package imgcache

import (
	"bytes"
	"io"
	"os"
	"path/filepath"
	"testing"
)

func TestContentStorage_StoreAndLoad(t *testing.T) {
	tmpDir := t.TempDir()
	storage, err := NewContentStorage(tmpDir)
	if err != nil {
		t.Fatalf("NewContentStorage() error = %v", err)
	}

	content := []byte("hello world")
	hash, size, err := storage.Store(bytes.NewReader(content))
	if err != nil {
		t.Fatalf("Store() error = %v", err)
	}

	if size != int64(len(content)) {
		t.Errorf("Store() size = %d, want %d", size, len(content))
	}

	if hash == "" {
		t.Error("Store() returned empty hash")
	}

	// Verify file exists at expected path
	expectedPath := filepath.Join(tmpDir, hash[0:2], hash[2:4], hash)
	if _, err := os.Stat(expectedPath); err != nil {
		t.Errorf("File not at expected path %s: %v", expectedPath, err)
	}

	// Load and verify content
	r, err := storage.Load(hash)
	if err != nil {
		t.Fatalf("Load() error = %v", err)
	}
	defer r.Close()

	loaded, err := io.ReadAll(r)
	if err != nil {
		t.Fatalf("ReadAll() error = %v", err)
	}

	if !bytes.Equal(loaded, content) {
		t.Errorf("Load() content = %q, want %q", loaded, content)
	}
}

func TestContentStorage_StoreIdempotent(t *testing.T) {
	tmpDir := t.TempDir()
	storage, err := NewContentStorage(tmpDir)
	if err != nil {
		t.Fatalf("NewContentStorage() error = %v", err)
	}

	content := []byte("same content")

	hash1, _, err := storage.Store(bytes.NewReader(content))
	if err != nil {
		t.Fatalf("Store() first error = %v", err)
	}

	hash2, _, err := storage.Store(bytes.NewReader(content))
	if err != nil {
		t.Fatalf("Store() second error = %v", err)
	}

	if hash1 != hash2 {
		t.Errorf("Store() hashes differ: %s vs %s", hash1, hash2)
	}
}

func TestContentStorage_LoadNotFound(t *testing.T) {
	tmpDir := t.TempDir()
	storage, err := NewContentStorage(tmpDir)
	if err != nil {
		t.Fatalf("NewContentStorage() error = %v", err)
	}

	_, err = storage.Load("nonexistent")
	if err != ErrNotFound {
		t.Errorf("Load() error = %v, want ErrNotFound", err)
	}
}

func TestContentStorage_Delete(t *testing.T) {
	tmpDir := t.TempDir()
	storage, err := NewContentStorage(tmpDir)
	if err != nil {
		t.Fatalf("NewContentStorage() error = %v", err)
	}

	content := []byte("to be deleted")
	hash, _, err := storage.Store(bytes.NewReader(content))
	if err != nil {
		t.Fatalf("Store() error = %v", err)
	}

	if !storage.Exists(hash) {
		t.Error("Exists() = false, want true")
	}

	if err := storage.Delete(hash); err != nil {
		t.Fatalf("Delete() error = %v", err)
	}

	if storage.Exists(hash) {
		t.Error("Exists() = true after delete, want false")
	}
}

func TestContentStorage_DeleteNonexistent(t *testing.T) {
	tmpDir := t.TempDir()
	storage, err := NewContentStorage(tmpDir)
	if err != nil {
		t.Fatalf("NewContentStorage() error = %v", err)
	}

	// Should not error
	if err := storage.Delete("nonexistent"); err != nil {
		t.Errorf("Delete() error = %v, want nil", err)
	}
}

func TestContentStorage_Path(t *testing.T) {
	tmpDir := t.TempDir()
	storage, err := NewContentStorage(tmpDir)
	if err != nil {
		t.Fatalf("NewContentStorage() error = %v", err)
	}

	hash := "abcdef0123456789"
	path := storage.Path(hash)
	expected := filepath.Join(tmpDir, "ab", "cd", hash)

	if path != expected {
		t.Errorf("Path() = %q, want %q", path, expected)
	}
}

func TestMetadataStorage_StoreAndLoad(t *testing.T) {
	tmpDir := t.TempDir()
	storage, err := NewMetadataStorage(tmpDir)
	if err != nil {
		t.Fatalf("NewMetadataStorage() error = %v", err)
	}

	meta := &SourceMetadata{
		Host:        "cdn.example.com",
		Path:        "/photos/cat.jpg",
		ContentHash: "abc123",
		StatusCode:  200,
		ContentType: "image/jpeg",
		FetchedAt:   1704067200,
		ETag:        `"etag123"`,
	}

	pathHash := HashPath("/photos/cat.jpg")

	err = storage.Store("cdn.example.com", pathHash, meta)
	if err != nil {
		t.Fatalf("Store() error = %v", err)
	}

	// Verify file exists at expected path
	expectedPath := filepath.Join(tmpDir, "cdn.example.com", pathHash+".json")
	if _, err := os.Stat(expectedPath); err != nil {
		t.Errorf("File not at expected path %s: %v", expectedPath, err)
	}

