package screens

import (
	"context"
	"fmt"

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

const addPurchaseCreativesPerPage = 5
const addPurchaseProjectsPerPage = 6

type AddPurchase struct {
	ProjectID         string
	ProjectTitle      string
	ProjectTelegramID int64
	ProjectUsername   string
	ProjectStatus     string
	CreativeID        string
	CreativeTitle     string
	ProjectPage       int
	CreativePage      int
	ActivePicker      string // "" | "project_list" | "creative_list"
	BackState         bot.State
	lastProjects      map[string]projectInfo
	lastCreatives     map[string]creativeInfo
}

type projectInfo struct {
	Title      string
	TelegramID int64
	Username   string
	Status     string
}

type creativeInfo struct {
	Title string
}

func (s *AddPurchase) Enter(b *bot.Bot, mode bot.RenderMode) {
	s.renderSelection(b, mode)
}

func (s *AddPurchase) renderSelection(b *bot.Bot, mode bot.RenderMode) {
	text := "<b>Создание закупа</b>\n\n"
	text += "Выберите проект и креатив.\n\n"

	var buttons [][]echotron.InlineKeyboardButton

	projectLabel := "Проект: не выбрано"
	if s.ProjectTitle != "" {
		projectLabel = fmt.Sprintf("Проект: %s", s.ProjectTitle)
	}
	creativeLabel := "Креатив: не выбрано"
	if s.CreativeTitle != "" {
		creativeLabel = fmt.Sprintf("Креатив: %s", s.CreativeTitle)
	}

	if s.ActivePicker == "" {
		buttons = append(buttons, Row(
			Button(projectLabel, "pick_project"),
		))
		buttons = append(buttons, Row(
			Button(creativeLabel, "pick_creative"),
		))
	}

	switch s.ActivePicker {
	case "project_list":
		page, err := b.Backend.GetProjects(context.Background(), b.Session.JWT, b.Session.WorkspaceID, s.ProjectPage+1, addPurchaseProjectsPerPage)
		if err != nil {
			log.Error().Err(err).Msg("Failed to get projects")
			b.SendNew("❌ Не удалось загрузить проекты", Keyboard())
			return
		}

		s.lastProjects = make(map[string]projectInfo)
		for _, project := range page.Items {
			username := ""
			if project.Username != nil {
				username = *project.Username
			}
			s.lastProjects[project.ID] = projectInfo{
				Title:      project.Title,
				TelegramID: project.TelegramID,
				Username:   username,
				Status:     project.Status,
			}
		}

		if len(page.Items) == 0 {
			text += "У вас нет проектов. Создайте проект и попробуйте снова.\n\n"
		} else {
			text += fmt.Sprintf("Проекты%s\n\n", ui.FormatPageInfo(s.ProjectPage, page.Pages))

			buttons = append(buttons, ui.BuildGrid(
				page.Items,
				2,
				addPurchaseProjectsPerPage,
				page.Pages,
				func(project backend.Project) (string, string) {
					return project.Title, "project:" + project.ID
				},
			)...)

			if navRow := ui.BuildNavigationRow(ui.PaginationConfig{
				CurrentPage: s.ProjectPage,
				TotalPages:  page.Pages,
			}); navRow != nil {
				buttons = append(buttons, navRow)
			}
		}

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

	case "creative_list":
		if s.ProjectID == "" {
			text += "Сначала выберите проект, чтобы увидеть список креативов.\n\n"
			buttons = append(buttons, Row(
				Button("← Назад", "back_to_selection"),
			))
			break
		}

		page, err := b.Backend.GetCreatives(context.Background(), b.Session.JWT, b.Session.WorkspaceID, &s.ProjectID, false, s.CreativePage+1, addPurchaseCreativesPerPage)
		if err != nil {
			log.Error().Err(err).Msg("Failed to get creatives")
			b.SendNew("❌ Не удалось загрузить креативы", Keyboard())
			return
		}

		s.lastCreatives = make(map[string]creativeInfo)
		for _, creative := range page.Items {
			s.lastCreatives[creative.ID] = creativeInfo{
				Title: creative.Name,
			}
		}

		if len(page.Items) == 0 {
			text += `Для создания закупа сначала нужно создать креатив.

