// Package logging formats tool diagnostics consistently across commands.
package logging

import (
	"fmt"
	"io"
	"os"
	"strings"
	"sync"
)

var outputMu sync.Mutex

// Info reports normal progress.
func Info(name, format string, args ...any) { output(os.Stdout, "I", name, format, args...) }

// Warn reports a condition that does not prevent the operation from continuing.
func Warn(name, format string, args ...any) { output(os.Stderr, "W", name, format, args...) }

// Error reports a recoverable operation failure.
func Error(name, format string, args ...any) { output(os.Stderr, "E", name, format, args...) }

// Fatal reports a command-ending failure. The caller controls the exit status.
func Fatal(name, format string, args ...any) { output(os.Stderr, "F", name, format, args...) }

func output(file *os.File, level, name, format string, args ...any) {
	stat, err := file.Stat()
	_, noColor := os.LookupEnv("NO_COLOR")
	color := err == nil && stat.Mode()&os.ModeCharDevice != 0 && !noColor && os.Getenv("TERM") != "dumb"
	outputMu.Lock()
	defer outputMu.Unlock()
	write(file, color, level, name, fmt.Sprintf(format, args...))
}

func write(w io.Writer, color bool, level, name, message string) {
	label := "[" + level + "]"
	if color {
		code := map[string]string{"I": "32", "W": "33", "E": "31", "F": "35"}[level]
		label = "\033[" + code + "m" + label + "\033[0m"
	}
	// Each physical line retains its level and component, including wrapped errors.
	message = strings.ReplaceAll(message, "\r\n", "\n")
	for _, line := range strings.Split(strings.TrimRight(message, "\n"), "\n") {
		fmt.Fprintf(w, "%s [%s] %s\n", label, name, line)
	}
}