dc_installer repost

local component = require("component");
local fs = require("filesystem");
local serialization = require("serialization");
local term = require("term");
local internet = nil;

--[[

--]]
local packages = {"oop", "libGUI", "draconic_control", "dc_gui"};
local repositoryURL = "http://xypm.tenyx.de/";

local gpu = component.gpu;

function fetchPackage(pack)
    local url = repositoryURL .. pack .. ".xypm";

    local request = internet.request(url);
    if request == nil then
        return nil;
    end

    local data = "";

    for chunk in request do
        data = data .. chunk;
    end

    return serialization.unserialize(data);
end

local function verifyPackage(package)
    if not component.isAvailable("data") then
        -- If we don't have a data card we can't verify anything.
        -- However in order to make data cards optional we just return true
        return true;
    end

    for fileName, fileChecksum in pairs(package.checksums or {}) do
        if package.files[fileName] and component.data.sha256(package.files[fileName]) ~= fileChecksum then
            return false;
        end
    end

    return true;
end

function installPackage(package_data)
    for fileName, fileContents in pairs(package_data.files) do
        local filePath = fs.path(fileName);
        if fs.exists(fileName) then
            fs.remove(fileName);
        end

        if filePath ~= nil then
            local pathSegments = fs.segments(filePath);
            local pathChecked = "/";
            for _, segment in pairs(pathSegments) do
                pathChecked = fs.concat(pathChecked, segment);
                if not fs.exists(pathChecked) then
                    fs.makeDirectory(pathChecked);
                end
            end
        end

        local file = io.open(fileName, "wb");
        if file == nil then
            return false;
        end
        file:write(fileContents);
        file:close();
    end

    for linkName, linkTarget in pairs(package_data.links) do
        local filePath = fs.path(fileName);
        if fs.exists(fileName) then
            fs.remove(fileName);
        end

        if filePath ~= nil then
            local pathSegments = fs.segments(filePath);
            local pathChecked = "/";
            for _, segment in pairs(pathSegments) do
                pathChecked = fs.concat(pathChecked, segment);
                if not fs.exists(pathChecked) then
                    fs.makeDirectory(pathChecked);
                end
            end
        end

        if not fs.link(linkTarget, linkname) then
            return false;
        end
    end

    return true;
end

print("XyFreaks' Package Deployment Tool");
print("The following packages are scheduled for deployment:");
local packageNameMaxLen = 0;

if component.isAvailable("internet") then
    internet = component.internet;
else
    print("You need an Internet Card for this to work.");
    return 1;
end

internet = require("internet");

for _, p in pairs(packages) do
    print(" - " .. p);
    packageNameMaxLen = math.max(packageNameMaxLen, string.len(p));
end
print("");

local termWidth = gpu.getResolution();
local _, termY = term.getCursor();
local barWidthMax = termWidth - packageNameMaxLen - 11;

for i, p in pairs(packages) do
    local percent = (2 * (i-1) / #packages / 2);
    local barRep = math.floor(barWidthMax * percent + 0.5);
    term.setCursor(1, termY);
    local pName = string.sub(p .. string.rep(" ", packageNameMaxLen), 1, packageNameMaxLen);

    term.write(pName .. " |" .. string.rep("=", barRep) .. ">" .. string.rep(" ", barWidthMax - barRep) .. "|" .. string.format("%6.2f%%", percent * 100), false);
    local packageData = fetchPackage(p);
    if packageData == nil then
        print("");
        print("Failed to download " .. p);
        return;
    end

    term.setCursor(1, termY);
    percent = ((2 * (i-1) + 1) / #packages / 2);
    barRep = math.floor(barWidthMax * percent + 0.5);
    term.write(pName .. " |" .. string.rep("=", barRep) .. ">" .. string.rep(" ", barWidthMax - barRep) .. "|" .. string.format("%6.2f%%", percent * 100), false);
    if not verifyPackage(packageData) then
        print("");
        print("Integrity check for " .. p .. " failed.");
    end

    if not installPackage(packageData) then
        print("");
        print("Failed to install " .. p);
    end
end
term.setCursor(1, termY);
local pName = string.sub("Done" .. string.rep(" ", packageNameMaxLen), 1, packageNameMaxLen);
term.write(pName .. " |" .. string.rep("=", barWidthMax) .. ">" .. "|" .. "100.00%", false);