From cc15f832d3b41e0a454721b3df4b65627f55ee93 Mon Sep 17 00:00:00 2001
From: Kirill Zaitsev <kirik910@gmail.com>
Date: Sun, 20 Mar 2016 20:55:38 +0300
Subject: [PATCH] Added grvm hook on CD

---
 grvm.go      |  6 +++++
 hook.go      | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 scripts/grvm |  6 +++++
 3 files changed, 78 insertions(+)
 create mode 100644 hook.go

diff --git a/grvm.go b/grvm.go
index f591100..10f114c 100644
--- a/grvm.go
+++ b/grvm.go
@@ -99,6 +99,12 @@ func main() {
 			Usage:   "Get upgrade information",
 			Action:  GetUpgrade,
 		},
+		{
+			Name:    "hook",
+			Aliases: []string{"h"},
+			Usage:   "Hook to read Gemfile",
+			Action:  GetHook,
+		},
 	}
 
 	app.Run(os.Args)
diff --git a/hook.go b/hook.go
new file mode 100644
index 0000000..842a203
--- /dev/null
+++ b/hook.go
@@ -0,0 +1,66 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"regexp"
+
+	"github.com/codegangsta/cli"
+)
+
+var gemfileRegexp = regexp.MustCompile(`^(\s*|)ruby\s*("|')(?P<version>.*)("|')(\s|)$`)
+
+func GetHook(c *cli.Context) {
+	var candidate string
+
+	db, err := getDB()
+	if err != nil {
+		Print(c, "Cannot open database file:", dbPath)
+		os.Exit(1)
+	}
+	defer db.Close()
+
+	tx, err := db.Begin(false)
+	if err != nil {
+		Print(c, err.Error())
+		os.Exit(1)
+	}
+	defer tx.Rollback()
+
+	dir, err := os.Getwd()
+	if err != nil {
+		Print(c, err.Error())
+		os.Exit(1)
+	}
+
+	gemfilePath := fmt.Sprintf("%s/%s", dir, "Gemfile")
+	if _, err := os.Stat(fmt.Sprintf("%s/%s", dir, "Gemfile")); err == nil {
+		file, err := os.Open(gemfilePath)
+		if err != nil {
+			Print(c, err.Error())
+			os.Exit(1)
+		}
+		defer file.Close()
+
+		scanner := bufio.NewScanner(file)
+		for scanner.Scan() {
+			scanResult := gemfileRegexp.FindStringSubmatch(scanner.Text())
+			if len(scanResult) > 3 && len(scanResult[3]) > 0 {
+				candidate = scanResult[3]
+				break
+			}
+		}
+
+		if len(candidate) > 0 {
+			if err := checkCandidate(tx, candidate); err != nil {
+				Print(c, err.Error())
+				os.Exit(1)
+			}
+
+			printEnv(candidate)
+		}
+	}
+
+	tx.Commit()
+}
diff --git a/scripts/grvm b/scripts/grvm
index 2c3fc9f..2a82598 100755
--- a/scripts/grvm
+++ b/scripts/grvm
@@ -42,6 +42,12 @@ function __grvmFn {
 	esac
 }
 
+function cd {
+	builtin cd $*
+	arg=`$HOME/.grvm/bin/grvm -s hook`
+	__grvmEval $arg
+}
+
 alias grvm=__grvmFn
 
 __grvmFn init