Вернитесь назад и создайте креатив в разделе <b>Креативы</b>`

			buttons = append(buttons, Row(
				Button("🎨 Перейти к креативам", "go_to_creatives"),
			))
		} else {
			text += fmt.Sprintf("Креативы%s\n\n", ui.FormatPageInfo(s.CreativePage, page.Pages))

			buttons = append(buttons, ui.BuildGrid(
				page.Items,
				2,
				addPurchaseCreativesPerPage,
				page.Pages,
				func(creative backend.Creative) (string, string) {
					return creative.Name, "creative:" + creative.ID
				},
			)...)

			if navRow := ui.BuildNavigationRow(ui.PaginationConfig{
				CurrentPage: s.CreativePage,
				TotalPages:  page.Pages,
			}); navRow != nil {
				buttons = append(buttons, navRow)
			}
		}

		buttons = append(buttons, Row(
			Button("← Назад", "back_to_selection"),
		))
	}

	if s.ActivePicker == "" {
		if s.ProjectID != "" && s.CreativeID != "" {
			buttons = append(buttons, Row(
				Button("← Отмена", "back"),
				Button("→ Далее", "next"),
			))
		} else {
			buttons = append(buttons, Row(
				Button("← Отмена", "back"),
			))
		}
	}

	keyboard := Keyboard(buttons...)
	b.Render(text, keyboard, mode)

	if s.ActivePicker == "" && s.ProjectTelegramID != 0 {
		messageID := b.LastMessageID
		updateProjectHeaderMedia(b, messageID, text, keyboard, s.ProjectTelegramID, s.ProjectTitle, s.ProjectUsername, s.ProjectStatus)
	}
}

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

	data := u.CallbackQuery.Data

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

	case "pick_project":
		s.ActivePicker = "project_list"
		s.Enter(b, bot.EditMessage)

	case "pick_creative":
		s.ActivePicker = "creative_list"
		s.Enter(b, bot.EditMessage)

	case "back_to_selection":
		s.ActivePicker = ""
		s.Enter(b, bot.EditMessage)

	case "go_to_creatives":
		b.SetState(&Creatives{
			CurrentPage:       0,
			ProjectID:         s.ProjectID,
			ProjectTitle:      s.ProjectTitle,
			ProjectTelegramID: s.ProjectTelegramID,
			ProjectUsername:   s.ProjectUsername,
			ProjectStatus:     s.ProjectStatus,
			BackState:         s,
		}, bot.EditMessage)

	case "prev":
		if s.ActivePicker == "project_list" {
			if s.ProjectPage > 0 {
				s.ProjectPage--
			}
			s.Enter(b, bot.EditMessage)
			return
		}
		if s.ActivePicker == "creative_list" {
			if s.CreativePage > 0 {
				s.CreativePage--
			}
			s.Enter(b, bot.EditMessage)
			return
		}

	case "next":
		if s.ActivePicker == "project_list" {
			s.ProjectPage++
			s.Enter(b, bot.EditMessage)
			return
		}
		if s.ActivePicker == "creative_list" {
			s.CreativePage++
			s.Enter(b, bot.EditMessage)
			return
		}
		if s.ProjectID != "" && s.CreativeID != "" {
			b.SetState(&SelectChannelsForPurchase{
				ProjectID:         s.ProjectID,
				ProjectTitle:      s.ProjectTitle,
				ProjectTelegramID: s.ProjectTelegramID,
				ProjectUsername:   s.ProjectUsername,
				ProjectStatus:     s.ProjectStatus,
				CreativeID:        s.CreativeID,
				CreativeTitle:     s.CreativeTitle,
				Channels:          []PurchaseChannelInput{},
				BackState:         s.BackState,
			}, bot.EditMessage)
		}

	default:
		if len(data) > 8 && data[:8] == "project:" {
			projectID := data[8:]
			if s.lastProjects != nil {
				if info, ok := s.lastProjects[projectID]; ok {
					s.ProjectTitle = info.Title
					s.ProjectTelegramID = info.TelegramID
					s.ProjectUsername = info.Username
					s.ProjectStatus = info.Status
				}
			}
			s.ProjectID = projectID
			s.CreativeID = ""
			s.CreativeTitle = ""
			s.CreativePage = 0
			s.ActivePicker = ""
			s.Enter(b, bot.EditMessage)
			return
		}
		if len(data) > 9 && data[:9] == "creative:" {
			creativeID := data[9:]
			if s.lastCreatives != nil {
				if info, ok := s.lastCreatives[creativeID]; ok {
					s.CreativeTitle = info.Title
				}
			}
			s.CreativeID = creativeID
			s.ActivePicker = ""
			s.Enter(b, bot.EditMessage)
			return
		} else {
			s.Enter(b, bot.NewMessage)
		}
	}
}

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

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

func (s *AddPurchase) Exit() {}