package testutils

import (
	"context"
	"crypto/sha256"
	"database/sql"
	"encoding/hex"
	"fmt"
	"os"
	"testing"

	"bugulma/backend/internal/domain"

	_ "github.com/jackc/pgx/v5/stdlib"
	"github.com/peterldowns/pgtestdb"
	"gorm.io/driver/postgres"
	"gorm.io/gorm"
	"gorm.io/gorm/logger"
)

// GormMigrator implements pgtestdb.Migrator interface for GORM migrations
// This migrator ensures PostGIS is properly set up before running migrations
type GormMigrator struct{}

// Hash returns a unique identifier for the migration state
// This is used by pgtestdb to identify template databases
// Update the version string when migrations change to force template recreation
func (m *GormMigrator) Hash() (string, error) {
	// Create a hash based on the migration state
	// This should be deterministic and change when migrations change
	hash := sha256.Sum256([]byte("bugulma-backend-migrations-v3"))
	return hex.EncodeToString(hash[:]), nil
}

// Migrate runs all GORM migrations including PostGIS setup
// This function is called by pgtestdb when creating template databases
// PostGIS extension MUST be created before any migrations that use geometry types
func (m *GormMigrator) Migrate(ctx context.Context, db *sql.DB, config pgtestdb.Config) error {
	// Step 1: Try to enable PostGIS extension FIRST (before any migrations)
	// This must be done using raw SQL connection, not GORM, to ensure it persists
	// If PostGIS cannot be enabled (e.g., permission issues), we'll skip PostGIS migrations
	postgisEnabled := false
	if err := enablePostGISExtension(db); err != nil {
		// PostGIS extension creation failed - this might happen if:
		// - User doesn't have permission to create extensions
		// - PostGIS is not installed in PostgreSQL
		// - Template database restrictions
		// We'll continue without PostGIS - tests that need it will fail with clear errors
		_ = err
		postgisEnabled = false
	} else {
		postgisEnabled = true
	}

	// Step 2: Create GORM connection
	gormDB, err := gorm.Open(postgres.New(postgres.Config{
		Conn: db,
	}), &gorm.Config{
		Logger: logger.Default.LogMode(logger.Silent),
	})
	if err != nil {
		return fmt.Errorf("failed to create GORM connection: %w", err)
	}

	// Step 3: Run domain migrations (creates tables, but not PostGIS columns)
	if err := domain.AutoMigrate(gormDB); err != nil {
		return fmt.Errorf("failed to run domain migrations: %w", err)
	}

	// Step 4: Run PostGIS-specific migrations (creates geometry columns, indexes)
	// Only run if PostGIS was successfully enabled
	if postgisEnabled {
		if err := domain.RunPostGISMigrations(gormDB); err != nil {
			// PostGIS migrations failed - this is critical for spatial operations
			// Return error to fail template creation - better to fail early than have broken tests
			return fmt.Errorf("failed to run PostGIS migrations: %w", err)
		}
	}
	// If PostGIS is not enabled, skip PostGIS migrations
	// Tests that need PostGIS will fail with appropriate error messages

	// Step 5: Create additional indexes
	if err := domain.CreateIndexes(gormDB); err != nil {
		// Index creation errors are non-fatal (indexes might already exist)
		// Log but don't fail - this allows migrations to be idempotent
		_ = err
	}

	// Step 6: Run geographical feature migrations manually
	// Since geographical features are created via golang-migrate, we need to run them manually
	if postgisEnabled {
		if err := runGeographicalFeatureMigrations(gormDB); err != nil {
			// Geographical migrations are important for geo tests but not critical for core functionality
			// Log the error but don't fail - tests that need geographical features will fail appropriately
			_ = err
		}
	}

	return nil
}

// runGeographicalFeatureMigrations runs the geographical feature table migrations
func runGeographicalFeatureMigrations(db *gorm.DB) error {
	// Create geographical_features table
	createTableSQL := `
		CREATE TABLE IF NOT EXISTS geographical_features (
			id TEXT PRIMARY KEY,
			name TEXT,
			feature_type VARCHAR(50) NOT NULL,
			osm_type VARCHAR(50),
			osm_id VARCHAR(50),
			properties JSONB DEFAULT '{}'::jsonb,
			processing_version VARCHAR(20) DEFAULT '1.0',
			quality_score DOUBLE PRECISION DEFAULT 0.0,
			source VARCHAR(100) DEFAULT 'osm',
			created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW(),
			updated_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()
		);
	`

	if err := db.Exec(createTableSQL).Error; err != nil {
		return fmt.Errorf("failed to create geographical_features table: %w", err)
	}

