--
-- ComputerCraft Mekanism SCADA System Installer Utility
--

--[[
Copyright (c) 2023 Mikayla Fischler

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
associated documentation files (the "Software"), to deal in the Software without restriction,
including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
]]--

local function println(message) print(tostring(message)) end
local function print(message) term.write(tostring(message)) end

local CCMSI_VERSION = "v1.7d"

local install_dir = "/.install-cache"
local manifest_path = "https://mikaylafischler.github.io/cc-mek-scada/manifests/"
local repo_path = "http://raw.githubusercontent.com/MikaylaFischler/cc-mek-scada/"

local opts = { ... }
local mode, app, target
local install_manifest = manifest_path .. "main/install_manifest.json"

local function red() term.setTextColor(colors.red) end
local function orange() term.setTextColor(colors.orange) end
local function yellow() term.setTextColor(colors.yellow) end
local function green() term.setTextColor(colors.green) end
local function blue() term.setTextColor(colors.blue) end
local function white() term.setTextColor(colors.white) end
local function lgray() term.setTextColor(colors.lightGray) end

-- get command line option in list
local function get_opt(opt, options)
    for _, v in pairs(options) do if opt == v then return v end end
    return nil
end

-- wait for any key to be pressed
---@diagnostic disable-next-line: undefined-field
local function any_key() os.pullEvent("key_up") end

-- ask the user yes or no
local function ask_y_n(question, default)
    print(question)
    if default == true then print(" (Y/n)? ") else print(" (y/N)? ") end
    local response = read();any_key()
    if response == "" then return default
    elseif response == "Y" or response == "y" then return true
    elseif response == "N" or response == "n" then return false
    else return nil end
end

-- print out a white + blue text message
local function pkg_message(message, package) white();print(message .. " ");blue();println(package);white() end

-- indicate actions to be taken based on package differences for installs/updates
local function show_pkg_change(name, v_local, v_remote)
    if v_local ~= nil then
        if v_local ~= v_remote then
            print("[" .. name .. "] updating ");blue();print(v_local);white();print(" \xbb ");blue();println(v_remote);white()
        elseif mode == "install" then
            pkg_message("[" .. name .. "] reinstalling", v_local)
        end
    else
        pkg_message("[" .. name .. "] new install of", v_remote)
    end
end

-- read the local manifest file
local function read_local_manifest()
    local local_ok = false
    local local_manifest = {}
    local imfile = fs.open("install_manifest.json", "r")
    if imfile ~= nil then
        local_ok, local_manifest = pcall(function () return textutils.unserializeJSON(imfile.readAll()) end)
        imfile.close()
    end
    return local_ok, local_manifest
end

-- get the manifest from GitHub
local function get_remote_manifest()
    local response, error = http.get(install_manifest)
    if response == nil then
        orange();println("failed to get installation manifest from GitHub, cannot update or install")
        red();println("HTTP error: " .. error);white()
        return false, {}
    end

    local ok, manifest = pcall(function () return textutils.unserializeJSON(response.readAll()) end)
    if not ok then red();println("error parsing remote installation manifest");white() end

    return ok, manifest
end

-- record the local installation manifest
local function write_install_manifest(manifest, dependencies)
    local versions = {}
    for key, value in pairs(manifest.versions) do
        local is_dependency = false
        for _, dependency in pairs(dependencies) do
            if (key == "bootloader" and dependency == "system") or key == dependency then
                is_dependency = true;break
            end
        end
        if key == app or key == "comms" or is_dependency then versions[key] = value end
    end

    manifest.versions = versions

    local imfile = fs.open("install_manifest.json", "w")
    imfile.write(textutils.serializeJSON(manifest))
    imfile.close()
end

-- recursively build a tree out of the file manifest
local function gen_tree(manifest)
    local function _tree_add(tree, split)
        if #split > 1 then
            local name = table.remove(split, 1)
            if tree[name] == nil then tree[name] = {} end
            table.insert(tree[name], _tree_add(tree[name], split))
        else return split[1] end
        return nil
    end

    local list, tree = {}, {}

    -- make a list of each and every file
    for _, files in pairs(manifest.files) do for i = 1, #files do table.insert(list, files[i]) end end

    for i = 1, #list do
        local split = {}
        string.gsub(list[i], "([^/]+)", function(c) split[#split + 1] = c end)
        if #split == 1 then table.insert(tree, list[i])
        else table.insert(tree, _tree_add(tree, split)) end
    end

    return tree
end

local function _in_array(val, array)
    for _, v in pairs(array) do if v == val then return true end end
    return false
end

local function _clean_dir(dir, tree)
    if tree == nil then tree = {} end
    local ls = fs.list(dir)
    for _, val in pairs(ls) do
        local path = dir .. "/" .. val
        if fs.isDir(path) then
            _clean_dir(path, tree[val])
            if #fs.list(path) == 0 then fs.delete(path);println("deleted " .. path) end
        elseif not _in_array(val, tree) then
            fs.delete(path)
            println("deleted " .. path)
        end
    end
end

