package backup_test

import (
	"context"
	"path/filepath"
	"testing"
	"time"

	"git.eeqj.de/sneak/vaultik/internal/backup"
	"git.eeqj.de/sneak/vaultik/internal/database"
	"github.com/spf13/afero"
)

func TestScannerSimpleDirectory(t *testing.T) {
	// Create in-memory filesystem
	fs := afero.NewMemMapFs()

	// Create test directory structure
	testFiles := map[string]string{
		"/source/file1.txt":         "Hello, world!",                // 13 bytes
		"/source/file2.txt":         "This is another file",         // 20 bytes
		"/source/subdir/file3.txt":  "File in subdirectory",         // 20 bytes
		"/source/subdir/file4.txt":  "Another file in subdirectory", // 28 bytes
		"/source/empty.txt":         "",                             // 0 bytes
		"/source/subdir2/file5.txt": "Yet another file",             // 16 bytes
	}

	// Create files with specific times
	testTime := time.Date(2024, 1, 1, 12, 0, 0, 0, time.UTC)
	for path, content := range testFiles {
		dir := filepath.Dir(path)
		if err := fs.MkdirAll(dir, 0755); err != nil {
			t.Fatalf("failed to create directory %s: %v", dir, err)
		}
		if err := afero.WriteFile(fs, path, []byte(content), 0644); err != nil {
			t.Fatalf("failed to write file %s: %v", path, err)
		}
		// Set times
		if err := fs.Chtimes(path, testTime, testTime); err != nil {
			t.Fatalf("failed to set times for %s: %v", path, err)
		}
	}

	// Create test database
	db, err := database.NewTestDB()
	if err != nil {
		t.Fatalf("failed to create test database: %v", err)
	}
	defer func() {
		if err := db.Close(); err != nil {
			t.Errorf("failed to close database: %v", err)
		}
	}()

	repos := database.NewRepositories(db)

	// Create scanner
	scanner := backup.NewScanner(backup.ScannerConfig{
		FS:           fs,
		ChunkSize:    1024 * 16, // 16KB chunks for testing
		Repositories: repos,
	})

	// Scan the directory
	ctx := context.Background()
	result, err := scanner.Scan(ctx, "/source")
	if err != nil {
		t.Fatalf("scan failed: %v", err)
	}

	// Verify results
	if result.FilesScanned != 6 {
		t.Errorf("expected 6 files scanned, got %d", result.FilesScanned)
	}

	if result.BytesScanned != 97 { // Total size of all test files: 13 + 20 + 20 + 28 + 0 + 16 = 97
		t.Errorf("expected 97 bytes scanned, got %d", result.BytesScanned)
	}

	// Verify files in database
	files, err := repos.Files.ListByPrefix(ctx, "/source")
	if err != nil {
		t.Fatalf("failed to list files: %v", err)
	}

	if len(files) != 6 {
		t.Errorf("expected 6 files in database, got %d", len(files))
	}

	// Verify specific file
	file1, err := repos.Files.GetByPath(ctx, "/source/file1.txt")
	if err != nil {
		t.Fatalf("failed to get file1.txt: %v", err)
	}

	if file1.Size != 13 {
		t.Errorf("expected file1.txt size 13, got %d", file1.Size)
	}

	if file1.Mode != 0644 {
		t.Errorf("expected file1.txt mode 0644, got %o", file1.Mode)
	}

	// Verify chunks were created
	chunks, err := repos.FileChunks.GetByFile(ctx, "/source/file1.txt")
	if err != nil {
		t.Fatalf("failed to get chunks for file1.txt: %v", err)
	}

	if len(chunks) != 1 { // Small file should be one chunk
		t.Errorf("expected 1 chunk for file1.txt, got %d", len(chunks))
	}

	// Verify deduplication - file3.txt and file4.txt have different content
	// but we should still have the correct number of unique chunks
	allChunks, err := repos.Chunks.List(ctx)
	if err != nil {
		t.Fatalf("failed to list all chunks: %v", err)
	}

	// We should have at most 6 chunks (one per unique file content)
	// Empty file might not create a chunk
	if len(allChunks) > 6 {
		t.Errorf("expected at most 6 chunks, got %d", len(allChunks))
	}
}

func TestScannerWithSymlinks(t *testing.T) {
	// Create in-memory filesystem
	fs := afero.NewMemMapFs()

