package rpc

import (
	"encoding/json"
	"errors"
	"math/big"
	"strings"

	"github.com/ethereum/go-ethereum/ethutil"
	"github.com/ethereum/go-ethereum/xeth"
)

type EthereumApi struct {
	pipe *xeth.JSXEth
}

type JsonArgs interface {
	requirements() error
}

type BlockResponse struct {
	JsonResponse
}
type GetBlockArgs struct {
	BlockNumber int
	Hash        string
}

type ErrorResponse struct {
	Error     bool   `json:"error"`
	ErrorText string `json:"errorText"`
}

type JsonResponse interface {
}

type SuccessRes struct {
	Error  bool         `json:"error"`
	Result JsonResponse `json:"result"`
}

func NewSuccessRes(object JsonResponse) string {
	e := SuccessRes{Error: false, Result: object}
	res, err := json.Marshal(e)
	if err != nil {
		// This should never happen
		panic("Creating json error response failed, help")
	}
	success := string(res)
	return success
}

func NewErrorResponse(msg string) error {
	e := ErrorResponse{Error: true, ErrorText: msg}
	res, err := json.Marshal(e)
	if err != nil {
		// This should never happen
		panic("Creating json error response failed, help")
	}
	newErr := errors.New(string(res))
	return newErr
}

func (b *GetBlockArgs) requirements() error {
	if b.BlockNumber == 0 && b.Hash == "" {
		return NewErrorResponse("GetBlock requires either a block 'number' or a block 'hash' as argument")
	}
	return nil
}

func (p *EthereumApi) GetBlock(args *GetBlockArgs, reply *string) error {
	err := args.requirements()
	if err != nil {
		return err
	}

	block := p.pipe.BlockByHash(args.Hash)
	*reply = NewSuccessRes(block)
	return nil
}

type NewTxArgs struct {
	Sec       string
	Recipient string
	Value     string
	Gas       string
	GasPrice  string
	Init      string
	Body      string
}
type TxResponse struct {
	Hash string
}

func (a *NewTxArgs) requirements() error {
	if a.Recipient == "" {
		return NewErrorResponse("Transact requires a 'recipient' address as argument")
	}
	if a.Value == "" {
		return NewErrorResponse("Transact requires a 'value' as argument")
	}
	if a.Gas == "" {
		return NewErrorResponse("Transact requires a 'gas' value as argument")
	}
	if a.GasPrice == "" {
		return NewErrorResponse("Transact requires a 'gasprice' value as argument")
	}
	return nil
}

func (a *NewTxArgs) requirementsContract() error {
	if a.Value == "" {
		return NewErrorResponse("Create requires a 'value' as argument")
	}
	if a.Gas == "" {
		return NewErrorResponse("Create requires a 'gas' value as argument")
	}
	if a.GasPrice == "" {
		return NewErrorResponse("Create requires a 'gasprice' value as argument")
	}
	if a.Body == "" {
		return NewErrorResponse("Create requires a 'body' value as argument")
	}
	return nil
}

func (p *EthereumApi) Transact(args *NewTxArgs, reply *string) error {
	err := args.requirements()
	if err != nil {
		return err
	}
	result, _ := p.pipe.Transact(p.pipe.Key().PrivateKey, args.Recipient, args.Value, args.Gas, args.GasPrice, args.Body)
	*reply = NewSuccessRes(result)
	return nil
}

func (p *EthereumApi) Create(args *NewTxArgs, reply *string) error {
	err := args.requirementsContract()
	if err != nil {
		return err
	}

	result, _ := p.pipe.Transact(p.pipe.Key().PrivateKey, "", args.Value, args.Gas, args.GasPrice, args.Body)
	*reply = NewSuccessRes(result)
	return nil
}

type PushTxArgs struct {
	Tx string
}

func (a *PushTxArgs) requirementsPushTx() error {
	if a.Tx == "" {
		return NewErrorResponse("PushTx requires a 'tx' as argument")
	}
	return nil
}

func (p *EthereumApi) PushTx(args *PushTxArgs, reply *string) error {
	err := args.requirementsPushTx()
	if err != nil {
		return err
	}
	result, _ := p.pipe.PushTx(args.Tx)
	*reply = NewSuccessRes(result)
	return nil
}

