package tui

import (
	"fmt"
	"strings"

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

// passwordPromptMode determines what the password prompt is for
type passwordPromptMode int

const (
	// passwordModeSetup — first time enabling encryption, ask for new password
	passwordModeSetup passwordPromptMode = iota
	// passwordModeUnlock — encryption already enabled, ask for existing password
	passwordModeUnlock
)

// PasswordPromptTab shows a password prompt for encryption setup or unlock
type PasswordPromptTab struct {
	mode       passwordPromptMode
	inputs     []textinput.Model
	focus      int
	width      int
	height     int
	err        error
	dataDir    string
	onComplete func(password string) // called with password on success
}

// NewPasswordPromptTab creates a new password prompt tab
func NewPasswordPromptTab(mode passwordPromptMode, dataDir string, onComplete func(string)) *PasswordPromptTab {
	p := &PasswordPromptTab{
		mode:       mode,
		dataDir:    dataDir,
		onComplete: onComplete,
	}

	// Password field
	passwordInput := textinput.New()
	passwordInput.Placeholder = "Enter master password"
	passwordInput.EchoMode = textinput.EchoPassword
	passwordInput.EchoCharacter = '•'
	passwordInput.Focus()

	// Confirm password field (only for setup mode)
	confirmInput := textinput.New()
	confirmInput.Placeholder = "Confirm password"
	confirmInput.EchoMode = textinput.EchoPassword
	confirmInput.EchoCharacter = '•'

	if mode == passwordModeSetup {
		p.inputs = []textinput.Model{passwordInput, confirmInput}
	} else {
		p.inputs = []textinput.Model{passwordInput}
	}

	return p
}

func (p *PasswordPromptTab) Name() string {
	if p.mode == passwordModeSetup {
		return "Setup Encryption"
	}
	return "Unlock Storage"
}

func (p *PasswordPromptTab) Init() tea.Cmd {
	return textinput.Blink
}

func (p *PasswordPromptTab) Update(msg tea.Msg) (Tab, tea.Cmd) {
	switch msg := msg.(type) {
	case tea.WindowSizeMsg:
		p.width = msg.Width
		p.height = msg.Height
		return p, nil

	case tea.KeyMsg:
		switch msg.String() {
		case "tab", "down":
			p.focus++
			if p.focus >= len(p.inputs) {
				p.focus = 0
			}
			for i := range p.inputs {
				if i == p.focus {
					p.inputs[i].Focus()
				} else {
					p.inputs[i].Blur()
				}
			}
			return p, nil

		case "shift+tab", "up":
			p.focus--
			if p.focus < 0 {
				p.focus = len(p.inputs) - 1
			}
			for i := range p.inputs {
				if i == p.focus {
					p.inputs[i].Focus()
				} else {
					p.inputs[i].Blur()
				}
			}
			return p, nil

		case "enter":
			password := p.inputs[0].Value()
			if password == "" {
				p.err = fmt.Errorf("password cannot be empty")
				return p, nil
			}

			if p.mode == passwordModeSetup && len(p.inputs) > 1 {
				confirm := p.inputs[1].Value()
				if password != confirm {
					p.err = fmt.Errorf("passwords do not match")
					return p, nil
				}
			}

			// Success — call onComplete
			if p.onComplete != nil {
				p.onComplete(password)
			}
			return p, func() tea.Msg { return passwordSetMsg{} }

		case "esc":
			// Cancel — go back or quit
			return p, func() tea.Msg { return closeFormMsg{} }

		default:
			// Update current input
			var cmd tea.Cmd
			p.inputs[p.focus], cmd = p.inputs[p.focus].Update(msg)
			return p, cmd
		}
	}

	return p, nil
}

func (p *PasswordPromptTab) Close() {
	// Nothing to clean up
}

func (p *PasswordPromptTab) View() string {
	var b strings.Builder

	title := "Setup Master Password"
	if p.mode == passwordModeUnlock {
		title = "Enter Master Password"
	}

	b.WriteString(lipgloss.PlaceHorizontal(p.width, lipgloss.Center,
		AppTitleStyle.Render(title)))
	b.WriteString("\n\n")

	if p.mode == passwordModeSetup {
		b.WriteString(lipgloss.PlaceHorizontal(p.width, lipgloss.Center,
			SubtitleStyle.Render("Encrypt all sensitive data (passwords, keys) with AES-256")))
		b.WriteString("\n")
		b.WriteString(lipgloss.PlaceHorizontal(p.width, lipgloss.Center,
			SubtitleStyle.Render("You will need this password to access your data")))
		b.WriteString("\n\n")
	}

	// Input fields
	contentW := p.width - 8
	if contentW > 60 {
		contentW = 60
	}

	box := lipgloss.NewStyle().
		Border(lipgloss.RoundedBorder()).
		BorderForeground(lipgloss.Color("62")).
		Padding(1, 2).
		Width(contentW)

	var fields strings.Builder
	for i, input := range p.inputs {
		label := "Password:"
		if i == 1 {
			label = "Confirm:"
		}
		fields.WriteString(SubtitleStyle.Render("  " + label))
		fields.WriteString("\n")
		fields.WriteString(input.View())
		fields.WriteString("\n\n")
	}

	b.WriteString(lipgloss.PlaceHorizontal(p.width, lipgloss.Center, box.Render(fields.String())))

	if p.err != nil {
		b.WriteString("\n")
		b.WriteString(lipgloss.PlaceHorizontal(p.width, lipgloss.Center,
			ErrorStyle.Render(p.err.Error())))
	}

	// Footer
	footerText := "Enter:confirm  Esc:cancel  Tab:next field"
	b.WriteString("\n\n")
	for _, line := range strings.Split(wrapFooter(footerText, p.width), "\n") {
		b.WriteString(lipgloss.PlaceHorizontal(p.width, lipgloss.Center, SubtitleStyle.Render(line)))
	}

	return b.String()
}

// passwordSetMsg is sent when password is successfully set
type passwordSetMsg struct {
	password string
}