package main

import (
	"context"
	"errors"
	"fmt"
	"net/http"
	"os"
	"os/signal"
	"runtime"
	"syscall"
	"time"

	"git.hongxiaowei.com/xiaowei/service/app/services/sales-api/handlers"

	"github.com/ardanlabs/conf"
	"go.uber.org/automaxprocs/maxprocs"
	"go.uber.org/zap"
	"go.uber.org/zap/zapcore"
)

var build = "develop"

func main() {
	log, err := initLog("SALES-API")
	if err != nil {
		fmt.Println(err)
		return
	}
	if err := run(log); err != nil {
		log.Errorw("err", err)
	}
}
func run(log *zap.SugaredLogger) error {
	if _, err := maxprocs.Set(); err != nil {
		return fmt.Errorf("maxprocs:%w", err)
	}
	log.Infow("startup", "GOMAXPROCS", runtime.GOMAXPROCS(0))
	//configuration
	cfg := struct {
		conf.Version
		Web struct {
			APIHost         string        `conf:"default:0.0.0.0:3000"`
			DebugHost       string        `conf:"default:0.0.0.0:4000"`
			ReadTimeout     time.Duration `conf:"default:5s"`
			WriteTimeout    time.Duration `conf:"default:10s"`
			IdleTimeout     time.Duration `conf:"default:10s"`
			ShutDownTimeout time.Duration `conf:"default:10s"`
		}
	}{
		Version: conf.Version{
			SVN:  build,
			Desc: "copyright information here",
		},
	}
	const prefix = "SALES"
	help, err := conf.ParseOSArgs(prefix, &cfg)
	if err != nil {
		if errors.Is(err, conf.ErrHelpWanted) {
			fmt.Println(help)
			return nil
		}
		return fmt.Errorf("parsing config:%w", err)
	}
	log.Infow("starting service", "version", build)
	defer log.Infow("shutdown complete")

	out, err := conf.String(&cfg)
	if err != nil {
		return err
	}
	log.Infow("startup", "config", out)
	// =========================================================
	// Start Debug Service
	log.Infow("startup", "status", "debug router started", "host", cfg.Web.DebugHost)
	debugMux := handlers.DebugMux(build, log)
	go func() {
		if err := http.ListenAndServe(cfg.Web.DebugHost, debugMux); err != nil {
			log.Errorw("shutdown", "status",
				"debug router closed", "host", cfg.Web.DebugHost, "ERROR", err)
		}
	}()
	log.Infow("startup", "status", "initializing API support")

	// Make a channel to listen for an interrupt or terminate signal from ths OS.
	// Use a buffered channel because the signal package requires it
	shutdown := make(chan os.Signal, 1)
	signal.Notify(shutdown, syscall.SIGINT, syscall.SIGTERM)

	// Construct the mux for the API calls
	apiMux := handlers.APIMux(handlers.APIMuxConfig{
		Shutdown: nil,
		Log:      nil,
	})

	// Construct a server to service the requests against the mux
	api := http.Server{
		Addr:         cfg.Web.APIHost,
		Handler:      apiMux,
		ReadTimeout:  cfg.Web.ReadTimeout,
		WriteTimeout: cfg.Web.WriteTimeout,
		IdleTimeout:  cfg.Web.IdleTimeout,
		ErrorLog:     zap.NewStdLog(log.Desugar()),
	}

	//Make a channel to listen for errors coming from the listener.Use a
	// bufferd channel so the goroutine can exit if we don't collect this error
	serverErrors := make(chan error, 1)

	// Start the service listening for api requests
	go func() {
		log.Infow("startup", "status", "api router started", "host", api.Addr)
		serverErrors <- api.ListenAndServe()
	}()

	// =====================================================
	// Shutdown

	// Blocking main and waiting for shutdown
	select {
	case err := <-serverErrors:
		return fmt.Errorf("server err:%w", err)
	case sig := <-shutdown:
		log.Infow("shutdown", "status", "shutdown started", "signal", sig)
		defer log.Infow("shutdown", "status", "shutdown complete", "signal", sig)

		// Give outstanding requests a deadline for completion
		ctx, cancel := context.WithTimeout(context.Background(), cfg.Web.ShutDownTimeout)
		defer cancel()

		if err := api.Shutdown(ctx); err != nil {
			api.Close()
			return err
		}
	}

	return nil
}

func initLog(service string) (*zap.SugaredLogger, error) {
	config := zap.NewProductionConfig()
	config.OutputPaths = []string{"stdout"}
	config.EncoderConfig.EncodeTime = zapcore.ISO8601TimeEncoder
	config.DisableStacktrace = true
	config.InitialFields = map[string]interface{}{
		"service": service,
	}

	log, err := config.Build()
	if err != nil {
		fmt.Println(err)
	}
	return log.Sugar(), err

}