CORDA-1848 Add example alias and autocomplete for CLI tools (#3700)

* Basic alias and autocomplete installation for bash in network bootstrapper

* Address review comments

* Update completion file if out of date

* Refactoring

* Some more minor tweaks

* Use manifest revision rather than recalculating hash

* Add zsh autocomplete compatibility

* Actually write .zshrc file

* Fix some descriptions

* Only rewrite settings files if changes have been made, and make a backup if so. Some refactoring

tools/bootstrapper/src/main/kotlin/net/corda/bootstrapper/Main.kt

@@ -1,12 +1,13 @@
 package net.corda.bootstrapper
 
 import com.jcabi.manifests.Manifests
-import net.corda.core.internal.rootMessage
+import net.corda.core.internal.*
 import net.corda.nodeapi.internal.network.NetworkBootstrapper
 import picocli.CommandLine
 import picocli.CommandLine.*
 import java.nio.file.Path
 import java.nio.file.Paths
+import java.nio.file.StandardCopyOption.REPLACE_EXISTING
 import kotlin.system.exitProcess
 
 fun main(args: Array<String>) {
@@ -29,13 +30,13 @@ fun main(args: Array<String>) {
         versionProvider = CordaVersionProvider::class,
         mixinStandardHelpOptions = true,
         showDefaultValues = true,
-        description = [ "Bootstrap a local test Corda network using a set of node conf files and CorDapp JARs" ]
+        description = ["Bootstrap a local test Corda network using a set of node configuration files and CorDapp JARs"]
 )
 class Main : Runnable {
     @Option(
             names = ["--dir"],
             description = [
-                "Root directory containing the node conf files and CorDapp JARs that will form the test network.",
+                "Root directory containing the node configuration files and CorDapp JARs that will form the test network.",
                 "It may also contain existing node directories."
             ]
     )
@@ -47,7 +48,123 @@ class Main : Runnable {
     @Option(names = ["--verbose"], description = ["Enable verbose output."])
     var verbose: Boolean = false
 
