package handlers

import (
	"encoding/json"
	"fmt"
	"net/http"

	"devone.aplikasi.web.id/gitea/mario/go-ohif-proxy/internal/api/models"
	"devone.aplikasi.web.id/gitea/mario/go-ohif-proxy/internal/api/service"
	"go.uber.org/zap"
)

// PydicomHandler handles operations related to PYDICOM uploads
type PydicomHandler struct {
	logger           *zap.Logger
	shortLinkService *service.ShortLinkService
	registerService  *service.RegisterService
}

// NewPydicomHandler creates a new PydicomHandler
func NewPydicomHandler(logger *zap.Logger, shortLinkService *service.ShortLinkService, registerService *service.RegisterService) *PydicomHandler {
	return &PydicomHandler{
		logger:           logger,
		shortLinkService: shortLinkService,
		registerService:  registerService,
	}
}

// HandleUploadedDicom processes a request from the PYDICOM uploader service to register a patient and generate a shortlink
func (h *PydicomHandler) HandleUploadedDicom(w http.ResponseWriter, r *http.Request) {
	// Parse the request body into a temporary struct that matches the expected JSON
	var reqData struct {
		Email    string `json:"email"`
		Password string `json:"password"`
		Name     string `json:"name"`
		Role     string `json:"role"`
		Patient  struct {
			PatientID   string `json:"patient_id"`
			PatientName string `json:"patient_name"`
			DateOfBirth string `json:"date_of_birth"`
		} `json:"patient"`
		Studies []struct {
			StudyInstanceUID string `json:"study_instance_uid"`
			AccessionNumber  string `json:"accession_number"`
			StudyDate        string `json:"study_date"`
			StudyDescription string `json:"study_description"`
		} `json:"studies"`
	}

	if err := json.NewDecoder(r.Body).Decode(&reqData); err != nil {
		h.logger.Error("Failed to parse uploaded DICOM request", zap.Error(err))
		http.Error(w, "Invalid request body", http.StatusBadRequest)
		return
	}

	// Validate the request
	if reqData.Email == "" || reqData.Password == "" || reqData.Name == "" {
		h.logger.Error("Missing required user fields in uploaded DICOM request")
		http.Error(w, "Missing required user fields", http.StatusBadRequest)
		return
	}

	if reqData.Patient.PatientID == "" || reqData.Patient.DateOfBirth == "" {
		h.logger.Error("Missing required patient fields in uploaded DICOM request")
		http.Error(w, "Missing required patient fields", http.StatusBadRequest)
		return
	}

	if len(reqData.Studies) == 0 || reqData.Studies[0].StudyInstanceUID == "" {
		h.logger.Error("Missing required study fields in uploaded DICOM request")
		http.Error(w, "Missing required study fields", http.StatusBadRequest)
		return
	}

	// Convert to our internal models
	patientDetails := &models.PatientDetails{
		PatientID:   reqData.Patient.PatientID,
		PatientName: reqData.Patient.PatientName,
		DateOfBirth: reqData.Patient.DateOfBirth,
	}

	// Convert studies to our internal model
	studies := make([]models.Study, len(reqData.Studies))
	for i, s := range reqData.Studies {
		studies[i] = models.Study{
			StudyInstanceUID: s.StudyInstanceUID,
			AccessionNumber:  s.AccessionNumber,
			StudyDate:        s.StudyDate,
			StudyDescription: s.StudyDescription,
		}
	}

	// Create registration request
	regRequest := &service.RegisterRequest{
		Email:    reqData.Email,
		Password: reqData.Password,
		Name:     reqData.Name,
		Role:     "patient", // Force the role to be "patient" regardless of what was sent
		Patient:  patientDetails,
		Studies:  studies,
	}

	// Register the patient (or confirm it exists) using the RegisterService
	user, err := h.registerService.Register(regRequest)
	if err != nil {
		// If the error is about duplicate email, we'll continue with generating a shortlink
		// Otherwise, return the error
		if err != service.ErrEmailExists {
			h.logger.Error("Failed to register patient", zap.Error(err))
			http.Error(w, fmt.Sprintf("Failed to register patient: %v", err), http.StatusInternalServerError)
			return
		}

		h.logger.Info("Patient already exists, continuing with shortlink generation",
			zap.String("email", reqData.Email),
			zap.String("patientID", reqData.Patient.PatientID))
	} else {
		h.logger.Info("Patient registered successfully",
			zap.String("userID", user.ID),
			zap.String("email", reqData.Email),
			zap.String("patientID", reqData.Patient.PatientID))
	}

	// For each study, generate a shortlink
	// For simplicity, we'll just use the first study in the array
	study := reqData.Studies[0]

	// Create a shortlink request
	shortLinkReq := &models.GenerateShortLinkRequest{
		PatientID: reqData.Patient.PatientID,
		StudyUID:  study.StudyInstanceUID,
		DOB:       reqData.Patient.DateOfBirth,
		ExpiresIn: 0, // Set to 0 to use the default expiry from config
	}

	// Generate a shortlink
	// We set empty string as creatorID because you mentioned ShortlinkCreate_UserID is now nullable
	shortLinkResp, err := h.shortLinkService.GenerateShortLink(shortLinkReq, "")
	if err != nil {
		h.logger.Error("Failed to generate shortlink",
			zap.Error(err),
			zap.String("patientID", reqData.Patient.PatientID),
			zap.String("studyUID", study.StudyInstanceUID))
		http.Error(w, fmt.Sprintf("Failed to generate shortlink: %v", err), http.StatusInternalServerError)
		return
	}

	// Log successful shortlink generation
	h.logger.Info("Shortlink generated for uploaded DICOM",
		zap.String("patientID", reqData.Patient.PatientID),
		zap.String("studyUID", study.StudyInstanceUID),
		zap.String("shortToken", shortLinkResp.ShortToken))

	// Return the shortlink response
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(http.StatusCreated)
	json.NewEncoder(w).Encode(shortLinkResp)
}