From 6011123ab16a4d1b329e51c32cb51ba338a2edc0 Mon Sep 17 00:00:00 2001
From: Lukas SP <kbrt@protonmail.com>
Date: Sun, 23 Aug 2020 00:06:29 +0200
Subject: [PATCH] Implement file storage driver

---
 cmd/pasty/main.go               | 23 ++++++++++-
 internal/storage/driver.go      | 38 ++++++++++++++++++
 internal/storage/file_driver.go | 69 +++++++++++++++++++++++++++++++++
 internal/storage/storage.go     | 14 -------
 4 files changed, 129 insertions(+), 15 deletions(-)
 create mode 100644 internal/storage/driver.go
 create mode 100644 internal/storage/file_driver.go
 delete mode 100644 internal/storage/storage.go

diff --git a/cmd/pasty/main.go b/cmd/pasty/main.go
index 7a3bb74..94d38dc 100644
--- a/cmd/pasty/main.go
+++ b/cmd/pasty/main.go
@@ -1,8 +1,29 @@
 package main
 
-import "github.com/Lukaesebrot/pasty/internal/env"
+import (
+	"github.com/Lukaesebrot/pasty/internal/env"
+	"github.com/Lukaesebrot/pasty/internal/storage"
+	"log"
+	"os"
+	"os/signal"
+	"syscall"
+)
 
 func main() {
 	// Load the optional .env file
+	log.Println("Loading the optional .env file...")
 	env.Load()
+
+	// Load the configured storage driver
+	log.Println("Loading the configured storage driver...")
+	err := storage.Load()
+	if err != nil {
+		panic(err)
+	}
+
+	// Wait for the program to exit
+	// TODO: Replace this through blocking API server
+	sc := make(chan os.Signal, 1)
+	signal.Notify(sc, syscall.SIGINT, syscall.SIGTERM, os.Interrupt, os.Kill)
+	<-sc
 }
diff --git a/internal/storage/driver.go b/internal/storage/driver.go
new file mode 100644
index 0000000..014c725
--- /dev/null
+++ b/internal/storage/driver.go
@@ -0,0 +1,38 @@
+package storage
+
+import (
+	"fmt"
+	"github.com/Lukaesebrot/pasty/internal/env"
+	"github.com/Lukaesebrot/pasty/internal/pastes"
+	"github.com/bwmarrin/snowflake"
+	"strings"
+)
+
+// Current holds the current storage driver
+var Current Driver
+
+// Driver represents a storage driver
+type Driver interface {
+	Initialize() error
+	Terminate() error
+	Get(id snowflake.ID) (*pastes.Paste, error)
+	Save(paste *pastes.Paste) error
+	Delete(id snowflake.ID) error
+}
+
+// Load loads the current storage driver
+func Load() error {
+	storageType := strings.ToLower(env.Get("STORAGE_TYPE", "file"))
+	switch storageType {
+	case "file":
+		driver := new(FileDriver)
+		err := driver.Initialize()
+		if err != nil {
+			return err
+		}
+		Current = driver
+		return nil
+	default:
+		return fmt.Errorf("invalid storage type '%s'", storageType)
+	}
+}
diff --git a/internal/storage/file_driver.go b/internal/storage/file_driver.go
new file mode 100644
index 0000000..310af97
--- /dev/null
+++ b/internal/storage/file_driver.go
@@ -0,0 +1,69 @@
+package storage
+
+import (
+	"encoding/json"
+	"github.com/Lukaesebrot/pasty/internal/env"
+	"github.com/Lukaesebrot/pasty/internal/pastes"
+	"github.com/bwmarrin/snowflake"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+)
+
+// FileDriver represents the file storage driver
+type FileDriver struct {
+	FilePath string
+}
+
+// Initialize initializes the file storage driver
+func (driver *FileDriver) Initialize() error {
+	driver.FilePath = env.Get("STORAGE_FILE_PATH", "./data")
+	return os.MkdirAll(driver.FilePath, os.ModePerm)
+}
+
+// Terminate terminates the file storage driver (does nothing, because the file storage driver does not need any termination)
+func (driver *FileDriver) Terminate() error {
+	return nil
+}
+
+// Get loads a paste out of a file
+func (driver *FileDriver) Get(id snowflake.ID) (*pastes.Paste, error) {
+	// Read the file
+	data, err := ioutil.ReadFile(filepath.Join(driver.FilePath, id.String()+".json"))
+	if err != nil {
+		return nil, err
+	}
+
+	// Unmarshal the file into a paste
+	paste := new(pastes.Paste)
+	err = json.Unmarshal(data, &paste)
+	if err != nil {
+		return nil, err
+	}
+	return paste, nil
+}
+
+// Save saves a paste into a file
+func (driver *FileDriver) Save(paste *pastes.Paste) error {
+	// Marshal the paste
+	jsonBytes, err := json.Marshal(paste)
+	if err != nil {
+		return err
+	}
+
+	// Create the file to save the paste to
+	file, err := os.Create(filepath.Join(driver.FilePath, paste.ID.String()+".json"))
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	// Write the JSON data into the file
+	_, err = file.Write(jsonBytes)
+	return err
+}
+
+// Delete deletes a paste
+func (driver *FileDriver) Delete(id snowflake.ID) error {
+	return os.Remove(filepath.Join(driver.FilePath, id.String()+".json"))
+}
diff --git a/internal/storage/storage.go b/internal/storage/storage.go
deleted file mode 100644
index 4b6d448..0000000
--- a/internal/storage/storage.go
+++ /dev/null
@@ -1,14 +0,0 @@
-package storage
-
-import (
-	"github.com/Lukaesebrot/pasty/internal/pastes"
-	"github.com/bwmarrin/snowflake"
-)
-
-// Storage represents a storage type
-type Storage interface {
-	initialize() error
-	get(id snowflake.ID) (*pastes.Paste, error)
-	save(paste *pastes.Paste) error
-	delete(id snowflake.ID) error
-}