package cli

import (
	"strings"
	"time"

	tea "github.com/charmbracelet/bubbletea"
	"github.com/charmbracelet/lipgloss"
)

// Two small widgets, written here rather than taken from bubbles: its
// packages ask the terminal for its colours as they load, so every llmgw
// command — llmgw --version included — sent a query and, in a terminal that
// never answers one, waited five seconds for it. Only the screens need to
// know the colours, and lipgloss asks when they first draw.

// spinTickMsg advances a spinner.
type spinTickMsg struct{}

var spinFrames = []string{"⠋", "⠙", "⠹", "⠸", "⠼", "⠴", "⠦", "⠧", "⠇", "⠏"}

type spinnerModel struct {
	frame int
	Style lipgloss.Style
}

func newSpinner() spinnerModel { return spinnerModel{Style: lipgloss.NewStyle().Foreground(tuiAccent)} }

// Tick starts the spinner turning; it is a tea.Cmd.
func (s spinnerModel) Tick() tea.Msg { return spinTickMsg{} }

func (s spinnerModel) Update(msg tea.Msg) (spinnerModel, tea.Cmd) {
	if _, ok := msg.(spinTickMsg); !ok {
		return s, nil
	}
	s.frame = (s.frame + 1) % len(spinFrames)
	return s, tea.Tick(100*time.Millisecond, func(time.Time) tea.Msg { return spinTickMsg{} })
}

func (s spinnerModel) View() string { return s.Style.Render(spinFrames[s.frame]) }

// textField is one line of text typed at its end: all a form here needs.
type textField struct {
	value       []rune
	focused     bool
	Prompt      string
	Placeholder string
	CharLimit   int
	Width       int
	// Mask shows a dot for every character: a password.
	Mask bool
}

func newTextField() textField { return textField{Prompt: "> "} }

func (f *textField) SetValue(s string) { f.value = []rune(s) }
func (f textField) Value() string      { return string(f.value) }
func (f *textField) Focus()            { f.focused = true }
func (f *textField) Blur()             { f.focused = false }

func (f textField) Update(msg tea.Msg) (textField, tea.Cmd) {
	k, ok := msg.(tea.KeyMsg)
	if !ok || !f.focused {
		return f, nil
	}
	switch k.Type {
	case tea.KeyRunes, tea.KeySpace:
		r := k.Runes
		if k.Type == tea.KeySpace {
			r = []rune{' '}
		}
		for _, c := range r {
			if f.CharLimit == 0 || len(f.value) < f.CharLimit {
				f.value = append(f.value, c)
			}
		}
	case tea.KeyBackspace:
		if len(f.value) > 0 {
			f.value = f.value[:len(f.value)-1]
		}
	case tea.KeyCtrlU:
		f.value = nil
	}
	return f, nil
}

func (f textField) View() string {
	text := string(f.value)
	if f.Mask {
		text = strings.Repeat("•", len(f.value))
	}
	shown := text
	if text == "" && f.Placeholder != "" {
		shown = sDim.Render(f.Placeholder)
	}
	if f.focused {
		shown += "█"
	}
	if pad := f.Width - len([]rune(text)); pad > 0 && text != "" {
		shown += strings.Repeat(" ", pad)
	}
	return f.Prompt + shown
}