//nolint:testpackage // needs the package logger; see TestWithAttributesReachTTYOutput
package log //nolint:revive,nolintlint // stdlib log unused here; see #76

import (
	"bytes"
	"log/slog"
	"regexp"
	"testing"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

// withTestANSIEscape matches the SGR sequences TTYHandler emits.
var withTestANSIEscape = regexp.MustCompile(`\x1b\[[0-9;]*m`)

// TestWithAttributesReachTTYOutput exercises the exported package-level
// With through a TTYHandler, which is the path the reported defect was
// on: the handler is selected by TTY-ness, so on a terminal With's
// attributes were silently dropped while the same code printed them
// correctly in CI.
//
// This is an in-package test so it can point the package logger at a
// buffer. Building an slog.Logger over a TTYHandler by hand would test
// slog, not this package's With, and there is no injectable sink to
// reach it from outside. The package logger is process-global, so this
// test must not run in parallel.
//
//nolint:paralleltest // replaces the process-global package logger
func TestWithAttributesReachTTYOutput(t *testing.T) {
	var buf bytes.Buffer

	previous := logger

	t.Cleanup(func() { logger = previous })

	logger = slog.New(NewTTYHandler(&buf, &slog.HandlerOptions{
		Level: slog.LevelDebug,
	}))

	With("key", "value").Info("hello")

	plain := withTestANSIEscape.ReplaceAllString(buf.String(), "")

	require.NotEmpty(t, plain)
	assert.Contains(t, plain, "hello")
	assert.Contains(t, plain, "key=value",
		"log.With attributes must reach TTYHandler output")
}

// TestWithoutInitializedLoggerFallsBack pins the documented behavior of
// With before Initialize has run: it hands back the slog default rather
// than a nil logger that would panic at the call site.
//
//nolint:paralleltest // replaces the process-global package logger
func TestWithoutInitializedLoggerFallsBack(t *testing.T) {
	previous := logger

	t.Cleanup(func() { logger = previous })

	logger = nil

	assert.NotNil(t, With("key", "value"))
}