initial package management

10 files changed, 198 insertions, 10 deletions

diff --git a/internal/exec/exec.go b/internal/exec/exec.go
new file mode 100644
index 0000000..87e861b
--- /dev/null
+++ b/internal/exec/exec.go
@@ -0,0 +1,38 @@
+package exec
+
+import (
+	"bytes"
+	"os/exec"
+)
+
+// Run executes a shell command with the given arguments and returns stdout, stderr, exit code, and any error encountered.
+func Run(name string, args ...string) (stdout, stderr string, exitCode int, err error) {
+	cmd := exec.Command(name, args...)
+
+	var stdoutBuf, stderrBuf bytes.Buffer
+	cmd.Stdout = &stdoutBuf
+	cmd.Stderr = &stderrBuf
+
+	err = cmd.Run()
+
+	stdout = stdoutBuf.String()
+	stderr = stderrBuf.String()
+
+	if err != nil {
+		if exitError, ok := err.(*exec.ExitError); ok {
+			exitCode = exitError.ExitCode()
+			// In this case, the error is just the non-zero exit code,
+			// which we've already captured. We return nil for err to indicate
+			// that the command actually ran and exited (even if non-zero).
+			err = nil
+		} else {
+			// This is a "real" error, e.g., binary not found
+			exitCode = -1
+			return stdout, stderr, exitCode, err
+		}
+	} else {
+		exitCode = 0
+	}
+
+	return stdout, stderr, exitCode, nil
+}
diff --git a/internal/exec/exec_test.go b/internal/exec/exec_test.go
new file mode 100644
index 0000000..4dc6505
--- /dev/null
+++ b/internal/exec/exec_test.go
@@ -0,0 +1,69 @@
+package exec
+
+import (
+	"testing"
+)
+
+func TestRun(t *testing.T) {
+	tests := []struct {
+		name           string
+		cmd            string
+		args           []string
+		wantStdout     string
+		wantStderr     string
+		wantExitCode   int
+		wantErr        bool
+	}{
+		{
+			name:         "success",
+			cmd:          "echo",
+			args:         []string{"hello world"},
+			wantStdout:   "hello world\n",
+			wantStderr:   "",
+			wantExitCode: 0,
+			wantErr:      false,
+		},
+		{
+			name:         "fail-exit-code",
+			cmd:          "ls",
+			args:         []string{"/non-existent-directory-12345"},
+			wantStdout:   "",
+			wantStderr:   "", // ls stderr varies by OS, but should not be empty usually.
+			wantExitCode: 2,  // Typical for ls non-existent
+			wantErr:      false,
+		},
+		{
+			name:         "fail-binary-not-found",
+			cmd:          "non-existent-command-12345",
+			args:         []string{},
+			wantStdout:   "",
+			wantStderr:   "",
+			wantExitCode: -1,
+			wantErr:      true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			stdout, stderr, exitCode, err := Run(tt.cmd, tt.args...)
+
+			if (err != nil) != tt.wantErr {
+				t.Errorf("Run() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+
+			if exitCode != tt.wantExitCode {
+				t.Errorf("Run() exitCode = %v, want %v", exitCode, tt.wantExitCode)
+			}
+
+			if tt.name == "success" && stdout != tt.wantStdout {
+				t.Errorf("Run() stdout = %q, want %q", stdout, tt.wantStdout)
+			}
+			
+			// For ls error, we just check that stderr is not empty since exact text varies
+			if tt.name == "fail-exit-code" && stderr == "" {
+				t.Errorf("Run() stderr = %q, want non-empty", stderr)
+			}
+		})
+	}
+}
diff --git a/internal/resource/dir/dir.go b/internal/resource/dir/dir.go
index 94220b7..83c017c 100644
--- a/internal/resource/dir/dir.go
+++ b/internal/resource/dir/dir.go
@@ -200,6 +200,6 @@ func Present(path string, opts ...opt.Option) resource.Resource {
 }
 
 func Absent(path string, opts ...opt.Option) resource.Resource {
-	opts = append(opts, opt.IsAbsent())
+	opts = append(opts, opt.IsAbsent)
 	return Present(path, opts...)
 }
diff --git a/internal/resource/dir/dir_test.go b/internal/resource/dir/dir_test.go
index c7ec92e..21af8e1 100644
--- a/internal/resource/dir/dir_test.go
+++ b/internal/resource/dir/dir_test.go
@@ -78,7 +78,7 @@ func TestPresentAbsentNonEmptyDirWithoutPruneFails(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	Present(path, IsAbsent())
+	Present(path, IsAbsent)
 	if err := resource.Apply(); err == nil {
 		t.Error("expected Apply to fail when removing non-empty directory without prune")
 	}
@@ -95,7 +95,7 @@ func TestPresentAbsentPruneDirectoryRecursive(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	Present(path, IsAbsent(), WithPrune())
+	Present(path, IsAbsent, WithPrune)
 	if err := resource.Apply(); err != nil {
 		t.Fatalf("Apply failed: %v", err)
 	}
@@ -116,7 +116,7 @@ func TestAbsentPruneDirectoryRecursive(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	Absent(path, WithPrune())
+	Absent(path, WithPrune)
 	if err := resource.Apply(); err != nil {
 		t.Fatalf("Apply failed: %v", err)
 	}
@@ -168,7 +168,7 @@ func TestPresentDirectoryWithSource(t *testing.T) {
 			t.Fatal(err)
 		}
 
