package screens

import (
	"context"
	"fmt"
	"strings"

	"github.com/NicoNex/echotron/v3"
	"github.com/TelegramExchange/tgex-backend/tg_bot/bot"
	"github.com/TelegramExchange/tgex-backend/tg_bot/screens/ui"
	"github.com/rs/zerolog/log"
)

type WorkspaceMenu struct {
	CurrentPage int
	BackState   bot.State
}

const msgWorkspaceEmpty = `
У вас пока нет рабочих пространств.
`

const workspacesPerPage = 6

func (s *WorkspaceMenu) Enter(b *bot.Bot, mode bot.RenderMode) {
	workspaces, err := b.Backend.GetWorkspaces(context.Background(), b.Session.JWT)
	if err != nil {
		log.Error().Err(err).Msg("Failed to get workspaces for workspace menu")
		b.SendNew("❌ Не удалось загрузить рабочие пространства", Keyboard(Row(Button("← Назад", "back"))))
		return
	}

	if len(workspaces) == 0 {
		kb := Keyboard(Row(Button("← Назад", "back")))
		b.Render(msgWorkspaceEmpty, kb, mode)
		return
	}

	var allButtons []echotron.InlineKeyboardButton
	for _, ws := range workspaces {
		label := ws.Name
		if ws.ID == b.Session.WorkspaceID {
			label = "● " + label
		}
		allButtons = append(allButtons, Button(label, fmt.Sprintf("workspace_select:%s", ws.ID)))
	}

	elementRows := ui.BuildElementRows(ui.ElementLayoutConfig{
		CurrentPage:  s.CurrentPage,
		ItemsPerPage: workspacesPerPage,
		ItemsPerRow:  2,
	}, allButtons)

	var buttons [][]echotron.InlineKeyboardButton
	buttons = append(buttons, elementRows...)

	if navRow := ui.BuildNavigationRow(ui.PaginationConfig{
		CurrentPage:  s.CurrentPage,
		TotalItems:   len(allButtons),
		ItemsPerPage: workspacesPerPage,
	}); navRow != nil {
		buttons = append(buttons, navRow)
	}

	buttons = append(buttons, Row(Button("← Назад", "back")))

	totalPages := ui.CalculatePages(len(allButtons), workspacesPerPage)
	text := fmt.Sprintf(`<b>Рабочие пространства</b>%s

Выберите текущее рабочее пространство.`, ui.FormatPageInfo(s.CurrentPage, totalPages))

	b.Render(text, Keyboard(buttons...), mode)
}

func (s *WorkspaceMenu) HandleCallback(b *bot.Bot, u *echotron.Update) {
	if u.CallbackQuery == nil || u.CallbackQuery.Data == "" {
		return
	}

	data := u.CallbackQuery.Data

	switch {
	case data == "prev":
		if s.CurrentPage > 0 {
			s.CurrentPage--
		}
		s.Enter(b, bot.EditMessage)

	case data == "next":
		s.CurrentPage++
		s.Enter(b, bot.EditMessage)

	case data == "back":
		if s.BackState != nil {
			b.SetState(s.BackState, bot.EditMessage)
			return
		}
		b.SetState(&MainMenu{}, bot.EditMessage)

	case strings.HasPrefix(data, "workspace_select:"):
		parts := strings.Split(data, ":")
		if len(parts) != 2 {
			return
		}
		workspaceID := parts[1]
		workspaces, err := b.Backend.GetWorkspaces(context.Background(), b.Session.JWT)
		if err != nil {
			log.Error().Err(err).Msg("Failed to get workspaces for selection")
			b.SendNew("❌ Не удалось загрузить рабочие пространства", Keyboard(Row(Button("← Назад", "back"))))
			return
		}
		for _, ws := range workspaces {
			if ws.ID == workspaceID {
				b.Session.WorkspaceID = ws.ID
				break
			}
		}

		if s.BackState != nil {
			b.SetState(s.BackState, bot.EditMessage)
			return
		}
		b.SetState(&MainMenu{}, bot.EditMessage)

	default:
		s.Enter(b, bot.NewMessage)
	}
}

func (s *WorkspaceMenu) HandleMessage(_ *bot.Bot, _ *echotron.Update) {}

func (s *WorkspaceMenu) Handle(_ *bot.Bot, _ *echotron.Update) {}

func (s *WorkspaceMenu) Exit() {}