Move things around, support subcommand help

6 files changed, 118 insertions, 80 deletions

diff --git a/cli/context.go b/cli/context.go
index c109281..ce82b17 100644
--- a/cli/context.go
+++ b/cli/context.go
@@ -14,10 +14,6 @@ func (self Context) Handlers() []*Handler {
     return self.handlers
 }
 
-func (self Context) FilterHandlers(prefix string) []*Handler {
-    return filterHandlers(self.handlers, prefix)
-}
-
 type Arguments map[string]interface{}
 
 func (self Arguments) String(key string) string {
diff --git a/cli/handler.go b/cli/handler.go
index 5cd13f8..a4aafef 100644
--- a/cli/handler.go
+++ b/cli/handler.go
@@ -20,7 +20,7 @@ type Handler struct {
 func (self *Handler) getParser() Parser {
     var parsers []Parser
 
-    for _, pattern := range splitPattern(self.Pattern) {
+    for _, pattern := range self.SplitPattern() {
         if isOptional(pattern) {
             name := optionalName(pattern)
             parser := getFlagParser(self.Flags[name])
@@ -35,6 +35,18 @@ func (self *Handler) getParser() Parser {
     return CompleteParser{parsers}
 }
 
+// Split on spaces but ignore spaces inside <...> and [...]
+func (self *Handler) SplitPattern() []string {
+    re := regexp.MustCompile(`(<[^>]+>|\[[^\]]+]|\S+)`)
+    matches := []string{}
+
+    for _, value := range re.FindAllStringSubmatch(self.Pattern, -1) {
+        matches = append(matches, value[1])
+    }
+
+    return matches
+}
+
 func SetHandlers(h []*Handler) {
     handlers = h
 }
@@ -74,32 +86,6 @@ func Handle(args []string) bool {
     return true
 }
 
-func filterHandlers(handlers []*Handler, prefix string) []*Handler {
-    matches := []*Handler{}
-
-    for _, h := range handlers {
-        pattern := strings.Join(stripOptionals(splitPattern(h.Pattern)), " ")
-        if strings.HasPrefix(pattern, prefix) {
-            matches = append(matches, h)
-        }
-    }
-
-    return matches
-}
-
-
-// Split on spaces but ignore spaces inside <...> and [...]
-func splitPattern(pattern string) []string {
-    re := regexp.MustCompile(`(<[^>]+>|\[[^\]]+]|\S+)`)
-    matches := []string{}
-
-    for _, value := range re.FindAllStringSubmatch(pattern, -1) {
-        matches = append(matches, value[1]) 
-    }
-
-    return matches
-}
-
 func isCaptureGroup(arg string) bool {
     return strings.HasPrefix(arg, "<") && strings.HasSuffix(arg, ">")
 }
@@ -111,15 +97,3 @@ func isOptional(arg string) bool {
 func optionalName(s string) string {
     return s[1:len(s) - 1]
 }
-
-// Strip optional groups from pattern
-func stripOptionals(pattern []string) []string {
-    newArgs := []string{}
-
-    for _, arg := range pattern {
-        if !isOptional(arg) {
-            newArgs = append(newArgs, arg)
-        }
-    }
-    return newArgs
-}
diff --git a/gdrive.go b/gdrive.go
index 78b168a..f20f9f3 100644
--- a/gdrive.go
+++ b/gdrive.go
@@ -339,10 +339,15 @@ func main() {
             Callback: printHelp,
         },
         &cli.Handler{
-            Pattern: "help <subcommand>",
-            Description: "Print subcommand help",
+            Pattern: "help <command>",
+            Description: "Print command help",
             Callback: printCommandHelp,
         },
+        &cli.Handler{
+            Pattern: "help <command> <subcommand>",
+            Description: "Print subcommand help",
+            Callback: printSubCommandHelp,
+        },
     }
 
     cli.SetHandlers(handlers)
diff --git a/handlers.go b/handlers_drive.go
index 5e681ab..21bf5f7 100644
--- a/handlers.go
+++ b/handlers_drive.go
@@ -3,7 +3,6 @@ package main
 import (
 	"fmt"
 	"os"
-	"strings"
     "./cli"
 	"./auth"
 	"./drive"
@@ -142,40 +141,6 @@ func aboutHandler(ctx cli.Context) {
     checkErr(err)
 }
 
