package tui

import (
	"strconv"

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

// Login holds the state for the login/add account form.
type Login struct {
	focusIndex int
	inputs     []textinput.Model
	showCustom bool // Show custom server fields
	isEditMode bool // Whether we're editing an existing account
	accountID  string
	width      int
	height     int
}

const (
	inputProvider = iota
	inputName
	inputEmail
	inputPassword
	inputIMAPServer
	inputIMAPPort
	inputSMTPServer
	inputSMTPPort
	inputCount
)

// NewLogin creates a new login model for adding accounts.
func NewLogin() *Login {
	m := &Login{
		inputs: make([]textinput.Model, inputCount),
	}

	var t textinput.Model
	for i := range m.inputs {
		t = textinput.New()
		t.Cursor.Style = focusedStyle
		t.CharLimit = 128

		switch i {
		case inputProvider:
			t.Placeholder = "Provider (gmail, icloud, or custom)"
			t.Focus()
			t.Prompt = "☁️ > "
		case inputName:
			t.Placeholder = "Display Name"
			t.Prompt = "👤 > "
		case inputEmail:
			t.Placeholder = "Email Address"
			t.Prompt = "✉️ > "
		case inputPassword:
			t.Placeholder = "Password / App Password"
			t.EchoMode = textinput.EchoPassword
			t.Prompt = "🔑 > "
		case inputIMAPServer:
			t.Placeholder = "IMAP Server (e.g., imap.example.com)"
			t.Prompt = "📥 > "
		case inputIMAPPort:
			t.Placeholder = "IMAP Port (default: 993)"
			t.Prompt = "🔢 > "
		case inputSMTPServer:
			t.Placeholder = "SMTP Server (e.g., smtp.example.com)"
			t.Prompt = "📤 > "
		case inputSMTPPort:
			t.Placeholder = "SMTP Port (default: 587)"
			t.Prompt = "🔢 > "
		}
		m.inputs[i] = t
	}

	return m
}

// Init initializes the login model.
func (m *Login) Init() tea.Cmd {
	return textinput.Blink
}

// Update handles messages for the login model.
func (m *Login) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
	switch msg := msg.(type) {
	case tea.WindowSizeMsg:
		m.width = msg.Width
		m.height = msg.Height
		for i := range m.inputs {
			m.inputs[i].Width = msg.Width - 6
		}

	case tea.KeyMsg:
		switch msg.Type {
		case tea.KeyEsc:
			return m, func() tea.Msg { return GoToChoiceMenuMsg{} }

		case tea.KeyEnter:
			// Check if provider is "custom" to show/hide custom fields
			provider := m.inputs[inputProvider].Value()
			if provider == "custom" {
				m.showCustom = true
			} else {
				m.showCustom = false
			}

			lastFieldIndex := inputPassword
			if m.showCustom {
				lastFieldIndex = inputSMTPPort
			}

			if m.focusIndex == lastFieldIndex {
				// Submit the form
				imapPort := 993
				smtpPort := 587
				if m.inputs[inputIMAPPort].Value() != "" {
					if p, err := strconv.Atoi(m.inputs[inputIMAPPort].Value()); err == nil {
						imapPort = p
					}
				}
				if m.inputs[inputSMTPPort].Value() != "" {
					if p, err := strconv.Atoi(m.inputs[inputSMTPPort].Value()); err == nil {
						smtpPort = p
					}
				}

				return m, func() tea.Msg {
					return Credentials{
						Provider:   m.inputs[inputProvider].Value(),
						Name:       m.inputs[inputName].Value(),
						Email:      m.inputs[inputEmail].Value(),
						Password:   m.inputs[inputPassword].Value(),
						IMAPServer: m.inputs[inputIMAPServer].Value(),
						IMAPPort:   imapPort,
						SMTPServer: m.inputs[inputSMTPServer].Value(),
						SMTPPort:   smtpPort,
					}
				}
			}
			fallthrough

		case tea.KeyTab, tea.KeyShiftTab, tea.KeyUp, tea.KeyDown:
			s := msg.String()

