package service

import (
	"encoding/json"
	"fmt"
	"gitea.pena/SQuiz/answerer/clients"
	quizdal "gitea.pena/SQuiz/answerer/dal"
	"gitea.pena/SQuiz/answerer/middleware"
	"gitea.pena/SQuiz/answerer/model"
	"github.com/gofiber/fiber/v2"
	"strconv"
	"strings"
	"time"
	"unicode/utf8"

	"github.com/rs/xid"
)

const (
	quizIdCookie      = "qud"
	fingerprintCookie = "fp"
)

type Service struct {
	dal            *quizdal.DAL
	aiClient       *clients.AIClient
	quizConfigData GetQuizDataResp
}

type ServiceDeps struct {
	Dal      *quizdal.DAL
	AiClient *clients.AIClient
}

func New(deps ServiceDeps) (*Service, error) {
	quizData, err := loadQuizDataConfig()
	if err != nil {
		return nil, err
	}

	return &Service{
		dal:            deps.Dal,
		aiClient:       deps.AiClient,
		quizConfigData: quizData,
	}, nil
}

func (s *Service) Register(app *fiber.App) *fiber.App {
	app.Post("/answer", s.PutAnswersOnePiece)
	app.Post("/settings", s.GetQuizData)
	return app
}

type GetQuizDataResp struct {
	Settings  *ShavedQuiz      `json:"settings,omitempty"`
	Items     []ShavedQuestion `json:"items"`
	Count     uint64           `json:"cnt"`
	ShowBadge bool             `json:"show_badge"`
}

type ShavedQuiz struct {
	Fingerprinting bool   `json:"fp"`
	Repeatable     bool   `json:"rep"`
	Name           string `json:"name"`
	Config         string `json:"cfg"`
	Limit          uint64 `json:"lim"`
	DueTo          uint64 `json:"due"`
	TimeOfPassing  uint64 `json:"delay"`
	Pausable       bool   `json:"pausable"`
	Status         string `json:"status"`
}

type ShavedQuestion struct {
	Id          uint64 `json:"id"`
	Title       string `json:"title"`
	Description string `json:"desc"`
	Type        string `json:"typ"`
	Required    bool   `json:"req"`
	Page        int    `json:"p"`
	Content     string `json:"c"`
}

// GetQuizData handler for obtaining data for quiz front rendering
func (s *Service) GetQuizData(c *fiber.Ctx) error {
	return c.Status(fiber.StatusOK).JSON(s.quizConfigData)
}

// MB Size constants
const (
	MB         = 1 << 20
	filePrefix = "file:"
)

type PutAnswersResponse struct {
	FileIDMap map[uint64]string `json:"fileIDMap"`
	Stored    []uint64          `json:"stored"`
}

func (s *Service) PutAnswersOnePiece(c *fiber.Ctx) error {
	cs, ok := c.Context().Value(middleware.ContextKey(middleware.SessionKey)).(string)
	if !ok {
		return c.Status(fiber.StatusUnauthorized).SendString("no session in cookie")
	}

	form, err := c.MultipartForm()
	if err != nil || form == nil || form.File == nil {
		return c.Status(fiber.StatusBadRequest).SendString("expecting multipart form file")
	}

	answersStr := form.Value["answers"]
	if len(answersStr) == 0 {
		return c.Status(fiber.StatusFailedDependency).SendString("no answers provided")
	}

	versionStr, ok := form.Value["version"]
	var version int64

	if ok && len(versionStr) > 0 {
		version, err = strconv.ParseInt(versionStr[0], 10, 32)
		if err != nil {
			return c.Status(fiber.StatusBadRequest).SendString(fmt.Sprintf("invalid version:%s", err.Error()))
		}
	}

	var (
		answersRaw, answers []model.Answer
		errs                []error
	)

	deviceType := c.Get("DeviceType")
	os := c.Get("OS")
	browser := c.Get("Browser")
	ip := c.IP()
	device := c.Get("Device")

	if err := json.Unmarshal([]byte(answersStr[0]), &answersRaw); err != nil {
		return c.Status(fiber.StatusBadRequest).SendString("not valid answers string")
	}

	quizID, ok := form.Value["qid"]
	if !ok {
		return c.Status(fiber.StatusFailedDependency).SendString("no quiz id provided")
	}

	fp := ""
	if cfp := c.Cookies(fingerprintCookie); cfp != "" {
		fp = cfp
	}

	quiz, err := s.dal.GetQuizByQid(c.Context(), quizID[0])
	if err != nil {
		return c.Status(fiber.StatusInternalServerError).SendString("can not get quiz")
	}

