package ui

import (
	tea "github.com/charmbracelet/bubbletea"
	"github.com/charmbracelet/lipgloss"

	"github.com/gmgauthier/gralculator/internal/calc"
)

// App is the root Bubble Tea model for the gralculator TUI.
// Phase 1/3 skeleton only — real implementation in phase 3.
type App struct {
	engine *calc.Engine
	width  int
	height int

	// flash state etc. will be added during spike (see gostations patterns)
}

func NewApp() *App {
	return &App{
		engine: calc.NewEngine(),
	}
}

func (a *App) Init() tea.Cmd {
	return nil
}

func (a *App) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
	switch msg := msg.(type) {
	case tea.WindowSizeMsg:
		a.width = msg.Width
		a.height = msg.Height
	case tea.KeyMsg:
		switch msg.String() {
		case "q", "ctrl+c", "esc":
			return a, tea.Quit
		case "tab":
			// Will drive engine.CycleBase() + possible CERR flash
			_ = a.engine.CycleBase()
			// TODO (phase 3): trigger flash on error, re-render small row
		}
	}
	return a, nil
}

func (a *App) View() string {
	// Placeholder view. Real two-row display + keypad grid in phase 3.
	// Will use lipgloss heavily for:
	// - large number area (tall + styled)
	// - small current-base row (highlighted label)
	// - centered content card (lipgloss.Place)
	// - button cells for keypad (including single "BASE")
	// - flash styles (140ms color 63)
	// - minimal hint row
	base := a.engine.CurrentBase()
	return lipgloss.NewStyle().Padding(1, 2).Render(
		"gralculator skeleton\n\n" +
			"Large number area (TODO)\n" +
			"Current base: " + string(base) + "   (press Tab to cycle)\n\n" +
			"See docs/UI_DESIGN.md and spec.md",
	)
}

// TODO (phase 3): full model with flashes, proper display rendering,
// keypad grid, Tab + other key handling wired to engine, resize/centering.