package mysql

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

// Config defines the config for storage.
type Config struct {
	// DB Will override ConnectionURI and all other authentication values if used
	//
	// Optional. Default is nil
	Db *sql.DB

	// Connection string to use for DB. Will override all other authentication values if used
	//
	// Optional. Default is ""
	ConnectionURI string

	// Host name where the DB is hosted
	//
	// Optional. Default is "127.0.0.1"
	Host string

	// Port where the DB is listening on
	//
	// Optional. Default is 3306
	Port int

	// Server username
	//
	// Optional. Default is ""
	Username string

	// Server password
	//
	// Optional. Default is ""
	Password string

	// Database name
	//
	// Optional. Default is "fiber"
	Database string

	// Table name
	//
	// Optional. Default is "fiber_storage"
	Table string

	// Reset clears any existing keys in existing Table
	//
	// Optional. Default is false
	Reset bool

	// Time before deleting expired keys
	//
	// Optional. Default is 10 * time.Second
	GCInterval time.Duration

	////////////////////////////////////
	// Adaptor related config options //
	////////////////////////////////////

	maxIdleConns    int
	maxOpenConns    int
	connMaxLifetime time.Duration
}

// ConfigDefault is the default config
var ConfigDefault = Config{
	Db:              nil,
	ConnectionURI:   "",
	Host:            "127.0.0.1",
	Port:            3306,
	Database:        "fiber",
	Table:           "fiber_storage",
	Reset:           false,
	GCInterval:      10 * time.Second,
	maxOpenConns:    100,
	maxIdleConns:    100,
	connMaxLifetime: 1 * time.Second,
}

func (c Config) dsn() string {
	if c.ConnectionURI != "" {
		return c.ConnectionURI
	}
	return fmt.Sprintf("%s:%s@tcp(%s:%d)/%s", c.Username, c.Password, c.Host, c.Port, c.Database)
}

// Helper function to set default values
func configDefault(config ...Config) Config {
	// Return default config if nothing provided
	if len(config) < 1 {
		return ConfigDefault
	}

	// Override default config
	cfg := config[0]

	// Set default values
	if cfg.Host == "" {
		cfg.Host = ConfigDefault.Host
	}
	if cfg.Port <= 0 {
		cfg.Port = ConfigDefault.Port
	}
	if cfg.Database == "" {
		cfg.Database = ConfigDefault.Database
	}
	if cfg.Table == "" {
		cfg.Table = ConfigDefault.Table
	}
	if int(cfg.GCInterval.Seconds()) <= 0 {
		cfg.GCInterval = ConfigDefault.GCInterval
	}
	return cfg
}