package kennel

import (
	"encoding/json"
	"log"
	"net/http"
	"strings"

	"git.hatecomputers.club/hatecomputers/hatecomputers.club/adapters/files"
	"git.hatecomputers.club/hatecomputers/hatecomputers.club/api/types"
	"git.hatecomputers.club/hatecomputers/hatecomputers.club/database"
	"git.hatecomputers.club/hatecomputers/hatecomputers.club/utils"
)

const MaxCatSize = 1024 * 100 // 60KB
const CatsPath = "cats/"
const CatsPrefix = "/uploads/cats/"
const DefaultCatSpritesheet = "/static/img/cat_spritesheets/default.gif"
const MaxUserCats = 15

func ListUserCatsContinuation(context *types.RequestContext, req *http.Request, resp http.ResponseWriter) types.ContinuationChain {
	return func(success types.Continuation, failure types.Continuation) types.ContinuationChain {
		userID := context.User.ID

		cats, err := database.GetUserKennelCats(context.DBConn, userID)
		if err != nil {
			log.Println(err)
			resp.WriteHeader(http.StatusInternalServerError)
			return failure(context, req, resp)
		}

		(*context.TemplateData)["Cats"] = cats
		return success(context, req, resp)
	}
}

func CreateCatContinuation(fileAdapter files.FilesAdapter, maxUserCats int, maxCatSize int, catsPath string, catsPrefix string, defaultCatSpritesheet string) func(context *types.RequestContext, req *http.Request, resp http.ResponseWriter) types.ContinuationChain {
	return func(context *types.RequestContext, req *http.Request, resp http.ResponseWriter) types.ContinuationChain {
		return func(success types.Continuation, failure types.Continuation) types.ContinuationChain {
			formErrors := types.BannerMessages{
				Messages: []string{},
			}

			numCats, err := database.CountUserKennelCats(context.DBConn, context.User.ID)
			if err != nil {
				log.Println(err)
				resp.WriteHeader(http.StatusInternalServerError)
				return failure(context, req, resp)
			}
			if numCats >= maxUserCats {
				formErrors.Messages = append(formErrors.Messages, "max cats reached for user")
			}

			err = req.ParseMultipartForm(int64(maxCatSize))
			if err != nil {
				formErrors.Messages = append(formErrors.Messages, "cat spritesheet too large")
			}

			catID := utils.RandomId()
			spritesheetPath := catsPrefix + catID

			if len(formErrors.Messages) == 0 {
				file, _, err := req.FormFile("spritesheet")
				if file != nil && err != nil {
					formErrors.Messages = append(formErrors.Messages, "error uploading spritesheet")
				} else if file != nil {
					defer file.Close()
					reader := http.MaxBytesReader(resp, file, int64(maxCatSize))
					defer reader.Close()

					_, err = fileAdapter.CreateFile(catsPath+catID, reader)
					if err != nil {
						log.Println(err)
						formErrors.Messages = append(formErrors.Messages, "error saving spritesheet (is it too big?)")
					}
				} else if file == nil && err != nil {
					spritesheetPath = defaultCatSpritesheet
				}
			}

			link := req.FormValue("link")
			description := req.FormValue("description")
			name := req.FormValue("name")

			cat := &database.KennelCat{
				ID:          catID,
				UserID:      context.User.ID,
				Name:        name,
				Link:        link,
				Description: description,
				Spritesheet: spritesheetPath,
			}
			formErrors.Messages = append(formErrors.Messages, validateCat(cat)...)
			if len(formErrors.Messages) == 0 {
				_, err := database.SaveKennelCat(context.DBConn, cat)
				if err != nil {
					log.Println(err)
					formErrors.Messages = append(formErrors.Messages, "failed to save cat")
				}
			}

			if len(formErrors.Messages) > 0 {
				(*context.TemplateData)["Error"] = formErrors
				(*context.TemplateData)["CatForm"] = cat
				resp.WriteHeader(http.StatusBadRequest)

				return failure(context, req, resp)
			}

			formSuccess := types.BannerMessages{
				Messages: []string{"cat added."},
			}
			(*context.TemplateData)["Success"] = formSuccess
			return success(context, req, resp)
		}
	}
}

