package bird

import (
	"os/exec"
	"strings"
	"sync"
	"time"
)

var BirdCmd string

var Cache = struct {
	sync.RWMutex
	m map[string]Parsed
}{m: make(map[string]Parsed)}

func fromCache(key string) (Parsed, bool) {
	Cache.RLock()
	val, ok := Cache.m[key]
	Cache.RUnlock()
	return val, ok
}

func toCache(key string, val Parsed) {
	val["ttl"] = time.Now().Add(5 * time.Minute)
	Cache.Lock()
	Cache.m[key] = val
	Cache.Unlock()
}

func Run(args string) ([]byte, error) {
	args = "show " + args
	argsList := strings.Split(args, " ")
	return exec.Command(BirdCmd, argsList...).Output()
}

func RunAndParse(cmd string, parser func([]byte) Parsed) (Parsed, bool) {
	if val, ok := fromCache(cmd); ok {
		return val, true
	}

	out, err := Run(cmd)

	if err != nil {
		// ignore errors for now
		return Parsed{}, false
	}

	parsed := parser(out)
	toCache(cmd, parsed)
	return parsed, false
}

func Status() (Parsed, bool) {
	return RunAndParse("status", parseStatus)
}

func Protocols() (Parsed, bool) {
	return RunAndParse("protocols all", parseProtocols)
}

func ProtocolsBgp() (Parsed, bool) {
	p, from_cache := Protocols()
	protocols := p["protocols"].([]string)

	bgpProto := Parsed{}

	for _, v := range protocols {
		if strings.Contains(v, " BGP ") {
			key := strings.Split(v, " ")[0]
			bgpProto[key] = parseBgp(v)
		}
	}

	return Parsed{"protocols": bgpProto}, from_cache
}

func Symbols() (Parsed, bool) {
	return RunAndParse("symbols", parseSymbols)
}

func RoutesProto(protocol string) (Parsed, bool) {
	return RunAndParse("route protocol '"+protocol+"' all",
		parseRoutes)
}

func RoutesProtoCount(protocol string) (Parsed, bool) {
	return RunAndParse("route protocol '"+protocol+"' count",
		parseRoutesCount)
}

func RoutesExport(protocol string) (Parsed, bool) {
	return RunAndParse("route export '"+protocol+"' all",
		parseRoutes)
}

func RoutesExportCount(protocol string) (Parsed, bool) {
	return RunAndParse("route export '"+protocol+"' count",
		parseRoutesCount)
}

func RoutesTable(table string) (Parsed, bool) {
	return RunAndParse("route table '"+table+"' all",
		parseRoutes)
}

func RoutesTableCount(table string) (Parsed, bool) {
	return RunAndParse("route table '"+table+"' count",
		parseRoutesCount)
}

func RoutesLookupTable(net string, table string) (Parsed, bool) {
	return RunAndParse("route for '"+net+"' table '"+table+"' all",
		parseRoutes)
}

func RoutesLookupProtocol(net string, protocol string) (Parsed, bool) {
	return RunAndParse("route for '"+net+"' protocol '"+protocol+"' all",
		parseRoutes)
}