solution: erc20 tokens config

src/main/kotlin/io/emeraldpay/dshackle/config/MainConfig.kt

@@ -22,5 +22,6 @@ class MainConfig {
     var cache: CacheConfig? = null
     var proxy: ProxyConfig? = null
     var upstreams: UpstreamsConfig? = null
+    var tokens: TokensConfig? = null
 
 }

src/main/kotlin/io/emeraldpay/dshackle/config/MainConfigReader.kt

@@ -32,6 +32,7 @@ class MainConfigReader(
     private val proxyConfigReader = ProxyConfigReader()
     private val upstreamsConfigReader = UpstreamsConfigReader(fileResolver)
     private val cacheConfigReader = CacheConfigReader()
+    private val tokensConfigReader = TokensConfigReader()
 
     fun read(input: InputStream): MainConfig? {
         val configNode = readNode(input)
@@ -59,6 +60,9 @@ class MainConfigReader(
         cacheConfigReader.read(input)?.let {
             config.cache = it
         }
+        tokensConfigReader.read(input)?.let {
+            config.tokens = it
+        }
         return config
     }
 

src/main/kotlin/io/emeraldpay/dshackle/config/TokensConfig.kt

@@ -0,0 +1,55 @@
+/**
+ * Copyright (c) 2020 EmeraldPay, Inc
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.emeraldpay.dshackle.config
+
+import io.emeraldpay.dshackle.BlockchainType
+import io.emeraldpay.grpc.Chain
+import io.infinitape.etherjar.domain.Address
+
+class TokensConfig(
+        val tokens: List<Token>
+) {
+
+    class Token {
+        // reference id, used by get balance and others
+        var id: String? = null
+        var blockchain: Chain? = null
+
+        // coin name
+        var name: String? = null
+        var type: Type? = null;
+        var address: String? = null
+
+        fun validate(): String? {
+            return when {
+                id.isNullOrBlank() -> "id"
+                blockchain == null -> "blockchain"
+                name.isNullOrBlank() -> "name"
+                type == null -> type
+                address.isNullOrBlank() -> "address"
+                blockchain != null
+                        && BlockchainType.fromBlockchain(blockchain!!) == BlockchainType.ETHEREUM
+                        && !Address.isValidAddress(address) -> "address"
+                else -> null
+            }
+        }
+    }
+
+    enum class Type {
+        ERC20
+    }
+
+}

src/main/kotlin/io/emeraldpay/dshackle/config/TokensConfigReader.kt

@@ -0,0 +1,63 @@
+/**
+ * Copyright (c) 2020 EmeraldPay, Inc
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.emeraldpay.dshackle.config
+
+import org.slf4j.LoggerFactory
+import org.yaml.snakeyaml.nodes.MappingNode
+import java.io.InputStream
+
+class TokensConfigReader : YamlConfigReader(), ConfigReader<TokensConfig> {
+
+    private val log = LoggerFactory.getLogger(TokensConfigReader::class.java)
+
+    fun read(input: InputStream): TokensConfig? {
+        val configNode = readNode(input)
+        return read(configNode)
+    }
+
+    override fun read(input: MappingNode?): TokensConfig? {
+        val tokens = getList<MappingNode>(input, "tokens")?.value?.map { node ->
+            val token = TokensConfig.Token()
+            token.id = getValueAsString(node, "id")
+            token.blockchain = getValueAsString(node, "blockchain")?.let {
+                getBlockchain(it)
+            }
+            token.address = getValueAsString(node, "address")
+            token.name = getValueAsString(node, "name")
+            token.type = getValueAsString(node, "type")?.let {
+                if (it.toUpperCase() == "ERC-20") {
+                    TokensConfig.Type.ERC20
+                } else {
+                    log.warn("Invalid token type: $it")
+                    null
+                }
+            }
+            token
+        }?.filter { token ->
+            val invalidField = token.validate()
+            if (invalidField != null) {
+                log.error("Failed to parse token ${token.id}. Invalid field: $invalidField")
+                false
+            } else {
+                true
+            }
+        }
+        return tokens?.let {
+            TokensConfig(it)
+        }
+    }
+
+}

src/test/groovy/io/emeraldpay/dshackle/config/TokensConfigReaderSpec.groovy

@@ -0,0 +1,50 @@
+/**
+ * Copyright (c) 2020 EmeraldPay, Inc
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.emeraldpay.dshackle.config
+
+import io.emeraldpay.grpc.Chain
+import spock.lang.Specification
+
+class TokensConfigReaderSpec extends Specification {
+
+    TokensConfigReader reader = new TokensConfigReader()
+
+    def "Read basic"() {
+        setup:
+        def config = this.class.getClassLoader().getResourceAsStream("tokens/basic.yaml")
+        when:
+        def act = reader.read(config)
+
+        then:
+        act != null
+        act.tokens.size() == 2
+        with(act.tokens[0]) {
+            id == "dai"
+            blockchain == Chain.ETHEREUM
+            name == "DAI"
+            type == TokensConfig.Type.ERC20
+            address == "0x6B175474E89094C44Da98b954EedeAC495271d0F"
+        }
+        with(act.tokens[1]) {
+            id == "tether"
+            blockchain == Chain.ETHEREUM
+            name == "Tether"
+            type == TokensConfig.Type.ERC20
+            address == "0xdac17f958d2ee523a2206206994597c13d831ec7"
+        }
+
+    }
+}

src/test/resources/tokens/basic.yaml

@@ -0,0 +1,11 @@
+tokens:
+  - id: dai
+    blockchain: ethereum
+    name: DAI
+    type: ERC-20
+    address: 0x6B175474E89094C44Da98b954EedeAC495271d0F
+  - id: tether
+    blockchain: ethereum
+    name: Tether
+    type: ERC-20
+    address: 0xdac17f958d2ee523a2206206994597c13d831ec7