package main

import (
	"bytes"
	"log"
	"os"

	"github.com/boltdb/bolt"
	"github.com/codegangsta/cli"
)

func main() {
	log.SetFlags(0)
	NewApp().Run(os.Args)
}

// NewApp creates an Application instance.
func NewApp() *cli.App {
	app := cli.NewApp()
	app.Name = "bolt"
	app.Usage = "BoltDB toolkit"
	app.Commands = []cli.Command{
		{
			Name:   "get",
			Usage:  "retrieve a value for given key",
			Action: Get,
		},
	}
	return app
}

// Get retrieves the value for a given bucket/key.
func Get(c *cli.Context) {
	path, name, key := c.Args().Get(0), c.Args().Get(1), c.Args().Get(2)
	if _, err := os.Stat(path); os.IsNotExist(err) {
		fatal(err)
		return
	}

	db, err := bolt.Open(path, 0600)
	if err != nil {
		fatal(err)
		return
	}
	defer db.Close()

	err = db.With(func(tx *bolt.Tx) error {
		// Find bucket.
		b := tx.Bucket(name)
		if b == nil {
			fatalf("bucket not found: %s", name)
			return nil
		}

		// Find value for a given key.
		value := b.Get([]byte(key))
		if value == nil {
			fatalf("key not found: %s", key)
			return nil
		}

		logger.Println(string(value))
		return nil
	})
	if err != nil {
		fatal(err)
		return
	}
}

var logger = log.New(os.Stderr, "", 0)
var logBuffer *bytes.Buffer

func fatal(v ...interface{}) {
	logger.Print(v...)
	if !testMode {
		os.Exit(1)
	}
}

func fatalf(format string, v ...interface{}) {
	logger.Printf(format, v...)
	if !testMode {
		os.Exit(1)
	}
}

func fatalln(v ...interface{}) {
	logger.Println(v...)
	if !testMode {
		os.Exit(1)
	}
}

// LogBuffer returns the contents of the log.
// This only works while the CLI is in test mode.
func LogBuffer() string {
	if logBuffer != nil {
		return logBuffer.String()
	}
	return ""
}

var testMode bool

// SetTestMode sets whether the CLI is running in test mode and resets the logger.
func SetTestMode(value bool) {
	testMode = value
	if testMode {
		logBuffer = bytes.NewBuffer(nil)
		logger = log.New(logBuffer, "", 0)
	} else {
		logger = log.New(os.Stderr, "", 0)
	}
}