// Frontend: Logging functions for programs using the safcm library

// SPDX-License-Identifier: GPL-3.0-or-later
// Copyright (C) 2021-2024  Simon Ruderich

package frontend

import (
	"fmt"
	"log"

	"ruderich.org/simon/safcm"
	"ruderich.org/simon/safcm/rpc"
)

type Event struct {
	Host Host

	// Only one of Error, Log and ConnEvent is set in a single event
	Error     error
	Log       Log
	ConnEvent rpc.ConnEvent

	Escaped bool // true if untrusted input is already escaped
}

type Log struct {
	Level safcm.LogLevel
	Text  string
}

func (l *Loop) Log(host Host, level safcm.LogLevel, escaped bool,
	msg string) {

	l.events <- Event{
		Host: host,
		Log: Log{
			Level: level,
			Text:  msg,
		},
		Escaped: escaped,
	}
}

// LogEvent logs events using the log package. It can be used to implement
// Loop.LogEventFunc. It's used by cmd/safcm to log events.
func LogEvent(x Event, level safcm.LogLevel, isTTY bool,
	failed *bool) {

	// We have multiple event sources so this is somewhat ugly.
	var prefix, data string
	var color Color
	if x.Error != nil {
		prefix = "[error]"
		data = x.Error.Error()
		color = ColorRed
		// We logged an error, tell the caller
		*failed = true
	} else if x.Log.Level != 0 {
		if level < x.Log.Level {
			return
		}
		// LogError and LogDebug3 should not occur here
		switch x.Log.Level {
		case safcm.LogInfo:
			prefix = "[info]"
		case safcm.LogVerbose:
			prefix = "[verbose]"
		case safcm.LogDebug:
			prefix = "[debug]"
		case safcm.LogDebug2:
			prefix = "[debug2]"
		default:
			prefix = fmt.Sprintf("[INVALID=%d]", x.Log.Level)
			color = ColorRed
		}
		data = x.Log.Text
	} else {
		switch x.ConnEvent.Type {
		case rpc.ConnEventStderr:
			prefix = "[stderr]"
		case rpc.ConnEventDebug:
			prefix = "[debug3]"
		case rpc.ConnEventUpload:
			if level < safcm.LogInfo {
				return
			}
			prefix = "[info]"
			x.ConnEvent.Data = "remote helper upload in progress"
		default:
			prefix = fmt.Sprintf("[INVALID=%d]", x.ConnEvent.Type)
			color = ColorRed
		}
		data = x.ConnEvent.Data
	}

	host := x.Host.Name()
	if color != 0 {
		host = ColorString(isTTY, color, host)
	}
	// Make sure to escape control characters to prevent terminal
	// injection attacks
	if !x.Escaped {
		data = EscapeControlCharacters(isTTY, data)
	}
	log.Printf("%-9s [%s] %s", prefix, host, data)
}