// Copyright (c) 2026 Storm Dragon
// Authors: Storm Dragon, Angus Kola
// SPDX-License-Identifier: GPL-3.0-or-later

package speech

import (
	"fmt"
	"net"
	"os"
	"os/user"
	"path/filepath"
	"strconv"
	"strings"
)

type serverAddress struct {
	network string
	address string
}

// default_socket_path follows Python speechd, retaining Fenrir's sudo-user
// runtime directory selection for console sessions.
func default_socket_path() string {
	if uid := os.Getenv("SUDO_UID"); uid != "" {
		if parsed, err := strconv.ParseUint(uid, 10, 32); err == nil {
			runtimeDirectory := os.Getenv("XDG_RUNTIME_DIR")
			if !owned_directory(runtimeDirectory, uint32(parsed)) {
				runtimeDirectory = filepath.Join("/run/user", uid)
			}
			if !owned_directory(runtimeDirectory, uint32(parsed)) {
				if account, err := user.LookupId(uid); err == nil {
					runtimeDirectory = filepath.Join(account.HomeDir, ".cache")
				}
			}
			return filepath.Join(runtimeDirectory, "speech-dispatcher/speechd.sock")
		}
	}
	runtimeDirectory := os.Getenv("XDG_RUNTIME_DIR")
	if runtimeDirectory == "" {
		runtimeDirectory = os.Getenv("XDG_CACHE_HOME")
	}
	if runtimeDirectory == "" {
		cacheDirectory, err := os.UserCacheDir()
		if err == nil {
			runtimeDirectory = cacheDirectory
		}
	}
	return filepath.Join(runtimeDirectory, "speech-dispatcher", "speechd.sock")
}

// resolve_server_address gives an internal socket override priority over speechd's
// standard address variables. SPEECHD_SOCKET is the older Unix-only setting.
func resolve_server_address(socket string) (serverAddress, error) {
	if socket != "" {
		return serverAddress{network: "unix", address: socket}, nil
	}
	if address := os.Getenv("SPEECHD_ADDRESS"); address != "" {
		return parse_server_address(address)
	}
	if socket := os.Getenv("SPEECHD_SOCKET"); socket != "" {
		return serverAddress{network: "unix", address: socket}, nil
	}
	return serverAddress{network: "unix", address: default_socket_path()}, nil
}

func parse_server_address(address string) (serverAddress, error) {
	method, value, _ := strings.Cut(address, ":")
	switch method {
	case "unix_socket":
		if value == "" {
			value = default_socket_path()
		}
		if !filepath.IsAbs(value) {
			return serverAddress{}, fmt.Errorf("Speech Dispatcher Unix socket must be an absolute path: %q", value)
		}
		return serverAddress{network: "unix", address: value}, nil
	case "inet_socket":
		host, port := "127.0.0.1", 6560
		if value != "" {
			parts := strings.Split(value, ":")
			if len(parts) > 2 {
				return serverAddress{}, fmt.Errorf("invalid Speech Dispatcher address %q", address)
			}
			if parts[0] != "" {
				host = parts[0]
			}
			if len(parts) == 2 {
				parsed, err := strconv.Atoi(parts[1])
				if err != nil || parsed < 1 || parsed > 65535 {
					return serverAddress{}, fmt.Errorf("invalid Speech Dispatcher port in %q", address)
				}
				port = parsed
			}
		}
		return serverAddress{network: "tcp4", address: net.JoinHostPort(host, strconv.Itoa(port))}, nil
	default:
		return serverAddress{}, fmt.Errorf("unsupported Speech Dispatcher address %q", address)
	}
}

// Explicit settings select exactly one server; only defaults use fallback.
func automatic_server_address(socket string) bool {
	return socket == "" && os.Getenv("SPEECHD_ADDRESS") == "" && os.Getenv("SPEECHD_SOCKET") == ""
}