func RemoveCatContinuation(fileAdapter files.FilesAdapter, catsPath string) func(context *types.RequestContext, req *http.Request, resp http.ResponseWriter) types.ContinuationChain {
	return func(context *types.RequestContext, req *http.Request, resp http.ResponseWriter) types.ContinuationChain {
		return func(success types.Continuation, failure types.Continuation) types.ContinuationChain {
			catID := req.FormValue("id")

			cat, err := database.GetKennelCat(context.DBConn, catID)
			if err != nil {
				log.Println(err)
				resp.WriteHeader(http.StatusInternalServerError)
				return failure(context, req, resp)
			}
			if cat == nil || cat.UserID != context.User.ID {
				resp.WriteHeader(http.StatusUnauthorized)
				return failure(context, req, resp)
			}

			err = database.DeleteKennelCat(context.DBConn, catID)
			if err != nil {
				log.Println(err)
				resp.WriteHeader(http.StatusInternalServerError)
				return failure(context, req, resp)
			}

			err = fileAdapter.DeleteFile(catsPath + catID)
			if err != nil && fileAdapter.FileExists(catsPath+catID) {
				log.Println(err)
				resp.WriteHeader(http.StatusInternalServerError)
				return failure(context, req, resp)
			}

			return success(context, req, resp)
		}
	}
}

func RingContinuation(context *types.RequestContext, req *http.Request, resp http.ResponseWriter) types.ContinuationChain {
	return func(success types.Continuation, failure types.Continuation) types.ContinuationChain {
		order := req.URL.Query().Get("order")

		if order == "random" {
			kennelCat, err := database.GetRandomKennelCat(context.DBConn)
			if err != nil {
				log.Println(err)
				resp.WriteHeader(http.StatusInternalServerError)
				return failure(context, req, resp)
			}
			http.Redirect(resp, req, kennelCat.Link, http.StatusFound)
			return success(context, req, resp)
		}

		id := req.URL.Query().Get("id")
		if id == "" {
			resp.WriteHeader(http.StatusBadRequest)
			return failure(context, req, resp)
		}
		if order != "random" && order != "next" && order != "prev" {
			kennelCat, err := database.GetKennelCat(context.DBConn, id)
			if err != nil {
				log.Println(err)
				resp.WriteHeader(http.StatusNotFound)
				return failure(context, req, resp)
			}
			http.Redirect(resp, req, kennelCat.Link, http.StatusFound)
			return success(context, req, resp)
		}

		nextCat, err := database.GetNextKennelCat(context.DBConn, id, order == "next")
		if err != nil {
			log.Println(err)
			resp.WriteHeader(http.StatusInternalServerError)
			return failure(context, req, resp)
		}

		http.Redirect(resp, req, nextCat.Link, http.StatusFound)
		return success(context, req, resp)
	}
}

func GetKennelContinuation(context *types.RequestContext, req *http.Request, resp http.ResponseWriter) types.ContinuationChain {
	return func(success types.Continuation, failure types.Continuation) types.ContinuationChain {
		cats, err := database.GetKennel(context.DBConn)
		if err != nil {
			log.Println(err)
			resp.WriteHeader(http.StatusInternalServerError)
			return failure(context, req, resp)
		}
		json, err := json.Marshal(cats)
		if err != nil {
			log.Println(err)
			resp.WriteHeader(http.StatusInternalServerError)
			return failure(context, req, resp)
		}

		resp.Header().Set("Content-Type", "application/json")
		resp.Write(json)
		return success(context, req, resp)
	}
}

func validateCat(cat *database.KennelCat) []string {
	errors := []string{}

	if cat.Name == "" {
		errors = append(errors, "name is required")
	}
	if cat.Link == "" {
		errors = append(errors, "link is required")
	}
	if !strings.HasPrefix(cat.Link, "http://") && !strings.HasPrefix(cat.Link, "https://") {
		errors = append(errors, "link must be a valid URL")
	}
	if cat.Description == "" {
		errors = append(errors, "description is required")
	}
	if len(cat.Description) > 100 {
		errors = append(errors, "description must be less than 100 characters")
	}

	return errors
}