// Package pager provides a pager (similar to less) for the terminal.
//
// $ cat file.txt | gum page
package pager

import (
	"github.com/charmbracelet/bubbles/viewport"
	tea "github.com/charmbracelet/bubbletea"
	"github.com/charmbracelet/lipgloss"
)

type model struct {
	viewport  viewport.Model
	helpStyle lipgloss.Style
}

func (m model) Init() tea.Cmd {
	return nil
}

func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
	switch msg := msg.(type) {
	case tea.WindowSizeMsg:
		m.viewport.Width = msg.Width
		m.viewport.Height = msg.Height - 1
	case tea.KeyMsg:
		switch msg.String() {
		case "q", "ctrl+c", "esc":
			return m, tea.Quit
		}
	}
	var cmd tea.Cmd
	m.viewport, cmd = m.viewport.Update(msg)
	return m, cmd
}

func (m model) View() string {
	return m.viewport.View() + "\n" + m.helpStyle.Render("↑/↓: Navigate • q: Quit")
}