package logger

import (
	"context"
	"encoding/json"
	"log/slog"
	"os"
	"path/filepath"
	"testing"
)

func TestNewAgentLogger_WritesJSONL(t *testing.T) {
	dir := t.TempDir()
	l, cleanup, err := NewAgentLogger(LoggerConfig{
		BaseDir: dir,
		AgentID: "test-bot",
		Level:   slog.LevelDebug,
	})
	if err != nil {
		t.Fatal(err)
	}
	defer cleanup()

	l.Info("hello world", FieldAction, "greet", FieldReason, "testing")

	// Force flush by closing.
	cleanup()

	files, _ := os.ReadDir(filepath.Join(dir, "test-bot"))
	if len(files) == 0 {
		t.Fatal("expected at least one log file")
	}

	data, err := os.ReadFile(filepath.Join(dir, "test-bot", files[0].Name()))
	if err != nil {
		t.Fatal(err)
	}

	var m map[string]any
	if err := json.Unmarshal(data, &m); err != nil {
		t.Fatalf("log line is not valid JSON: %s", data)
	}
	if m["msg"] != "hello world" {
		t.Errorf("msg = %v, want hello world", m["msg"])
	}
	if m[FieldAgentID] != "test-bot" {
		t.Errorf("agent_id = %v, want test-bot", m[FieldAgentID])
	}
	if m[FieldAction] != "greet" {
		t.Errorf("action = %v, want greet", m[FieldAction])
	}
}

func TestNewAgentLogger_Stdout(t *testing.T) {
	l, cleanup, err := NewAgentLogger(LoggerConfig{
		BaseDir: "stdout",
		AgentID: "dev-bot",
	})
	if err != nil {
		t.Fatal(err)
	}
	defer cleanup()
	// Just verify it doesn't panic.
	l.Info("stdout test")
}

func TestTraceIDContext(t *testing.T) {
	ctx := context.Background()
	if got := TraceIDFromCtx(ctx); got != "" {
		t.Errorf("empty ctx should return empty trace, got %q", got)
	}

	ctx = WithTraceID(ctx, "abc-123")
	if got := TraceIDFromCtx(ctx); got != "abc-123" {
		t.Errorf("trace = %q, want abc-123", got)
	}
}