From 9233e357166d894936f0ab54be5573498eb56a3e Mon Sep 17 00:00:00 2001
From: Ethan Buchman <ethan@coinculture.info>
Date: Mon, 25 Jun 2018 21:55:23 -0400
Subject: [PATCH] example app1

---
 docs/core/examples/app1/main.go | 167 ++++++++++++++++++++++++++++++++
 1 file changed, 167 insertions(+)
 create mode 100644 docs/core/examples/app1/main.go

diff --git a/docs/core/examples/app1/main.go b/docs/core/examples/app1/main.go
new file mode 100644
index 0000000000..59cc39e08c
--- /dev/null
+++ b/docs/core/examples/app1/main.go
@@ -0,0 +1,167 @@
+package app
+
+import (
+	"encoding/json"
+	"reflect"
+
+	cmn "github.com/tendermint/tmlibs/common"
+	dbm "github.com/tendermint/tmlibs/db"
+	"github.com/tendermint/tmlibs/log"
+
+	bapp "github.com/cosmos/cosmos-sdk/baseapp"
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/cosmos/cosmos-sdk/wire"
+)
+
+const (
+	appName = "MyApp"
+)
+
+func NewApp(logger log.Logger, db dbm.DB) *bapp.BaseApp {
+
+	// TODO: make this an interface or pass in
+	// a TxDecoder instead.
+	cdc := wire.NewCodec()
+
+	// Create the base application object.
+	app := bapp.NewBaseApp(appName, cdc, logger, db)
+
+	// Create a key for accessing the account store.
+	keyAccount := sdk.NewKVStoreKey("acc")
+
+	// Determine how transactions are decoded.
+	app.SetTxDecoder(txDecoder)
+
+	// Register message routes.
+	// Note the handler gets access to the account store.
+	app.Router().
+		AddRoute("bank", NewHandler(keyAccount))
+
+	// Mount stores and load the latest state.
+	app.MountStoresIAVL(keyAccount)
+	err := app.LoadLatestVersion(keyAccount)
+	if err != nil {
+		cmn.Exit(err.Error())
+	}
+	return app
+}
+
+//------------------------------------------------------------------
+// Msg
+
+// MsgSend implements sdk.Msg
+var _ sdk.Msg = MsgSend{}
+
+// MsgSend to send coins from Input to Output
+type MsgSend struct {
+	From   sdk.Address `json:"from"`
+	To     sdk.Address `json:"to"`
+	Amount sdk.Coins   `json:"amount"`
+}
+
+// NewMsgSend
+func NewMsgSend(from, to sdk.Address, amt sdk.Coins) MsgSend {
+	return MsgSend{from, to, amt}
+}
+
+// Implements Msg.
+func (msg MsgSend) Type() string { return "bank" }
+
+// Implements Msg. Ensure the addresses are good and the
+// amount is positive.
+func (msg MsgSend) ValidateBasic() sdk.Error {
+	if len(msg.From) == 0 {
+		return sdk.ErrInvalidAddress("From address is empty")
+	}
+	if len(msg.To) == 0 {
+		return sdk.ErrInvalidAddress("To address is empty")
+	}
+	if !msg.Amount.IsPositive() {
+		return sdk.ErrInvalidCoins("Amount is not positive")
+	}
+	return nil
+}
+
+// Implements Msg. JSON encode the message.
+func (msg MsgSend) GetSignBytes() []byte {
+	bz, err := json.Marshal(msg)
+	if err != nil {
+		panic(err)
+	}
+	return bz
+}
+
+// Implements Msg. Return the signer.
+func (msg MsgSend) GetSigners() []sdk.Address {
+	return []sdk.Address{msg.From}
+}
+
+//------------------------------------------------------------------
+// Handler for the message
+
+func NewHandler(keyAcc *sdk.KVStoreKey) sdk.Handler {
+	return func(ctx sdk.Context, msg sdk.Msg) sdk.Result {
+		switch msg := msg.(type) {
+		case MsgSend:
+			return handleMsgSend(ctx, keyAcc, msg)
+		default:
+			errMsg := "Unrecognized bank Msg type: " + reflect.TypeOf(msg).Name()
+			return sdk.ErrUnknownRequest(errMsg).Result()
+		}
+	}
+}
+
+// Handle MsgSend.
+func handleMsgSend(ctx sdk.Context, key *sdk.KVStoreKey, msg MsgSend) sdk.Result {
+	// NOTE: from, to, and amount were already validated
+
+	store := ctx.KVStore(key)
+	bz := store.Get(msg.From)
+	if bz == nil {
+		// TODO
+	}
+
+	var acc acc
+	err := json.Unmarshal(bz, &acc)
+	if err != nil {
+		// InternalError
+	}
+
+	// TODO: finish the logic
+
+	return sdk.Result{
+	// TODO: Tags
+	}
+}
+
+type acc struct {
+	Coins sdk.Coins `json:"coins"`
+}
+
+//------------------------------------------------------------------
+// Tx
+
+// Simple tx to wrap the Msg.
+type tx struct {
+	MsgSend
+}
+
+// This tx only has one Msg.
+func (tx tx) GetMsgs() []sdk.Msg {
+	return []sdk.Msg{tx.MsgSend}
+}
+
+// TODO: remove the need for this
+func (tx tx) GetMemo() string {
+	return ""
+}
+
+// JSON decode MsgSend.
+func txDecoder(txBytes []byte) (sdk.Tx, sdk.Error) {
+	var tx tx
+	err := json.Unmarshal(txBytes, &tx)
+	if err != nil {
+		return nil, sdk.ErrTxDecode(err.Error())
+	}
+	return tx, nil
+}