// Copyright (C) 2026 Dcntrlized
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published
// by the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.

// dlv-restart is a minimal JSON-RPC client (delve service/rpc2) that restarts
// the debug target of a persistent headless dlv server and resumes it.
//
// Why not `printf 'restart\n' | dlv connect ...`? `dlv connect` is an
// interactive terminal client: its stdout/stderr is distinct from the debug
// target's, it always reads go-ahead from the same stream, and its stdin EOF
// makes it drop into the (dlv) prompt and exit with a "kill the headless
// instance?" prompt — dumping the debugee's full state and racing the attached
// vscode-go client. This helper speaks rpc2 directly, so it only issues the
// RPCs we want, prints nothing, and exits without disturbing the target or the
// VS Code session.
//
// Usage: dlv-restart [addr]   (addr defaults to 127.0.0.1:2345)
package main

import (
	"fmt"
	"os"

	"github.com/go-delve/delve/service/rpc2"
)

func main() {
	addr := "127.0.0.1:2345"
	if len(os.Args) > 1 {
		addr = os.Args[1]
	}

	client := rpc2.NewClient(addr)

	discarded, err := client.RestartFrom(false, "", false, nil, [3]string{}, false)
	if err != nil {
		fmt.Fprintf(os.Stderr, "dlv-restart: Restart failed: %v\n", err)
		os.Exit(1)
	}
	for _, d := range discarded {
		fmt.Fprintf(os.Stderr, "discarded %s: %v\n", d.Breakpoint.Name, d.Reason)
	}

	// The restarted process begins halted, so resume it with Continue, then
	// close the connection. --accept-multiclient keeps the server and target
	// running while our short-lived client disconnects; an attached vscode-go
	// client is undisturbed.
	if err := client.Disconnect(true); err != nil {
		fmt.Fprintf(os.Stderr, "dlv-restart: disconnect failed: %v\n", err)
	}
}