JumboPetstore/api/petApiHandlers.go

package api

import (
	"encoding/json"
	"errors"
	"fmt"
	"io/ioutil"
	"log"
	"mime/multipart"
	"net/http"
	"os"
	"path/filepath"
	"strconv"
	"strings"

	"git.tovijaeschke.xyz/tovi/JumboPetstore/database"
	"git.tovijaeschke.xyz/tovi/JumboPetstore/models"

	schema "github.com/Kangaroux/go-map-schema"
	"github.com/gorilla/mux"
)

func deserialsePetJson(data []byte) (models.Pet, error) {
	var (
		petData                  models.Pet             = models.Pet{}
		jsonStructureTest        map[string]interface{} = make(map[string]interface{})
		jsonStructureTestResults *schema.CompareResults
		err                      error
	)

	// Verify the JSON has the correct structure
	json.Unmarshal(data, &jsonStructureTest)
	jsonStructureTestResults, err = schema.CompareMapToStruct(
		&petData,
		jsonStructureTest,
		&schema.CompareOpts{
			ConvertibleFunc: CanConvert,
			TypeNameFunc:    schema.DetailedTypeName,
		})
	if err != nil {
		return petData, err
	}

	if len(jsonStructureTestResults.MismatchedFields) > 0 {
		fmt.Println(jsonStructureTestResults.MismatchedFields)
		return petData, errors.New("MismatchedFields found when deserializing data")
	}

	if len(jsonStructureTestResults.MissingFields) > 0 {
		fmt.Println(jsonStructureTestResults.MissingFields)
		return petData, errors.New("MissingFields found when deserializing data")
	}

	// Deserialize the JSON into the struct
	err = json.Unmarshal(data, &petData)
	return petData, err
}

func genericJsonReturn(w http.ResponseWriter, code int, msg, typ string) {
	var (
		responseJsonMap map[string]interface{}
		responseJson    []byte
		err             error
	)

	responseJsonMap = make(map[string]interface{})

	w.WriteHeader(code)
	responseJsonMap["code"] = code
	responseJsonMap["type"] = typ
	responseJsonMap["message"] = msg
	responseJson, err = json.MarshalIndent(responseJsonMap, "", "  ")
	if err != nil {
		log.Printf("Error occured creating response: %s\n", err.Error())
	}
	w.Write(responseJson)
}

func PetHandlerCreateUpdate(w http.ResponseWriter, r *http.Request) {
	var (
		requestBody []byte
		petData     models.Pet
		returnJson  []byte
		err         error
	)

	log.Printf("Pet handler recieved %s request", r.Method)

	requestBody, err = ioutil.ReadAll(r.Body)
	if err != nil {
		log.Printf("Error encountered reading POST body: %s\n", err.Error())
		genericJsonReturn(w, 500, "An error occured", "unknown")
		return
	}

	petData, err = deserialsePetJson(requestBody)
	if err != nil {
		log.Printf("Invalid data provided to pet POST API: %s\n", err.Error())
		genericJsonReturn(w, 405, "Invalid data", "unknown")
		return
	}

	switch r.Method {
	case "POST":
		petData, err = database.CreatePet(petData)
		if err != nil {
			panic(err)
		}
		break
	case "PUT":
		petData, err = database.UpdatePet(petData)
		if err != nil {
			panic(err)
		}
		break
	}

	returnJson, err = json.MarshalIndent(petData, "", "  ")
	if err != nil {
		log.Printf("Error encountered when creating pet record: %s\n", err.Error())
		w.WriteHeader(http.StatusInternalServerError)
		w.Write([]byte("500 - An error has occured\n"))
		return
	}

	// Return updated json
	w.WriteHeader(http.StatusOK)
	w.Write(returnJson)
}

func PetHandlerId(w http.ResponseWriter, r *http.Request) {
	var (
		petData      models.Pet
		urlVars      map[string]string
		returnJson   []byte
		notFoundJson map[string]interface{} = make(map[string]interface{})
		id_str       string
		id           int
		ok           bool
		err          error
	)

	urlVars = mux.Vars(r)
	id_str, ok = urlVars["petId"]
	if !ok {
		log.Printf("Error encountered getting id\n")
		w.WriteHeader(http.StatusInternalServerError)
		w.Write([]byte("500 - An error has occured\n"))
		return
	}

	id, err = strconv.Atoi(id_str)
	if err != nil {
		log.Printf("Error encountered converting id to string: %s\n", err.Error())
		w.WriteHeader(http.StatusInternalServerError)
		w.Write([]byte("500 - An error has occured\n"))
		return
	}

	petData = database.GetPetById(id)
	if petData.Id == 0 {
		log.Printf("Could not find pet with id %d\n", id)
		w.WriteHeader(http.StatusNotFound)
		notFoundJson["code"] = 404
		notFoundJson["type"] = "unknown"
		notFoundJson["message"] = "not found"
		returnJson, err = json.MarshalIndent(notFoundJson, "", "  ")
		w.Write(returnJson)
		return
	}

	switch r.Method {
	case "GET":
		returnJson, err = json.MarshalIndent(petData, "", "  ")
		if err != nil {
			log.Printf("Error encountered when creating pet record: %s\n", err.Error())
			w.WriteHeader(http.StatusInternalServerError)
			w.Write([]byte("500 - An error has occured\n"))
			return
		}

