//go:build linux || freebsd
// +build linux freebsd

package protocol

import (
	"fmt"
	"net/url"

	"codeberg.org/petrbalvin/goget/internal/core"
)

// ProtocolInfo contains metadata about a protocol
type ProtocolInfo struct {
	// Protocol name
	Name string

	// URL scheme
	Scheme string

	// Protocol version
	Version string

	// Supported operations
	Operations []string

	// Supported features
	Features []string

	// Default port
	DefaultPort int
}

// BaseProtocol is the base implementation for all protocols
type BaseProtocol struct {
	info ProtocolInfo
}

// NewBaseProtocol creates a new base protocol
func NewBaseProtocol(info ProtocolInfo) *BaseProtocol {
	return &BaseProtocol{info: info}
}

// Scheme returns the protocol scheme
func (bp *BaseProtocol) Scheme() string {
	return bp.info.Scheme
}

// Name returns the protocol name
func (bp *BaseProtocol) Name() string {
	return bp.info.Name
}

// Capabilities returns the list of supported features
func (bp *BaseProtocol) Capabilities() []string {
	return bp.info.Features
}

// SupportsResume returns whether the protocol supports resume
func (bp *BaseProtocol) SupportsResume() bool {
	return contains(bp.info.Features, "resume")
}

// SupportsCompression returns whether the protocol supports compression
func (bp *BaseProtocol) SupportsCompression() bool {
	return contains(bp.info.Features, "compression")
}

// SupportsUpload returns whether the protocol supports upload
func (bp *BaseProtocol) SupportsUpload() bool {
	return contains(bp.info.Features, "upload")
}

// SupportsRange returns whether the protocol supports range requests
func (bp *BaseProtocol) SupportsRange() bool {
	return contains(bp.info.Features, "range")
}

// CanHandle checks if this protocol can handle the given URL.
func (bp *BaseProtocol) CanHandle(url *url.URL) bool {
	if url == nil {
		return false
	}
	return url.Scheme == bp.info.Scheme
}

// SupportsParallel returns whether the protocol supports parallel downloads.
func (bp *BaseProtocol) SupportsParallel() bool {
	return contains(bp.info.Features, "parallel")
}

// SupportsRecursive returns whether the protocol supports recursive downloads.
func (bp *BaseProtocol) SupportsRecursive() bool {
	return contains(bp.info.Features, "recursive")
}

// contains is a helper function
func contains(slice []string, item string) bool {
	for _, s := range slice {
		if s == item {
			return true
		}
	}
	return false
}

// ValidateURL validates a URL for the given protocol
func ValidateURL(u *url.URL, scheme string) error {
	if u == nil {
		return core.NewProtocolError("URL is nil", nil, "")
	}

	if u.Scheme != scheme {
		return core.NewProtocolError(
			fmt.Sprintf("expected scheme %s, got %s", scheme, u.Scheme),
			nil,
			u.String(),
		)
	}

	if u.Host == "" {
		return core.NewProtocolError("missing host in URL", nil, u.String())
	}

	return nil
}

// GetDefaultPort returns the default port for a scheme
func GetDefaultPort(scheme string) int {
	switch scheme {
	case "http":
		return 80
	case "https", "webdavs":
		return 443
	case "webdav":
		// Plain WebDAV (no TLS) defaults to 80, matching HTTP.
		// Previously this returned 443 — a leftover from bundling
		// "webdav" with the TLS-bearing schemes — which made
		// non-TLS WebDAV connections fail against servers not
		// listening on 443.
		return 80
	case "ftp":
		return 21
	case "ftps":
		return 990
	case "sftp":
		return 22
	default:
		return 0
	}
}