Update data path resolution

Makefile

@@ -4,4 +4,4 @@ help: ## display this help
 	@awk 'BEGIN{FS = ":.*##"; printf "\033[1m\nUsage\n \033[1;92m make\033[0;36m <target>\033[0m\n"} /^[a-zA-Z0-9_-]+:.*?##/ { printf "  \033[36m%-15s\033[0m %s\n", $$1, $$2 } ' $(MAKEFILE_LIST)
 
 serve: ## Run "intake serve" with live reload
-	@air -build.cmd "go build -o tmp/intake" -build.bin tmp/intake -build.args_bin serve,--db,tmp/db.sqlite
+	@air -build.cmd "go build -o tmp/intake" -build.bin tmp/intake -build.args_bin serve,--data-dir,tmp

README.md

@@ -72,6 +72,8 @@ When a deactivated item is no longer returned by `fetch`, it is deleted.
 This allows you to consume feed content at your own pace without missing anything.
 
 Intake stores all its data in a SQLite database.
+This database is stored in `$INTAKE_DATA_DIR`, `$XDG_DATA_HOME/intake`, or `$HOME/.local/share/intake`, whichever is resolved first.
+The database can also be specified on the command line via `--data-dir`/`-d` instead of the environment.
 
 ### Items
 

cmd/root.go

@@ -23,14 +23,14 @@ func Execute() {
 	}
 }
 
-var dbPath string
+var dataPath string
 
 func init() {
 	// Disable the automatic help command
 	rootCmd.SetHelpCommand(&cobra.Command{Hidden: true})
 
 	// All commands need to operate on a database
-	rootCmd.PersistentFlags().StringVarP(&dbPath, "db", "d", "", "Path to the intake sqlite database (default: INTAKE_DB)")
+	rootCmd.PersistentFlags().StringVarP(&dataPath, "data-dir", "d", "", "Path to the intake data directory containing the database")
 }
 
 //
@@ -38,22 +38,22 @@ func init() {
 //
 
 func getDbPath() string {
-	if dbPath != "" {
-		return dbPath
+	if dataPath != "" {
+		return core.DatabasePath(dataPath)
 	}
-	env := os.Getenv("INTAKE_DB")
-	if env != "" {
-		return env
+	if dataDir := core.ResolveDataDir(); dataDir != "" {
+		return core.DatabasePath(dataDir)
 	}
 	fmt.Println("error: no database specified")
-	fmt.Println("Either --db or the environment variable INTAKE_DB must be set.")
+	fmt.Println("One of --data-dir, INTAKE_DATA_DIR, XDG_DATA_HOME, or HOME must be defined.")
 	os.Exit(1)
 	return ""
 }
 
 // Attempt to open the specified database and exit with an error if it fails.
 func openDb() *core.DB {
-	db, err := core.OpenDb(getDbPath())
+	dbPath := getDbPath()
+	db, err := core.OpenDb(dbPath)
 	if err != nil {
 		log.Fatalf("error: failed to open %s", dbPath)
 	}

core/data.go

@@ -0,0 +1,21 @@
+package core
+
+import (
+	"os"
+	"path/filepath"
+)
+
+func ResolveDataDir() string {
+	if intakeData := os.Getenv("INTAKE_DATA_DIR"); intakeData != "" {
+		return intakeData
+	} else if xdgData := os.Getenv("XDG_DATA_HOME"); xdgData != "" {
+		return filepath.Join(xdgData, "intake")
+	} else if home := os.Getenv("HOME"); home != "" {
+		return filepath.Join(home, ".local", "share", "intake")
+	}
+	return ""
+}
+
+func DatabasePath(dataDir string) string {
+	return filepath.Join(dataDir, "intake.db")
+}

test/test_items.sh

@@ -2,8 +2,8 @@
 set -eu
 
 go build -o tmp/intake
-rm "$1" || true
-export INTAKE_DB="$1"
+rm tmp/intake.db* || true
+export INTAKE_DATA_DIR="tmp"
 tmp/intake migrate
 tmp/intake source add -s feedtest
 tmp/intake item add -s feedtest --id "this-item-has-no-title"