package domain

import (
	"fmt"

	"gorm.io/gorm"
)

// AutoMigrate runs all migrations for the database schema
func AutoMigrate(db *gorm.DB) error {
	// Run AutoMigrate first to create tables
	if err := db.AutoMigrate(
		&Address{},
		&Organization{},
		&Site{},
		&SiteOperatingBusiness{},
		&ResourceFlow{},
		&ResourceFlowVersion{},
		&SharedAsset{},
		&Match{},
		&NegotiationHistoryEntry{},
		&User{},
		&Localization{},
		&Product{},
		&Service{},
		&ServiceNeed{},
	); err != nil {
		return err
	}

	// Fix JSONB column issues after tables are created
	if err := FixJSONBColumns(db); err != nil {
		return fmt.Errorf("failed to fix JSONB columns: %v", err)
	}

	return nil
}

// RunPostGISMigrations runs PostGIS-specific migrations only on PostgreSQL databases
func RunPostGISMigrations(db *gorm.DB) error {
	// Only run PostGIS migrations for PostgreSQL databases
	if db.Dialector.Name() != "postgres" {
		return nil
	}

	// First, check if PostGIS extension is enabled
	var postgisEnabled bool
	if err := db.Raw("SELECT EXISTS(SELECT 1 FROM pg_extension WHERE extname = 'postgis')").Scan(&postgisEnabled).Error; err != nil {
		return fmt.Errorf("failed to check PostGIS extension: %v", err)
	}
	if !postgisEnabled {
		return fmt.Errorf("PostGIS extension is not enabled in this database")
	}

	// Verify PostGIS functions are available
	var postgisVersion string
	if err := db.Raw("SELECT PostGIS_Version()").Scan(&postgisVersion).Error; err != nil {
		return fmt.Errorf("PostGIS not available: %v", err)
	}

	// Handle geometry column setup - ensure it exists with correct type
	// First, check if column exists and what type it is
	var columnExists bool
	var dataType, udtName string
	if err := db.Raw(`
		SELECT EXISTS(
			SELECT 1 FROM information_schema.columns
			WHERE table_name = 'sites' AND column_name = 'location_geometry'
		)
	`).Scan(&columnExists).Error; err != nil {
		return fmt.Errorf("failed to check geometry column: %v", err)
	}

	if columnExists {
		// Get detailed column information
		type ColumnInfo struct {
			DataType string
			UdtName  string
		}
		var info ColumnInfo
		if err := db.Raw(`
			SELECT
				c.data_type,
				COALESCE(c.udt_name, '') as udt_name
			FROM information_schema.columns c
			WHERE c.table_name = 'sites' AND c.column_name = 'location_geometry'
		`).Scan(&info).Error; err != nil {
			return fmt.Errorf("failed to check column type: %v", err)
		}
		dataType = info.DataType
		udtName = info.UdtName

		// If column exists but is wrong type (not geometry), we need to handle it carefully
		if dataType != "USER-DEFINED" || udtName != "geometry" {
			// Drop any existing index first
			if err := db.Exec("DROP INDEX IF EXISTS idx_site_geometry").Error; err != nil {
				return fmt.Errorf("failed to drop existing geometry index: %v", err)
			}
			// Drop the column
			if err := db.Exec("ALTER TABLE sites DROP COLUMN location_geometry").Error; err != nil {
				return fmt.Errorf("failed to drop incorrect geometry column: %v", err)
			}
			columnExists = false
		}
	}

	// Create column if it doesn't exist or was dropped
	if !columnExists {
		if err := db.Exec("ALTER TABLE sites ADD COLUMN location_geometry geometry(Point, 4326)").Error; err != nil {
			return fmt.Errorf("failed to create geometry column: %v", err)
		}
	}

	// Create spatial index for efficient queries
	if err := db.Exec(`
		CREATE INDEX IF NOT EXISTS idx_site_geometry ON sites USING GIST (location_geometry);
	`).Error; err != nil {
		return fmt.Errorf("failed to create spatial index: %v", err)
	}

	// Update existing records to populate geometry from lat/lng
	// Using ST_SetSRID and ST_MakePoint (2025 best practice) instead of ST_GeogFromText
	// This is more efficient and ensures proper SRID handling
	if err := db.Exec(`
		UPDATE sites
		SET location_geometry = ST_SetSRID(ST_MakePoint(longitude, latitude), 4326)
		WHERE latitude IS NOT NULL
		  AND longitude IS NOT NULL
		  AND (location_geometry IS NULL OR NOT ST_IsValid(location_geometry));
	`).Error; err != nil {
		return fmt.Errorf("failed to populate geometry data: %v", err)
	}

