package main

import (
	"crypto/sha256"
	"encoding/json"
	"fmt"
	"io/ioutil"
	"math"
	"os"
	"time"
)

type Offer struct {
	ID                         string            `json:"id"`
	Date                       int               `json:"date"`
	OwnerNodeAddress           NodeAddress       `json:"ownerNodeAddress"`
	Direction                  string            `json:"direction"`
	Price                      int               `json:"price"`
	MarketPriceMargin          float64           `json:"marketPriceMargin"`
	UseMarketBasedPrice        bool              `json:"useMarketBasedPrice"`
	Amount                     int64             `json:"amount"`
	MinAmount                  int64             `json:"minAmount"`
	BaseCurrencyCode           string            `json:"baseCurrencyCode"`
	CounterCurrencyCode        string            `json:"counterCurrencyCode"`
	ArbitratorNodeAddresses    []NodeAddress     `json:"arbitratorNodeAddresses"`
	MediatorNodeAddress        []NodeAddress     `json:"mediatorNodeAddresses"`
	PaymentMethodId            string            `json:"paymentMethodId"`
	MakerPaymentAccountId      string            `json:"makerPaymentAccountId"`
	OfferFeePaymentTxId        string            `json:"offerFeePaymentTxId"`
	VersionNR                  string            `json:"versionNr"`
	BlockHeightAtOfferCreation int               `json:"blockHeightAtOfferCreation"`
	TxFee                      int               `json:"txFee"`
	MakerFee                   int               `json:"makerFee"`
	IsCurrencyForMakerFeeBtc   bool              `json:"isCurrencyForMakerFeeBtc"`
	BuyerSecurityDeposit       int               `json:"buyerSecurityDeposit"`
	SellerSecurityDeposit      int               `json:"sellerSecurityDeposit"`
	MaxTradeLimit              int               `json:"maxTradeLimit"`
	MaxTradePeriod             int               `json:"maxTradePeriod"`
	UseAutoClose               bool              `json:"useAutoClose"`
	UseReOpenAfterAutoClose    bool              `json:"useReOpenAfterAutoClose"`
	LowerClosePrice            int               `json:"lowerClosePrice"`
	UpperClosePrice            int               `json:"upperClosePrice"`
	IsPrivateOffer             bool              `json:"isPrivateOffer"`
	ExtraDataMap               map[string]string `json:"extraDataMap"`
	ProtocolVersion            int               `json:"protocolVersion"`
}

type NodeAddress struct {
	HostName string `json:"hostName"`
	Port     int    `json:"port"`
}

type AccountPayload struct {
	Address         string `json:"address"`
	PaymentMethodId string `json:"paymentMethodId"`
	ID              string `json:"id"`
	MaxTradePeriod  int    `json:"maxTradePeriod"`
}

type BisqContract struct {
	OfferPayload               Offer          `json:"offerPayload"`
	TradeAmount                int            `json:"tradeAmount"`
	TradePrice                 int            `json:"tradePrice"`
	TakerFeeTXID               string         `json:"takerFeeTxID"`
	BuyerNodeAddress           NodeAddress    `json:"buyerNodeAddress"`
	SellerNodeAddress          NodeAddress    `json:"sellerNodeAddress"`
	MediatorNodeAddress        NodeAddress    `json:"mediatorNodeAddress"`
	IsBuyerMakerAndSellerTaker bool           `json:"isBuyerMakerAndSellerTaker"`
	MakerAccountId             string         `json:"makerAccountId"`
	TakerAccountId             string         `json:"takerAccountId"`
	MakerPaymentAccountPayload AccountPayload `json:"makerPaymentAccountPayload"`
	TakerPaymentAccountPayload AccountPayload `json:"takerPaymentAccountPayload"`
	MakerPayoutAddressString   string         `json:"makerPayoutAddressString"`
	TakerPayoutAddressString   string         `json:"takerPayoutAddressString"`
	LockTime                   int            `json:"lockTime"`
	RefundAgentNodeAddress     NodeAddress    `json:"refundAgentNodeAddress"`
}

// Ideally this should be 10 minutes, but realistically...
const AverageBlockTime = 9.465
const BisqLockTime = 6 * 24 * 10 // 6 blocks an hour * 24 hours a day * 10 days (for alt coin trades)

func EstimateBlockHeightTime(blockHeight int) time.Time {
	loc, _ := time.LoadLocation("America/Vancouver")
	return time.Date(2009, 01, 03, 18, 15, 00, 00, loc).Add(time.Minute * time.Duration(int64(math.Round(float64(blockHeight)*AverageBlockTime))))
}

func main() {
	contractBytes, _ := ioutil.ReadFile(os.Args[1])
	contract := new(BisqContract)
	err := json.Unmarshal(contractBytes, contract)
	if err == nil {
		// Deal with general formatting weirdness. The canonical Bisq hash output is over the contract
		// when it has been formatted to separated fields by newlines, and with an indent of 2 spaces
		contractOut, _ := json.MarshalIndent(contract, "", "  ")
		fmt.Printf("Successfully Validated Contract\n")
		fmt.Printf("Contract Offer Date: %s\n", time.Unix(int64(contract.OfferPayload.Date/1000), 0))
		fmt.Printf("Contract Block Height %d (estimated)  / %s (estimated)\n", contract.LockTime-BisqLockTime, EstimateBlockHeightTime(contract.LockTime-BisqLockTime))
		fmt.Printf("Contract Hash: %x\n", sha256.Sum256(contractOut))
	} else {
		fmt.Printf("Error %v", err)
	}
}