package database

import (
	"database/sql"
	"fmt"
	"time"

	"github.com/rs/zerolog"
	"gorm.io/driver/postgres"
	"gorm.io/gorm"

	"base/config"
	"base/pkg/metrics"
)

// NewRWDatabaseConnection creates a new database connection
func NewRWDatabaseConnection(cfg *config.AppConfig, logger zerolog.Logger, metric *metrics.Metrics) (*gorm.DB, error) {
	start := time.Now()

	lg := logger.
		With().
		Str("module", "database").
		Int("maxOpenConnection", cfg.Database.MaxOpenConns).
		Int("maxIdleConnection", cfg.Database.MaxIdleConns).
		Logger()

	gormConfig := &gorm.Config{Logger: NewGormLogger(logger, time.Second*5)}

	wrDB, sqlDB, err := wr(cfg, gormConfig)
	if err != nil {
		fmt.Println("[DATABASE CONNECTION ERROR]Failed to connect to database", err.Error())
		metric.RecordDatabaseQuery("ConnectWR", "database", time.Since(start), err)

		lg.Error().
			Err(err).
			Msg("failed to connect to database")

		return nil, err
	}

	metric.RecordDatabaseQuery("ConnectWR", "database", time.Since(start), nil)

	// Start monitoring connection pool metrics
	go monitorConnectionPool(sqlDB, metric, logger)

	duration := time.Since(start)
	metric.RecordDatabaseQuery("Connect", "database", duration, nil)

	lg.Info().Msg("Database connection established")

	return wrDB, nil
}

func wr(config *config.AppConfig, gormConfig *gorm.Config) (*gorm.DB, *sql.DB, error) {
	// PostgreSQL DSN format: postgres://user:password@host:port/dbname?sslmode=disable
	dsn := fmt.Sprintf(
		"host=%s user=%s password=%s dbname=%s port=%d sslmode=%s TimeZone=UTC",
		config.PgDatabaseConfig.Host,
		config.PgDatabaseConfig.User,
		config.PgDatabaseConfig.Password,
		config.PgDatabaseConfig.Name,
		config.PgDatabaseConfig.Port,
		config.PgDatabaseConfig.SSLMode,
	)

	db, err := gorm.Open(postgres.Open(dsn), gormConfig)
	if err != nil {
		return nil, nil, err
	}

	// Get the underlying sql.DB
	sqlDB, err := db.DB()
	if err != nil {
		return nil, nil, err
	}

	sqlDB.SetMaxIdleConns(int(config.PgDatabaseConfig.PoolConfig.MinConn))
	sqlDB.SetMaxOpenConns(int(config.PgDatabaseConfig.PoolConfig.MaxConn))

	// Parse and set connection timeouts from config
	// TODO: this is not type safe
	if config.PgDatabaseConfig.PoolConfig.MaxConnIdleTime.String() != "" {
		if idleTime, parseDurationErr := time.ParseDuration(config.PgDatabaseConfig.PoolConfig.MaxConnIdleTime.String()); parseDurationErr == nil {
			sqlDB.SetConnMaxIdleTime(idleTime)
		} else {
			sqlDB.SetConnMaxIdleTime(5 * time.Minute)
		}
	}

	if config.PgDatabaseConfig.PoolConfig.MaxConnLifetime.String() != "" {
		if lifetime, parseDurationErr := time.ParseDuration(config.PgDatabaseConfig.PoolConfig.MaxConnLifetime.String()); parseDurationErr == nil {
			sqlDB.SetConnMaxLifetime(lifetime)
		} else {
			sqlDB.SetConnMaxLifetime(30 * time.Minute)
		}
	}

	return db, sqlDB, nil
}