	// Add geometry column
	addGeometrySQL := `
		DO $$
		BEGIN
			IF NOT EXISTS (
				SELECT 1 FROM information_schema.columns
				WHERE table_name = 'geographical_features' AND column_name = 'geometry'
			) THEN
				ALTER TABLE geographical_features ADD COLUMN geometry GEOMETRY(Geometry, 4326);
			END IF;
		END $$;
	`

	if err := db.Exec(addGeometrySQL).Error; err != nil {
		return fmt.Errorf("failed to add geometry column: %w", err)
	}

	// Create indexes
	indexSQLs := []string{
		`CREATE INDEX IF NOT EXISTS idx_geographical_features_geometry ON geographical_features USING GIST (geometry)`,
		`CREATE INDEX IF NOT EXISTS idx_geographical_features_type ON geographical_features (feature_type)`,
		`CREATE INDEX IF NOT EXISTS idx_geographical_features_osm_id ON geographical_features (osm_type, osm_id)`,
		`CREATE INDEX IF NOT EXISTS idx_geographical_features_properties ON geographical_features USING GIN (properties)`,
		`CREATE INDEX IF NOT EXISTS idx_geographical_features_created_at ON geographical_features (created_at)`,
	}

	for _, sql := range indexSQLs {
		if err := db.Exec(sql).Error; err != nil {
			return fmt.Errorf("failed to create index: %w", err)
		}
	}

	// Add site footprint geometry column
	addFootprintSQL := `
		DO $$
		BEGIN
			IF NOT EXISTS (
				SELECT 1 FROM information_schema.columns
				WHERE table_name = 'sites' AND column_name = 'footprint_geometry'
			) THEN
				ALTER TABLE sites ADD COLUMN footprint_geometry geometry(Polygon, 4326);
				CREATE INDEX IF NOT EXISTS idx_sites_footprint_geometry ON sites USING GIST (footprint_geometry);
			END IF;
		END $$;
	`

	if err := db.Exec(addFootprintSQL).Error; err != nil {
		return fmt.Errorf("failed to add footprint geometry column: %w", err)
	}

	return nil
}

// enablePostGISExtension enables the PostGIS extension in the database
// This must be done using raw SQL connection to ensure it persists
// PostGIS extension is required for spatial operations and geometry types
// The extension must be created BEFORE any migrations that use geometry types
func enablePostGISExtension(db *sql.DB) error {
	// Always try to create the extension (IF NOT EXISTS handles existing case)
	// This ensures PostGIS is available even if the database was cloned without extensions
	if _, err := db.Exec("CREATE EXTENSION IF NOT EXISTS postgis"); err != nil {
		return fmt.Errorf("failed to create PostGIS extension: %w", err)
	}

	// Verify PostGIS is properly initialized by checking for PostGIS functions
	var version string
	if err := db.QueryRow("SELECT PostGIS_Version()").Scan(&version); err != nil {
		return fmt.Errorf("PostGIS extension exists but functions are not available: %w", err)
	}

	// PostGIS is properly initialized
	return nil
}

// getEnv gets environment variable or returns default value
func getEnv(key, defaultValue string) string {
	if value := os.Getenv(key); value != "" {
		return value
	}
	return defaultValue
}

// ginkgoTBWrapper wraps Ginkgo's FullGinkgoTInterface to work with pgtestdb
// pgtestdb requires a testing.TB interface, but Ginkgo provides a different interface
type ginkgoTBWrapper struct {
	t interface {
		Helper()
		Logf(format string, args ...interface{})
		Fatalf(format string, args ...interface{})
		Failed() bool
	}
	cleanups []func()
}

func (w *ginkgoTBWrapper) Helper()                                   { w.t.Helper() }
func (w *ginkgoTBWrapper) Logf(format string, args ...interface{})   { w.t.Logf(format, args...) }
func (w *ginkgoTBWrapper) Fatalf(format string, args ...interface{}) { w.t.Fatalf(format, args...) }
func (w *ginkgoTBWrapper) Failed() bool                              { return w.t.Failed() }
func (w *ginkgoTBWrapper) Cleanup(fn func())                         { w.cleanups = append(w.cleanups, fn) }

// SetupTestDB creates an isolated PostgreSQL database for testing using pgtestdb
// Each test gets its own temporary database with migrations already applied
// This function accepts testing.TB interface, compatible with *testing.T
//
// Example usage:
//
//	func TestMyFeature(t *testing.T) {
//	    db := testutils.SetupTestDB(t)
//	    repo := repository.NewMyRepository(db)
//	    // Your test code here
//	}
func SetupTestDB(t testing.TB) *gorm.DB {
	return setupTestDBWithTB(t)
}

