package tui

import (
	"fmt"
	"hosts-go/internal/core"
	"strings"

	list "github.com/charmbracelet/bubbles/list"
	viewport "github.com/charmbracelet/bubbles/viewport"
	tea "github.com/charmbracelet/bubbletea"
)

// entryItem wraps a HostEntry for display in a list component.
type entryItem struct{ entry *core.HostEntry }

func (e entryItem) Title() string {
	prefix := "[ ]"
	if e.entry.Active {
		prefix = "[✓]"
	}
	return fmt.Sprintf("%s %s", prefix, e.entry.Hostname)
}

func (e entryItem) Description() string { return e.entry.IP }
func (e entryItem) FilterValue() string { return e.entry.Hostname }

// Model is the main Bubble Tea model for the application.
type Mode int

const (
	ViewMode Mode = iota
	EditMode
)

type pane int

const (
	listPane pane = iota
	detailPane
)

type Model struct {
	list   list.Model
	detail viewport.Model
	hosts  *core.HostsFile
	width  int
	height int
	mode   Mode
	focus  pane
}

// NewModel constructs the TUI model from a parsed HostsFile.
func NewModel(hf *core.HostsFile) Model {
	items := make([]list.Item, len(hf.Entries))
	for i, e := range hf.Entries {
		items[i] = entryItem{entry: e}
	}

	l := list.New(items, list.NewDefaultDelegate(), 0, 0)
	l.SetShowStatusBar(false)
	l.SetFilteringEnabled(false)
	l.SetShowHelp(false)
	l.SetShowPagination(false)

	m := Model{
		list:   l,
		detail: viewport.New(0, 0),
		hosts:  hf,
		mode:   ViewMode,
		focus:  listPane,
	}
	m.refreshDetail()
	return m
}

func (m *Model) refreshDetail() {
	if len(m.hosts.Entries) == 0 {
		m.detail.SetContent("")
		return
	}
	entry := m.hosts.Entries[m.list.Index()]
	var b strings.Builder
	status := "active"
	if !entry.Active {
		status = "inactive"
	}
	fmt.Fprintf(&b, "IP: %s\n", entry.IP)
	fmt.Fprintf(&b, "Host: %s\n", entry.Hostname)
	if len(entry.Aliases) > 0 {
		fmt.Fprintf(&b, "Aliases: %s\n", strings.Join(entry.Aliases, ", "))
	}
	if entry.Comment != "" {
		fmt.Fprintf(&b, "Comment: %s\n", entry.Comment)
	}
	fmt.Fprintf(&b, "Status: %s", status)
	m.detail.SetContent(b.String())
	m.detail.YOffset = 0
}

// Init satisfies tea.Model.
func (m Model) Init() tea.Cmd { return nil }

// SelectedEntry returns the currently selected host entry.
func (m Model) SelectedEntry() *core.HostEntry {
	if len(m.hosts.Entries) == 0 {
		return nil
	}
	idx := m.list.Index()
	if idx < 0 || idx >= len(m.hosts.Entries) {
		return nil
	}
	return m.hosts.Entries[idx]
}

// Mode returns the current operating mode of the TUI.
func (m Model) Mode() Mode {
	return m.mode
}