+    @Option(names = ["--install-shell-extensions"], description = ["Install bootstrapper alias and autocompletion for bash and zsh"])
+    var installShellExtensions: Boolean = false
+
+    private class SettingsFile(val filePath: Path) {
+        private val lines: MutableList<String> by lazy { getFileLines() }
+        var fileModified: Boolean = false
+
+        // Return the lines in the file if it exists, else return an empty mutable list
+        private fun getFileLines(): MutableList<String> {
+            return if (filePath.exists()) {
+                filePath.toFile().readLines().toMutableList()
+            } else {
+                emptyList<String>().toMutableList()
+            }
+        }
+
+        fun addOrReplaceIfStartsWith(startsWith: String, replaceWith: String) {
+            val index = lines.indexOfFirst { it.startsWith(startsWith) }
+            if (index >= 0) {
+                if (lines[index] != replaceWith) {
+                    lines[index] = replaceWith
+                    fileModified = true
+                }
+            } else {
+                lines.add(replaceWith)
+                fileModified = true
+            }
+        }
+
+        fun addIfNotExists(line: String) {
+            if (!lines.contains(line)) {
+                lines.add(line)
+                fileModified = true
+            }
+        }
+
+        fun updateAndBackupIfNecessary() {
+            if (fileModified) {
+                val backupFilePath = filePath.parent / "${filePath.fileName}.backup"
+                println("Updating settings in ${filePath.fileName} - existing settings file has been backed up to $backupFilePath")
+                if (filePath.exists()) filePath.copyTo(backupFilePath, REPLACE_EXISTING)
+                filePath.writeLines(lines)
+            }
+        }
+    }
+
+    private val userHome: Path by lazy { Paths.get(System.getProperty("user.home")) }
+    private val jarLocation: Path by lazy { this.javaClass.location.toPath() }
+
+    // If on Windows, Path.toString() returns a path with \ instead of /, but for bash Windows users we want to convert those back to /'s
+    private fun Path.toStringWithDeWindowsfication(): String = this.toAbsolutePath().toString().replace("\\", "/")
+    private fun jarVersion(alias: String) = "# $alias - Version: ${CordaVersionProvider.releaseVersion}, Revision: ${CordaVersionProvider.revision}"
+    private fun getAutoCompleteFileLocation(alias: String) = userHome / ".completion" / alias
+
+    private fun generateAutoCompleteFile(alias: String) {
+        println("Generating $alias auto completion file")
+        val autoCompleteFile = getAutoCompleteFileLocation(alias)
+        autoCompleteFile.parent.createDirectories()
+        picocli.AutoComplete.main("-f", "-n", alias, this.javaClass.name, "-o", autoCompleteFile.toStringWithDeWindowsfication())
+
+        // Append hash of file to autocomplete file
+        autoCompleteFile.toFile().appendText(jarVersion(alias))
+    }
+
+    private fun installShellExtensions(alias: String) {
+        // Get jar location and generate alias command
+        val command = "alias $alias='java -jar \"${jarLocation.toStringWithDeWindowsfication()}\"'"
+        generateAutoCompleteFile(alias)
+
+        // Get bash settings file
+        val bashSettingsFile = SettingsFile(userHome / ".bashrc")
+        // Replace any existing bootstrapper alias. There can be only one.
+        bashSettingsFile.addOrReplaceIfStartsWith("alias $alias", command)
+        val completionFileCommand = "for bcfile in ~/.completion/* ; do . \$bcfile; done"
+        bashSettingsFile.addIfNotExists(completionFileCommand)
+        bashSettingsFile.updateAndBackupIfNecessary()
+
+        // Get zsh settings file
+        val zshSettingsFile = SettingsFile(userHome / ".zshrc")
+        zshSettingsFile.addIfNotExists("autoload -U +X compinit && compinit")
+        zshSettingsFile.addIfNotExists("autoload -U +X bashcompinit && bashcompinit")
+        zshSettingsFile.addOrReplaceIfStartsWith("alias $alias", command)
+        zshSettingsFile.addIfNotExists(completionFileCommand)
+        zshSettingsFile.updateAndBackupIfNecessary()
+
+        println("Installation complete, $alias is available in bash with autocompletion. ")
+        println("Type `$alias <options>` from the commandline.")
+        println("Restart bash for this to take effect, or run `. ~/.bashrc` in bash or `. ~/.zshrc` in zsh to re-initialise your shell now")
+    }
+
+    private fun checkForAutoCompleteUpdate(alias: String) {
+        val autoCompleteFile = getAutoCompleteFileLocation(alias)
+
+        // If no autocomplete file, it hasn't been installed, so don't do anything
+        if (!autoCompleteFile.exists()) return
+
+        var lastLine = ""
+        autoCompleteFile.toFile().forEachLine { lastLine = it }
+
+        if (lastLine != jarVersion(alias)) {
+            println("Old auto completion file detected... regenerating")
+            generateAutoCompleteFile(alias)
+            println("Restart bash for this to take effect, or run `. ~/.bashrc` to re-initialise bash now")
+        }
+    }
+
+    private fun installOrUpdateShellExtensions(alias: String) {
+        if (installShellExtensions) {
+            installShellExtensions(alias)
+            exitProcess(0)
+        } else {
+            checkForAutoCompleteUpdate(alias)
+        }
+    }
+
     override fun run() {
+        installOrUpdateShellExtensions("bootstrapper")
         if (verbose) {
             System.setProperty("logLevel", "trace")
         }
@@ -56,10 +173,15 @@ class Main : Runnable {
 }
 
 private class CordaVersionProvider : IVersionProvider {
+    companion object {
+        val releaseVersion: String by lazy { Manifests.read("Corda-Release-Version") }
+        val revision: String by lazy { Manifests.read("Corda-Revision") }
+    }
+
     override fun getVersion(): Array<String> {
         return arrayOf(
-                "Version: ${Manifests.read("Corda-Release-Version")}",
-                "Revision: ${Manifests.read("Corda-Revision")}"
+                "Version: $releaseVersion",
+                "Revision: $revision"
         )
     }
 }