	// Drop existing constraint if it exists and recreate
	if err := db.Exec(`
		ALTER TABLE sites DROP CONSTRAINT IF EXISTS check_location_geometry;
		ALTER TABLE sites ADD CONSTRAINT check_location_geometry
		    CHECK (location_geometry IS NULL OR ST_IsValid(location_geometry));
	`).Error; err != nil {
		return fmt.Errorf("failed to add geometry constraint: %v", err)
	}

	// Add comment for documentation
	if err := db.Exec(`
		COMMENT ON COLUMN sites.location_geometry IS 'PostGIS geometry field for spatial operations (SRID 4326 = WGS84)';
	`).Error; err != nil {
		return fmt.Errorf("failed to add column comment: %v", err)
	}

	return nil
}

// FixJSONBColumns fixes JSONB column conversion issues that GORM can't handle automatically
func FixJSONBColumns(db *gorm.DB) error {
	// Fix certifications column - remove default, convert to JSONB, add default back
	if err := db.Exec(`
		ALTER TABLE organizations ALTER COLUMN certifications DROP DEFAULT;
	`).Error; err != nil {
		return fmt.Errorf("failed to drop certifications default: %v", err)
	}

	if err := db.Exec(`
		ALTER TABLE organizations ALTER COLUMN certifications TYPE JSONB USING certifications::JSONB;
	`).Error; err != nil {
		return fmt.Errorf("failed to convert certifications to JSONB: %v", err)
	}

	if err := db.Exec(`
		ALTER TABLE organizations ALTER COLUMN certifications SET DEFAULT '[]'::jsonb;
	`).Error; err != nil {
		return fmt.Errorf("failed to set certifications default: %v", err)
	}

	// Fix other JSONB columns similarly
	jsonbColumns := []string{
		"business_focus",
		"technical_expertise",
		"available_technology",
		"management_systems",
		"trust_network",
		"existing_symbiotic_relationships",
		"gallery_images",
	}

	for _, col := range jsonbColumns {
		if err := db.Exec(fmt.Sprintf(`
			ALTER TABLE organizations ALTER COLUMN %s DROP DEFAULT;
		`, col)).Error; err != nil {
			return fmt.Errorf("failed to drop %s default: %v", col, err)
		}

		if err := db.Exec(fmt.Sprintf(`
			ALTER TABLE organizations ALTER COLUMN %s TYPE JSONB USING %s::JSONB;
		`, col, col)).Error; err != nil {
			return fmt.Errorf("failed to convert %s to JSONB: %v", col, err)
		}

		if err := db.Exec(fmt.Sprintf(`
			ALTER TABLE organizations ALTER COLUMN %s SET DEFAULT '[]'::jsonb;
		`, col)).Error; err != nil {
			return fmt.Errorf("failed to set %s default: %v", col, err)
		}
	}

	return nil
}

// RunSearchMigrations enables pg_trgm extension and creates search indexes for PostgreSQL
func RunSearchMigrations(db *gorm.DB) error {
	// Only run search migrations for PostgreSQL databases
	if db.Dialector.Name() != "postgres" {
		return nil
	}

	// Enable pg_trgm extension for fuzzy search
	if err := db.Exec("CREATE EXTENSION IF NOT EXISTS pg_trgm").Error; err != nil {
		return fmt.Errorf("failed to enable pg_trgm extension: %v", err)
	}

	// Create trigram indexes for fuzzy search on organizations
	// These indexes significantly speed up similarity searches
	if err := db.Exec(`
		CREATE INDEX IF NOT EXISTS idx_org_name_trgm
		ON organizations USING GIN (name gin_trgm_ops);
	`).Error; err != nil {
		return fmt.Errorf("failed to create name trigram index: %v", err)
	}

	if err := db.Exec(`
		CREATE INDEX IF NOT EXISTS idx_org_description_trgm
		ON organizations USING GIN (description gin_trgm_ops);
	`).Error; err != nil {
		return fmt.Errorf("failed to create description trigram index: %v", err)
	}

	if err := db.Exec(`
		CREATE INDEX IF NOT EXISTS idx_org_sector_trgm
		ON organizations USING GIN (sector gin_trgm_ops);
	`).Error; err != nil {
		return fmt.Errorf("failed to create sector trigram index: %v", err)
	}

	return nil
}

// CreateIndexes creates additional indexes that GORM doesn't handle automatically
func CreateIndexes(db *gorm.DB) error {
	// Composite indexes for organizations
	if err := db.Exec(`
		CREATE INDEX IF NOT EXISTS idx_org_subtype_sector
		ON organizations(subtype, sector);
	`).Error; err != nil {
		return err
	}

	if err := db.Exec(`
		CREATE INDEX IF NOT EXISTS idx_org_verified_subtype
		ON organizations(verified, subtype);
	`).Error; err != nil {
		return err
	}

