package chaincode

import (
	"encoding/json"
	"fmt"

	"github.com/hyperledger/fabric-contract-api-go/contractapi"
)

type SmartContract struct {
	contractapi.Contract
}

type Application struct {
	Hash   string `json:"Hash"`
	Name   string `json:"Name"`
	SDK    string `json:"SDK"`
	Size   string `json:"Size"`
	Model  string `json:"Model"`
}

func (s *SmartContract) Save(ctx contractapi.TransactionContextInterface, hash string, name string, sdk string, size string, model string) error {
	exists, err := s.Check(ctx, hash)
	if err != nil {
		return err
	}
	if exists {
		return fmt.Errorf("application %s is already registered!", hash)
	}

	application := Application{
		Hash:   hash,
		Name:   name,
		SDK:    sdk,
		Size:   size,
		Model:  model,
	}
	applicationJSON, err := json.Marshal(application)
	if err != nil {
		return err
	}

	return ctx.GetStub().PutState(hash, applicationJSON)
}

func (s *SmartContract) Query(ctx contractapi.TransactionContextInterface, hash string) (*Application, error) {
	applicationJSON, err := ctx.GetStub().GetState(hash)
	if err != nil {
		return nil, fmt.Errorf("failed to read from blockchain!: %v", err)
	}
	if applicationJSON == nil {
		return nil, fmt.Errorf("application %s not found", hash)
	}

	var application Application
	err = json.Unmarshal(applicationJSON, &application)
	if err != nil {
		return nil, err
	}

	return &application, nil
}

func (s *SmartContract) Update(ctx contractapi.TransactionContextInterface, hash string, name string, sdk string, size string, model string) error {
	exists, err := s.Check(ctx, hash)
	if err != nil {
		return err
	}
	if !exists {
		return fmt.Errorf("application %s not found", hash)
	}

	application := Application{
		Hash:   hash,
		Name:   name,
		SDK:    sdk,
		Size:   size,
		Model:  model,
	}
	applicationJSON, err := json.Marshal(application)
	if err != nil {
		return err
	}

	return ctx.GetStub().PutState(hash, applicationJSON)
}

func (s *SmartContract) Delete(ctx contractapi.TransactionContextInterface, hash string) error {
	exists, err := s.Check(ctx, hash)
	if err != nil {
		return err
	}
	if !exists {
		return fmt.Errorf("application %s not found", hash)
	}

	return ctx.GetStub().DelState(hash)
}

func (s *SmartContract) Check(ctx contractapi.TransactionContextInterface, hash string) (bool, error) {
	applicationJSON, err := ctx.GetStub().GetState(hash)
	if err != nil {
		return false, fmt.Errorf("failed to read from blockchain: %v", err)
	}

	return applicationJSON != nil, nil
}