// Simple Counter for Browser
// Compile with: lux compile examples/web/counter.lux --target js -o examples/web/counter.js

// ============================================================================
// Model
// ============================================================================

type Model = | Counter(Int)

fn getCount(m: Model): Int = match m { Counter(n) => n }

fn init(): Model = Counter(0)

// ============================================================================
// Messages
// ============================================================================

type Msg = | Increment | Decrement | Reset

// ============================================================================
// Update
// ============================================================================

fn update(model: Model, msg: Msg): Model =
    match msg {
        Increment => Counter(getCount(model) + 1),
        Decrement => Counter(getCount(model) - 1),
        Reset => Counter(0)
    }

// ============================================================================
// View - Returns HTML string for simplicity
// ============================================================================

fn view(model: Model): String = {
    let count = getCount(model)
    "<div class=\"counter\">" +
        "<h1>Lux Counter</h1>" +
        "<div class=\"display\">" + toString(count) + "</div>" +
        "<div class=\"buttons\">" +
            "<button onclick=\"dispatch('Decrement')\">-</button>" +
            "<button onclick=\"dispatch('Reset')\">Reset</button>" +
            "<button onclick=\"dispatch('Increment')\">+</button>" +
        "</div>" +
    "</div>"
}

// ============================================================================
// Export for browser runtime
// ============================================================================

fn luxInit(): Model = init()

fn luxUpdate(model: Model, msgName: String): Model =
    match msgName {
        "Increment" => update(model, Increment),
        "Decrement" => update(model, Decrement),
        "Reset" => update(model, Reset),
        _ => model
    }

fn luxView(model: Model): String = view(model)