-- go through app/common directories to delete unused files
local function clean(manifest)
    local root_ext = false
    local tree = gen_tree(manifest)

    table.insert(tree, "install_manifest.json")
    table.insert(tree, "ccmsi.lua")
    table.insert(tree, "log.txt")

    lgray()

    local ls = fs.list("/")
    for _, val in pairs(ls) do
        if fs.isDir(val) then
            if tree[val] ~= nil then _clean_dir("/" .. val, tree[val]) end
            if #fs.list(val) == 0 then fs.delete(val);println("deleted " .. val) end
        elseif not _in_array(val, tree) then
            root_ext = true
            yellow();println(val .. " not used")
        end
    end

    white()
    if root_ext then println("Files in root directory won't be automatically deleted.") end
end

-- get and validate command line options

println("-- CC Mekanism SCADA Installer " .. CCMSI_VERSION .. " --")

if #opts == 0 or opts[1] == "help" then
    println("usage: ccmsi <mode> <app> <branch>")
    println("<mode>")
    lgray()
    println(" check       - check latest versions avilable")
    yellow()
    println("               ccmsi check <branch> for target")
    lgray()
    println(" install     - fresh install, overwrites config")
    println(" update      - update files EXCEPT for config/logs")
    println(" remove      - delete files EXCEPT for config/logs")
    println(" purge       - delete files INCLUDING config/logs")
    white();println("<app>");lgray()
    println(" reactor-plc - reactor PLC firmware")
    println(" rtu         - RTU firmware")
    println(" supervisor  - supervisor server application")
    println(" coordinator - coordinator application")
    println(" pocket      - pocket application")
    white();println("<branch>");yellow()
    println(" second parameter when used with check")
    lgray();println(" main (default) | latest | devel");white()
    return
else
    mode = get_opt(opts[1], { "check", "install", "update", "remove", "purge" })
    if mode == nil then
        red();println("Unrecognized mode.");white()
        return
    end

    app = get_opt(opts[2], { "reactor-plc", "rtu", "supervisor", "coordinator", "pocket" })
    if app == nil and mode ~= "check" then
        red();println("Unrecognized application.");white()
        return
    end

    -- determine target
    if mode == "check" then target = opts[2] else target = opts[3] end
    if (target ~= "main") and (target ~= "latest") and (target ~= "devel") then
        if (target and target ~= "") then yellow();println("Unknown target, defaulting to 'main'");white() end
        target = "main"
    end

    -- set paths
    install_manifest = manifest_path .. target .. "/install_manifest.json"
    repo_path = repo_path .. target .. "/"
end

-- run selected mode

if mode == "check" then
    local ok, manifest = get_remote_manifest()
    if not ok then return end

    local local_ok, local_manifest = read_local_manifest()
    if not local_ok then
        yellow();println("failed to load local installation information");white()
        local_manifest = { versions = { installer = CCMSI_VERSION } }
    else
        local_manifest.versions.installer = CCMSI_VERSION
    end

    -- list all versions
    for key, value in pairs(manifest.versions) do
        term.setTextColor(colors.purple)
        print(string.format("%-14s", "[" .. key .. "]"))
        if key == "installer" or (local_ok and (local_manifest.versions[key] ~= nil)) then
            blue();print(local_manifest.versions[key])
            if value ~= local_manifest.versions[key] then
                white();print(" (")
                term.setTextColor(colors.cyan)
                print(value);white();println(" available)")
            else green();println(" (up to date)") end
        else
            lgray();print("not installed");white();print(" (latest ")
            term.setTextColor(colors.cyan)
            print(value);white();println(")")
        end
    end
elseif mode == "install" or mode == "update" then
    local ok, manifest = get_remote_manifest()
    if not ok then return end

    local ver = {
        app = { v_local = nil, v_remote = nil, changed = false },
        boot = { v_local = nil, v_remote = nil, changed = false },
        comms = { v_local = nil, v_remote = nil, changed = false },
        graphics = { v_local = nil, v_remote = nil, changed = false },
        lockbox = { v_local = nil, v_remote = nil, changed = false }
    }

