Fix #28 - add ~/.nimble/bin to PATH on Windows (#164)

* Fix #28 - add ~/.nimble/bin to PATH on Windows

* Minor message changes

* Incorporate feedback

* Fix #28 - add ~/.nimble/bin to PATH on Windows

* Minor message changes

* Windows fixes

* Cleanup

src/choosenim.nim

@@ -9,6 +9,9 @@ from nimblepkg/packageinfo import getNameVersion
 import choosenimpkg/[download, builder, switcher, common, cliparams, versions]
 import choosenimpkg/[utils, channel, telemetry]
 
+when defined(windows):
+  import choosenimpkg/env
+
 proc installVersion(version: Version, params: CliParams) =
   # Install the requested version.
   let path = download(version, params)
@@ -69,6 +72,11 @@ proc choose(params: CliParams) =
     else:
       chooseVersion(params.command, params)
 
+  when defined(windows):
+    # Check and add ~/.nimble/bin to PATH
+    if not isNimbleBinInPath(params) and params.firstInstall:
+      setNimbleBinPath(params)
+
 proc updateSelf(params: CliParams) =
   display("Updating", "choosenim", priority = HighPriority)
 

src/choosenimpkg/builder.nim

@@ -3,7 +3,10 @@ import os, times
 import nimblepkg/[version, cli]
 import nimblepkg/common as nimble_common
 
-import cliparams, download, utils, common, switcher, telemetry
+import cliparams, download, utils, common, telemetry
+
+when defined(windows):
+  import switcher
 
 proc buildFromCSources(params: CliParams) =
   when defined(windows):

src/choosenimpkg/cliparams.nim

@@ -99,13 +99,8 @@ proc getCurrentChannelFile*(params: CliParams): string =
 proc getAnalyticsFile*(params: CliParams): string =
   return params.chooseNimDir / "analytics"
 
-var cpuArch = 0
-
 proc getCpuArch*(): int =
   ## Get CPU arch on Windows - get env var PROCESSOR_ARCHITECTURE
-  if cpuArch != 0:
-    return cpuArch
-
   var failMsg = ""
 
   let
@@ -128,9 +123,6 @@ proc getCpuArch*(): int =
     raise newException(ChooseNimError,
       "Could not detect CPU architecture: " & failMsg)
 
-  # Only once
-  cpuArch = result
-
 proc getMingwPath*(params: CliParams): string =
   let arch = getCpuArch()
   return params.getInstallDir() / "mingw" & $arch

src/choosenimpkg/download.nim

@@ -1,4 +1,7 @@
-import httpclient, strutils, os, terminal, times, math, json, uri
+import httpclient, strutils, os, terminal, times, json, uri
+
+when defined(macosx):
+  import math
 
 import nimblepkg/[version, cli]
 when defined(curl):

src/choosenimpkg/env.nim

@@ -0,0 +1,64 @@
+import os, strutils
+
+import nimblepkg/[cli, options]
+
+import cliparams
+
+when defined(windows):
+  # From finish.nim in nim-lang/Nim/tools
+  import registry
+
+  proc tryGetUnicodeValue(path, key: string, handle: HKEY): string =
+    # Get a unicode value from the registry or ""
+    try:
+      result = getUnicodeValue(path, key, handle)
+    except:
+      result = ""
+
+  proc addToPathEnv(path: string) =
+    # Append path to user PATH to registry
+    var paths = tryGetUnicodeValue(r"Environment", "Path", HKEY_CURRENT_USER)
+    let path = if path.contains(Whitespace): "\"" & path & "\"" else: path
+    if paths.len > 0:
+      if paths[^1] != PathSep:
+        paths.add PathSep
+      paths.add path
+    else:
+      paths = path
+    setUnicodeValue(r"Environment", "Path", paths, HKEY_CURRENT_USER)
+
+  proc setNimbleBinPath*(params: CliParams) =
+    # Ask the user and add nimble bin to PATH
+    let nimbleDesiredPath = params.getBinDir()
+    if prompt(params.nimbleOptions.forcePrompts,
+              nimbleDesiredPath & " is not in your PATH environment variable.\n" &
+              "            Should it be added permanently?"):
+      addToPathEnv(nimbleDesiredPath)
+      display("Note:", "PATH changes will only take effect in new sessions.",
+              priority = HighPriority)
+  
+  proc isNimbleBinInPath*(params: CliParams): bool =
+    # This proc searches the $PATH variable for the nimble bin directory,
+    # typically ~/.nimble/bin
+    result = false
+    let nimbleDesiredPath = params.getBinDir()
+    when defined(windows):
+      # Getting PATH from registry since it is the ultimate source of
+      # truth and session local $PATH can be changed.
+      let paths = tryGetUnicodeValue(r"Environment", "Path",
+        HKEY_CURRENT_USER) & PathSep & tryGetUnicodeValue(
+        r"System\CurrentControlSet\Control\Session Manager\Environment", "Path",
+        HKEY_LOCAL_MACHINE)
+    else:
+      let paths = getEnv("PATH")
+    for path in paths.split(PathSep):
+      if path.len == 0: continue
+      let path = path.strip(chars = {'"'})
+      let expandedPath =
+        try:
+          expandFilename(path)
+        except:
+          ""
+      if expandedPath.cmpIgnoreCase(nimbleDesiredPath) == 0:
+        result = true
+        break

src/choosenimpkg/switcher.nim

@@ -5,6 +5,9 @@ from nimblepkg/packageinfo import getNameVersion
 
 import cliparams, common
 
+when defined(windows):
+  import env
+
 proc compileProxyexe() =
   var cmd = "nim c"
   when defined(release):
@@ -118,7 +121,13 @@ proc writeProxy(bin: string, params: CliParams) =
   # Don't write the file again if it already exists.
   if fileExists(proxyPath) and readFile(proxyPath) == proxyExe: return
 
-  writeFile(proxyPath, proxyExe)
+  try:
+    writeFile(proxyPath, proxyExe)
+  except IOError:
+    display("Warning:", "component '$1' possibly in use, write failed" % bin, Warning,
+            priority = HighPriority)
+    return
+
   # Make sure the exe has +x flag.
   setFilePermissions(proxyPath,
                      getFilePermissions(proxyPath) + {fpUserExec})
@@ -127,8 +136,13 @@ proc writeProxy(bin: string, params: CliParams) =
   # Check whether this is in the user's PATH.
   let fromPATH = findExe(bin)
   if fromPATH == "" and not params.firstInstall:
-      display("Hint:", "Binary '$1' isn't in your PATH. Add '$2' to your PATH." %
-              [bin, params.getBinDir()], Warning, HighPriority)
+    let msg =
+      when defined(windows):
+        "Binary '$1' isn't in your PATH" % bin
+      else:
+        "Binary '$1' isn't in your PATH. Ensure that '$2' is in your PATH." %
+          [bin, params.getBinDir()]
+    display("Hint:", msg, Warning, HighPriority)
   elif fromPATH != "" and fromPATH != proxyPath:
     display("Warning:", "Binary '$1' is shadowed by '$2'." %
             [bin, fromPATH], Warning, HighPriority)
@@ -181,6 +195,11 @@ proc switchToPath(filepath: string, params: CliParams): bool =
   for proxy in proxiesToInstall:
     writeProxy(proxy, params)
 
+  when defined(windows):
+    if not isNimbleBinInPath(params):
+      display("Hint:", "Use 'choosenim <version/channel> --firstInstall' to add\n" &
+                  "$1 to your PATH." % params.getBinDir(), Warning, HighPriority)
+
 proc switchTo*(version: Version, params: CliParams) =
   ## Switches to the specified version by writing the appropriate proxy
   ## into $nimbleDir/bin.

src/choosenimpkg/utils.nim

@@ -3,7 +3,10 @@ import httpclient, os, strutils, osproc, uri
 import nimblepkg/[cli, version]
 import nimarchive
 
-import switcher, cliparams, common
+import cliparams, common
+
+when defined(windows):
+  import switcher
 
 proc parseVersion*(versionStr: string): Version =
   if versionStr[0] notin {'#', '\0'} + Digits: