Add REPL launcher for Windows

scripts/datajure.ps1

@@ -0,0 +1,123 @@
+$ErrorActionPreference = "Stop"
+
+function Print-Help {
+    Write-Output "Downloads the latest release of Datajure REPL if it is not found."
+    Write-Output "Runs the Datajure REPL + starts an nREPL server with an .nrepl-port file."
+    Write-Output "Usage:"
+    Write-Output "`tdatajure [<path>] [--force-download] [--proxy <https-proxy>] [--help]"
+    Write-Output "The optional input file should be a Datajure source file (.dtj suffix)."
+}
+
+$ScriptPath = $false
+$ForceDownload = $false
+$UseProxy = $false
+$HttpsProxy = $false
+for ($i = 0; $i -lt $args.count;) {
+    $Key = $args[$i]
+    switch -Wildcard ($Key) {
+        "*.dtj" {
+            $ScriptPath = $Key
+            $i++
+        }
+        "--force-download" {
+            $ForceDownload = $true
+            $i++
+        }
+        "--proxy" {
+            $UseProxy = $true
+            $i++
+            if ($i -ge $args.count) {
+                Write-Output "Missing proxy server address!"
+                Print-Help
+                Exit 1
+            }
+            HttpsProxy = $aegs[$i]
+            $i++
+        }
+        "--help" {
+            Print-Help
+            Exit 0
+        }
+        Default {
+            Write-Output "Unrecognised option!"
+            Print-Help
+            Exit 1
+        }
+    }
+}
+
+function Get-LatestRelease($RepoName) {
+    if ($UseProxy) {
+        (Invoke-WebRequest "https://api.github.com/repos/$RepoName/releases/latest" -Proxy "$HttpsProxy").Content | ConvertFrom-Json | Select-Object -expand "tag_name"
+    } else {
+        (Invoke-WebRequest "https://api.github.com/repos/$RepoName/releases/latest").Content | ConvertFrom-Json | Select-Object -expand "tag_name"
+    }
+}
+
+$RepoName = "clojure-finance/datajure"
+$Version = get-LatestRelease($RepoName)
+$OriginalDir = Get-Location | Foreach-Object { $_.Path }
+$DatajureDir = "$HOME\.datajure"
+$DownloadDir = "$DatajureDir\downloads"
+$UberjarDownloadUrl = "https://github.com/$RepoName/releases/download/$Version/datajure-$Version-standalone.jar"
+$WinutilsDownloadUrl = "https://github.com/cdarlint/winutils/raw/master/hadoop-3.3.5/bin/winutils.exe"
+$UberjarName = "datajure.jar"
+$WinutilsName = "winutils.exe"
+$JvmOpts = @(
+    "-Dhadoop.home.dir=$DatajureDir"
+    "--add-opens=java.base/java.nio=ALL-UNNAMED"
+    "--add-opens=java.base/java.net=ALL-UNNAMED"
+    "--add-opens=java.base/java.lang=ALL-UNNAMED"
+    "--add-opens=java.base/java.util=ALL-UNNAMED"
+    "--add-opens=java.base/java.util.concurrent=ALL-UNNAMED"
+    "--add-opens=java.base/sun.nio.ch=ALL-UNNAMED"
+) -join " "
+
+if (!(Test-Path $DatajureDir -PathType Container)) {
+    New-Item $DatajureDir -ItemType Directory
+}
+Set-Location -Path $DatajureDir
+# download uberjar
+if (!(Test-Path $UberjarName -PathType Leaf) -or $ForceDownload) {
+    if (!(Test-Path $DownloadDir -PathType Container)) {
+        New-Item $DownloadDir -ItemType Directory
+    }
+    Set-Location -Path $DownloadDir
+    if ($UseProxy) {
+        Write-Output "Downloading $UberjarDownloadUrl to $DownloadDir via proxy server $HttpsProxy ..."
+        Invoke-WebRequest -OutFile $UberjarName -Uri $UberjarDownloadUrl -Proxy "$HttpsProxy"
+    } else {
+        Write-Output "Downloading $UberjarDownloadUrl to $DownloadDir ..."
+        Invoke-WebRequest -OutFile $UberjarName -Uri $UberjarDownloadUrl
+    }
+    Write-Output "Moving $DownloadDir\$UberjarName to $DatajureDir\$UberjarName"
+    Move-Item -Path "$UberjarName" -Destination "$DatajureDir\$UberjarName"
+    Write-Output "Successfully downloaded Datajure REPL uberjar in $DatajureDir\$UberjarName"
+}
+# download winutils
+if (!(Test-Path "bin\$WinutilsName" -PathType Leaf) -or $ForceDownload) {
+    if (!(Test-Path $DownloadDir -PathType Container)) {
+        New-Item $DownloadDir -ItemType Directory
+    }
+    Set-Location -Path $DownloadDir
+    if ($UseProxy) {
+        Write-Output "Downloading $WinutilsDownloadUrl to $DownloadDir via proxy server $HttpsProxy ..."
+        Invoke-WebRequest -OutFile $WinutilsName -Uri $WinutilsDownloadUrl -Proxy "$HttpsProxy"
+    } else {
+        Write-Output "Downloading $WinutilsDownloadUrl to $DownloadDir ..."
+        Invoke-WebRequest -OutFile $WinutilsName -Uri $WinutilsDownloadUrl
+    }
+    if (!(Test-Path "$DatajureDir\bin" -PathType Container)) {
+        New-Item "$DatajureDir\bin" -ItemType Directory
+    }
+    Write-Output "Moving $DownloadDir\$WinutilsName to $DatajureDir\bin\$WinutilsName"
+    Move-Item -Path "$WinutilsName" -Destination "$DatajureDir\bin\$WinutilsName"
+    Write-Output "Successfully downloaded Hadoop Windows Utilities in $DatajureDir\bin\$WinutilsName"
+}
+
+Set-Location -Path $OriginalDir
+if (!$ScriptPath) {
+    cmd.exe /c "java $JvmOpts -jar $DatajureDir\$UberjarName"
+} else {
+    cmd.exe /c "java $JvmOpts -jar $DatajureDir\$UberjarName $ScriptPath"
+}