    -- try to find local versions
    local local_ok, local_manifest = read_local_manifest()
    if not local_ok then
        if mode == "update" then
            red();println("failed to load local installation information, cannot update");white()
            return
        end
    else
        ver.boot.v_local = local_manifest.versions.bootloader
        ver.app.v_local = local_manifest.versions[app]
        ver.comms.v_local = local_manifest.versions.comms
        ver.graphics.v_local = local_manifest.versions.graphics
        ver.lockbox.v_local = local_manifest.versions.lockbox

        if local_manifest.versions[app] == nil then
            red();println("another application is already installed, please purge it before installing a new application");white()
            return
        end

        local_manifest.versions.installer = CCMSI_VERSION
        if manifest.versions.installer ~= CCMSI_VERSION then
            yellow();println("a newer version of the installer is available, it is recommended to download it");white()
        end
    end

    ver.boot.v_remote = manifest.versions.bootloader
    ver.app.v_remote = manifest.versions[app]
    ver.comms.v_remote = manifest.versions.comms
    ver.graphics.v_remote = manifest.versions.graphics
    ver.lockbox.v_remote = manifest.versions.lockbox

    green()
    if mode == "install" then
        println("Installing " .. app .. " files...")
    elseif mode == "update" then
        println("Updating " .. app .. " files... (keeping old config.lua)")
    end
    white()

    -- display bootloader version change information
    show_pkg_change("bootldr", ver.boot.v_local, ver.boot.v_remote)
    ver.boot.changed = ver.boot.v_local ~= ver.boot.v_remote

    -- display app version change information
    show_pkg_change(app, ver.app.v_local, ver.app.v_remote)
    ver.app.changed = ver.app.v_local ~= ver.app.v_remote

    -- display comms version change information
    show_pkg_change("comms", ver.comms.v_local, ver.comms.v_remote)
    ver.comms.changed = ver.comms.v_local ~= ver.comms.v_remote
    if ver.comms.changed and ver.comms.v_local ~= nil then
        print("[comms] ");yellow();println("other devices on the network will require an update");white()
    end

    -- display graphics version change information
    show_pkg_change("graphics", ver.graphics.v_local, ver.graphics.v_remote)
    ver.graphics.changed = ver.graphics.v_local ~= ver.graphics.v_remote

    -- display lockbox version change information
    show_pkg_change("lockbox", ver.lockbox.v_local, ver.lockbox.v_remote)
    ver.lockbox.changed = ver.lockbox.v_local ~= ver.lockbox.v_remote

    -- ask for confirmation
    if not ask_y_n("Continue", false) then return end

    --------------------------
    -- START INSTALL/UPDATE --
    --------------------------

    local space_required = manifest.sizes.manifest
    local space_available = fs.getFreeSpace("/")

    local single_file_mode = false
    local file_list = manifest.files
    local size_list = manifest.sizes
    local dependencies = manifest.depends[app]
    local config_file = app .. "/config.lua"

    table.insert(dependencies, app)

    for _, dependency in pairs(dependencies) do
        local size = size_list[dependency]
        space_required = space_required + size
    end

    -- check space constraints
    if space_available < space_required then
        single_file_mode = true
        yellow();println("WARNING: Insufficient space available for a full download!");white()
        println("Files can be downloaded one by one, so if you are replacing a current install this will not be a problem unless installation fails.")
        if mode == "update" then println("If installation still fails, delete this device's log file or uninstall the app (not purge) and try again.") end
        if not ask_y_n("Do you wish to continue?", false) then
            println("Operation cancelled.")
            return
        end
    end

    local success = true

    -- helper function to check if a dependency is unchanged
    local function unchanged(dependency)
        if dependency == "system" then return not ver.boot.changed
        elseif dependency == "graphics" then return not ver.graphics.changed
        elseif dependency == "lockbox" then return not ver.lockbox.changed
        elseif dependency == "common" then return not (ver.app.changed or ver.comms.changed)
        elseif dependency == app then return not ver.app.changed
        else return true end
    end

    if not single_file_mode then
        if fs.exists(install_dir) then
            fs.delete(install_dir)
            fs.makeDir(install_dir)
        end

        -- download all dependencies
        for _, dependency in pairs(dependencies) do
            if mode == "update" and unchanged(dependency) then
                pkg_message("skipping download of unchanged package", dependency)
            else
                pkg_message("downloading package", dependency)
                lgray()

                local files = file_list[dependency]
                for _, file in pairs(files) do
                    println("GET " .. file)
                    local dl, err = http.get(repo_path .. file)

                    if dl == nil then
                        red();println("GET HTTP Error " .. err)
                        success = false
                        break
                    else
                        local handle = fs.open(install_dir .. "/" .. file, "w")
                        handle.write(dl.readAll())
                        handle.close()
                    end
                end
            end
        end