// SetupTestDBForGinkgo creates an isolated PostgreSQL database for Ginkgo tests
// Use this function in Ginkgo BeforeEach blocks
//
// Example usage:
//
//	BeforeEach(func() {
//	    db = testutils.SetupTestDBForGinkgo(GinkgoT())
//	    repo = repository.NewMyRepository(db)
//	})
func SetupTestDBForGinkgo(ginkgoT interface {
	Helper()
	Logf(format string, args ...interface{})
	Fatalf(format string, args ...interface{})
	Failed() bool
}) *gorm.DB {
	wrapper := &ginkgoTBWrapper{t: ginkgoT}
	return setupTestDBWithTB(wrapper)
}

// setupTestDBWithTB is the internal implementation that works with both
// standard testing.T and Ginkgo's testing interface
func setupTestDBWithTB(t interface {
	Helper()
	Logf(format string, args ...interface{})
	Fatalf(format string, args ...interface{})
	Failed() bool
	Cleanup(func())
}) *gorm.DB {
	// Configure PostgreSQL connection
	// Defaults match the running Docker Compose PostgreSQL container (turash-postgres)
	//
	// IMPORTANT: pgtestdb creates ISOLATED test databases - it does NOT touch production data!
	// - Connects to 'postgres' database (admin database) to CREATE new test databases
	// - Each test gets a unique temporary database (e.g., pgtestdb_abc123)
	// - Test databases are automatically DROPPED after each test completes
	// - Production database 'turash' is NEVER modified or accessed
	conf := pgtestdb.Config{
		DriverName: "pgx",
		User:       getEnv("POSTGRES_USER", "turash"),
		Password:   getEnv("POSTGRES_PASSWORD", "turash123"),
		Host:       getEnv("POSTGRES_HOST", "localhost"),
		Port:       getEnv("POSTGRES_PORT", "5432"),
		Database:   getEnv("POSTGRES_DB", "postgres"), // Connect to 'postgres' database to create test databases
		Options:    "sslmode=disable",
	}

	// Create migrator instance
	migrator := &GormMigrator{}

	// Create isolated test database with migrations
	// pgtestdb.New accepts any type that implements the TB interface methods
	// It will:
	// 1. Check if a template database exists (by Hash())
	// 2. Create template if needed (runs Migrate function)
	// 3. Clone template for this test (fast, milliseconds)
	// 4. Return connection to cloned database
	sqlDB := pgtestdb.New(t, conf, migrator)

	// Check if PostGIS is already enabled or if geometry column exists
	// If geometry column exists, PostGIS was set up in the template
	var postgisEnabled bool
	var columnExists bool

	// Check if PostGIS extension exists
	if err := sqlDB.QueryRow("SELECT EXISTS(SELECT 1 FROM pg_extension WHERE extname = 'postgis')").Scan(&postgisEnabled); err != nil {
		postgisEnabled = false
	}

	// Check if geometry column exists (indicates PostGIS was set up)
	if err := sqlDB.QueryRow("SELECT EXISTS(SELECT 1 FROM information_schema.columns WHERE table_name = 'sites' AND column_name = 'location_geometry')").Scan(&columnExists); err != nil {
		columnExists = false
	}

	// If PostGIS is not enabled but column exists, try to enable PostGIS
	// This handles cases where template had PostGIS but cloned database doesn't inherit it
	if !postgisEnabled && columnExists {
		// Try to enable PostGIS - if it fails, that's OK since column already exists
		if err := enablePostGISExtension(sqlDB); err == nil {
			postgisEnabled = true
		}
	} else if !postgisEnabled && !columnExists {
		// PostGIS not enabled and column doesn't exist - try to enable PostGIS
		if err := enablePostGISExtension(sqlDB); err != nil {
			// Can't enable PostGIS - tests that need it will fail
			t.Logf("Warning: Failed to enable PostGIS extension: %v", err)
		} else {
			postgisEnabled = true
		}
	}

	// Convert to GORM DB for use in tests
	gormDB, err := gorm.Open(postgres.New(postgres.Config{
		Conn: sqlDB,
	}), &gorm.Config{
		Logger: logger.Default.LogMode(logger.Silent),
	})
	if err != nil {
		t.Fatalf("Failed to create GORM DB: %v", err)
	}

	// Run PostGIS migrations if PostGIS is enabled
	// This ensures geometry columns exist even if they weren't in the template
	if postgisEnabled {
		if err := domain.RunPostGISMigrations(gormDB); err != nil {
			// PostGIS migrations failed - this is critical for spatial operations
			// Fail the test setup rather than continuing with broken database
			t.Fatalf("Failed to run PostGIS migrations: %v", err)
		}
	}

	return gormDB
}