package scanner

import (
	"os"
	"path/filepath"
	"strings"
	"testing"
	"time"
)

func testScanner(t *testing.T) (*Scanner, string) {
	t.Helper()
	root := t.TempDir()
	s := New(Config{
		StorageRoot:   root,
		IncomingDir:   "incoming",
		ProcessingDir: "processing",
		FailedDir:     "failed",
		StableWindow:  time.Millisecond,
		StableChecks:  1,
	})
	if err := s.EnsureDirs(); err != nil {
		t.Fatalf("EnsureDirs: %v", err)
	}
	return s, root
}

func TestEnsureDirs(t *testing.T) {
	_, root := testScanner(t)
	for _, dir := range []string{"incoming", "processing", "failed"} {
		p := filepath.Join(root, dir)
		if st, err := os.Stat(p); err != nil || !st.IsDir() {
			t.Fatalf("dir %s missing: %v", dir, err)
		}
	}
}

func TestScanOnceClaimsStableAudio(t *testing.T) {
	s, root := testScanner(t)
	incoming := filepath.Join(root, "incoming")
	if err := os.WriteFile(filepath.Join(incoming, "call.wav"), []byte("audio"), 0o644); err != nil {
		t.Fatal(err)
	}

	claimed, err := s.ScanOnce()
	if err != nil {
		t.Fatal(err)
	}
	if len(claimed) != 1 {
		t.Fatalf("claimed %d files, want 1", len(claimed))
	}
	cf := claimed[0]
	if cf.Filename != "call.wav" {
		t.Fatalf("filename: got %q", cf.Filename)
	}
	if cf.TaskID == "" {
		t.Fatal("empty task_id")
	}
	if !strings.HasPrefix(cf.FilePath, filepath.Join(root, "processing")) {
		t.Fatalf("unexpected path: %s", cf.FilePath)
	}
	if _, err := os.Stat(cf.FilePath); err != nil {
		t.Fatalf("claimed file missing: %v", err)
	}
	if _, err := os.Stat(filepath.Join(incoming, "call.wav")); !os.IsNotExist(err) {
		t.Fatal("source file should be moved")
	}
}

func TestScanOnceSkipsUnsupportedAndHidden(t *testing.T) {
	s, root := testScanner(t)
	incoming := filepath.Join(root, "incoming")
	files := map[string][]byte{
		".hidden.wav":  []byte("x"),
		"notes.txt":    []byte("x"),
		"upload.tmp":   []byte("x"),
		"valid.mp3":    []byte("audio"),
	}
	for name, data := range files {
		if err := os.WriteFile(filepath.Join(incoming, name), data, 0o644); err != nil {
			t.Fatal(err)
		}
	}

	claimed, err := s.ScanOnce()
	if err != nil {
		t.Fatal(err)
	}
	if len(claimed) != 1 {
		t.Fatalf("claimed %d files, want 1 (valid.mp3)", len(claimed))
	}
	if claimed[0].Filename != "valid.mp3" {
		t.Fatalf("filename: got %q", claimed[0].Filename)
	}
}

func TestScanOnceEmptyIncoming(t *testing.T) {
	s, _ := testScanner(t)
	claimed, err := s.ScanOnce()
	if err != nil {
		t.Fatal(err)
	}
	if len(claimed) != 0 {
		t.Fatalf("expected 0 claimed, got %d", len(claimed))
	}
}

func TestRollbackToIncoming(t *testing.T) {
	s, root := testScanner(t)
	processing := filepath.Join(root, "processing")
	incoming := filepath.Join(root, "incoming")
	processingFile := filepath.Join(processing, "01TASK.wav")
	if err := os.WriteFile(processingFile, []byte("data"), 0o644); err != nil {
		t.Fatal(err)
	}

	if err := s.RollbackToIncoming(processingFile, "call.wav"); err != nil {
		t.Fatal(err)
	}
	if _, err := os.Stat(filepath.Join(incoming, "call.wav")); err != nil {
		t.Fatalf("file not restored to incoming: %v", err)
	}
	if _, err := os.Stat(processingFile); !os.IsNotExist(err) {
		t.Fatal("processing file should be gone")
	}
}

func TestMoveToFailed(t *testing.T) {
	s, root := testScanner(t)
	processing := filepath.Join(root, "processing")
	processingFile := filepath.Join(processing, "broken.wav")
	if err := os.WriteFile(processingFile, []byte("data"), 0o644); err != nil {
		t.Fatal(err)
	}

	if err := s.MoveToFailed(processingFile, "broken.wav"); err != nil {
		t.Fatal(err)
	}
	failedPath := filepath.Join(root, "failed", "broken.wav")
	if _, err := os.Stat(failedPath); err != nil {
		t.Fatalf("file not in failed: %v", err)
	}
}

func TestIsStableStableFile(t *testing.T) {
	s, root := testScanner(t)
	path := filepath.Join(root, "incoming", "stable.wav")
	if err := os.WriteFile(path, []byte("fixed-content"), 0o644); err != nil {
		t.Fatal(err)
	}
	if !s.isStable(path) {
		t.Fatal("expected stable file")
	}
}

func TestIsStableMissingFile(t *testing.T) {
	s, root := testScanner(t)
	path := filepath.Join(root, "incoming", "missing.wav")
	if s.isStable(path) {
		t.Fatal("missing file should not be stable")
	}
}