        -- copy in downloaded files (installation)
        if success then
            for _, dependency in pairs(dependencies) do
                if mode == "update" and unchanged(dependency) then
                    pkg_message("skipping install of unchanged package", dependency)
                else
                    pkg_message("installing package", dependency)
                    lgray()

                    local files = file_list[dependency]
                    for _, file in pairs(files) do
                        if mode == "install" or file ~= config_file then
                            local temp_file = install_dir .. "/" .. file
                            if fs.exists(file) then fs.delete(file) end
                            fs.move(temp_file, file)
                        end
                    end
                end
            end
        end

        fs.delete(install_dir)

        if success then
            write_install_manifest(manifest, dependencies)
            green()
            if mode == "install" then
                println("Installation completed successfully.")
            else println("Update completed successfully.") end
            white();println("Ready to clean up unused files, press any key to continue...")
            any_key();clean(manifest)
            white();println("Done.")
        else
            if mode == "install" then
                red();println("Installation failed.")
            else orange();println("Update failed, existing files unmodified.") end
        end
    else
        -- go through all files and replace one by one
        for _, dependency in pairs(dependencies) do
            if mode == "update" and unchanged(dependency) then
                pkg_message("skipping install of unchanged package", dependency)
            else
                pkg_message("installing package", dependency)
                lgray()

                local files = file_list[dependency]
                for _, file in pairs(files) do
                    if mode == "install" or file ~= config_file then
                        println("GET " .. file)
                        local dl, err = http.get(repo_path .. file)

                        if dl == nil then
                            red();println("GET HTTP Error " .. err)
                            success = false
                            break
                        else
                            local handle = fs.open("/" .. file, "w")
                            handle.write(dl.readAll())
                            handle.close()
                        end
                    end
                end
            end
        end

        if success then
            write_install_manifest(manifest, dependencies)
            green()
            if mode == "install" then
                println("Installation completed successfully.")
            else println("Update completed successfully.") end
            white();println("Ready to clean up unused files, press any key to continue...")
            any_key();clean(manifest)
            white();println("Done.")
        else
            red()
            if mode == "install" then
                println("Installation failed, files may have been skipped.")
            else println("Update failed, files may have been skipped.") end
        end
    end
elseif mode == "remove" or mode == "purge" then
    local ok, manifest = read_local_manifest()
    if not ok then
        red();println("Error parsing local installation manifest.");white()
        return
    elseif mode == "remove" and manifest.versions[app] == nil then
        red();println(app .. " is not installed, cannot remove.");white()
        return
    end

    orange()
    if mode == "remove" then
        println("Removing all " .. app .. " files except for config and log...")
    elseif mode == "purge" then
        println("Purging all " .. app .. " files including config and log...")
    end

    -- ask for confirmation
    if not ask_y_n("Continue", false) then return end

    -- delete unused files first
    clean(manifest)

    local file_list = manifest.files
    local dependencies = manifest.depends[app]
    local config_file = app .. "/config.lua"

    table.insert(dependencies, app)

    -- delete log file if purging
    lgray()
    if mode == "purge" and fs.exists(config_file) then
        local log_deleted = pcall(function ()
            local config = require(app .. ".config")
            if fs.exists(config.LOG_PATH) then
                fs.delete(config.LOG_PATH)
                println("deleted log file " .. config.LOG_PATH)
            end
        end)

        if not log_deleted then
            red();println("failed to delete log file")
            white();println("press any key to continue...")
            any_key();lgray()
        end
    end

    -- delete all files except config unless purging
    for _, dependency in pairs(dependencies) do
        local files = file_list[dependency]
        for _, file in pairs(files) do
            if mode == "purge" or file ~= config_file then
                if fs.exists(file) then fs.delete(file);println("deleted " .. file) end
            end
        end

        -- delete folders that we should be deleteing
        if mode == "purge" or dependency ~= app then
            local folder = files[1]
            while true do
                local dir = fs.getDir(folder)
                if dir == "" or dir == ".." then break else folder = dir end
            end

            if fs.isDir(folder) then
                fs.delete(folder)
                println("deleted directory " .. folder)
            end
        elseif dependency == app then
            -- delete individual subdirectories so we can leave the config
            for _, folder in pairs(files) do
                while true do
                    local dir = fs.getDir(folder)
                    if dir == "" or dir == ".." or dir == app then break else folder = dir end
                end

                if folder ~= app and fs.isDir(folder) then
                    fs.delete(folder);println("deleted app subdirectory " .. folder)
                end
            end
        end
    end

    -- only delete manifest if purging
    if mode == "purge" then
        fs.delete("install_manifest.json")
        println("deleted install_manifest.json")
    else
        -- remove all data from versions list to show nothing is installed
        manifest.versions = {}
        local imfile = fs.open("install_manifest.json", "w")
        imfile.write(textutils.serializeJSON(manifest))
        imfile.close()
    end

    green();println("Done!")
end

white()