package database

import (
	"api_bb/migrations"
	"database/sql"
	"fmt"
	"strings"
	"time"

	"github.com/golang-migrate/migrate/v4"
	migratepg "github.com/golang-migrate/migrate/v4/database/postgres"
	"github.com/golang-migrate/migrate/v4/source/iofs"
	"go.uber.org/zap"
	gormpg "gorm.io/driver/postgres"
	"gorm.io/gorm"

	"api_bb/pkg/logger"
)

type Database struct {
	DB  *gorm.DB
	cfg *Config
}

type Config struct {
	URL    string
	Schema string
}

func NewDatabase(cfg *Config) *Database {
	if cfg.Schema == "" {
		cfg.Schema = "public"
	}
	return &Database{
		cfg: cfg,
	}
}

func (d *Database) Connect() error {
	zapLogger := logger.Get()

	zapLogger.Info("attempting to connect to database",
		zap.String("host", ExtractHostFromDSN(d.cfg.URL)),
		zap.String("database", ExtractDBNameFromDSN(d.cfg.URL)),
		zap.String("schema", d.cfg.Schema),
	)

	dsn := d.cfg.URL
	if d.cfg.Schema != "public" {
		dsn = dsn + fmt.Sprintf(" search_path=%s", d.cfg.Schema)
	}

	db, err := gorm.Open(gormpg.Open(dsn), &gorm.Config{})
	if err != nil {
		zapLogger.Error("failed to connect to database",
			zap.Error(err),
			zap.String("database_url", MaskPassword(d.cfg.URL)),
		)
		return fmt.Errorf("failed to connect to database: %w", err)
	}

	d.DB = db

	zapLogger.Info("Configure connection pool")
	sqlDB, err := d.DB.DB()
	if err != nil {
		return fmt.Errorf("failed to get underlying sql.DB: %w", err)
	}
	sqlDB.SetMaxOpenConns(25)
	sqlDB.SetMaxIdleConns(10)
	sqlDB.SetConnMaxLifetime(30 * time.Minute)

	zapLogger.Info("Run database migrations")
	if err := d.runMigrations(sqlDB); err != nil {
		return fmt.Errorf("failed to run migrations: %w", err)
	}
	zapLogger.Info("Migrations completed successfully")

	zapLogger.Info("successfully connected to database",
		zap.String("host", ExtractHostFromDSN(d.cfg.URL)),
		zap.String("database", ExtractDBNameFromDSN(d.cfg.URL)),
	)

	return nil
}

func (d *Database) runMigrations(sqlDB *sql.DB) error {
	zapLogger := logger.Get()

	source, err := iofs.New(migrations.FS, ".")
	if err != nil {
		return fmt.Errorf("failed to create migration source: %w", err)
	}

	driver, err := migratepg.WithInstance(sqlDB, &migratepg.Config{})
	if err != nil {
		return fmt.Errorf("failed to create postgres driver: %w", err)
	}

	m, err := migrate.NewWithInstance("iofs", source, "postgres", driver)
	if err != nil {
		return fmt.Errorf("failed to create migrate instance: %w", err)
	}

	if err := m.Up(); err != nil && err != migrate.ErrNoChange {
		zapLogger.Error("Migration error", zap.Error(err))
		return fmt.Errorf("failed to apply migrations: %w", err)
	}

	return nil
}

func (d *Database) Ping() error {
	zapLogger := logger.Get()

	sqlDB, err := d.DB.DB()
	if err != nil {
		zapLogger.Error("failed to get database instance", zap.Error(err))
		return fmt.Errorf("failed to get database instance: %w", err)
	}

	if err := sqlDB.Ping(); err != nil {
		zapLogger.Error("database ping failed", zap.Error(err))
		return fmt.Errorf("database ping failed: %w", err)
	}

	zapLogger.Info("database ping successful")
	return nil
}

func (d *Database) Close() error {
	zapLogger := logger.Get()

	if d.DB == nil {
		return nil
	}

	sqlDB, err := d.DB.DB()
	if err != nil {
		zapLogger.Error("failed to get database instance for closing", zap.Error(err))
		return fmt.Errorf("failed to get database instance: %w", err)
	}

	zapLogger.Info("closing database connection")
	if err := sqlDB.Close(); err != nil {
		zapLogger.Error("failed to close database connection", zap.Error(err))
		return fmt.Errorf("failed to close database connection: %w", err)
	}

	zapLogger.Info("database connection closed successfully")
	return nil
}

func ExtractHostFromDSN(dsn string) string {
	parts := strings.Split(dsn, " ")
	for _, part := range parts {
		if strings.HasPrefix(part, "host=") {
			return strings.TrimPrefix(part, "host=")
		}
	}
	return "unknown"
}

func ExtractDBNameFromDSN(dsn string) string {
	parts := strings.Split(dsn, " ")
	for _, part := range parts {
		if strings.HasPrefix(part, "dbname=") {
			return strings.TrimPrefix(part, "dbname=")
		}
	}
	return "unknown"
}

func MaskPassword(dsn string) string {
	parts := strings.Split(dsn, " ")
	for i, part := range parts {
		if strings.HasPrefix(part, "password=") {
			parts[i] = "password=***"
			break
		}
	}
	return strings.Join(parts, " ")
}