fabric-samples/commercial-paper/organization/digibank/contract-go/commercial-paper/papercontract.go

/*
 * SPDX-License-Identifier: Apache-2.0
 */

package commercialpaper

import (
	"fmt"

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

// Contract chaincode that defines
// the business logic for managing commercial
// paper
type Contract struct {
	contractapi.Contract
}

// Instantiate does nothing
func (c *Contract) Instantiate() {
	fmt.Println("Instantiated")
}

// Issue creates a new commercial paper and stores it in the world state
func (c *Contract) Issue(ctx TransactionContextInterface, issuer string, paperNumber string, issueDateTime string, maturityDateTime string, faceValue int) (*CommercialPaper, error) {
	paper := CommercialPaper{PaperNumber: paperNumber, Issuer: issuer, IssueDateTime: issueDateTime, FaceValue: faceValue, MaturityDateTime: maturityDateTime, Owner: issuer}
	paper.SetIssued()

	err := ctx.GetPaperList().AddPaper(&paper)

	if err != nil {
		return nil, err
	}

	return &paper, nil
}

// Buy updates a commercial paper to be in trading status and sets the new owner
func (c *Contract) Buy(ctx TransactionContextInterface, issuer string, paperNumber string, currentOwner string, newOwner string, price int, purchaseDateTime string) (*CommercialPaper, error) {
	paper, err := ctx.GetPaperList().GetPaper(issuer, paperNumber)

	if err != nil {
		return nil, err
	}

	if paper.Owner != currentOwner {
		return nil, fmt.Errorf("Paper %s:%s is not owned by %s", issuer, paperNumber, currentOwner)
	}

	if paper.IsIssued() {
		paper.SetTrading()
	}

	if !paper.IsTrading() {
		return nil, fmt.Errorf("Paper %s:%s is not trading. Current state = %s", issuer, paperNumber, paper.GetState())
	}

	paper.Owner = newOwner

	err = ctx.GetPaperList().UpdatePaper(paper)

	if err != nil {
		return nil, err
	}

	return paper, nil
}

// Redeem updates a commercial paper status to be redeemed
func (c *Contract) Redeem(ctx TransactionContextInterface, issuer string, paperNumber string, redeemingOwner string, redeenDateTime string) (*CommercialPaper, error) {
	paper, err := ctx.GetPaperList().GetPaper(issuer, paperNumber)

	if err != nil {
		return nil, err
	}

	if paper.Owner != redeemingOwner {
		return nil, fmt.Errorf("Paper %s:%s is not owned by %s", issuer, paperNumber, redeemingOwner)
	}

	if paper.IsRedeemed() {
		return nil, fmt.Errorf("Paper %s:%s is already redeemed", issuer, paperNumber)
	}

	paper.Owner = paper.Issuer
	paper.SetRedeemed()

	err = ctx.GetPaperList().UpdatePaper(paper)

	if err != nil {
		return nil, err
	}

	return paper, nil
}