config-lsp/root-handler/lsp-utils.go

package roothandler

import (
	"config-lsp/common"
	"config-lsp/utils"
	"fmt"
	"regexp"
	"strings"

	protocol "github.com/tliron/glsp/protocol_3_16"
)

type SupportedLanguage string

const (
	LanguageSSHDConfig SupportedLanguage = "sshd_config"
	LanguageFstab      SupportedLanguage = "fstab"
)

var AllSupportedLanguages = []string{
	string(LanguageSSHDConfig),
	string(LanguageFstab),
}

type FatalFileNotReadableError struct {
	FileURI protocol.DocumentUri
	Err     error
}

func (e FatalFileNotReadableError) Error() string {
	return fmt.Sprint("Fatal error! config-lsp was unable to read the file (%s); error: %s", e.FileURI, e.Err.Error())
}

type UnsupportedLanguageError struct {
	SuggestedLanguage string
}

func (e UnsupportedLanguageError) Error() string {
	return fmt.Sprint("Language '%s' is not supported. Choose one of: %s", e.SuggestedLanguage, strings.Join(AllSupportedLanguages, ", "))
}

type LanguageUndetectableError struct{}

func (e LanguageUndetectableError) Error() string {
	return "Please add: '#?lsp.language=<language>' to the top of the file. config-lsp was unable to detect the appropriate language for this file."
}

var valueToLanguageMap = map[string]SupportedLanguage{
	"sshd_config": LanguageSSHDConfig,
	"sshdconfig":  LanguageSSHDConfig,
	"ssh_config":  LanguageSSHDConfig,
	"sshconfig":   LanguageSSHDConfig,

	"fstab":     LanguageFstab,
	"etc/fstab": LanguageFstab,
}

var typeOverwriteRegex = regexp.MustCompile(`^#\?\s*lsp\.language\s*=\s*(\w+)\s*$`)

func DetectLanguage(
	content string,
	advertisedLanguage string,
	uri protocol.DocumentUri,
) (SupportedLanguage, error) {
	if match := typeOverwriteRegex.FindStringSubmatch(content); match != nil {
		suggestedLanguage := strings.ToLower(match[1])

		foundLanguage, ok := valueToLanguageMap[suggestedLanguage]

		if ok {
			return foundLanguage, nil
		}

		matchIndex := strings.Index(content, match[0])
		contentUntilMatch := content[:matchIndex]

		return "", common.ParseError{
			Line: uint32(utils.CountCharacterOccurrences(contentUntilMatch, '\n')),
			Err: UnsupportedLanguageError{
				SuggestedLanguage: suggestedLanguage,
			},
		}
	}

	if language, ok := valueToLanguageMap[advertisedLanguage]; ok {
		return language, nil
	}

	switch uri {
	case "file:///etc/ssh/sshd_config":
	case "file:///etc/ssh/ssh_config":
		return LanguageSSHDConfig, nil
	case "file:///etc/fstab":
		return LanguageFstab, nil
	}

	return "", common.ParseError{
		Line: 0,
		Err:  LanguageUndetectableError{},
	}
}