// Copyright (c) 2013 Conformal Systems LLC.
// Use of this source code is governed by an ISC
// license that can be found in the LICENSE file.

package main

import (
	"net"
	"net/http"
	_ "net/http/pprof"
	"os"
	"runtime"
)

var (
	cfg *config
)

// btcdMain is the real main function for btcd.  It is necessary to work around
// the fact that deferred functions do not run when os.Exit() is called.
func btcdMain() error {
	// Initialize logging and setup deferred flushing to ensure all
	// outstanding messages are written on shutdown.
	loggers := setLogLevel(defaultLogLevel)
	defer func() {
		for _, logger := range loggers {
			logger.Flush()
		}
	}()

	// Load configuration and parse command line.
	tcfg, _, err := loadConfig()
	if err != nil {
		return err
	}
	cfg = tcfg

	// Change the logging level if needed.
	if cfg.DebugLevel != defaultLogLevel {
		loggers = setLogLevel(cfg.DebugLevel)
	}

	// See if we want to enable profiling.
	if cfg.Profile != "" {
		go func() {
			listenAddr := net.JoinHostPort("", cfg.Profile)
			log.Infof("BTCD: Profile server listening on %s", listenAddr)
			log.Errorf("%v", http.ListenAndServe(listenAddr, nil))
		}()
	}

	// Perform upgrades to btcd as new versions require it.
	if err := doUpgrades(); err != nil {
		log.Errorf("%v", err)
		return err
	}

	// Load the block database.
	db, err := loadBlockDB()
	if err != nil {
		log.Errorf("%v", err)
		return err
	}
	defer db.Close()

	// Ensure the database is sync'd and closed on Ctrl+C.
	addInterruptHandler(func() {
		db.RollbackClose()
	})

	// Create server and start it.
	listenAddr := net.JoinHostPort("", cfg.Port)
	server, err := newServer(listenAddr, db, activeNetParams.btcnet)
	if err != nil {
		log.Errorf("Unable to start server on %v", listenAddr)
		log.Errorf("%v", err)
		return err
	}
	server.Start()

	server.WaitForShutdown()
	return nil
}

func main() {
	// Use all processor cores.
	runtime.GOMAXPROCS(runtime.NumCPU())

	// Up some limits.
	if err := setLimits(); err != nil {
		os.Exit(1)
	}

	// Work around defer not working after os.Exit()
	if err := btcdMain(); err != nil {
		os.Exit(1)
	}
}