func (p *EthereumApi) GetKey(args interface{}, reply *string) error {
	*reply = NewSuccessRes(p.pipe.Key())
	return nil
}

type GetStorageArgs struct {
	Address string
	Key     string
}

func (a *GetStorageArgs) requirements() error {
	if a.Address == "" {
		return NewErrorResponse("GetStorageAt requires an 'address' value as argument")
	}
	if a.Key == "" {
		return NewErrorResponse("GetStorageAt requires an 'key' value as argument")
	}
	return nil
}

type GetStorageAtRes struct {
	Key     string `json:"key"`
	Value   string `json:"value"`
	Address string `json:"address"`
}

func (p *EthereumApi) GetStorageAt(args *GetStorageArgs, reply *string) error {
	err := args.requirements()
	if err != nil {
		return err
	}

	state := p.pipe.World().SafeGet(ethutil.Hex2Bytes(args.Address))

	var hx string
	if strings.Index(args.Key, "0x") == 0 {
		hx = string([]byte(args.Key)[2:])
	} else {
		// Convert the incoming string (which is a bigint) into hex
		i, _ := new(big.Int).SetString(args.Key, 10)
		hx = ethutil.Bytes2Hex(i.Bytes())
	}
	jsonlogger.Debugf("GetStorageAt(%s, %s)\n", args.Address, hx)
	value := state.Storage(ethutil.Hex2Bytes(hx))
	*reply = NewSuccessRes(GetStorageAtRes{Address: args.Address, Key: args.Key, Value: value.Str()})
	return nil
}

type GetTxCountArgs struct {
	Address string `json:"address"`
}
type GetTxCountRes struct {
	Nonce int `json:"nonce"`
}

func (a *GetTxCountArgs) requirements() error {
	if a.Address == "" {
		return NewErrorResponse("GetTxCountAt requires an 'address' value as argument")
	}
	return nil
}

type GetPeerCountRes struct {
	PeerCount int `json:"peerCount"`
}

func (p *EthereumApi) GetPeerCount(args *interface{}, reply *string) error {
	*reply = NewSuccessRes(GetPeerCountRes{PeerCount: p.pipe.PeerCount()})
	return nil
}

type GetListeningRes struct {
	IsListening bool `json:"isListening"`
}

func (p *EthereumApi) GetIsListening(args *interface{}, reply *string) error {
	*reply = NewSuccessRes(GetListeningRes{IsListening: p.pipe.IsListening()})
	return nil
}

type GetCoinbaseRes struct {
	Coinbase string `json:"coinbase"`
}

func (p *EthereumApi) GetCoinbase(args *interface{}, reply *string) error {
	*reply = NewSuccessRes(GetCoinbaseRes{Coinbase: p.pipe.CoinBase()})
	return nil
}

type GetMiningRes struct {
	IsMining bool `json:"isMining"`
}

func (p *EthereumApi) GetIsMining(args *interface{}, reply *string) error {
	*reply = NewSuccessRes(GetMiningRes{IsMining: p.pipe.IsMining()})
	return nil
}

func (p *EthereumApi) GetTxCountAt(args *GetTxCountArgs, reply *string) error {
	err := args.requirements()
	if err != nil {
		return err
	}
	state := p.pipe.TxCountAt(args.Address)
	*reply = NewSuccessRes(GetTxCountRes{Nonce: state})
	return nil
}

type GetBalanceArgs struct {
	Address string
}

func (a *GetBalanceArgs) requirements() error {
	if a.Address == "" {
		return NewErrorResponse("GetBalanceAt requires an 'address' value as argument")
	}
	return nil
}

type BalanceRes struct {
	Balance string `json:"balance"`
	Address string `json:"address"`
}

func (p *EthereumApi) GetBalanceAt(args *GetBalanceArgs, reply *string) error {
	err := args.requirements()
	if err != nil {
		return err
	}
	state := p.pipe.World().SafeGet(ethutil.Hex2Bytes(args.Address))
	*reply = NewSuccessRes(BalanceRes{Balance: state.Balance().String(), Address: args.Address})
	return nil
}

type TestRes struct {
	JsonResponse `json:"-"`
	Answer       int `json:"answer"`
}

func (p *EthereumApi) Test(args *GetBlockArgs, reply *string) error {
	*reply = NewSuccessRes(TestRes{Answer: 15})
	return nil
}