	// Load and verify
	loaded, err := storage.Load("cdn.example.com", pathHash)
	if err != nil {
		t.Fatalf("Load() error = %v", err)
	}

	if loaded.Host != meta.Host {
		t.Errorf("Host = %q, want %q", loaded.Host, meta.Host)
	}

	if loaded.Path != meta.Path {
		t.Errorf("Path = %q, want %q", loaded.Path, meta.Path)
	}

	if loaded.ContentHash != meta.ContentHash {
		t.Errorf("ContentHash = %q, want %q", loaded.ContentHash, meta.ContentHash)
	}

	if loaded.StatusCode != meta.StatusCode {
		t.Errorf("StatusCode = %d, want %d", loaded.StatusCode, meta.StatusCode)
	}

	if loaded.ETag != meta.ETag {
		t.Errorf("ETag = %q, want %q", loaded.ETag, meta.ETag)
	}
}

func TestMetadataStorage_LoadNotFound(t *testing.T) {
	tmpDir := t.TempDir()
	storage, err := NewMetadataStorage(tmpDir)
	if err != nil {
		t.Fatalf("NewMetadataStorage() error = %v", err)
	}

	_, err = storage.Load("example.com", "nonexistent")
	if err != ErrNotFound {
		t.Errorf("Load() error = %v, want ErrNotFound", err)
	}
}

func TestMetadataStorage_Delete(t *testing.T) {
	tmpDir := t.TempDir()
	storage, err := NewMetadataStorage(tmpDir)
	if err != nil {
		t.Fatalf("NewMetadataStorage() error = %v", err)
	}

	meta := &SourceMetadata{
		Host:       "example.com",
		Path:       "/test.jpg",
		StatusCode: 200,
	}

	pathHash := HashPath("/test.jpg")

	err = storage.Store("example.com", pathHash, meta)
	if err != nil {
		t.Fatalf("Store() error = %v", err)
	}

	if !storage.Exists("example.com", pathHash) {
		t.Error("Exists() = false, want true")
	}

	if err := storage.Delete("example.com", pathHash); err != nil {
		t.Fatalf("Delete() error = %v", err)
	}

	if storage.Exists("example.com", pathHash) {
		t.Error("Exists() = true after delete, want false")
	}
}

func TestHashPath(t *testing.T) {
	// Same input should produce same hash
	hash1 := HashPath("/photos/cat.jpg")
	hash2 := HashPath("/photos/cat.jpg")

	if hash1 != hash2 {
		t.Errorf("HashPath() not deterministic: %s vs %s", hash1, hash2)
	}

	// Different input should produce different hash
	hash3 := HashPath("/photos/dog.jpg")

	if hash1 == hash3 {
		t.Error("HashPath() produced same hash for different inputs")
	}

	// Hash should be 64 hex chars (256 bits)
	if len(hash1) != 64 {
		t.Errorf("HashPath() length = %d, want 64", len(hash1))
	}
}

func TestCacheKey(t *testing.T) {
	req1 := &ImageRequest{
		SourceHost:  "cdn.example.com",
		SourcePath:  "/photos/cat.jpg",
		SourceQuery: "",
		Size:        Size{Width: 800, Height: 600},
		Format:      FormatWebP,
		Quality:     85,
		FitMode:     FitCover,
	}

	req2 := &ImageRequest{
		SourceHost:  "cdn.example.com",
		SourcePath:  "/photos/cat.jpg",
		SourceQuery: "",
		Size:        Size{Width: 800, Height: 600},
		Format:      FormatWebP,
		Quality:     85,
		FitMode:     FitCover,
	}

	// Same request should produce same key
	key1 := CacheKey(req1)
	key2 := CacheKey(req2)

	if key1 != key2 {
		t.Errorf("CacheKey() not deterministic: %s vs %s", key1, key2)
	}

	// Key should be 64 hex chars
	if len(key1) != 64 {
		t.Errorf("CacheKey() length = %d, want 64", len(key1))
	}

	// Different size should produce different key
	req3 := &ImageRequest{
		SourceHost:  "cdn.example.com",
		SourcePath:  "/photos/cat.jpg",
		SourceQuery: "",
		Size:        Size{Width: 400, Height: 300}, // Different size
		Format:      FormatWebP,
		Quality:     85,
		FitMode:     FitCover,
	}

	key3 := CacheKey(req3)
	if key1 == key3 {
		t.Error("CacheKey() produced same key for different sizes")
	}

	// Different format should produce different key
	req4 := &ImageRequest{
		SourceHost:  "cdn.example.com",
		SourcePath:  "/photos/cat.jpg",
		SourceQuery: "",
		Size:        Size{Width: 800, Height: 600},
		Format:      FormatPNG, // Different format
		Quality:     85,
		FitMode:     FitCover,
	}

	key4 := CacheKey(req4)
	if key1 == key4 {
		t.Error("CacheKey() produced same key for different formats")
	}

	// Different quality should produce different key
	req5 := &ImageRequest{
		SourceHost:  "cdn.example.com",
		SourcePath:  "/photos/cat.jpg",
		SourceQuery: "",
		Size:        Size{Width: 800, Height: 600},
		Format:      FormatWebP,
		Quality:     50, // Different quality
		FitMode:     FitCover,
	}

	key5 := CacheKey(req5)
	if key1 == key5 {
		t.Error("CacheKey() produced same key for different quality")
	}
}