// Package lsp implements a minimal Language Server Protocol server for glint.
package lsp

import "encoding/json"

// Message is a JSON-RPC 2.0 message (request, response, or notification).
type Message struct {
	JSONRPC string          `json:"jsonrpc"`
	ID      json.RawMessage `json:"id,omitempty"`
	Method  string          `json:"method,omitempty"`
	Params  json.RawMessage `json:"params,omitempty"`
	Result  json.RawMessage `json:"result,omitempty"`
	Error   *RPCError       `json:"error,omitempty"`
}

// RPCError is a JSON-RPC 2.0 error object.
type RPCError struct {
	Code    int    `json:"code"`
	Message string `json:"message"`
}

// InitializeResult is the server's response to the initialize request.
type InitializeResult struct {
	Capabilities ServerCapabilities `json:"capabilities"`
	ServerInfo   *ServerInfo        `json:"serverInfo,omitempty"`
}

// ServerCapabilities advertises what the server supports.
type ServerCapabilities struct {
	// TextDocumentSync: 1 = Full (send entire document on every change).
	TextDocumentSync int `json:"textDocumentSync"`
}

// ServerInfo identifies the server to the client.
type ServerInfo struct {
	Name    string `json:"name"`
	Version string `json:"version,omitempty"`
}

// TextDocumentItem is a text document opened by the client.
type TextDocumentItem struct {
	URI        string `json:"uri"`
	LanguageID string `json:"languageId"`
	Version    int    `json:"version"`
	Text       string `json:"text"`
}

// TextDocumentIdentifier references a text document by URI.
type TextDocumentIdentifier struct {
	URI string `json:"uri"`
}

// VersionedTextDocumentIdentifier includes a version number.
type VersionedTextDocumentIdentifier struct {
	URI     string `json:"uri"`
	Version int    `json:"version"`
}

// TextDocumentContentChangeEvent is a single content change event.
// With Full sync the Text field contains the complete new document text.
type TextDocumentContentChangeEvent struct {
	Text string `json:"text"`
}

// DidOpenTextDocumentParams is the params for textDocument/didOpen.
type DidOpenTextDocumentParams struct {
	TextDocument TextDocumentItem `json:"textDocument"`
}

// DidChangeTextDocumentParams is the params for textDocument/didChange.
type DidChangeTextDocumentParams struct {
	TextDocument   VersionedTextDocumentIdentifier  `json:"textDocument"`
	ContentChanges []TextDocumentContentChangeEvent `json:"contentChanges"`
}

// DidSaveTextDocumentParams is the params for textDocument/didSave.
type DidSaveTextDocumentParams struct {
	TextDocument TextDocumentIdentifier `json:"textDocument"`
	Text         *string                `json:"text,omitempty"`
}

// DidCloseTextDocumentParams is the params for textDocument/didClose.
type DidCloseTextDocumentParams struct {
	TextDocument TextDocumentIdentifier `json:"textDocument"`
}

// PublishDiagnosticsParams is the params for textDocument/publishDiagnostics.
type PublishDiagnosticsParams struct {
	URI         string       `json:"uri"`
	Diagnostics []Diagnostic `json:"diagnostics"`
}

// Diagnostic is a lint finding expressed in LSP terms.
type Diagnostic struct {
	Range    Range  `json:"range"`
	Severity int    `json:"severity"` // 1=Error, 2=Warning, 3=Information, 4=Hint
	Code     string `json:"code,omitempty"`
	Source   string `json:"source,omitempty"`
	Message  string `json:"message"`
}

// Range is a zero-based line/character range within a text document.
type Range struct {
	Start Position `json:"start"`
	End   Position `json:"end"`
}

// Position is a zero-based line and character offset.
type Position struct {
	Line      int `json:"line"`
	Character int `json:"character"`
}