	// Create test files
	if err := fs.MkdirAll("/source", 0755); err != nil {
		t.Fatal(err)
	}
	if err := afero.WriteFile(fs, "/source/target.txt", []byte("target content"), 0644); err != nil {
		t.Fatal(err)
	}
	if err := afero.WriteFile(fs, "/outside/file.txt", []byte("outside content"), 0644); err != nil {
		t.Fatal(err)
	}

	// Create symlinks (if supported by the filesystem)
	linker, ok := fs.(afero.Symlinker)
	if !ok {
		t.Skip("filesystem does not support symlinks")
	}

	// Symlink to file in source
	if err := linker.SymlinkIfPossible("target.txt", "/source/link1.txt"); err != nil {
		t.Fatal(err)
	}

	// Symlink to file outside source
	if err := linker.SymlinkIfPossible("/outside/file.txt", "/source/link2.txt"); err != nil {
		t.Fatal(err)
	}

	// Create test database
	db, err := database.NewTestDB()
	if err != nil {
		t.Fatalf("failed to create test database: %v", err)
	}
	defer func() {
		if err := db.Close(); err != nil {
			t.Errorf("failed to close database: %v", err)
		}
	}()

	repos := database.NewRepositories(db)

	// Create scanner
	scanner := backup.NewScanner(backup.ScannerConfig{
		FS:           fs,
		ChunkSize:    1024 * 16,
		Repositories: repos,
	})

	// Scan the directory
	ctx := context.Background()
	result, err := scanner.Scan(ctx, "/source")
	if err != nil {
		t.Fatalf("scan failed: %v", err)
	}

	// Should have scanned 3 files (target + 2 symlinks)
	if result.FilesScanned != 3 {
		t.Errorf("expected 3 files scanned, got %d", result.FilesScanned)
	}

	// Check symlinks in database
	link1, err := repos.Files.GetByPath(ctx, "/source/link1.txt")
	if err != nil {
		t.Fatalf("failed to get link1.txt: %v", err)
	}

	if link1.LinkTarget != "target.txt" {
		t.Errorf("expected link1.txt target 'target.txt', got %q", link1.LinkTarget)
	}

	link2, err := repos.Files.GetByPath(ctx, "/source/link2.txt")
	if err != nil {
		t.Fatalf("failed to get link2.txt: %v", err)
	}

	if link2.LinkTarget != "/outside/file.txt" {
		t.Errorf("expected link2.txt target '/outside/file.txt', got %q", link2.LinkTarget)
	}
}

func TestScannerLargeFile(t *testing.T) {
	// Create in-memory filesystem
	fs := afero.NewMemMapFs()

	// Create a large file that will require multiple chunks
	largeContent := make([]byte, 1024*1024) // 1MB
	for i := range largeContent {
		largeContent[i] = byte(i % 256)
	}

	if err := fs.MkdirAll("/source", 0755); err != nil {
		t.Fatal(err)
	}
	if err := afero.WriteFile(fs, "/source/large.bin", largeContent, 0644); err != nil {
		t.Fatal(err)
	}

	// Create test database
	db, err := database.NewTestDB()
	if err != nil {
		t.Fatalf("failed to create test database: %v", err)
	}
	defer func() {
		if err := db.Close(); err != nil {
			t.Errorf("failed to close database: %v", err)
		}
	}()

	repos := database.NewRepositories(db)

	// Create scanner with 64KB chunks
	scanner := backup.NewScanner(backup.ScannerConfig{
		FS:           fs,
		ChunkSize:    1024 * 64, // 64KB chunks
		Repositories: repos,
	})

	// Scan the directory
	ctx := context.Background()
	result, err := scanner.Scan(ctx, "/source")
	if err != nil {
		t.Fatalf("scan failed: %v", err)
	}

	if result.BytesScanned != 1024*1024 {
		t.Errorf("expected %d bytes scanned, got %d", 1024*1024, result.BytesScanned)
	}

	// Verify chunks
	chunks, err := repos.FileChunks.GetByFile(ctx, "/source/large.bin")
	if err != nil {
		t.Fatalf("failed to get chunks: %v", err)
	}

	expectedChunks := 16 // 1MB / 64KB
	if len(chunks) != expectedChunks {
		t.Errorf("expected %d chunks, got %d", expectedChunks, len(chunks))
	}

	// Verify chunk sequence
	for i, fc := range chunks {
		if fc.Idx != i {
			t.Errorf("chunk %d has incorrect sequence %d", i, fc.Idx)
		}
	}
}