-func printVersion(ctx cli.Context) {
-    fmt.Printf("%s v%s\n", Name, Version)
-}
-
-func printHelp(ctx cli.Context) {
-    fmt.Printf("%s usage:\n\n", Name)
-
-    for _, h := range ctx.Handlers() {
-        fmt.Printf("%s %s  (%s)\n", Name, h.Pattern, h.Description)
-    }
-}
-
-func printCommandHelp(ctx cli.Context) {
-    handlers := ctx.FilterHandlers(ctx.Args().String("subcommand"))
-
-    if len(handlers) == 0 {
-        ExitF("Subcommand not found")
-    }
-
-    if len(handlers) > 1 {
-        ExitF("More than one matching subcommand, be more specific")
-    }
-
-    handler := handlers[0]
-
-    fmt.Printf("%s %s  (%s)\n", Name, handler.Pattern, handler.Description)
-    for name, flags := range handler.Flags {
-        fmt.Printf("\n%s:\n", name)
-        for _, flag := range flags {
-            fmt.Printf("  %s  (%s)\n", strings.Join(flag.GetPatterns(), ", "), flag.GetDescription())
-        }
-    }
-}
-
 func newDrive(args cli.Arguments) *drive.Drive {
     configDir := args.String("configDir")
     tokenPath := ConfigFilePath(configDir, TokenFilename)
diff --git a/handlers_meta.go b/handlers_meta.go
new file mode 100644
index 0000000..f0f7ef7
--- /dev/null
+++ b/handlers_meta.go
@@ -0,0 +1,76 @@
+package main
+
+import (
+	"fmt"
+	"strings"
+    "./cli"
+)
+
+func printVersion(ctx cli.Context) {
+    fmt.Printf("%s v%s\n", Name, Version)
+}
+
+func printHelp(ctx cli.Context) {
+    fmt.Printf("%s usage:\n\n", Name)
+
+    for _, h := range ctx.Handlers() {
+        fmt.Printf("%s %s  (%s)\n", Name, h.Pattern, h.Description)
+    }
+}
+
+func printCommandHelp(ctx cli.Context) {
+    args := ctx.Args()
+    prefix := []string{args.String("command")}
+    printCommandPrefixHelp(prefix, ctx)
+}
+
+func printSubCommandHelp(ctx cli.Context) {
+    args := ctx.Args()
+    prefix := []string{args.String("command"), args.String("subcommand")}
+    printCommandPrefixHelp(prefix, ctx)
+}
+
+func printCommandPrefixHelp(prefix []string, ctx cli.Context) {
+    handler := getHandler(ctx.Handlers(), prefix)
+
+    if handler == nil {
+        ExitF("Command not found")
+    }
+
+    fmt.Printf("%s %s  (%s)\n", Name, handler.Pattern, handler.Description)
+    for name, flags := range handler.Flags {
+        fmt.Printf("\n%s:\n", name)
+        for _, flag := range flags {
+            fmt.Printf("  %s  (%s)\n", strings.Join(flag.GetPatterns(), ", "), flag.GetDescription())
+        }
+    }
+}
+
+func getHandler(handlers []*cli.Handler, prefix []string) *cli.Handler {
+    for _, h := range handlers {
+        pattern := stripOptionals(h.SplitPattern())
+
+        if len(prefix) > len(pattern) {
+            continue
+        }
+
+        if equal(prefix, pattern[:len(prefix)]) {
+            return h
+        }
+    }
+
+    return nil
+}
+
+// Strip optional groups (<...>) from pattern
+func stripOptionals(pattern []string) []string {
+    newArgs := []string{}
+
+    for _, arg := range pattern {
+        if strings.HasPrefix(arg, "[") && strings.HasSuffix(arg, "]") {
+            continue
+        }
+        newArgs = append(newArgs, arg)
+    }
+    return newArgs
+}
diff --git a/util.go b/util.go
index 4416696..d40d33e 100644
--- a/util.go
+++ b/util.go
@@ -22,6 +22,28 @@ func Homedir() string {
 	return os.Getenv("HOME")
 }
 
+func equal(a, b []string) bool {
+    if a == nil && b == nil {
+        return true;
+    }
+
+    if a == nil || b == nil {
+        return false;
+    }
+
+    if len(a) != len(b) {
+        return false
+    }
+
+    for i := range a {
+        if a[i] != b[i] {
+            return false
+        }
+    }
+
+    return true
+}
+
 func ExitF(format string, a ...interface{}) {
 	fmt.Fprintf(os.Stderr, format, a...)
 	fmt.Println("")