feat: rename config to cli

internal/cli/destination.go

@@ -0,0 +1,27 @@
+package cli
+
+import (
+	"fmt"
+	"os"
+)
+
+// A Destination is method of writing output to the user.
+type Destination interface {
+	// Write data to this destination.
+	Write(data string) error
+}
+
+// An StdoutDestination writes to stdout.
+type StdoutDestination struct{}
+
+func (d StdoutDestination) Write(data string) error {
+	fmt.Println(data)
+	return nil
+}
+
+// A FileDestination writes to a file.
+type FileDestination struct{ Path string }
+
+func (d FileDestination) Write(data string) error {
+	return os.WriteFile(d.Path, []byte(data+"\n"), 0644)
+}

internal/cli/source.go

@@ -0,0 +1,41 @@
+package cli
+
+import (
+	"io"
+	"os"
+)
+
+// A method of extracting input from the user.
+type Source interface {
+	// Fetch data from this source.
+	Extract() (string, error)
+}
+
+// A source defined by a string.
+type StringSource struct{ Data string }
+
+func (s StringSource) Extract() (string, error) { return s.Data, nil }
+
+// A source pulling from standard input.
+type StdinSource struct{}
+
+func (s StdinSource) Extract() (string, error) {
+	data, err := io.ReadAll(os.Stdin)
+	if err != nil {
+		return "", err
+	}
+
+	return string(data), nil
+}
+
+// A source reading from a file.
+type FileSource struct{ Path string }
+
+func (s FileSource) Extract() (string, error) {
+	data, err := os.ReadFile(s.Path)
+	if err != nil {
+		return "", err
+	}
+
+	return string(data), nil
+}