From 1fc847d523b808cffc3ad512391a87af0baaf82a Mon Sep 17 00:00:00 2001
From: Myzel394 <50424412+Myzel394@users.noreply.github.com>
Date: Wed, 16 Oct 2024 16:34:11 +0200
Subject: [PATCH] feat(ssh_config): Add support for signature help

---
 .../ssh_config/handlers/signature_help.go     | 150 ++++++++++++++++++
 .../lsp/text-document-signature-help.go       |  41 ++++-
 .../text-document-signature-help.go           |   3 +-
 3 files changed, 192 insertions(+), 2 deletions(-)
 create mode 100644 server/handlers/ssh_config/handlers/signature_help.go

diff --git a/server/handlers/ssh_config/handlers/signature_help.go b/server/handlers/ssh_config/handlers/signature_help.go
new file mode 100644
index 0000000..5bdacbb
--- /dev/null
+++ b/server/handlers/ssh_config/handlers/signature_help.go
@@ -0,0 +1,150 @@
+package handlers
+
+import (
+	"config-lsp/common"
+	"config-lsp/handlers/ssh_config/ast"
+
+	protocol "github.com/tliron/glsp/protocol_3_16"
+)
+
+func GetOptionSignatureHelp(
+	option *ast.SSHOption,
+	cursor common.CursorPosition,
+) *protocol.SignatureHelp {
+	var index uint32
+
+	if option == nil || option.Key == nil || (option.OptionValue == nil || option.Key.ContainsPosition(cursor)) {
+		index = 0
+	} else {
+		index = 1
+	}
+
+	signature := uint32(0)
+	return &protocol.SignatureHelp{
+		ActiveSignature: &signature,
+		Signatures: []protocol.SignatureInformation{
+			{
+				Label:           "<option> <value>",
+				ActiveParameter: &index,
+				Parameters: []protocol.ParameterInformation{
+					{
+						Label: []uint32{
+							0,
+							uint32(len("<option>") + 1),
+						},
+						Documentation: "The option name",
+					},
+					{
+						Label: []uint32{
+							uint32(len("<option>")),
+							uint32(len("<option>") + len("<value>") + 1),
+						},
+						Documentation: "The value for the option",
+					},
+				},
+			},
+		},
+	}
+}
+
+func GetMatchSignatureHelp(
+	match *ast.SSHMatchBlock,
+	cursor common.CursorPosition,
+) *protocol.SignatureHelp {
+	var index uint32
+
+	if match.MatchOption.Key.ContainsPosition(cursor) {
+		index = 0
+	} else {
+		entry := match.MatchValue.GetEntryAtPosition(cursor)
+
+		if entry == nil || entry.Criteria.ContainsPosition(cursor) {
+			index = 1
+		} else {
+			index = 2
+		}
+	}
+
+	signature := uint32(0)
+	return &protocol.SignatureHelp{
+		ActiveSignature: &signature,
+		Signatures: []protocol.SignatureInformation{
+			{
+				Label:           "Match <criteria> <values>",
+				ActiveParameter: &index,
+				Parameters: []protocol.ParameterInformation{
+					{
+						Label: []uint32{
+							0,
+							uint32(len("Match") + 1),
+						},
+						Documentation: "The \"Match\" keyword",
+					},
+					{
+						Label: []uint32{
+							uint32(len("Match ")),
+							uint32(len("Match ") + len("<criteria>")),
+						},
+						Documentation: "The criteria name",
+					},
+					{
+						Label: []uint32{
+							uint32(len("Host <criteria> ")),
+							uint32(len("Host <criteria> ") + len("<values>") + 1),
+						},
+						Documentation: "Values for the criteria",
+					},
+				},
+			},
+		},
+	}
+}
+
+func GetHostSignatureHelp(
+	host *ast.SSHHostBlock,
+	cursor common.CursorPosition,
+) *protocol.SignatureHelp {
+	var index uint32
+
+	if host.HostOption.Key.ContainsPosition(cursor) {
+		index = 0
+	} else if len(host.HostValue.Hosts) >= 1 && host.HostValue.Hosts[0].ContainsPosition(cursor) {
+		index = 1
+	} else {
+		index = 2
+	}
+
+	signature := uint32(0)
+	return &protocol.SignatureHelp{
+		ActiveSignature: &signature,
+		Signatures: []protocol.SignatureInformation{
+			{
+				Label:           "Host <host1> [<host2> ...]",
+				ActiveParameter: &index,
+				Parameters: []protocol.ParameterInformation{
+					{
+						Label: []uint32{
+							0,
+							uint32(len("Host") + 1),
+						},
+						Documentation: "The \"Host\" keyword",
+					},
+					{
+						Label: []uint32{
+							uint32(len("Host ")),
+							uint32(len("Host ") + len("<host1>") + 1),
+						},
+						Documentation: "A host that should match",
+					},
+					{
+						Label: []uint32{
+							uint32(len("Host <host1> ")),
+							uint32(len("Host <host1> ") + len("[<host2> ...]") + 1),
+						},
+						Documentation: "Additional (optional) hosts that should match",
+					},
+				},
+			},
+		},
+	}
+}
diff --git a/server/handlers/ssh_config/lsp/text-document-signature-help.go b/server/handlers/ssh_config/lsp/text-document-signature-help.go
index eff0052..6ba48b0 100644
--- a/server/handlers/ssh_config/lsp/text-document-signature-help.go
+++ b/server/handlers/ssh_config/lsp/text-document-signature-help.go
@@ -1,10 +1,49 @@
 package lsp
 
