package imgcache

import (
	"context"
	"database/sql"
	"os"
	"testing"
	"time"

	"github.com/prometheus/client_golang/prometheus"
	_ "modernc.org/sqlite"
)

func setupTestDB(t *testing.T) *sql.DB {
	t.Helper()

	db, err := sql.Open("sqlite", ":memory:")
	if err != nil {
		t.Fatalf("failed to open test db: %v", err)
	}

	// Create schema
	schema := `
		CREATE TABLE source_content (
			source_key TEXT PRIMARY KEY,
			size_bytes INTEGER NOT NULL,
			last_accessed_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP
		);
		CREATE TABLE negative_cache (
			id INTEGER PRIMARY KEY AUTOINCREMENT,
			source_host TEXT NOT NULL,
			source_path TEXT NOT NULL,
			source_query TEXT NOT NULL DEFAULT '',
			expires_at DATETIME NOT NULL,
			UNIQUE(source_host, source_path, source_query)
		);
	`

	_, err = db.ExecContext(t.Context(), schema)
	if err != nil {
		t.Fatalf("failed to create schema: %v", err)
	}

	return db
}

func TestCache_CleanExpired(t *testing.T) {
	t.Parallel()

	tmpDir := t.TempDir()
	db := setupTestDB(t)

	cache, _ := NewCache(db, CacheConfig{
		StateDir:    tmpDir,
		NegativeTTL: 1 * time.Millisecond,
		MaxBytes:    1 << 30,
	}, prometheus.NewRegistry())

	ctx := context.Background()

	// Insert expired negative cache entry directly
	_, err := db.ExecContext(ctx, `
		INSERT INTO negative_cache
			(source_host, source_path, source_query, expires_at)
		VALUES ('example.com', '/old.jpg', '', datetime('now', '-1 hour'))
	`)
	if err != nil {
		t.Fatalf("failed to insert test data: %v", err)
	}

	// Verify it exists
	var count int

	err = db.QueryRowContext(ctx, `SELECT COUNT(*) FROM negative_cache`).Scan(&count)
	if err != nil {
		t.Fatalf("failed to count negative cache entries: %v", err)
	}

	if count != 1 {
		t.Fatalf("expected 1 negative cache entry, got %d", count)
	}

	// Clean expired
	err = cache.CleanExpired(ctx)
	if err != nil {
		t.Fatalf("CleanExpired() error = %v", err)
	}

	// Verify it's gone
	err = db.QueryRowContext(ctx, `SELECT COUNT(*) FROM negative_cache`).Scan(&count)
	if err != nil {
		t.Fatalf("failed to count negative cache entries: %v", err)
	}

	if count != 0 {
		t.Errorf("expected 0 negative cache entries after clean, got %d", count)
	}
}

func TestCache_StorageDirectoriesCreated(t *testing.T) {
	t.Parallel()

	tmpDir := t.TempDir()
	db := setupTestDB(t)

	_, err := NewCache(db, CacheConfig{
		StateDir: tmpDir,
		MaxBytes: 1 << 30,
	}, prometheus.NewRegistry())
	if err != nil {
		t.Fatalf("NewCache() error = %v", err)
	}

	// Verify directories were created
	dirs := []string{
		"cache/sources",
		"cache/variants",
	}

	for _, dir := range dirs {
		path := tmpDir + "/" + dir

		_, err := os.Stat(path)
		if os.IsNotExist(err) {
			t.Errorf("directory %s was not created", dir)
		}
	}
}