package handlers

import (
	"slices"

	"git.odit.services/lfk/document-server/models"
	"github.com/gofiber/fiber/v2"
)

// GenerateCard godoc
//
//	@Summary		Generate runner cards
//	@Description	Generate cards based on the provided data
//	@Tags			pdfs
//	@Accept			json
//	@Param			data	body	models.CardRequest	true	"Card data"
//	@Produce		application/pdf
//	@Security		ApiKeyAuth
//	@Router			/v1/pdfs/cards [post]
func (h *DefaultHandler) GenerateCard(c *fiber.Ctx) error {

	logger := h.Logger.Named("GenerateCard")

	cardRequest := new(models.CardRequest)
	if err := c.BodyParser(cardRequest); err != nil {
		logger.Errorw("Invalid request", "error", err)
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{
			"error": err.Error(),
		})
	}
	if !slices.Contains([]string{"en", "de"}, cardRequest.Locale) {
		logger.Errorw("Invalid locale", "locale", cardRequest.Locale)
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{
			"error": "Invalid locale",
		})
	}

	logger = logger.With("locale", cardRequest.Locale)

	templateString, err := h.StaticService.GetTemplate(cardRequest.Locale, "card")
	if err != nil {
		logger.Errorw("Template not found", "error", err)
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{
			"error": "Template not found",
		})
	}
	template, err := h.Templater.StringToTemplate(templateString)
	if err != nil {
		logger.Errorw("Error parsing template", "error", err)
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{
			"error": err.Error(),
		})
	}

	genConfig := &models.CardTemplateOptions{
		CardSegments:  splitCardSegments(cardRequest.Cards),
		EventName:     h.Config.EventName,
		CardSubtitle:  h.Config.CardSubtitle,
		BarcodeFormat: h.Config.CardBarcodeFormat,
		BarcodePrefix: h.Config.CardBarcodePrefix,
	}

	logger.Info("Generating card html")
	result, err := h.Templater.Execute(template, genConfig)
	if err != nil {
		logger.Errorw("Error executing template", "error", err)
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{
			"error": err.Error(),
		})
	}
	logger.Info("Generated card html")
	c.Set(fiber.HeaderContentType, "text/html")

	logger.Info("Converting html to pdf")
	pdf, err := h.Converter.ToPdf(result, "a4", false)
	if err != nil {
		logger.Errorw("Error converting html to pdf", "error", err)
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{
			"error": err.Error(),
		})
	}
	logger.Info("Converted html to pdf")

	c.Set(fiber.HeaderContentType, "application/pdf")
	c.Set(fiber.HeaderContentDisposition, "attachment; filename=runner-cards.pdf")
	return c.Send(pdf)
}

func invertCardArrayItemPairs(cards []models.Card) []models.Card {
	inverted := make([]models.Card, 0)
	for i := 0; i < len(cards); i += 2 {
		if i+1 < len(cards) {
			inverted = append(inverted, cards[i+1])
		}
		inverted = append(inverted, cards[i])
	}
	return inverted
}

func splitCardSegments(cards []models.Card) []models.CardTemplateSegment {
	cardSegments := make([]models.CardTemplateSegment, 0)
	const currentCards = 0
	for i := 0; i < len(cards); i += 10 {
		segmentLength := 10
		if len(cards)-i < 10 {
			segmentLength = len(cards) - i
		}
		segment := cards[i : i+segmentLength]
		if segmentLength%2 != 0 {
			segment = append(segment, models.Card{
				ID:      0,
				Enabled: false,
				Runner:  models.Runner{},
				Code:    "",
			})
		}
		cardSegments = append(cardSegments, models.CardTemplateSegment{
			Cards:        segment,
			CardsSwapped: invertCardArrayItemPairs(segment),
		})
	}
	return cardSegments
}