package keeper

import (
	"bytes"
	"context"
	"crypto/sha256"
	"encoding/json"
	"fmt"
	"io"
	"log"
	"net/http"
	"strconv"
	"strings"

	config "github.com/planetmint/planetmint-go/config"
	"github.com/planetmint/planetmint-go/util"
	"github.com/planetmint/planetmint-go/x/machine/types"
	elements "github.com/rddl-network/elements-rpc"

	"github.com/btcsuite/btcd/btcutil/hdkeychain"
	"github.com/btcsuite/btcd/chaincfg"

	errorsmod "cosmossdk.io/errors"
	sdk "github.com/cosmos/cosmos-sdk/types"
)

func (k msgServer) AttestMachine(goCtx context.Context, msg *types.MsgAttestMachine) (*types.MsgAttestMachineResponse, error) {
	ctx := sdk.UnwrapSDKContext(goCtx)

	// the ante handler verifies that the MachineID exists. Additional result checks got moved to the ante-handler
	// and removed from here due to inconsistency or checking the same thing over and over again.
	ta, _, _ := k.GetTrustAnchor(ctx, msg.Machine.MachineId)

	isValidMachineID, err := util.ValidateSignature(msg.Machine.MachineId, msg.Machine.MachineIdSignature, msg.Machine.MachineId)
	if !isValidMachineID {
		return nil, err
	}

	isValidIssuerPlanetmint := validateExtendedPublicKey(msg.Machine.IssuerPlanetmint, config.PlmntNetParams)
	if !isValidIssuerPlanetmint {
		return nil, errorsmod.Wrap(types.ErrInvalidKey, "planetmint")
	}
	isValidIssuerLiquid := validateExtendedPublicKey(msg.Machine.IssuerLiquid, config.LiquidNetParams)
	if !isValidIssuerLiquid {
		return nil, errorsmod.Wrap(types.ErrInvalidKey, "liquid")
	}

	if msg.Machine.GetType() == 0 { // 0 == RDDL_MACHINE_UNDEFINED
		return nil, types.ErrMachineTypeUndefined
	}

	if util.IsValidatorBlockProposer(ctx, ctx.BlockHeader().ProposerAddress) {
		util.GetAppLogger().Info(ctx, "Issuing Machine NFT: "+msg.Machine.String())
		err := k.issueMachineNFT(goCtx, msg.Machine)
		if err != nil {
			util.GetAppLogger().Error(ctx, "Machine NFT issuance failed : "+err.Error())
		} else {
			util.GetAppLogger().Info(ctx, "Machine NFT issuance successful: "+msg.Machine.String())
		}
	} else {
		util.GetAppLogger().Info(ctx, "Not block proposer: skipping Machine NFT issuance")
	}

	k.StoreMachine(ctx, *msg.Machine)
	k.StoreMachineIndex(ctx, *msg.Machine)
	err = k.StoreTrustAnchor(ctx, ta, true)
	if err != nil {
		return nil, err
	}
	return &types.MsgAttestMachineResponse{}, err
}

func validateExtendedPublicKey(issuer string, cfg chaincfg.Params) bool {
	xpubKey, err := hdkeychain.NewKeyFromString(issuer)
	if err != nil {
		return false
	}
	isValidExtendedPublicKey := xpubKey.IsForNet(&cfg)
	return isValidExtendedPublicKey
}

func (k msgServer) issueNFTAsset(goCtx context.Context, name string, machineAddress string) (assetID string, contract string, err error) {
	ctx := sdk.UnwrapSDKContext(goCtx)
	conf := config.GetConfig()

	url := conf.GetRPCURL()
	address, err := elements.GetNewAddress(url, []string{``})
	if err != nil {
		return
	}

	addressInfo, err := elements.GetAddressInfo(url, []string{address})
	if err != nil {
		return
	}

	hex, err := elements.CreateRawTransaction(url, []string{`[]`, `[{"data":"00"}]`})
	if err != nil {
		return
	}

	fundRawTransactionResult, err := elements.FundRawTransaction(url, []string{hex, `{"feeRate":0.00001000}`})
	if err != nil {
		return
	}

	c := types.Contract{
		Entity: types.Entity{
			Domain: k.GetParams(ctx).AssetRegistryDomain,
		},
		IssuerPubkey: addressInfo.Pubkey,
		MachineAddr:  machineAddress,
		Name:         name,
		Precision:    0,
		Version:      0,
	}
	contractBytes, err := json.Marshal(c)
	if err != nil {
		return
	}
	// e.g. {"entity":{"domain":"testnet-assets.rddl.io"}, "issuer_pubkey":"02...}
	contract = string(contractBytes)

	h := sha256.New()
	_, err = h.Write(contractBytes)
	if err != nil {
		return
	}
	// e.g. 7ca8bb403ee5dccddef7b89b163048cf39439553f0402351217a4a03d2224df8
	hash := h.Sum(nil)

