package adminui

import (
	"fmt"
	"strconv"
	"strings"

	tea "github.com/charmbracelet/bubbletea"
	"skyrama-tui/internal/db"
)

// ── Messages ──────────────────────────────────────────────────────────────────

type userLoadedMsg []db.AdminUser
type userDoneMsg struct{ err error }

// ── Field indices ─────────────────────────────────────────────────────────────

const (
	ufUsername    = 0
	ufPassword    = 1
	ufAirportName = 2
	ufCountryID   = 3
)

// ── Model ─────────────────────────────────────────────────────────────────────

type usersTab struct {
	client      *db.AdminClient
	items       []db.AdminUser
	cursor      int
	inForm      bool
	isEdit      bool
	editUsername string
	fields      []field
	focusIdx    int
	status      string
	isErr       bool
	w, h        int
}

func newUsersTab(client *db.AdminClient) *usersTab {
	return &usersTab{client: client}
}

func (t *usersTab) InForm() bool { return t.inForm }
func (t *usersTab) Init() tea.Cmd { return t.load() }

func (t *usersTab) load() tea.Cmd {
	return func() tea.Msg {
		items, err := t.client.ListUsers()
		if err != nil {
			return userDoneMsg{err}
		}
		return userLoadedMsg(items)
	}
}

func (t *usersTab) openForm() {
	t.fields = []field{
		newTextField("Username", "e.g. alice"),
		newPasswordField("Password"),
		newTextField("Airport Name", "e.g. Alice's Airport"),
		newTextField("Country ID", "1"),
	}
	t.fields[ufUsername].input.Focus()
	t.focusIdx = ufUsername
	t.isEdit = false
	t.inForm = true
	t.status = ""
}

func (t *usersTab) openEditForm(u db.AdminUser) {
	f := newPasswordField("New Password")
	f.input.Focus()
	t.fields = []field{f}
	t.focusIdx = 0
	t.isEdit = true
	t.editUsername = u.Username
	t.inForm = true
	t.status = ""
}

func (t *usersTab) submit() tea.Cmd {
	if t.isEdit {
		password := t.fields[0].value()
		if len(password) < 4 {
			t.status = "password must be at least 4 characters"
			t.isErr = true
			return nil
		}
		username := t.editUsername
		return func() tea.Msg {
			return userDoneMsg{t.client.UpdateUserPassword(username, password)}
		}
	}

	username := strings.TrimSpace(t.fields[ufUsername].value())
	password := t.fields[ufPassword].value()
	airportName := strings.TrimSpace(t.fields[ufAirportName].value())
	countryIDStr := strings.TrimSpace(t.fields[ufCountryID].value())

	if username == "" {
		t.status = "username is required"
		t.isErr = true
		return nil
	}
	if len(password) < 4 {
		t.status = "password must be at least 4 characters"
		t.isErr = true
		return nil
	}
	if airportName == "" {
		t.status = "airport name is required"
		t.isErr = true
		return nil
	}
	countryID, err := strconv.Atoi(countryIDStr)
	if err != nil || countryID <= 0 {
		t.status = "country ID must be a positive number"
		t.isErr = true
		return nil
	}
	return func() tea.Msg {
		return userDoneMsg{t.client.CreateUserWithAirport(username, password, airportName, countryID)}
	}
}

func (t *usersTab) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
	switch m := msg.(type) {
	case tea.WindowSizeMsg:
		t.w, t.h = m.Width, m.Height
		return t, nil

	case userLoadedMsg:
		t.items = []db.AdminUser(m)
		if t.cursor >= len(t.items) && t.cursor > 0 {
			t.cursor = len(t.items) - 1
		}
		return t, nil

	case userDoneMsg:
		if m.err != nil {
			t.status = m.err.Error()
			t.isErr = true
			return t, nil
		}
		t.inForm = false
		t.status = "saved"
		t.isErr = false
		return t, t.load()

	case tea.KeyMsg:
		if t.inForm {
			switch m.String() {
			case "esc":
				t.inForm = false
				t.status = ""
			case "ctrl+s":
				return t, t.submit()
			default:
				var cmd tea.Cmd
				t.focusIdx, cmd = handleFormKey(t.fields, t.focusIdx, m)
				return t, cmd
			}
			return t, nil
		}
		switch m.String() {
		case "q":
			return t, tea.Quit
		case "j", "down":
			if t.cursor < len(t.items)-1 {
				t.cursor++
			}
		case "k", "up":
			if t.cursor > 0 {
				t.cursor--
			}
		case "a":
			t.openForm()
		case "e":
			if len(t.items) > 0 {
				t.openEditForm(t.items[t.cursor])
			}
		case "d":
			if len(t.items) > 0 {
				username := t.items[t.cursor].Username
				return t, func() tea.Msg {
					return userDoneMsg{t.client.DeleteUser(username)}
				}
			}
		case "r":
			return t, t.load()
		}
	}
	return t, nil
}

func (t *usersTab) View() string {
	var sb strings.Builder
	sb.WriteString(hdrSt.Render("  Users") + "\n\n")

	if t.inForm {
		formTitle := "Add User + Airport"
		if t.isEdit {
			formTitle = fmt.Sprintf("Change Password — %s", t.editUsername)
		}
		sb.WriteString(titleSt.Render("  "+formTitle) + "\n\n")
		sb.WriteString(renderForm(t.fields, t.focusIdx))
		sb.WriteString("\n  " + renderStatus(t.status, t.isErr))
		sb.WriteString("\n\n  " + dimSt.Render(helpForm))
		return sb.String()
	}

	header := fmt.Sprintf("  %-5s  %-20s  %-20s  %s", "ID", "Username", "Created", "Status")
	sb.WriteString(dimSt.Render(header) + "\n")
	sb.WriteString(dimSt.Render("  "+strings.Repeat("─", 60)) + "\n")

	if len(t.items) == 0 {
		sb.WriteString(dimSt.Render("  (no users — press a to add)") + "\n")
	}
	for i, u := range t.items {
		status := okSt.Render("active")
		if u.Deleted {
			status = errSt.Render("deleted")
		}
		created := u.CreatedAt.Format("2006-01-02")
		line := fmt.Sprintf("  %-5d  %-20s  %-20s  ", u.ID, u.Username, created)
		if i == t.cursor {
			sb.WriteString(cursorSt.Render("▸") + activeTS.Render(line[1:]) + status + "\n")
		} else {
			sb.WriteString(line + status + "\n")
		}
	}
	sb.WriteString("\n  " + renderStatus(t.status, t.isErr))
	sb.WriteString("\n\n  " + dimSt.Render("a:add  e:edit(pw)  d:soft-delete  j/k:nav  r:reload  q:quit"))
	return sb.String()
}