	// GIN indexes for JSONB fields
	if err := db.Exec(`
		CREATE INDEX IF NOT EXISTS idx_org_products
		ON organizations USING GIN (products);
	`).Error; err != nil {
		return err
	}

	if err := db.Exec(`
		CREATE INDEX IF NOT EXISTS idx_org_certifications
		ON organizations USING GIN (certifications);
	`).Error; err != nil {
		return err
	}

	// Indexes for products table
	if err := db.Exec(`
		CREATE INDEX IF NOT EXISTS idx_products_category
		ON products(category);
	`).Error; err != nil {
		return err
	}

	if err := db.Exec(`
		CREATE INDEX IF NOT EXISTS idx_products_organization
		ON products(organization_id);
	`).Error; err != nil {
		return err
	}

	if err := db.Exec(`
		CREATE INDEX IF NOT EXISTS idx_products_price
		ON products(unit_price);
	`).Error; err != nil {
		return err
	}

	// Indexes for services table
	if err := db.Exec(`
		CREATE INDEX IF NOT EXISTS idx_services_type
		ON services(type);
	`).Error; err != nil {
		return err
	}

	if err := db.Exec(`
		CREATE INDEX IF NOT EXISTS idx_services_domain
		ON services(domain);
	`).Error; err != nil {
		return err
	}

	if err := db.Exec(`
		CREATE INDEX IF NOT EXISTS idx_services_organization
		ON services(organization_id);
	`).Error; err != nil {
		return err
	}

	// Indexes for service_needs table
	if err := db.Exec(`
		CREATE INDEX IF NOT EXISTS idx_service_needs_type
		ON service_needs(type);
	`).Error; err != nil {
		return err
	}

	if err := db.Exec(`
		CREATE INDEX IF NOT EXISTS idx_service_needs_organization
		ON service_needs(organization_id);
	`).Error; err != nil {
		return err
	}

	if err := db.Exec(`
		CREATE INDEX IF NOT EXISTS idx_service_needs_urgency
		ON service_needs(urgency);
	`).Error; err != nil {
		return err
	}

	if err := db.Exec(`
		CREATE INDEX IF NOT EXISTS idx_site_utilities
		ON sites USING GIN (available_utilities);
	`).Error; err != nil {
		return err
	}

	if err := db.Exec(`
		CREATE INDEX IF NOT EXISTS idx_site_waste_mgmt
		ON sites USING GIN (waste_management);
	`).Error; err != nil {
		return err
	}

	// Partial indexes for resource flows
	if err := db.Exec(`
		CREATE INDEX IF NOT EXISTS idx_rf_output_heat
		ON resource_flows (site_id, (quality->>'temperature_celsius')::numeric)
		WHERE direction = 'output' AND type = 'heat';
	`).Error; err != nil {
		return err
	}

	if err := db.Exec(`
		CREATE INDEX IF NOT EXISTS idx_rf_input_heat
		ON resource_flows (site_id, (quality->>'temperature_celsius')::numeric)
		WHERE direction = 'input' AND type = 'heat';
	`).Error; err != nil {
		return err
	}

	// Composite index for match queries
	if err := db.Exec(`
		CREATE INDEX IF NOT EXISTS idx_match_status_score
		ON matches(status, compatibility_score DESC);
	`).Error; err != nil {
		return err
	}

	if err := db.Exec(`
		CREATE INDEX IF NOT EXISTS idx_match_economic_value
		ON matches(economic_value DESC, status);
	`).Error; err != nil {
		return err
	}

	return nil
}

// CreateConstraints creates additional constraints
func CreateConstraints(db *gorm.DB) error {
	// Unique constraint on resource flow version
	if err := db.Exec(`
		ALTER TABLE resource_flow_versions
		ADD CONSTRAINT IF NOT EXISTS unique_flow_version
		UNIQUE (resource_flow_id, version_number);
	`).Error; err != nil {
		return err
	}

	// Check constraint for match priority
	if err := db.Exec(`
		ALTER TABLE matches
		ADD CONSTRAINT IF NOT EXISTS check_match_priority
		CHECK (priority BETWEEN 1 AND 10);
	`).Error; err != nil {
		return err
	}

	// Check constraint for organization readiness maturity
	if err := db.Exec(`
		ALTER TABLE organizations
		ADD CONSTRAINT IF NOT EXISTS check_readiness_maturity
		CHECK (readiness_maturity BETWEEN 1 AND 5);
	`).Error; err != nil {
		return err
	}

	// Check constraint for shared asset utilization
	if err := db.Exec(`
		ALTER TABLE shared_assets
		ADD CONSTRAINT IF NOT EXISTS check_utilization_rate
		CHECK (utilization_rate BETWEEN 0 AND 1);
	`).Error; err != nil {
		return err
	}

	return nil
}