package api

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

	"gorm.io/gorm"
)

type PetStore struct {
	DB *gorm.DB
}

// Make sure we conform to ServerInterface
var _ ServerInterface = (*PetStore)(nil)

// sendPetStoreError wraps sending of an error in the Error format, and
// handling the failure to marshal that.
func sendPetStoreError(w http.ResponseWriter, code int, message string) {
	petErr := Error{
		Code:    int32(code),
		Message: message,
	}
	w.WriteHeader(code)
	_ = json.NewEncoder(w).Encode(petErr)
}

// FindPets implements all the handlers in the ServerInterface
func (p *PetStore) FindPets(w http.ResponseWriter, r *http.Request, params FindPetsParams) {
	var pets []Pet
	query := p.DB

	if params.Tags != nil {
		query = query.Where("tag IN ?", *params.Tags)
	}

	if params.Limit != nil {
		query = query.Limit(int(*params.Limit))
	}

	if err := query.Find(&pets).Error; err != nil {
		sendPetStoreError(w, http.StatusInternalServerError, "Database error")
		return
	}

	w.WriteHeader(http.StatusOK)
	_ = json.NewEncoder(w).Encode(pets)
}

func (p *PetStore) AddPet(w http.ResponseWriter, r *http.Request) {
	// We expect a NewPet object in the request body.
	var newPet NewPet
	if err := json.NewDecoder(r.Body).Decode(&newPet); err != nil {
		sendPetStoreError(w, http.StatusBadRequest, "Invalid format for NewPet")
		return
	}

	pet := Pet{
		Name: newPet.Name,
		Tag:  newPet.Tag,
	}

	if err := p.DB.Create(&pet).Error; err != nil {
		sendPetStoreError(w, http.StatusInternalServerError, "Failed to create pet")
		return
	}

	// Now, we have to return the NewPet
	w.WriteHeader(http.StatusCreated)
	_ = json.NewEncoder(w).Encode(pet)
}

func (p *PetStore) FindPetByID(w http.ResponseWriter, r *http.Request, id int64) {
	var pet Pet
	if err := p.DB.First(&pet, id).Error; err != nil {
		sendPetStoreError(w, http.StatusNotFound, fmt.Sprintf("Pet with ID %d not found", id))
		return
	}

	w.WriteHeader(http.StatusOK)
	_ = json.NewEncoder(w).Encode(pet)
}

func (p *PetStore) DeletePet(w http.ResponseWriter, r *http.Request, id int64) {
	if err := p.DB.Delete(&Pet{}, id).Error; err != nil {
		sendPetStoreError(w, http.StatusNotFound, fmt.Sprintf("Pet with ID %d not found", id))
		return
	}

	w.WriteHeader(http.StatusNoContent)
}