ndisk

-- ndisk.lua

local modem = peripheral.find("modem") or error("No modem found")
modem.open(1) -- Open channel 1 for communication

local nodes = {}
local chunkMap = {}

-- Function to save the node IDs
local function saveNodeIds()
    local file = fs.open("ids.txt", "w")
    for hierarchicalNum, nodeId in pairs(nodes) do
        file.writeLine(nodeId .. " " .. hierarchicalNum)
    end
    file.close()
end

-- Function to load the node IDs
local function loadNodeIds()
    nodes = {}
    if fs.exists("ids.txt") then
        local file = fs.open("ids.txt", "r")
        for line in file.readLine do
            local nodeId, hierarchicalNum = line:match("(%d+)%s+(%d+)")
            if nodeId and hierarchicalNum then
                nodes[tonumber(hierarchicalNum)] = tonumber(nodeId)
            end
        end
        file.close()
    end
end

-- Function to save the chunk map
local function saveChunkMap()
    local file = fs.open("chunklocation.txt", "w")
    for filename, chunks in pairs(chunkMap) do
        for chunkNum, nodeId in pairs(chunks) do
            file.writeLine(filename .. " chunk" .. chunkNum .. " " .. nodeId)
        end
    end
    file.close()
end

-- Function to load the chunk map
local function loadChunkMap()
    chunkMap = {}
    if fs.exists("chunklocation.txt") then
        local file = fs.open("chunklocation.txt", "r")
        for line in file.readLine do
            local filename, chunk, nodeId = line:match("(%S+)%s+(%S+)%s+(%S+)")
            if filename and chunk and nodeId then
                chunkMap[filename] = chunkMap[filename] or {}
                local chunkNum = tonumber(chunk:match("chunk(%d+)"))
                chunkMap[filename][chunkNum] = tonumber(nodeId)
            end
        end
        file.close()
    end
end

-- Function to discover storage nodes
local function discoverNodes()
    print("Discovering storage nodes...")
    modem.transmit(1, 1, {type = "discovery"})
    local timer = os.startTimer(5)
    local discoveredNodes = {}
    local nextHierarchicalNum = 1
    for num, _ in pairs(nodes) do
        if num > nextHierarchicalNum then
            nextHierarchicalNum = num + 1
        end
    end
    while true do
        local event, param1, param2, param3, param4, param5 = os.pullEvent()
        if event == "modem_message" and param4.type == "discovery_response" then
            local nodeId = param4.id
            local hierarchicalNum = nil
            for num, id in pairs(nodes) do
                if id == nodeId then
                    hierarchicalNum = num
                    break
                end
            end
            if not hierarchicalNum then
                hierarchicalNum = nextHierarchicalNum
                nodes[hierarchicalNum] = nodeId
                nextHierarchicalNum = nextHierarchicalNum + 1
                print("Discovered new node: " .. nodeId .. " (Hierarchical #" .. hierarchicalNum .. ")")
            else
                print("Rediscovered node: " .. nodeId .. " (Hierarchical #" .. hierarchicalNum .. ")")
            end
            discoveredNodes[nodeId] = hierarchicalNum
        elseif event == "timer" and param1 == timer then
            break
        end
    end
    saveNodeIds()
    return nodes
end

-- Function to send a request to a node
local function sendRequest(nodeId, request)
    request.targetNode = nodeId
    modem.transmit(1, 1, request)
    local timer = os.startTimer(5)
    while true do
        local event, param1, param2, param3, param4, param5 = os.pullEvent()
        if event == "modem_message" and param4.id == request.id then
            return param4.response
        elseif event == "timer" and param1 == timer then
            error("Request timed out for node: " .. nodeId)
        end
    end
end

-- Function to distribute a file across nodes
local function distributeFile(path, content)
    local nodeCount = 0
    for _ in pairs(nodes) do nodeCount = nodeCount + 1 end
    local chunkSize = math.ceil(#content / nodeCount)
    chunkMap[path] = {}
    local chunkNum = 1
    for hierarchicalNum, nodeId in pairs(nodes) do
        local start = (chunkNum - 1) * chunkSize + 1
        local chunk = content:sub(start, math.min(start + chunkSize - 1, #content))
        local response = sendRequest(nodeId, {
            id = os.getComputerID() .. "_" .. os.clock(),
            action = "write",
            path = path,
            chunk = chunkNum,
            content = chunk
        })
        if not response.success then
            error("Failed to write chunk " .. chunkNum .. " to node " .. nodeId)
        end
        chunkMap[path][chunkNum] = nodeId
        chunkNum = chunkNum + 1
    end
    saveChunkMap()
end

-- Function to read a file from nodes
local function readFile(path)
    if not chunkMap[path] then
        error("File not found: " .. path)
    end
    local content = {}
    for chunkNum, nodeId in pairs(chunkMap[path]) do
        local response = sendRequest(nodeId, {
            id = os.getComputerID() .. "_" .. os.clock(),
            action = "read",
            path = path,
            chunk = chunkNum
        })
        if response.success then
            content[chunkNum] = response.content
        else
            error("Failed to read chunk " .. chunkNum .. " from node " .. nodeId)
        end
    end
    return table.concat(content)
end

-- Function to delete a file from nodes
local function deleteFile(path)
    if not chunkMap[path] then
        error("File not found: " .. path)
    end
    for chunkNum, nodeId in pairs(chunkMap[path]) do
        local response = sendRequest(nodeId, {
            id = os.getComputerID() .. "_" .. os.clock(),
            action = "delete",
            path = path,
            chunk = chunkNum
        })
        if not response.success then
            error("Failed to delete chunk " .. chunkNum .. " from node " .. nodeId)
        end
    end
    chunkMap[path] = nil
    saveChunkMap()
end

-- Function to list files
local function listFiles()
    local files = {}
    for file, _ in pairs(chunkMap) do
        table.insert(files, file)
    end
    return files
end

-- Function to get total storage space
local function getTotalStorage()
    local total = 0
    for _, nodeId in pairs(nodes) do
        local response = sendRequest(nodeId, {
            id = os.getComputerID() .. "_" .. os.clock(),
            action = "getSpace"
        })
        if response.success then
            total = total + response.space
        end
    end
    return total
end

-- Main program
loadNodeIds()
nodes = discoverNodes()
if next(nodes) == nil then
    error("No storage nodes found. Make sure the storage nodes are running and connected.")
end
print("Found " .. #nodes .. " storage node(s)")
loadChunkMap()

-- Command loop
while true do
    write("ndisk> ")
    local input = read()
    local command = {}
    for word in input:gmatch("%S+") do
        table.insert(command, word)
    end

    if command[1] == "list" then
        local files = listFiles()
        for _, file in ipairs(files) do
            print(file)
        end
    elseif command[1] == "read" and command[2] then
        local content = readFile(command[2])
        print(content)
    elseif command[1] == "write" and command[2] then
        print("Enter file content (press Enter twice to finish):")
        local content = ""
        while true do
            local line = read()
            if line == "" then break end
            content = content .. line .. "\n"
        end
        distributeFile(command[2], content)
        print("File written successfully.")
    elseif command[1] == "delete" and command[2] then
        deleteFile(command[2])
        print("File deleted successfully.")
    elseif command[1] == "space" then
        local space = getTotalStorage()
        print("Total storage space: " .. space .. " bytes")
    elseif command[1] == "exit" then
        break
    else
        print("Unknown command. Available commands: list, read <filename>, write <filename>, delete <filename>, space, exit")
    end
end

print("Exiting ndisk.")