			// Check provider to update showCustom
			provider := m.inputs[inputProvider].Value()
			m.showCustom = provider == "custom"

			maxIndex := inputPassword
			if m.showCustom {
				maxIndex = inputSMTPPort
			}

			if s == "up" || s == "shift+tab" {
				m.focusIndex--
			} else {
				m.focusIndex++
			}

			if m.focusIndex > maxIndex {
				m.focusIndex = 0
			} else if m.focusIndex < 0 {
				m.focusIndex = maxIndex
			}

			// Skip custom fields if not showing them
			if !m.showCustom && m.focusIndex > inputPassword {
				if s == "up" || s == "shift+tab" {
					m.focusIndex = inputPassword
				} else {
					m.focusIndex = 0
				}
			}

			cmds := make([]tea.Cmd, len(m.inputs))
			for i := 0; i < len(m.inputs); i++ {
				if i == m.focusIndex {
					cmds[i] = m.inputs[i].Focus()
				} else {
					m.inputs[i].Blur()
				}
			}
			return m, tea.Batch(cmds...)
		}
	}

	// Update the focused input field
	var cmds = make([]tea.Cmd, len(m.inputs))
	for i := range m.inputs {
		m.inputs[i], cmds[i] = m.inputs[i].Update(msg)
	}

	// Check if provider changed
	provider := m.inputs[inputProvider].Value()
	m.showCustom = provider == "custom"

	return m, tea.Batch(cmds...)
}

// View renders the login form.
func (m *Login) View() string {
	title := "Add Account"
	if m.isEditMode {
		title = "Edit Account"
	}

	customHint := ""
	if m.inputs[inputProvider].Value() == "custom" || m.showCustom {
		customHint = "\n" + accountEmailStyle.Render("Custom provider selected - configure server settings below")
	}

	views := []string{
		titleStyle.Render(title),
		"Enter your email account credentials.",
		customHint,
		m.inputs[inputProvider].View(),
		m.inputs[inputName].View(),
		m.inputs[inputEmail].View(),
		m.inputs[inputPassword].View(),
	}

	if m.showCustom {
		views = append(views,
			"",
			listHeader.Render("Custom Server Settings:"),
			m.inputs[inputIMAPServer].View(),
			m.inputs[inputIMAPPort].View(),
			m.inputs[inputSMTPServer].View(),
			m.inputs[inputSMTPPort].View(),
		)
	}

	views = append(views, helpStyle.Render("\nenter: save • tab: next field • esc: back to menu"))

	return lipgloss.JoinVertical(lipgloss.Left, views...)
}

// SetEditMode sets the login form to edit an existing account.
func (m *Login) SetEditMode(accountID, provider, name, email, imapServer string, imapPort int, smtpServer string, smtpPort int) {
	m.isEditMode = true
	m.accountID = accountID
	m.inputs[inputProvider].SetValue(provider)
	m.inputs[inputName].SetValue(name)
	m.inputs[inputEmail].SetValue(email)
	m.showCustom = provider == "custom"

	if m.showCustom {
		m.inputs[inputIMAPServer].SetValue(imapServer)
		if imapPort != 0 {
			m.inputs[inputIMAPPort].SetValue(strconv.Itoa(imapPort))
		}
		m.inputs[inputSMTPServer].SetValue(smtpServer)
		if smtpPort != 0 {
			m.inputs[inputSMTPPort].SetValue(strconv.Itoa(smtpPort))
		}
	}
}

// GetAccountID returns the account ID being edited (if in edit mode).
func (m *Login) GetAccountID() string {
	return m.accountID
}

// IsEditMode returns whether the form is in edit mode.
func (m *Login) IsEditMode() bool {
	return m.isEditMode
}