	// Reverse hash, e.g. f84d22d2034a7a21512340f053954339cf4830169bb8f7decddce53e40bba87c
	for i, j := 0, len(hash)-1; i < j; i, j = i+1, j-1 {
		hash[i], hash[j] = hash[j], hash[i]
	}

	rawIssueAssetResults, err := elements.RawIssueAsset(url, []string{fundRawTransactionResult.Hex,
		`[{"asset_amount":0.00000001, "asset_address":"` + address + `", "blind":false, "contract_hash":"` + fmt.Sprintf("%+x", hash) + `"}]`,
	})
	if err != nil {
		return
	}

	rawIssueAssetResult := rawIssueAssetResults[len(rawIssueAssetResults)-1]
	hex, err = elements.BlindRawTransaction(url, []string{rawIssueAssetResult.Hex, `true`, `[]`, `false`})
	if err != nil {
		return
	}
	assetID = rawIssueAssetResult.Asset

	signRawTransactionWithWalletResult, err := elements.SignRawTransactionWithWallet(url, []string{hex})
	if err != nil {
		return
	}

	testMempoolAcceptResults, err := elements.TestMempoolAccept(url, []string{`["` + signRawTransactionWithWalletResult.Hex + `"]`})
	if err != nil {
		return
	}

	testMempoolAcceptResult := testMempoolAcceptResults[len(testMempoolAcceptResults)-1]
	if !testMempoolAcceptResult.Allowed {
		log.Fatalln("not accepted by mempool")
	}

	hex, err = elements.SendRawTransaction(url, []string{signRawTransactionWithWalletResult.Hex})
	if err != nil {
		return
	}

	util.GetAppLogger().Info(ctx, "Liquid Token Issuance assetID: "+assetID+" contract: "+contract+" tx: "+hex)
	return assetID, contract, err
}

func (k msgServer) issueMachineNFT(goCtx context.Context, machine *types.Machine) error {
	ctx := sdk.UnwrapSDKContext(goCtx)
	// asset registration is in order to have the contact published
	var notarizedAsset types.LiquidAsset
	notarizedAsset.Registered = true
	assetID, contract, err := k.issueNFTAsset(goCtx, machine.Name, machine.Address)
	if err != nil {
		util.GetAppLogger().Error(ctx, err.Error())
		return err
	}
	err = k.registerAsset(goCtx, assetID, contract)
	if err != nil {
		util.GetAppLogger().Error(ctx, err.Error())
		notarizedAsset.Registered = false
	}
	// issue message with:
	notarizedAsset.AssetID = assetID
	notarizedAsset.MachineID = machine.GetMachineId()
	notarizedAsset.MachineAddress = machine.Address

	util.SendLiquidAssetRegistration(goCtx, notarizedAsset)
	return err
}

func (k msgServer) registerAsset(goCtx context.Context, assetID string, contract string) error {
	ctx := sdk.UnwrapSDKContext(goCtx)

	var contractMap map[string]interface{}
	err := json.Unmarshal([]byte(contract), &contractMap)
	if err != nil {
		return errorsmod.Wrap(types.ErrAssetRegistryReqFailure, "Unmarshal "+err.Error())
	}
	// Create your request payload
	data := map[string]interface{}{
		"asset_id": assetID,
		"contract": contractMap,
	}

	jsonData, err := json.Marshal(data)
	if err != nil {
		return errorsmod.Wrap(types.ErrAssetRegistryReqFailure, "Marshall "+err.Error())
	}

	assetRegistryEndpoint := fmt.Sprintf("%s://%s/%s", k.GetParams(ctx).AssetRegistryScheme, k.GetParams(ctx).AssetRegistryDomain, k.GetParams(ctx).AssetRegistryPath)
	req, err := http.NewRequestWithContext(goCtx, http.MethodPost, assetRegistryEndpoint, bytes.NewBuffer(jsonData))
	if err != nil {
		return errorsmod.Wrap(types.ErrAssetRegistryReqFailure, "Request creation: "+err.Error())
	}

	// Set headers
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("accept", "application/json")

	// Send request
	client := &http.Client{}
	resp, err := client.Do(req)
	if err != nil {
		return errorsmod.Wrap(types.ErrAssetRegistryReqSending, err.Error())
	}
	defer resp.Body.Close()

	// Read response
	if resp.StatusCode > 299 {
		return errorsmod.Wrap(types.ErrAssetRegistryRepsonse, "Error reading response body:"+strconv.Itoa(resp.StatusCode))
	}
	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return errorsmod.Wrap(types.ErrAssetRegistryRepsonse, "Error reading response body:"+err.Error())
	}
	resultObj := string(body)
	if strings.Contains(resultObj, assetID) {
		return nil
	}
	return errorsmod.Wrap(types.ErrAssetRegistryRepsonse, "does not confirm asset registration")
}