		// Return updated json
		w.WriteHeader(http.StatusOK)
		w.Write(returnJson)
		break
	case "POST":
		err = r.ParseForm()
		if err != nil {
			log.Printf("Error encountered parsing form: %s\n", err.Error())
			w.WriteHeader(http.StatusInternalServerError)
			w.Write([]byte("500 - An error has occured\n"))
			return
		}

		if r.FormValue("name") != "" {
			petData.Name = r.FormValue("name")
		}
		if r.FormValue("status") != "" {
			petData.Status = r.FormValue("status")
		}

		_, err = database.UpdatePet(petData)
		if err != nil {
			log.Printf("Error updating pet: %s\n", err.Error())
			w.WriteHeader(http.StatusInternalServerError)
			w.Write([]byte("500 - An error has occured\n"))
			return
		}

		break
	case "DELETE":
		log.Printf("Marking pet %d as deleted\n", id)

		database.DeletePet(petData)

		w.WriteHeader(http.StatusOK)
		notFoundJson["code"] = 200
		notFoundJson["type"] = "unknown"
		notFoundJson["message"] = id_str
		returnJson, err = json.MarshalIndent(notFoundJson, "", "  ")
		w.Write(returnJson)

		break
	}
}

func PetHandlerFindByStatus(w http.ResponseWriter, r *http.Request) {
	var (
		status     string
		petData    []models.Pet
		returnJson []byte
		err        error
	)

	status = r.URL.Query().Get("status")
	if status != "available" && status != "pending" && status != "sold" {
		log.Printf("Invalid status provided to /pet/findByStatus")
		w.WriteHeader(http.StatusInternalServerError)
		w.Write([]byte("500 - An error has occured\n"))
		return
	}

	petData, err = database.GetPetsByStatus(status)
	if err != nil {
		log.Printf("An error occured in GetPetsByStatus")
		w.WriteHeader(http.StatusInternalServerError)
		w.Write([]byte("500 - An error has occured\n"))
		return
	}

	returnJson, err = json.MarshalIndent(petData, "", "  ")
	if err != nil {
		log.Printf("An error occured while serializing pet data to JSON")
		w.WriteHeader(http.StatusInternalServerError)
		w.Write([]byte("500 - An error has occured\n"))
		return
	}

	w.Write(returnJson)

}

func PetHandlerUploadImage(w http.ResponseWriter, r *http.Request) {
	var (
		urlVars   map[string]string
		file      multipart.File
		handler   *multipart.FileHeader
		tempFile  *os.File
		nameSplit []string
		fileBytes []byte
		id_str    string
		id        int
		ok        bool
		err       error
	)

	urlVars = mux.Vars(r)
	id_str, ok = urlVars["petId"]
	if !ok {
		log.Printf("Error encountered getting id\n")
		w.WriteHeader(http.StatusInternalServerError)
		w.Write([]byte("500 - An error has occured\n"))
		return
	}

	id, err = strconv.Atoi(id_str)
	if err != nil {
		log.Printf("Error encountered converting id to string: %s\n", err.Error())
		w.WriteHeader(http.StatusInternalServerError)
		w.Write([]byte("500 - An error has occured\n"))
		return
	}

	fmt.Println(id)

	// Upload 10Mb files
	r.ParseMultipartForm(10 << 20)
	file, handler, err = r.FormFile("file")
	if err != nil {
		log.Printf("Error retrieving file: %s\n", err.Error())
		w.WriteHeader(http.StatusInternalServerError)
		w.Write([]byte("500 - An error has occured\n"))
		return
	}
	defer file.Close()

	nameSplit = strings.Split(handler.Filename, ".")

	tempFile, err = ioutil.TempFile("./uploads", "upload-*."+nameSplit[len(nameSplit)-1])
	if err != nil {
		fmt.Println(err)
		return
	}
	defer tempFile.Close()

	fileBytes, err = ioutil.ReadAll(file)
	if err != nil {
		fmt.Println(err)
		return
	}

	tempFile.Write(fileBytes)

	err = database.AddPhotoToPet(id, filepath.Base(tempFile.Name()))
	if err != nil {
		fmt.Println(err)
		return
	}

	fmt.Fprintf(w, "Successfully Uploaded File\n")
}