
    sp = state.sp
    locals = state.locals
    globals = state.globals
    version = state.version

    file.close()
    return true
end

-- Download Zork 3
local function downloadZork3()
    local url = "https://eblong.com/infocom/gamefiles/zork3-r16-s830410.z3"
    local response = http.get(url)
    if response then
        local content = response.readAll()
        response.close()

        local file = fs.open("zork3.z3", "wb")
        file.write(content)
        file.close()
        return true
    else
        return false
    end
end

-- GUI
local function drawGUI()
    term.clear()
    term.setCursorPos(1, 1)
    term.write("Advanced Z-machine for ComputerCraft")
    term.setCursorPos(1, 3)
    term.write("1. Download Zork 3")
    term.setCursorPos(1, 4)
    term.write("2. Play Zork 3")
    term.setCursorPos(1, 5)
    term.write("3. Exit")
end

-- Main function
local function main()
    while true do
        drawGUI()
        term.setCursorPos(1, 7)
        term.write("Enter your choice: ")
        local choice = read()

        if choice == "1" then
            term.setCursorPos(1, 9)
            term.write("Downloading Zork 3...")
            if downloadZork3() then
                term.setCursorPos(1, 10)
                term.write("Download complete!")
            else
                term.setCursorPos(1, 10)
                term.write("Download failed.")
            end
            os.sleep(2)
        elseif choice == "2" then
            if fs.exists("zork3.z3") then
                term.clear()
                term.setCursorPos(1, 1)
                loadGame("zork3.z3")
                local result = execute()
                term.setCursorPos(1, 23)
                term.write("Game finished with result: " .. result)
                term.setCursorPos(1, 24)
                term.write("Press any key to continue...")
                os.pullEvent("key")
            else
                term.setCursorPos(1, 9)
                term.write("Zork 3 not found. Please download it first.")
                os.sleep(2)
            end
        elseif choice == "3" then
            term.clear()
            term.setCursorPos(1, 1)
            term.write("Goodbye!")
            break
        else
            term.setCursorPos(1, 9)
            term.write("Invalid choice. Please try again.")
            os.sleep(2)
        end
    end
end

main()