-		Present(dst, WithSource(src), WithPrune())
+		Present(dst, WithSource(src), WithPrune)
 		if err := resource.Apply(); err != nil {
 			t.Fatalf("Apply failed: %v", err)
 		}
@@ -284,7 +284,7 @@ func TestSourceCopyWithPruneKeepsTemplatedFile(t *testing.T) {
 
 	// Now apply with prune
 	resource.ResetRepository()
-	Present(dst, WithSource(src), WithPrune())
+	Present(dst, WithSource(src), WithPrune)
 	if err := resource.Apply(); err != nil {
 		t.Fatalf("Apply failed: %v", err)
 	}
diff --git a/internal/resource/file/file.go b/internal/resource/file/file.go
index 9d8a0d9..88b0bca 100644
--- a/internal/resource/file/file.go
+++ b/internal/resource/file/file.go
@@ -231,6 +231,6 @@ func Present(path string, opts ...opt.Option) resource.Resource {
 }
 
 func Absent(path string, opts ...opt.Option) resource.Resource {
-	opts = append(opts, opt.IsAbsent())
+	opts = append(opts, opt.IsAbsent)
 	return Present(path, opts...)
 }
diff --git a/internal/resource/file/file_test.go b/internal/resource/file/file_test.go
index b158657..3ae183c 100644
--- a/internal/resource/file/file_test.go
+++ b/internal/resource/file/file_test.go
@@ -194,7 +194,7 @@ func TestPresentAbsent(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	Present(path, IsAbsent())
+	Present(path, IsAbsent)
 	if err := resource.Apply(); err != nil {
 		t.Fatalf("Apply failed: %v", err)
 	}
diff --git a/internal/resource/link/link.go b/internal/resource/link/link.go
index a5c5122..b40ce65 100644
--- a/internal/resource/link/link.go
+++ b/internal/resource/link/link.go
@@ -95,7 +95,7 @@ func Present(path string, opts ...opt.Option) resource.Resource {
 }
 
 func Absent(path string, opts ...opt.Option) resource.Resource {
-	opts = append(opts, opt.IsAbsent())
+	opts = append(opts, opt.IsAbsent)
 	return Present(path, opts...)
 }
 
diff --git a/internal/resource/link/link_test.go b/internal/resource/link/link_test.go
index 862d5f7..170fbdd 100644
--- a/internal/resource/link/link_test.go
+++ b/internal/resource/link/link_test.go
@@ -183,7 +183,7 @@ func TestPresentAbsentSymlink(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	Present(path, IsAbsent())
+	Present(path, IsAbsent)
 	if err := resource.Apply(); err != nil {
 		t.Fatalf("Apply failed: %v", err)
 	}
diff --git a/internal/resource/pkg/dnf.go b/internal/resource/pkg/dnf.go
new file mode 100644
index 0000000..ad03da2
--- /dev/null
+++ b/internal/resource/pkg/dnf.go
@@ -0,0 +1,34 @@
+package pkg
+
+import (
+	"fmt"
+	"log"
+
+	"codeberg.org/snonux/gonf/internal/exec"
+)
+
+func applyDNF(name string, ensure Ensure) error {
+	var args []string
+
+	switch ensure {
+	case PkgPresent:
+		args = []string{"install", "-y", name}
+	case PkgAbsent:
+		args = []string{"remove", "-y", name}
+	case PkgLatest:
+		args = []string{"install", "-y", name}
+	default:
+		log.Fatalf("unsupported ensure state: %v", ensure)
+	}
+
+	stdout, stderr, exitCode, err := exec.Run("dnf", args...)
+	if err != nil {
+		return fmt.Errorf("failed to execute dnf: %w", err)
+	}
+
+	if exitCode != 0 {
+		return fmt.Errorf("dnf failed with exit code %d: %s\n%s", exitCode, stdout, stderr)
+	}
+
+	return nil
+}
diff --git a/internal/resource/pkg/pkg.go b/internal/resource/pkg/pkg.go
new file mode 100644
index 0000000..72f098c
--- /dev/null
+++ b/internal/resource/pkg/pkg.go
@@ -0,0 +1,47 @@
+package pkg
+
+import (
+	"errors"
+	"os"
+)
+
+type Ensure int
+
+const (
+	PkgPresent Ensure = iota
+	PkgAbsent
+	PkgLatest
+)
+
+type applyFunc func(name string, ensure Ensure) error
+
+func Present(name string, ensure Ensure) error {
+	bin, err := detect()
+	if err != nil {
+		return err
+	}
+
+	var applyFunc applyFunc
+
+	switch bin {
+	case "dnf":
+		applyFunc = applyDNF
+	}
+
+	return applyFunc(name, ensure)
+}
+
+func detect() (string, error) {
+	switch {
+	case exists("/etc/fedora-release"):
+		fallthrough
+	case exists("/etc/rocky-release"):
+		return "dnf", nil
+	}
+	return "", errors.New("unable to detect package manager!")
+}
+
+func exists(path string) bool {
+	_, err := os.Stat(path)
+	return err == nil
+}