package graph

import (
	"context"
	"fmt"
	"time"

	"github.com/neo4j/neo4j-go-driver/v5/neo4j"
)

// SessionManager manages Neo4j sessions with proper lifecycle management
type SessionManager struct {
	driver   neo4j.DriverWithContext
	database string
	config   *Config
}

// NewSessionManager creates a new session manager
func NewSessionManager(driver neo4j.DriverWithContext, database string, config *Config) *SessionManager {
	return &SessionManager{
		driver:   driver,
		database: database,
		config:   config,
	}
}

// ExecuteRead executes a read transaction with proper error handling
func (sm *SessionManager) ExecuteRead(ctx context.Context, fn func(neo4j.ManagedTransaction) (interface{}, error)) (interface{}, error) {
	// Create context with timeout
	queryCtx, cancel := context.WithTimeout(ctx, time.Duration(sm.config.QueryTimeoutSeconds)*time.Second)
	defer cancel()

	session := sm.driver.NewSession(queryCtx, neo4j.SessionConfig{
		AccessMode:   neo4j.AccessModeRead,
		DatabaseName: sm.database,
	})
	defer session.Close(queryCtx)

	result, err := session.ExecuteRead(queryCtx, func(tx neo4j.ManagedTransaction) (interface{}, error) {
		return fn(tx)
	})

	if err != nil {
		return nil, fmt.Errorf("read transaction failed: %w", err)
	}

	return result, nil
}

// ExecuteWrite executes a write transaction with proper error handling
func (sm *SessionManager) ExecuteWrite(ctx context.Context, fn func(neo4j.ManagedTransaction) (interface{}, error)) (interface{}, error) {
	// Create context with timeout
	queryCtx, cancel := context.WithTimeout(ctx, time.Duration(sm.config.QueryTimeoutSeconds)*time.Second)
	defer cancel()

	session := sm.driver.NewSession(queryCtx, neo4j.SessionConfig{
		AccessMode:   neo4j.AccessModeWrite,
		DatabaseName: sm.database,
	})
	defer session.Close(queryCtx)

	result, err := session.ExecuteWrite(queryCtx, func(tx neo4j.ManagedTransaction) (interface{}, error) {
		return fn(tx)
	})

	if err != nil {
		return nil, fmt.Errorf("write transaction failed: %w", err)
	}

	return result, nil
}

// GetSession creates a new session (for advanced use cases)
func (sm *SessionManager) GetSession(ctx context.Context, accessMode neo4j.AccessMode) neo4j.SessionWithContext {
	return sm.driver.NewSession(ctx, neo4j.SessionConfig{
		AccessMode:   accessMode,
		DatabaseName: sm.database,
	})
}