package logger_test

import (
	"bytes"
	"encoding/json"
	"errors"
	"log/slog"
	"testing"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"go.uber.org/fx"
	"go.uber.org/fx/fxevent"
	"go.uber.org/fx/fxtest"
	"sneak.berlin/go/webhooker/internal/globals"
	"sneak.berlin/go/webhooker/internal/logger"
)

var errStopHook = errors.New("stop hook failed on purpose")

func testGlobals() *globals.Globals {
	return &globals.Globals{
		Appname: "test-app",
		Version: "1.0.0",
	}
}

func TestNew(t *testing.T) {
	t.Parallel()

	lc := fxtest.NewLifecycle(t)

	params := logger.LoggerParams{
		Globals: testGlobals(),
	}

	l, err := logger.New(lc, params)
	if err != nil {
		t.Fatalf("New() error = %v", err)
	}

	if l.Get() == nil {
		t.Error("Get() returned nil logger")
	}

	// Test that we can log without panic
	l.Get().Info("test message", "key", "value")
}

func TestEnableDebugLogging(t *testing.T) {
	t.Parallel()

	lc := fxtest.NewLifecycle(t)

	params := logger.LoggerParams{
		Globals: testGlobals(),
	}

	l, err := logger.New(lc, params)
	if err != nil {
		t.Fatalf("New() error = %v", err)
	}

	// Enable debug logging should not panic
	l.EnableDebugLogging()

	// Test debug logging
	l.Get().Debug("debug message", "test", true)
}

// TestFxLogger_Levels starts and stops an fx app that reports its own
// events through NewFxLogger, as cmd/webhooker does, and reads back
// what reached the handler: the graph at DEBUG, the start at INFO and
// a failed stop hook at ERROR, each as a structured record.
func TestFxLogger_Levels(t *testing.T) {
	t.Parallel()

	var out bytes.Buffer

	log := slog.New(slog.NewJSONHandler(
		&out, &slog.HandlerOptions{Level: slog.LevelDebug},
	))

	app := fx.New(
		fx.WithLogger(func() fxevent.Logger {
			return logger.NewFxLogger(log)
		}),
		fx.Invoke(func(lc fx.Lifecycle) {
			lc.Append(fx.StopHook(func() error { return errStopHook }))
		}),
	)

	require.NoError(t, app.Start(t.Context()))
	require.ErrorIs(t, app.Stop(t.Context()), errStopHook)

	levels := map[string]string{}

	decoder := json.NewDecoder(&out)
	for decoder.More() {
		var record struct {
			Level string `json:"level"`
			Msg   string `json:"msg"`
		}

		require.NoError(t, decoder.Decode(&record))

		levels[record.Msg] = record.Level
	}

	assert.Equal(t, "DEBUG", levels["provided"])
	assert.Equal(t, "INFO", levels["started"])
	assert.Equal(t, "ERROR", levels["OnStop hook failed"])
}