-- --- CONFIGURATION & STATE ---
local mobs = {"Zombie", "Skeleton", "Spider", "Creeper", "Enderman", "Blaze", "Witch"}
local state = {
    currentMenu = "main", 
    power = false,
    spawnerActive = false,
    selectedMob = "Select Spawner" -- Corrected default text
}

-- Get monitor/screen dimensions dynamically
local termWidth, termHeight = term.getSize()

-- --- DRAWING UTILITIES ---
local function clearScreen()
    term.setBackgroundColor(colors.black)
    term.clear()
end

local function drawRect(x, y, width, height, color)
    term.setBackgroundColor(color)
    for i = 0, height - 1 do
        term.setCursorPos(x, y + i)
        term.write(string.rep(" ", width))
    end
end

local function drawText(x, y, text, bg, fg)
    term.setBackgroundColor(bg)
    term.setTextColor(fg)
    term.setCursorPos(x, y)
    term.write(text)
end

-- --- DRAW TOGGLE SWITCH ---
local function drawToggle(x, y, isOn)
    drawRect(x, y, 5, 1, colors.gray)
    if isOn then
        drawRect(x + 3, y, 2, 1, colors.green)
        drawText(x + 1, y, "ON", colors.gray, colors.white)
    else
        drawRect(x, y, 2, 1, colors.red)
        drawText(x + 2, y, "OFF", colors.gray, colors.white)
    end
end

-- --- PERFECT CENTERING MATH ---
-- Extra wide 32-block gray button background boxes
local btnWidth = 32
local btnX = math.floor((termWidth - btnWidth) / 2) + 1

-- Width for alignment of the switch labels
local contentWidth = 22
local contentX = math.floor((termWidth - contentWidth) / 2) + 1

-- --- SCREEN RENDERERS ---
local function drawMainMenu()
    clearScreen()
    
    -- Centered Title Banner
    drawRect(1, 1, termWidth, 3, colors.blue)
    local titleText = "SPAWNER GRID"
    local titleX = math.floor((termWidth - #titleText) / 2) + 1
    drawText(titleX, 2, titleText, colors.blue, colors.white)
    
    -- Power Section (Row 5) - Centered
    drawText(contentX, 5, "Power System:", colors.black, colors.white)
    drawToggle(contentX + 17, 5, state.power)
    
    -- Pull Spawner Button (Row 8) - Widened & Centered
    drawRect(btnX, 8, btnWidth, 3, colors.lightGray)
    local txtPull = " [ PULL SPAWNER ] "
    local txtPullX = btnX + math.floor((btnWidth - #txtPull) / 2)
    drawText(txtPullX, 9, txtPull, colors.lightGray, colors.black)
    
    -- Selected Mob Display (Row 12) - Centered
    local activeText = "Active Mob: " .. state.selectedMob
    local activeX = math.floor((termWidth - #activeText) / 2) + 1
    drawText(activeX, 12, activeText, colors.black, colors.yellow)
    
    -- Spawner Active Switch (Row 14) - Centered
    drawText(contentX, 14, "Spawner Status:", colors.black, colors.white)
    drawToggle(contentX + 17, 14, state.spawnerActive)
    
    -- Put Spawner Away Button (Row 17) - Widened & Centered
    drawRect(btnX, 17, btnWidth, 3, colors.lightGray)
    local txtPut = " [ PUT SPAWNER AWAY ] "
    local txtPutX = btnX + math.floor((btnWidth - #txtPut) / 2)
    drawText(txtPutX, 18, txtPut, colors.lightGray, colors.black)
end

local function drawMobMenu()
    clearScreen()
    
    -- Centered Title
    drawRect(1, 1, termWidth, 3, colors.purple)
    local mobTitle = "SELECT A MONSTER"
    local mobTitleX = math.floor((termWidth - #mobTitle) / 2) + 1
    drawText(mobTitleX, 2, mobTitle, colors.purple, colors.white)
    
    -- List of Mobs - Centered boxes
    local listWidth = 26
    local listX = math.floor((termWidth - listWidth) / 2) + 1
    for i, mob in ipairs(mobs) do
        local yPos = 4 + i
        drawRect(listX, yPos, listWidth, 1, colors.gray)
        -- Center text inside the row box
        local mobTxtX = listX + math.floor((listWidth - #mob) / 2)
        drawText(mobTxtX, yPos, mob, colors.gray, colors.white)
    end
    
    -- Back Button - Bottom center
    local backWidth = 12
    local backX = math.floor((termWidth - backWidth) / 2) + 1
    drawRect(backX, 17, backWidth, 3, colors.red)
    drawText(backX + 4, 18, "BACK", colors.red, colors.white)
end

local function render()
    if state.currentMenu == "main" then
        drawMainMenu()
    else
        drawMobMenu()
    end
end

-- --- INPUT HANDLING ---
local function handleMainClick(x, y)
    -- Power Toggle Click Detection
    if x >= (contentX + 17) and x <= (contentX + 21) and y == 5 then
        state.power = not state.power
        return true
    end
    
    -- Pull Spawner Button Click Detection
    if x >= btnX and x <= (btnX + btnWidth - 1) and y >= 8 and y <= 10 then
        state.currentMenu = "mobs"
        return true
    end
    
    -- Spawner Status Toggle Click Detection
    if x >= (contentX + 17) and x <= (contentX + 21) and y == 14 then
        state.spawnerActive = not state.spawnerActive
        return true
    end
    
    -- Put Spawner Away Button Click Detection
    if x >= btnX and x <= (btnX + btnWidth - 1) and y >= 17 and y <= 19 then
        state.selectedMob = "Select Spawner" -- Resets to your default label
        state.spawnerActive = false
        return true
    end
    
    return false
end

local function handleMobClick(x, y)
    -- Back Button Click Detection
    local backWidth = 12
    local backX = math.floor((termWidth - backWidth) / 2) + 1
    if x >= backX and x <= (backX + backWidth - 1) and y >= 17 and y <= 19 then
        state.currentMenu = "main"
        return true
    end
    
    -- Mob Selection List Click Detection
    local listWidth = 26
    local listX = math.floor((termWidth - listWidth) / 2) + 1
    for i, mob in ipairs(mobs) do
        local yPos = 4 + i
        if x >= listX and x <= (listX + listWidth - 1) and y == yPos then
            state.selectedMob = mob
            state.currentMenu = "main"
            return true
        end
    end
    
    return false
end

-- --- MAIN PROGRAM LOOP ---
render()

while true do
    -- Works for both computer screen clicks and peripheral monitor clicks
    local event, side, x, y = os.pullEvent()
    
    if event == "mouse_click" or event == "monitor_touch" then
        local clicked = false
        if state.currentMenu == "main" then
            clicked = handleMainClick(x, y)
        elseif state.currentMenu == "mobs" then
            clicked = handleMobClick(x, y)
        end
        
        if clicked then
            render()
        end
    end
end