package tui

import (
	"fmt"
	"strings"

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

	"tsplay/internal/discovery"
)

func (m Model) updateLogin(msg tea.Msg) (tea.Model, tea.Cmd) {
	if key, ok := msg.(tea.KeyMsg); ok {
		switch key.String() {
		case "ctrl+c", "esc":
			return m, tea.Quit
		case "ctrl+n":
			// Cycle through discovered servers, filling the URL field.
			if len(m.discovered) > 1 {
				m.discIdx = (m.discIdx + 1) % len(m.discovered)
				m.inputs[0].SetValue(m.discovered[m.discIdx].Address)
				m.status = discoveryStatus(m.discovered, m.discIdx)
			}
			return m, nil
		case "ctrl+r":
			m.status = "Scanning the network for Jellyfin servers…"
			return m, discoverCmd()
		case "tab", "down":
			m.focusField(m.focus + 1)
			return m, textinput.Blink
		case "shift+tab", "up":
			m.focusField(m.focus - 1)
			return m, textinput.Blink
		case "enter":
			server := strings.TrimSpace(m.inputs[0].Value())
			user := strings.TrimSpace(m.inputs[1].Value())
			pass := m.inputs[2].Value()
			if server == "" || user == "" {
				m.status = "Server URL and username are required."
				return m, nil
			}
			if m.logging {
				return m, nil
			}
			m.logging = true
			m.status = "Connecting…"
			return m, m.doLogin(server, user, pass)
		}
	}

	// Feed the event to every input so the cursor blinks and the focused one
	// receives text.
	var cmds []tea.Cmd
	for i := range m.inputs {
		var c tea.Cmd
		m.inputs[i], c = m.inputs[i].Update(msg)
		cmds = append(cmds, c)
	}
	return m, tea.Batch(cmds...)
}

func (m *Model) focusField(i int) {
	n := len(m.inputs)
	i = ((i % n) + n) % n // wrap
	for j := range m.inputs {
		if j == i {
			m.inputs[j].Focus()
		} else {
			m.inputs[j].Blur()
		}
	}
	m.focus = i
}

// discoveryStatus formats the "found N servers" line shown under the form.
func discoveryStatus(servers []discovery.Server, idx int) string {
	s := servers[idx]
	name := s.Name
	if name == "" {
		name = s.Address
	}
	if len(servers) == 1 {
		return "Found: " + name
	}
	return fmt.Sprintf("Found %d servers — using %s [%d/%d]", len(servers), name, idx+1, len(servers))
}

func (m Model) viewLogin() string {
	var b strings.Builder
	b.WriteString(m.st.title.Render("tsplay") + m.st.muted.Render("  — Jellyfin terminal player"))
	b.WriteString("\n\n")
	for i := range m.inputs {
		b.WriteString(m.inputs[i].View())
		b.WriteString("\n")
	}
	b.WriteString("\n")
	help := "tab move · enter sign in · esc quit"
	if len(m.discovered) > 1 {
		help = "tab move · ctrl+n next server · enter sign in · esc quit"
	} else {
		help += " · ctrl+r rescan"
	}
	b.WriteString(m.st.help.Render(help))
	body := m.st.box.Render(b.String())

	// Discovery messages are informational (accent); real errors stay red.
	footer := ""
	if m.status != "" {
		style := m.st.accent
		if strings.HasPrefix(m.status, "Login failed") || strings.HasPrefix(m.status, "No servers") {
			style = m.st.bad
		}
		footer = "\n" + style.Render(m.status)
	}
	return lipgloss.JoinVertical(lipgloss.Left, body, footer)
}