-- LemonOS: Pocket Shell for Lemonphone
-- by ChatGPT (GPT-5)
-- Features: Persistent settings, live clock, signal bars, auto-netchat install, firmware info

local CONFIG_PATH = "/lemonos.cfg"
local NETCHAT_PATH = "/netchat"
local STARTUP_PATH = "/startup.lua"

-- Firmware info
local firmware = {
    device = "Lemonphone Pocket Computer",
    version = "LemonOS v1.0.0",
}

local config = {
    username = "User",
    accentColor = colors.yellow,
    bgColor = colors.black,
    rednetSide = "back",
}

-- === CONFIG LOAD/SAVE ===
local function saveConfig()
    local file = fs.open(CONFIG_PATH, "w")
    if file then
        file.write(textutils.serialize(config))
        file.close()
    end
end

local function loadConfig()
    if fs.exists(CONFIG_PATH) then
        local file = fs.open(CONFIG_PATH, "r")
        if file then
            local data = file.readAll()
            file.close()
            local ok, tbl = pcall(textutils.unserialize, data)
            if ok and type(tbl) == "table" then
                for k, v in pairs(tbl) do
                    config[k] = v
                end
            end
        end
    end
end
loadConfig()

-- === AUTO DOWNLOAD NETCHAT ===
if not fs.exists(NETCHAT_PATH) then
    print("Downloading netchat...")
    if http then
        local success, response = pcall(http.get, "https://pastebin.com/raw/GwmGxjwy")
        if success and response then
            local content = response.readAll()
            response.close()
            local file = fs.open(NETCHAT_PATH, "w")
            file.write(content)
            file.close()
            print("netchat installed!")
        else
            print("Failed to download netchat.")
        end
    else
        print("HTTP API not enabled, cannot download netchat.")
    end
    -- Set startup to shell.run("firm.lpsw")
    local file = fs.open(STARTUP_PATH, "w")
    file.write('shell.run("firm.lpsw")')
    file.close()
end

-- === INITIALIZE REDNET ===
if peripheral.find("modem") then
    rednet.open(config.rednetSide)
else
    rednet.close(config.rednetSide)
end

-- === UTILITIES ===
local function centerText(y, text, color)
    local w = term.getSize()
    local x = math.floor((w - #text) / 2)
    term.setCursorPos(x, y)
    if color then term.setTextColor(color) end
    term.write(text)
    term.setTextColor(colors.white)
end

local function getSignalStrength()
    if not rednet.isOpen(config.rednetSide) then return 0 end
    local peers = { rednet.lookup("lemonphone_ping") }
    if #peers == 0 then
        return 1
    elseif #peers < 3 then
        return 2
    else
        return 3
    end
end

local function drawSignalBars(strength)
    local barChar = "|"
    local maxBars = 3
    for i = 1, maxBars do
        if i <= strength then
            term.setTextColor(colors.lime)
        else
            term.setTextColor(colors.gray)
        end
        term.write(barChar)
    end
    term.setTextColor(colors.white)
end

local function drawTopBar()
    local w = term.getSize()
    term.setCursorPos(1, 1)
    term.setBackgroundColor(config.accentColor)
    term.clearLine()

    -- Left: signal strength
    term.setCursorPos(2, 1)
    if rednet.isOpen(config.rednetSide) then
        drawSignalBars(getSignalStrength())
        term.write(" Net")
    else
        term.setTextColor(colors.red)
        term.write("X NoNet")
        term.setTextColor(colors.white)
    end

    -- Right: time and date
    local timeStr = textutils.formatTime(os.time(), true)
    local dateStr = os.date("%b %d")
    local clock = timeStr .. " | " .. dateStr
    term.setCursorPos(w - #clock - 1, 1)
    term.setTextColor(colors.white)
    term.write(clock)
end

local function drawMenu(selected)
    local apps = {
        {name = "Messages", cmd = "netchat join"},
        {name = "Files", cmd = "shell"},
        {name = "Settings", cmd = "settings"},
        {name = "About Lemonphone", cmd = "about"},
        {name = "Reboot", cmd = "reboot"}
    }

    local _, h = term.getSize()
    local startY = 4
    term.setTextColor(colors.white)
    for i, app in ipairs(apps) do
        term.setCursorPos(4, startY + i - 1)
        if i == selected then
            term.setBackgroundColor(colors.gray)
            term.setTextColor(colors.black)
        else
            term.setBackgroundColor(config.bgColor)
            term.setTextColor(colors.white)
        end
        term.clearLine()
        term.setCursorPos(4, startY + i - 1)
        term.write(app.name)
    end

    term.setBackgroundColor(config.bgColor)
    return apps
end

-- === SETTINGS MENU ===
local function openSettings()
    while true do
        term.setBackgroundColor(config.bgColor)
        term.clear()
        centerText(3, "Settings", config.accentColor)
        term.setCursorPos(2, 5)
        term.write("1. Change Username")
        term.setCursorPos(2, 6)
        term.write("2. Change Accent Color")
        term.setCursorPos(2, 7)
        term.write("3. Back")

        local _, key = os.pullEvent("key")
        if key == keys.one then
            term.setCursorPos(2, 9)
            term.clearLine()
            term.write("Enter new username: ")
            config.username = read()
            saveConfig()
        elseif key == keys.two then
            term.setCursorPos(2, 9)
            term.clearLine()
            term.write("Color name (e.g. yellow): ")
            local colorName = read()
            if colors[colorName] then
                config.accentColor = colors[colorName]
                saveConfig()
            else
                term.setCursorPos(2, 10)
                term.write("Invalid color.")
                sleep(1)
            end
        elseif key == keys.three then
            return
        end
    end
end

-- === ABOUT LEMONPHONE ===
local function aboutLemonphone()
    term.setBackgroundColor(config.bgColor)
    term.clear()
    centerText(3, "About Lemonphone", config.accentColor)
    term.setCursorPos(2, 5)
    term.write("Device: " .. firmware.device)
    term.setCursorPos(2, 6)
    term.write("Firmware: " .. firmware.version)
    term.setCursorPos(2, 8)
    term.write("Press any key to return...")
    os.pullEvent("key")
end

-- === MAIN LOOP ===
local selected = 1
local refreshRate = 1.0
local timer = os.startTimer(refreshRate)

while true do
    term.setBackgroundColor(config.bgColor)
    term.clear()
    drawTopBar()
    centerText(3, config.username .. "'s Lemonphone", config.accentColor)
    local apps = drawMenu(selected)

    local event, key = os.pullEvent()
    if event == "key" then
        if key == keys.up then
            selected = math.max(1, selected - 1)
        elseif key == keys.down then
            selected = math.min(#apps, selected + 1)
        elseif key == keys.enter then
            local chosen = apps[selected]
            if chosen.name == "Settings" then
                openSettings()
            elseif chosen.name == "About Lemonphone" then
                aboutLemonphone()
            else
                term.setBackgroundColor(config.bgColor)
                term.clear()
                term.setCursorPos(1, 1)
                shell.run(chosen.cmd)
            end
        end
    elseif event == "timer" then
        timer = os.startTimer(refreshRate)
        drawTopBar()
    end
end