11

tui/internal/logging/logger.go

@@ -0,0 +1,100 @@
+package logging
+
+import (
+	"sync"
+	"time"
+)
+
+// Level classifies the severity of a log entry.
+type Level int
+
+const (
+	LevelInfo Level = iota
+	LevelWarn
+	LevelError
+)
+
+// Entry is a single log record.
+type Entry struct {
+	Ts      int64
+	Level   Level
+	Source  string
+	Message string
+	Details string
+}
+
+// Logger is a thread-safe ring-buffer log with cap 500.
+type Logger struct {
+	mu        sync.Mutex
+	buf       []Entry
+	listeners []func(Entry)
+	now       func() int64
+}
+
+const bufCap = 500
+
+// NewLogger creates a Logger with a 500-entry ring buffer.
+func NewLogger() *Logger {
+	return &Logger{
+		now: func() int64 { return time.Now().UnixMilli() },
+	}
+}
+
+func (l *Logger) add(level Level, source, message string, details []string) {
+	var d string
+	if len(details) > 0 {
+		d = details[0]
+	}
+	e := Entry{
+		Ts:      l.now(),
+		Level:   level,
+		Source:  source,
+		Message: message,
+		Details: d,
+	}
+	l.mu.Lock()
+	l.buf = append(l.buf, e)
+	if len(l.buf) > bufCap {
+		l.buf = l.buf[len(l.buf)-bufCap:]
+	}
+	fns := l.listeners
+	l.mu.Unlock()
+
+	for _, fn := range fns {
+		fn(e)
+	}
+}
+
+// Info records an info-level entry.
+func (l *Logger) Info(source, message string, details ...string) {
+	l.add(LevelInfo, source, message, details)
+}
+
+// Warn records a warn-level entry.
+func (l *Logger) Warn(source, message string, details ...string) {
+	l.add(LevelWarn, source, message, details)
+}
+
+// Error records an error-level entry.
+func (l *Logger) Error(source, message string, details ...string) {
+	l.add(LevelError, source, message, details)
+}
+
+// Snapshot returns a copy of all buffered entries, oldest first.
+func (l *Logger) Snapshot() []Entry {
+	l.mu.Lock()
+	out := make([]Entry, len(l.buf))
+	copy(out, l.buf)
+	l.mu.Unlock()
+	return out
+}
+
+// Subscribe registers fn to be called for every new entry.
+func (l *Logger) Subscribe(fn func(Entry)) {
+	l.mu.Lock()
+	l.listeners = append(l.listeners, fn)
+	l.mu.Unlock()
+}
+
+// Default is the package-level logger instance.
+var Default = NewLogger()