 import (
+	"config-lsp/common"
+	sshconfig "config-lsp/handlers/ssh_config"
+	"config-lsp/handlers/ssh_config/ast"
+	"config-lsp/handlers/ssh_config/fields"
+	"config-lsp/handlers/ssh_config/handlers"
+
 	"github.com/tliron/glsp"
 	protocol "github.com/tliron/glsp/protocol_3_16"
 )
 
+var hostOption = fields.CreateNormalizedName("Host")
+
 func TextDocumentSignatureHelp(context *glsp.Context, params *protocol.SignatureHelpParams) (*protocol.SignatureHelp, error) {
-	return nil, nil
+	document := sshconfig.DocumentParserMap[params.TextDocument.URI]
+
+	line := uint32(params.Position.Line)
+	cursor := common.LSPCharacterAsCursorPosition(params.Position.Character)
+
+	if _, found := document.Config.CommentLines[line]; found {
+		// Comment
+		return nil, nil
+	}
+
+	option, block := document.Config.FindOption(line)
+
+	if option != nil {
+		if option.Key != nil {
+			switch option.Key.Key {
+			case matchOption:
+				return handlers.GetMatchSignatureHelp(
+					block.(*ast.SSHMatchBlock),
+					cursor,
+				), nil
+			case hostOption:
+				return handlers.GetHostSignatureHelp(
+					block.(*ast.SSHHostBlock),
+					cursor,
+				), nil
+			}
+		}
+
+		return handlers.GetOptionSignatureHelp(option, cursor), nil
+	} else {
+		return handlers.GetOptionSignatureHelp(option, cursor), nil
+	}
 }
diff --git a/server/root-handler/text-document-signature-help.go b/server/root-handler/text-document-signature-help.go
index 0e6ca33..a144644 100644
--- a/server/root-handler/text-document-signature-help.go
+++ b/server/root-handler/text-document-signature-help.go
@@ -2,6 +2,7 @@ package roothandler
 
 import (
 	aliases "config-lsp/handlers/aliases/lsp"
+	sshconfig "config-lsp/handlers/ssh_config/lsp"
 	sshdconfig "config-lsp/handlers/sshd_config/lsp"
 
 	"github.com/tliron/glsp"
@@ -27,7 +28,7 @@ func TextDocumentSignatureHelp(context *glsp.Context, params *protocol.Signature
 	case LanguageSSHDConfig:
 		return sshdconfig.TextDocumentSignatureHelp(context, params)
 	case LanguageSSHConfig:
-		return nil, nil
+		return sshconfig.TextDocumentSignatureHelp(context, params)
 	case LanguageFstab:
 		return nil, nil
 	case LanguageWireguard: