Implemented tag querying for git. Ref #18.

download.nim

@@ -36,12 +36,14 @@ proc doPull(meth: TDownloadMethod, downloadDir: string) =
     cd downloadDir:
       doCmd("hg pull")
 
-proc doClone(meth: TDownloadMethod, url, downloadDir: string) =
+proc doClone(meth: TDownloadMethod, url, downloadDir: string, branch = "") =
+  let branchArg = if branch == "": "" else: "-b " & branch & " "
   case meth
   of TDownloadMethod.Git:
-    doCmd("git clone --depth 1 " & url & " " & downloadDir)
+    # TODO: Get rid of the annoying 'detached HEAD' message somehow?
+    doCmd("git clone --depth 1 " & branchArg & url & " " & downloadDir)
   of TDownloadMethod.Hg:
-    doCmd("hg clone -r tip " & url & " " & downloadDir)
+    doCmd("hg clone -r tip " & branchArg & url & " " & downloadDir)
 
 proc getTagsList(dir: string, meth: TDownloadMethod): seq[string] =
   cd dir:
@@ -65,11 +67,24 @@ proc getTagsList(dir: string, meth: TDownloadMethod): seq[string] =
   else:
     result = @[]
 
-proc getVersionList(dir: string,
-                    meth: TDownloadMethod): TTable[TVersion, string] =
+proc getTagsListRemote(url: string, meth: TDownloadMethod): seq[string] =
+  result = @[]
+  case meth
+  of TDownloadMethod.Git:
+    var output = execProcess("git ls-remote --tags " & url)
+    for i in output.splitLines():
+      if i == "": continue
+      let start = i.find("refs/tags/")+"refs/tags/".len
+      let tag = i[start .. -1]
+      if not tag.endswith("^{}"): result.add(tag)
+    
+  of TDownloadMethod.Hg:
+    # http://stackoverflow.com/questions/2039150/show-tags-for-remote-hg-repository
+    raise newException(EInvalidValue, "Hg doesn't support remote tag querying.")
+  
+proc getVersionList(tags: seq[string]): TTable[TVersion, string] =
   # Returns: TTable of version -> git tag name
   result = initTable[TVersion, string]()
-  let tags = getTagsList(dir, meth)
   for tag in tags:
     let i = skipUntil(tag, digits) # skip any chars before the version
     # TODO: Better checking, tags can have any names. Add warnings and such.
@@ -84,34 +99,52 @@ proc getDownloadMethod(meth: string): TDownloadMethod =
 
 proc doDownload*(pkg: TPackage, downloadDir: string, verRange: PVersionRange) =
   let downMethod = pkg.downloadMethod.getDownloadMethod()
-  echo "Executing ", downMethod, "..."
+  echo "Downloading ", pkg.name, " using ", downMethod, "..."
   
-  if existsDir(downloadDir / getSpecificDir(downMethod)):
-    doPull(downMethod, downloadDir)
-  else:
+  case downMethod
+  of TDownloadMethod.Git:
+    # For Git we have to query the repo remotely for its tags. This is
+    # necessary as cloning with a --depth of 1 removes all tag info.
+    let versions = getTagsListRemote(pkg.url, downMethod).getVersionList()
+    if versions.len > 0:
+      echo("Found tags...")
+      var latest = findLatest(verRange, versions)
+      ## Note: HEAD is not used when verRange.kind is verAny. This is
+      ## intended behaviour, the latest tagged version will be used in this case.
+      if latest.tag != "":
+        echo("Cloning latest tagged version: ", latest.tag)
+        removeDir(downloadDir)
+        doClone(downMethod, pkg.url, downloadDir, latest.tag)
+    else:
+      # If no commits have been tagged on the repo we just clone HEAD.
+      removeDir(downloadDir)
+      doClone(downMethod, pkg.url, downloadDir) # Grab HEAD.
+      if verRange.kind != verAny:
+        # Make sure that HEAD satisfies the requested version range.
+        let pkginfo = getPkgInfo(downloadDir)
+        if pkginfo.version.newVersion notin verRange:
+          raise newException(EBabel,
+                "No versions of " & pkg.name &
+                " exist (this usually means that `git tag` returned nothing)." &
+                "Git HEAD also does not satisfy version range: " & $verRange)
+  of TDownloadMethod.Hg:
     removeDir(downloadDir)
     doClone(downMethod, pkg.url, downloadDir)
+    let versions = getTagsList(downloadDir, downMethod).getVersionList()
   
-  # TODO: Determine if version is a commit hash, if it is. Move the
-  # git repo to ``babelDir/pkgs``, then babel can simply checkout
-  # the correct hash instead of constantly cloning and copying.
-  # N.B. This may still partly be required, as one lib may require hash A
-  # whereas another lib requires hash B and they are both required by the
-  # project you want to build.
-  let versions = getVersionList(downloadDir, downMethod)
-  if versions.len > 0:
-    echo("Found tags...")
-    var latest = findLatest(verRange, versions)
-    ## Note: HEAD is not used when verRange.kind is verAny. This is
-    ## intended behaviour, the latest tagged version will be used in this case.
-    if latest.tag != "":
-      echo("Switching to latest tagged version: ", latest.tag)
-      doCheckout(downMethod, downloadDir, latest.tag)
-  elif verRange.kind != verAny:
-    let pkginfo = getPkgInfo(downloadDir)
-    if pkginfo.version.newVersion notin verRange:
-      raise newException(EBabel,
-            "No versions of " & pkg.name &
-            " exist (this usually means that `git tag` returned nothing)." &
-            "Git HEAD also does not satisfy version range: " & $verRange)
-    # We use GIT HEAD if it satisfies our ver range
+    if versions.len > 0:
+      echo("Found tags...")
+      var latest = findLatest(verRange, versions)
+      ## Note: HEAD is not used when verRange.kind is verAny. This is
+      ## intended behaviour, the latest tagged version will be used in this case.
+      if latest.tag != "":
+        echo("Switching to latest tagged version: ", latest.tag)
+        doCheckout(downMethod, downloadDir, latest.tag)
+    elif verRange.kind != verAny:
+      let pkginfo = getPkgInfo(downloadDir)
+      if pkginfo.version.newVersion notin verRange:
+        raise newException(EBabel,
+              "No versions of " & pkg.name &
+              " exist (this usually means that `git tag` returned nothing)." &
+              "Git HEAD also does not satisfy version range: " & $verRange)
+      # We use GIT HEAD if it satisfies our ver range