package openldaplog

import (
	"fmt"
	"time"
	"errors"
	"regexp"
	"strconv"
)

const (
	SyslogPri         = `(?:<\d{1,3}>)?`
	TimeFormat        = "Jan  2 15:04:05"
	TimeFormatISO8601 = "2006-01-02T15:04:05.999999-07:00"
	// group[1]
	TimeRE            = `([A-Za-z]{3}\s*[0-9]{1,2} [0-9]{2}:[0-9]{2}:[0-9]{2}|^\d{4}-[01]\d-[0-3]\dT[0-2]\d:[0-5]\d:[0-5]\d(?:\.\d+)?(?:[+-][0-2]\d:[0-5]\d|Z))`
	IPv4RE            = `(?:\b25[0-5]|\b2[0-4][0-9]|\b[01]?[0-9][0-9]?)(?:\.(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)){3}`
	// FIXME: Not very strict
	IPv6RE            = `(?:(?:[0-9a-fA-F]{1,4}\:){7})[0-9a-fA-F]{1,4}`
	HostRE            = `([0-9A-Za-z\-\_\.]*)`
	ProcessRE         = `(slapd\[[0-9]{1,7}\])(?:\:)?`
	// group[4]
	ConnIdRE          = `conn=([0-9]{4,10})`
	ConnFdRE          = `(?:fd=([0-9]{1,10}))?`
	OperationIdRE     = `(?:op=([0-9]{1,10}))?`
	AcceptRE          = `(?:ACCEPT from IP=(` + IPv4RE + `)\:([0-9]{1,5}) \(IP=(` + IPv4RE + `)\:([0-9]{1,5})\))?`
	// group[11]
	STARTTLSRE        = `(STARTTLS$)?`
	// group[12], group[13]
	BindMethodRE      = `(?:BIND dn="(.*)" method=([0-9]{1,3}))?`
	BindMechRE        = `(?:BIND dn=".*" mech=([a-zA-Z]*) (?:bind_ssf=([0-9]{1,3}) )?ssf=([0-9]{1,3}))?`
	// group[17], group[18], group[19], group[20], group[21], group[22], group[23]
	ResultRE          = `(?:(RESULT) (?:tag=([0-9]{1,3})|oid=([0-9\.]*)) err=([0-9]{1,3}) (?:qtime=([0-9\.]{1,10}) )?(?:etime=([0-9\.]{1,10}) )?text=(.*))?`
	SearchBaseRE      = `(?:SRCH base="(.*)" scope=([0-2]) deref=([0-3]) filter="(.*)")?`
	// group[28]
	SearchAttrRE      = `(?:SRCH attr=(.*))?`
	// group[29], group[30], group[31], group[32], group[33], group[34], group[35]
	SearchResultRE    = `(?:(SEARCH RESULT) tag=([0-9]{1,3}) err=([0-9]{1,3}) (?:qtime=([0-9\.]{1,10}) )?(?:etime=([0-9\.]{1,10}) )?nentries=([0-9]{1,9}) text=(.*))?`
	ModDnRE           = `(?:MOD dn="(.*)")?`
	ModAttrRE         = `(?:MOD attr=(.*))?`
	// group[38]
	PassModRE         = `(?:PASSMOD id="(.*)" new)?`
	UnbindRE          = `(UNBIND)?`
	// group[40]
	ConnClosedRE      = `(closed)?(?: \(connection lost\))?`
	// group[41]
	AddDnRE           = `(?:ADD dn="(.*)")?`
	// group[42]
	DelDnRE           = `(?:DEL dn="(.*)")?`
	
	LogLineRE = SyslogPri + TimeRE + ` ` + HostRE + ` ` + ProcessRE + ` ` + ConnIdRE + ` ` + ConnFdRE + OperationIdRE + ` ` +
				AcceptRE + STARTTLSRE + BindMethodRE + BindMechRE + ResultRE + SearchBaseRE + SearchAttrRE + SearchResultRE + ModDnRE + ModAttrRE + 
				PassModRE + UnbindRE + ConnClosedRE + AddDnRE + DelDnRE
)

type (
	OpenldapLog struct {
		LogFormat LogFormat
		Regexp    *regexp.Regexp
	}
	
	LogFormat struct {
		Time           *time.Time `json:"time"`
		Hostname       string     `json:"hostname"`
		Process        string     `json:"process"`
		ClientIp       string     `json:"client_ip"`
		ClientPort     int        `json:"client_port"`
		ServerIp       string     `json:"server_ip"`
		ServerPort     int        `json:"server_port"`
		BindDN         string     `json:"bind_dn"`
		ConnId         int        `json:"conn_id"`
		ConnFd         int        `json:"conn_fd"`
		OpId           int        `json:"op_id"`
		OpType         string     `json:"op_type"`
		BindMethod     string     `json:"bind_method"`
		BindMech       string     `json:"bind_mech"`
		BindSSF        string     `json:"bind_ssf"`
		SSF            string     `json:"ssf"`
		ModDN          string     `json:"mod_dn"`
		ModAttr        string     `json:"mod_attr"`
		AddDN          string     `json:"add_dn"`
		DelDN          string     `json:"del_dn"`
		PassModDN      string     `json:"passmod_dn"`
		Result         bool
		ResTag         string     `json:"result_tag"`
		ResOid         string     `json:"result_oid"`
		ResErr         int        `json:"result_err"`
		ResQTime       string     `json:"result_qtime"`
		ResETime       string     `json:"result_etime"`
		ResText        string     `json:"result_text"`
		SearchResult   bool
		SearchBase     string     `json:"search_base"`
		SearchScope    string     `json:"search_scope"`
		SearchDeref    string     `json:"search_deref"`
		SearchFilter   string     `json:"search_filter"`
		SearchAttr     string     `json:"search_attr"`
		SearchResTag   string     `json:"search_res_tag"`
		SearchResErr   int        `json:"search_res_err"`
		SearchResQTime string     `json:"search_res_qtime"`
		SearchResETime string     `json:"search_res_etime"`
		SearchResNEntries int     `json:"search_res_nentries"`
		SearchResText  string     `json:"search_res_text"`
	}
)

var (
	gDebug bool
)

func NewOpenldapLog(debug bool) *OpenldapLog {
	if debug {
		gDebug = true
		fmt.Printf("DEBUG: Regexp will display on next line\n")
		fmt.Printf("%s\n", LogLineRE)
	}
	return &OpenldapLog{
		Regexp: regexp.MustCompile(LogLineRE),
	}
}

func (o *OpenldapLog) Parse(text []byte) (LogFormat, error) {
	re := o.Regexp.Copy()
	group := re.FindSubmatch(text)
	if len(group) == 0 {
		err := errors.New("Error: Line do not match regex")
		return LogFormat{}, err
	}
	var t time.Time
	t, err := time.ParseInLocation(TimeFormat, string(group[1]), time.Local)
	if err != nil {
		t, err = time.ParseInLocation(TimeFormatISO8601, string(group[1]), time.Local)
		if err != nil {
			return LogFormat{}, err
		}
	}

	cid,_ := strconv.Atoi(string(group[4]))
	cfd,_ := strconv.Atoi(string(group[5]))
	opid,_ := strconv.Atoi(string(group[6]))
	cport,_ := strconv.Atoi(string(group[8]))
	sport,_ := strconv.Atoi(string(group[10]))
	result := false
	if string(group[17]) == "RESULT" {
		result = true
	}
	rerr,_ := strconv.Atoi(string(group[20]))
	sresult := false
	if string(group[29]) == "SEARCH RESULT" {
		sresult = true
	}
	serr,_ := strconv.Atoi(string(group[31]))
	srentries, _ := strconv.Atoi(string(group[34]))
	
	logFormat := LogFormat{
		Time:         &t,
		Hostname:     string(group[2]),
		Process:      string(group[3]),
		ConnId:       cid,
		ConnFd:       cfd,
		OpId:         opid,
		ClientIp:     string(group[7]),
		ClientPort:   cport,
		ServerIp:     string(group[9]),
		ServerPort:   sport,
		// "STARTTLS"
		BindDN:       string(group[12]),
		BindMethod:   string(group[13]),
		BindMech:     string(group[14]),
		BindSSF:      string(group[15]),
		SSF:          string(group[16]),
		Result:       result,
		ResTag:       string(group[18]),
		ResOid:       string(group[19]),
		ResErr:       rerr,
		ResQTime:     string(group[21]),
		ResETime:     string(group[22]),
		ResText:      string(group[23]),
		SearchBase:   string(group[24]),
		SearchScope:  string(group[25]),
		SearchDeref:  string(group[26]),
		SearchFilter: string(group[27]),
		SearchAttr:   string(group[28]),
		SearchResult:      sresult,
		SearchResTag:      string(group[30]),
		SearchResErr:      serr,
		SearchResQTime:    string(group[32]),
		SearchResETime:    string(group[33]),
		SearchResNEntries: srentries,
		SearchResText:     string(group[35]),
		ModDN:             string(group[36]),
		ModAttr:           string(group[37]),
		PassModDN:         string(group[38]),
		AddDN:             string(group[41]),
		DelDN:             string(group[42]),
	}

	// Now handle Operation Type
	if len(group[12]) > 0 || len(group[13]) > 0 || len(group[14]) > 0 || len(group[15]) > 0 || len(group[16]) > 0 {
		logFormat.OpType = "bind"
	} else if len(group[11]) > 0 {
		logFormat.OpType = "starttls"
	} else if len(group[24]) > 0 {
		logFormat.OpType = "search"
	} else if len(group[7]) > 0 {
		logFormat.OpType = "accept"
	} else if len(group[36]) > 0 || len(group[37]) > 0 {
		logFormat.OpType = "mod"
	} else if len(group[38]) > 0 {
		logFormat.OpType = "passmod"
	} else if len(group[39]) > 0 {
		logFormat.OpType = "unbind"
	} else if len(group[40]) > 0 {
		logFormat.OpType = "close"
	} else if len(group[41]) > 0 {
		logFormat.OpType = "add"
	} else if len(group[42]) > 0 {
		logFormat.OpType = "del"
	}

	return logFormat, nil
}