	fileIDMap := make(map[uint64]string)

	for _, ans := range answersRaw {
		final := false
		if finalStr, exists := form.Value["final"]; exists && len(finalStr) > 0 {
			parsedFinal, err := strconv.ParseBool(finalStr[0])
			if err != nil {
				return c.Status(fiber.StatusBadRequest).SendString("invalid final value")
			}
			final = parsedFinal
		}

		question, err := s.dal.GetQuestionListByIDs(c.Context(), []int32{int32(ans.QuestionId)})
		if err != nil {
			return c.Status(fiber.StatusInternalServerError).SendString("can not get questions")
		}

		if len(question) == 0 {
			return c.Status(fiber.StatusNotFound).SendString("no questions found")
		}

		questionText, err := s.aiClient.SendAnswerer(final, question[0].Type, ans.Content, cs)
		if err != nil {
			return c.Status(fiber.StatusInternalServerError).SendString(fmt.Sprintf("failed send answer to ai, err: %s", err.Error()))
		}

		_, err = s.dal.CreateQuestion(c.Context(), &model.Question{
			QuizId:      quiz.Id,
			Title:       truncateUTF8(questionText, 512),
			Type:        model.TypeText,
			Session:     cs,
			Content:     `{"id":"gcZ-9SET-sM6stZSzQMmu","hint":{"text":" ","video":" "},"rule":{"children":[],"main":[],"parentId":" ","default":" "},"back":" ","originalBack":" ","autofill":false,"placeholder":" ","innerNameCheck":false,"innerName":" ","required":false,"answerType":"single","onlyNumbers":false}`,
			Description: questionText,
		})
		if err != nil {
			return c.Status(fiber.StatusInternalServerError).SendString(fmt.Sprintf("failed create question type ai, err: %s", err.Error()))
		}

		ans.DeviceType = deviceType
		ans.OS = os
		ans.Browser = browser
		ans.IP = ip
		ans.Device = device
		ans.Version = int32(version)
		if strings.HasPrefix(ans.Content, filePrefix) {
			filekey := strings.TrimPrefix(ans.Content, filePrefix)
			filenameparts := strings.Split(filekey, ".")
			filetail := filenameparts[len(filenameparts)-1]
			fileparts := form.File[filekey]

			if len(fileparts) == 0 {
				errs = append(errs, fmt.Errorf("no parts for file: %s", filekey))
				continue
			}

			fname := fmt.Sprintf("%s.%s", xid.New().String(), filetail)

			ans.Content = fname

			fileIDMap[ans.QuestionId] = fname
		}

		ans.Session = cs
		ans.QuizId = quiz.Id
		ans.CreatedAt = time.Now()
		answers = append(answers, ans)
		if ans.Result {
			content := model.ResultContent{}
			err := json.Unmarshal([]byte(ans.Content), &content)
			if err != nil {
				return c.Status(fiber.StatusInternalServerError).SendString("error unmarshalling answer content: " + err.Error())
			}
			ans.Email = content.Email
		}
	}

	quizConfig := model.QuizConfig{}
	err = json.Unmarshal([]byte(quiz.Config), &quizConfig)
	if err != nil {
		return c.Status(fiber.StatusInternalServerError).SendString("can not unmarshal quiz config")
	}

	stored, ers := s.dal.CreateAnswers(c.Context(), answers, cs, fp, quiz.Id)
	if len(ers) != 0 {
		for _, err := range ers {
			if strings.Contains(err.Error(), "duplicate key value") {
				return c.Status(fiber.StatusAlreadyReported).SendString("User has already passed the quiz")
			}
		}

		return c.Status(fiber.StatusInternalServerError).SendString("some errors are casualted: " + fmt.Sprint(ers))
	}
	var questionIDs []uint64
	for _, ans := range stored {
		questionIDs = append(questionIDs, ans.QuestionId)
	}

	response := PutAnswersResponse{
		FileIDMap: fileIDMap,
		Stored:    questionIDs,
	}

	return c.Status(fiber.StatusOK).JSON(response)
}

func truncateUTF8(s string, maxLen int) string {
	if utf8.RuneCountInString(s) <= maxLen {
		return s
	}

	// Конвертируем строку в руны для корректной обработки Unicode
	runes := []rune(s)
	return string(runes[:maxLen])
}