package admin

import (
	"strconv"

	"github.com/dmitriygnatenko/internal/helpers"
	"github.com/dmitriygnatenko/internal/interfaces"
	"github.com/dmitriygnatenko/internal/mapper"
	"github.com/dmitriygnatenko/internal/models"
	"github.com/go-playground/validator/v10"
	"github.com/gofiber/fiber/v2"
)

const errArticleExists = "Статья с данным URL уже существует"

func ArticleHandler(app interfaces.IApp) fiber.Handler {
	return func(ctx *fiber.Ctx) error {
		articles, err := app.GetArticleRepository().GetAll(ctx.Context())
		if err != nil {
			return err
		}

		articlesDTO, err := mapper.ConvertArticleModelsToDTO(articles)
		if err != nil {
			return err
		}

		return ctx.Render("admin/article", fiber.Map{
			"articles": articlesDTO,
			"section":  "article",
		}, "admin/_layout")
	}
}

func AddArticleHandler(app interfaces.IApp) fiber.Handler {
	return func(ctx *fiber.Ctx) error {
		var validate = validator.New()
		validateErrors := make(map[string]string)

		trans, err := helpers.GetDefaultTranslator(validate)
		if err != nil {
			return err
		}

		form := models.ArticleForm{
			ActiveTags: make(map[int]bool),
		}

		tags, err := app.GetTagRepository().GetAll(ctx.Context())
		if err != nil {
			return err
		}

		tagsDTO, err := mapper.ConvertTagModelsToDTO(tags)
		if err != nil {
			return err
		}

		if ctx.Method() == fiber.MethodPost {
			if err = ctx.BodyParser(&form); err != nil {
				return err
			}

			if err = validate.Struct(form); err != nil {
				validateErrors = helpers.FormatValidateErrors(err, trans)
			}

			if res, _ := app.GetArticleRepository().GetByURL(ctx.Context(), form.URL); res != nil {
				validateErrors["ArticleForm.URL"] = errArticleExists
			}

			tagIDs := make([]int, 0, len(form.Tags))
			for i := range form.Tags {
				tagID, tagErr := strconv.Atoi(form.Tags[i])
				if tagErr != nil {
					return tagErr
				}

				tagIDs = append(tagIDs, tagID)
			}

			for i := range tagIDs {
				form.ActiveTags[tagIDs[i]] = true
			}

			if len(validateErrors) == 0 {
				articleID, articleErr := app.GetArticleRepository().Add(ctx.Context(), mapper.ConvertArticleFormToModel(form))
				if articleErr != nil {
					return articleErr
				}

				if len(form.Tags) > 0 {
					if err = app.GetArticleTagRepository().Add(ctx.Context(), articleID, tagIDs); err != nil {
						return err
					}
				}

				app.GetCacheService().FlushAll()

				if err = ctx.Redirect("/admin"); err != nil {
					return err
				}
			}
		}

		return ctx.Render("admin/article_edit", fiber.Map{
			"form":       form,
			"errors":     validateErrors,
			"tags":       tagsDTO,
			"section":    "article",
			"title":      "Добавление статьи",
			"show_apply": false,
		}, "admin/_layout")
	}
}

func EditArticleHandler(app interfaces.IApp) fiber.Handler {
	return func(ctx *fiber.Ctx) error {
		var validate = validator.New()
		validateErrors := make(map[string]string)

		trans, err := helpers.GetDefaultTranslator(validate)
		if err != nil {
			return err
		}

		ID, err := strconv.Atoi(ctx.Params("id"))
		if err != nil {
			return err
		}

		article, err := app.GetArticleRepository().GetByID(ctx.Context(), ID)
		if err != nil {
			return err
		}
		if article == nil {
			return fiber.ErrNotFound
		}

		articleTags, err := app.GetTagRepository().GetByArticleID(ctx.Context(), ID)
		if err != nil {
			return err
		}

		tags, err := app.GetTagRepository().GetAll(ctx.Context())
		if err != nil {
			return err
		}

		tagsDTO, err := mapper.ConvertTagModelsToDTO(tags)
		if err != nil {
			return err
		}

		var form *models.ArticleForm
		if ctx.Method() == fiber.MethodGet {
			form, err = mapper.ConvertArticleModelToForm(*article, articleTags)
			if err != nil {
				return err
			}
		} else if ctx.Method() == fiber.MethodPost {
			form = &models.ArticleForm{
				ID:         ID,
				ActiveTags: make(map[int]bool),
			}

			if err = ctx.BodyParser(form); err != nil {
				return err
			}

			if err = validate.Struct(*form); err != nil {
				validateErrors = helpers.FormatValidateErrors(err, trans)
			}

			if res, _ := app.GetArticleRepository().GetByURL(ctx.Context(), form.URL); res != nil {
				if res.ID != ID {
					validateErrors["ArticleForm.URL"] = errArticleExists
				}
			}

			tagIDs := make([]int, 0, len(form.Tags))
			for i := range form.Tags {
				tagID, tagErr := strconv.Atoi(form.Tags[i])
				if tagErr != nil {
					return tagErr
				}

				tagIDs = append(tagIDs, tagID)
			}

			for i := range tagIDs {
				form.ActiveTags[tagIDs[i]] = true
			}

			if len(validateErrors) == 0 {
				err = app.GetArticleRepository().Update(ctx.Context(), mapper.ConvertArticleFormToModel(*form))
				if err != nil {
					return err
				}

				var tagsToAdd, tagsToDelete []int

				oldTagsMap := make(map[int]struct{}, len(articleTags))
				for i := range articleTags {
					oldTagsMap[articleTags[i].ID] = struct{}{}
					if _, ok := form.ActiveTags[articleTags[i].ID]; !ok {
						tagsToDelete = append(tagsToDelete, articleTags[i].ID)
					}
				}

				for i := range tagIDs {
					if _, ok := oldTagsMap[tagIDs[i]]; !ok {
						tagsToAdd = append(tagsToAdd, tagIDs[i])
					}
				}

				if len(tagsToAdd) > 0 {
					if err = app.GetArticleTagRepository().Add(ctx.Context(), ID, tagsToAdd); err != nil {
						return err
					}
				}

				if len(tagsToDelete) > 0 {
					if err = app.GetArticleTagRepository().Delete(ctx.Context(), ID, tagsToDelete); err != nil {
						return err
					}
				}

				app.GetCacheService().FlushAll()

				if ctx.FormValue("action", "save") == "save" {
					if err = ctx.Redirect("/admin"); err != nil {
						return err
					}
				}
			}
		}

		return ctx.Render("admin/article_edit", fiber.Map{
			"form":       form,
			"errors":     validateErrors,
			"tags":       tagsDTO,
			"show_apply": true,
			"section":    "article",
			"title":      "Редактирование статьи",
		}, "admin/_layout")
	}
}

func DeleteArticleHandler(app interfaces.IApp) fiber.Handler {
	return func(ctx *fiber.Ctx) error {
		return nil
	}
}