package app

import (
	"context"
	"errors"
	"github.com/gofiber/fiber/v2/log"
	"github.com/themakers/hlog"
	"go.uber.org/zap"
	"go.uber.org/zap/zapcore"
	"penahub.gitlab.yandexcloud.net/backend/quiz/answerer/internal/initialize"
	"penahub.gitlab.yandexcloud.net/backend/quiz/answerer/internal/models"
	savewc "penahub.gitlab.yandexcloud.net/backend/quiz/answerer/internal/savewc"
	"penahub.gitlab.yandexcloud.net/backend/quiz/answerer/internal/server/http"
	"penahub.gitlab.yandexcloud.net/backend/quiz/answerer/pkg/closer"
	"penahub.gitlab.yandexcloud.net/backend/quiz/common.git/model"
	"penahub.gitlab.yandexcloud.net/backend/quiz/common.git/utils"
	"penahub.gitlab.yandexcloud.net/external/trashlog/wrappers/zaptrashlog"
	"time"
)

type Build struct {
	Commit  string
	Version string
}

var zapOptions = []zap.Option{
	zap.AddCaller(),
	zap.AddCallerSkip(2),
	zap.AddStacktrace(zap.ErrorLevel),
}

func New(ctx context.Context, cfg initialize.Config, build Build) error {
	var (
		err       error
		zapLogger *zap.Logger
		errChan   = make(chan error)
	)

	defer func() {
		if r := recover(); r != nil {
			log.Error("Recovered from a panic", zap.Any("error", r))
		}
	}()

	ctx, cancel := context.WithCancel(ctx)
	defer cancel()

	if cfg.LoggerProdMode {
		zapLogger, err = zap.NewProduction(zapOptions...)
		if err != nil {
			return err
		}
	} else {
		zapLogger, err = zap.NewDevelopment(zapOptions...)
		if err != nil {
			return err
		}
	}

	zapLogger = zapLogger.With(
		zap.String("SvcCommit", build.Commit),
		zap.String("SvcVersion", build.Version),
		zap.String("SvcBuildTime", time.Now().String()),
	)

	clickHouseLogger, err := zaptrashlog.NewCore(ctx, zap.InfoLevel, cfg.TrashLogHost, build.Version, build.Commit, time.Now().Unix())
	if err != nil {
		panic(err)
	}

	loggerForHlog := zapLogger.WithOptions(zap.WrapCore(func(core zapcore.Core) zapcore.Core {
		return zapcore.NewTee(core, clickHouseLogger)
	}))

	loggerHlog := hlog.New(loggerForHlog).Module(cfg.ModuleLogger)
	loggerHlog.With(models.AllFields{})
	loggerHlog.Emit(InfoSvcStarted{})

	shutdownGroup := closer.NewCloserGroup()

	// Initialize minio client object.
	minioClient, err := initialize.NewMinio(cfg)
	if err != nil {
		zapLogger.Error("failed to initialize minio client", zap.Error(err))
		return err
	}

	dalS, err := initialize.NewDALs(ctx, cfg, minioClient)
	if err != nil {
		zapLogger.Error("failed to initialize dals", zap.Error(err))
		return err
	}

	redisClient, err := initialize.Redis(ctx, cfg)
	if err != nil {
		zapLogger.Error("failed to initialize redis client", zap.Error(err))
		return err
	}

	encrypt := utils.NewEncrypt(cfg.PubKey, cfg.PrivKey)

	workerSendClientCh := make(chan model.Answer, 50)
	workerRespondentCh := make(chan []model.Answer, 50)

	saveRespWcData := savewc.DepsForResp{
		WorkerRespondentCh: workerRespondentCh,
		Redis:              redisClient,
	}
	saveClientWcData := savewc.DepsForClient{
		WorkerSendClientCh: workerSendClientCh,
		Redis:              redisClient,
	}

	saveRespWorker := savewc.NewSaveRespWorker(saveRespWcData, errChan, loggerHlog)
	saveClientWorker := savewc.NewSaveClientWorker(saveClientWcData, errChan, loggerHlog)

	go saveRespWorker.Start(ctx)
	go saveClientWorker.Start(ctx)

	controllers := initialize.NewControllers(initialize.ControllerDeps{
		DALs:               dalS,
		Config:             cfg,
		RedisClient:        redisClient,
		WorkerSendClientCh: workerSendClientCh,
		WorkerRespondentCh: workerRespondentCh,
		Encrypt:            encrypt,
	})

	srv := http.NewServer(http.ServerConfig{
		Logger:      zapLogger,
		Controllers: []http.Controller{controllers.HttpControllers.Common},
		Hlogger:     loggerHlog,
	})

	go func() {
		if err := srv.Start(cfg.HttpHost + ":" + cfg.NumberPort); err != nil {
			zapLogger.Error("HTTP server startup error", zap.Error(err))
			cancel()
		}
	}()

	srv.ListRoutes()
	loggerHlog.Emit(InfoSvcReady{})

	shutdownGroup.Add(closer.CloserFunc(srv.Shutdown))
	shutdownGroup.Add(closer.CloserFunc(dalS.PgDAL.Close))

	<-ctx.Done()

	timeoutCtx, timeoutCancel := context.WithTimeout(context.Background(), 10*time.Second)
	defer timeoutCancel()
	if err := shutdownGroup.Call(timeoutCtx); err != nil {
		if errors.Is(err, context.DeadlineExceeded) {
			zapLogger.Error("Shutdown timed out", zap.Error(err))
		} else {
			zapLogger.Error("Failed to shutdown services gracefully", zap.Error(err))
		}
		return err
	}

	zapLogger.Info("Application has stopped")
	return nil
}