package api

import (
	"fmt"
	"regexp"
	"strings"
)

var (
	iqnRegex = regexp.MustCompile(`^iqn\.\d{4}-\d{2}\.[^:]+:[^:]+$`)
)

func validateIQN(iqn string) error {
	if !iqnRegex.MatchString(iqn) {
		return fmt.Errorf("invalid IQN format: %s (expected format: iqn.YYYY-MM.reversed.domain:identifier)", iqn)
	}
	return nil
}

func validateRepositoryName(name string) error {
	if name == "" {
		return fmt.Errorf("repository name cannot be empty")
	}
	if len(name) > 64 {
		return fmt.Errorf("repository name too long (max 64 characters)")
	}
	// Allow alphanumeric, dash, underscore
	matched, _ := regexp.MatchString(`^[a-zA-Z0-9_-]+$`, name)
	if !matched {
		return fmt.Errorf("repository name contains invalid characters (only alphanumeric, dash, underscore allowed)")
	}
	return nil
}

func validateSize(size string) error {
	if size == "" {
		return fmt.Errorf("size cannot be empty")
	}
	// Basic validation for size format (e.g., "10G", "500M")
	matched, _ := regexp.MatchString(`^\d+[KMGT]?$`, strings.ToUpper(size))
	if !matched {
		return fmt.Errorf("invalid size format: %s (expected format: 10G, 500M, etc.)", size)
	}
	return nil
}

func validateIP(ip string) error {
	// Basic IP validation
	parts := strings.Split(ip, ":")
	if len(parts) != 2 {
		return fmt.Errorf("invalid IP:port format: %s", ip)
	}
	ipParts := strings.Split(parts[0], ".")
	if len(ipParts) != 4 {
		return fmt.Errorf("invalid IP address: %s", parts[0])
	}
	return nil
}

func validatePortal(portal string) error {
	if portal == "" {
		return fmt.Errorf("portal cannot be empty")
	}
	// Format: IP:port or hostname:port
	parts := strings.Split(portal, ":")
	if len(parts) != 2 {
		return fmt.Errorf("invalid portal format: %s (expected IP:port or hostname:port)", portal)
	}
	// If it looks like an IP, validate it
	if matched, _ := regexp.MatchString(`^\d+\.\d+\.\d+\.\d+$`, parts[0]); matched {
		return validateIP(portal)
	}
	return nil
}