package main

import (
    "fmt"
    "github.com/erweixin/rego"
)

func App(c rego.C) rego.Node {
    count := rego.Use(c, "count", 0)
    
    rego.UseKey(c, func(key rego.Key, r rune) {
        switch r {
        case '+': count.Set(count.Val + 1)
        case '-': count.Set(count.Val - 1)
        case 'q': c.Quit()
        }
    })
    
    return rego.VStack(
        rego.Text("Rego Counter").Bold(),
        rego.Text(fmt.Sprintf("Count: %d", count.Val)),
        rego.Spacer(),
        rego.Text("[+] Increment  [-] Decrement  [q] Quit").Dim(),
    )
}

func main() {
    rego.Run(App)
}

// State management
count := rego.Use(c, "count", 0)        // Declare state
count.Set(10)                            // Set value
count.Update(func(v int) int { return v + 1 }) // Functional update

// Side effects
rego.UseEffect(c, func() func() {
    ticker := time.NewTicker(time.Second)
    go func() {
        for range ticker.C {
            c.Refresh()
        }
    }()
    return ticker.Stop  // Return cleanup function
}, dep1, dep2)  // Dependency list

// Keyboard events
rego.UseKey(c, func(key rego.Key, r rune) {
    if key == rego.KeyEnter { /* ... */ }
    if r == 'q' { c.Quit() }
})

// Mouse events
rego.UseMouse(c, func(ev rego.MouseEvent) {
    if ev.Type == rego.MouseEventClick { /* ... */ }
})

// Focus management
focus := rego.UseFocus(c)
if focus.IsFocused { /* Current component has focus */ }

// Memoization
result := rego.UseMemo(c, func() int {
    return expensiveCalculation()
}, dep1, dep2)

// Refs (solve closure traps)
ref := rego.UseRef(c, &someValue)

func App(c rego.C) rego.Node {
    return rego.VStack(
        Header(c.Child("header")),   // Isolated state space
        Content(c.Child("content")),
        Footer(c.Child("footer")),
    )
}

// Use index in lists
rego.For(items, func(item Item, i int) rego.Node {
    return ItemComponent(c.Child("item", i), item)
})

// Vertical stack
rego.VStack(
    rego.Text("Title").Bold(),
    rego.Divider(),
    rego.Text("Content"),
    rego.Spacer(),  // Flexible space
    rego.Text("Footer").Dim(),
)

// Horizontal stack
rego.HStack(
    rego.Text("Left"),
    rego.Spacer(),
    rego.Text("Right"),
).Gap(2)

// Container with border
rego.Box(
    rego.Text("Boxed Content"),
).Border(rego.BorderRounded).Padding(1, 2)

// Flex layout
rego.VStack(
    rego.Text("Header").Height(1),
    rego.Box(content).Flex(1),  // Take remaining space
    rego.Text("Footer").Height(1),
)

rego.Text("Styled Text").
    Bold().
    Italic().
    Underline().
    Color(rego.Cyan).
    Background(rego.Black)

rego.Box(child).
    Border(rego.BorderDouble).
    BorderColor(rego.Green).
    Padding(1, 2).
    Width(40).
    Height(10)

rego.Button(c.Child("btn"), rego.ButtonProps{
    Label:   "Submit",
    Primary: true,
    OnClick: func() { /* ... */ },
})

rego.TextInput(c.Child("input"), rego.TextInputProps{
    Value:       value.Val,
    Placeholder: "Enter text...",
    OnChanged:   func(s string) { value.Set(s) },
    OnSubmit:    func(s string) { /* On Enter */ },
})

rego.Checkbox(c.Child("check"), rego.CheckboxProps{
    Label:     "Accept terms",
    Checked:   agreed.Val,
    OnChanged: func(v bool) { agreed.Set(v) },
})

rego.Spinner(c.Child("loading"), "Loading...")

// Scrollable container
rego.ScrollBox(c.Child("scroll"), longContent)

// Auto-scroll to bottom (ideal for logs/chat)
rego.TailBox(c.Child("logs"), logContent)

rego.Markdown("# Hello\n\nThis is **markdown** content.")

func AgentUI(c rego.C) rego.Node {
    bridge := rego.UseBridge[AgentState, Question, Answer](c, AgentState{})
    
    rego.UseEffect(c, func() func() {
        go agent.Run(bridge.Handle())  // Run Agent in background
        return nil
    })
    
    return rego.VStack(
        // Render streaming output
        rego.Markdown(bridge.State().Response),
        
        // Render interaction requests (e.g., confirmation dialog)
        rego.When(bridge.HasInteraction(),
            ConfirmDialog(c.Child("confirm"), bridge),
        ),
    )
}