package main

import (
	"flag"
	"fmt"
	"io/ioutil"
	"os"
	"reflect"
	"regexp"
	"strings"
	"text/tabwriter"

	"github.com/alecthomas/template"
	"github.com/jweir/csv"
	"github.com/kopolindo/cve-scraper/db"
)

func Printbanner() {
	tmpl := template.New("banner")
	template.Must(tmpl.Parse(banner))
	_ = tmpl.Execute(os.Stderr, ActualVersion)
}

func Usage() {
	Printbanner()
	fmt.Println("\nUsage flags:")
	flag.PrintDefaults()
	return
}

func Init() {
	flag.Parse()
	if flag.NFlag() == 0 {
		Usage()
		os.Exit(0)
	}
	if *version {
		Printbanner()
	}
	if *fields != "" {
		if *fields != "help" {
			fieldsToPrint = ValidateFields()
		}
		if *fields == "help" {
			fmt.Println("Cve\t\tCVE Identification (CVE-YYYY-ID)")
			fmt.Println("CveDesc\t\tVulnerability Description")
			fmt.Println("Cwe\t\tCommon Weakness Enumeration ID")
			fmt.Println("CweDesc\t\tCWE Description (type of vulnerability)")
			fmt.Println("Exploit\t\tExistence of known exploits")
			fmt.Println("Refs\t\tReferences")
			fmt.Println("Cvssv2\t\tCommon Vulnerability Scoring System Vector (v2)")
			fmt.Println("Cvssv3\t\tCommon Vulnerability Scoring System Vector (v3)")
			fmt.Println("Software\tSoftware name")
			fmt.Println("Version\t\tSoftware version")
			os.Exit(0)
		}
	}
	if *fields == "" {
		fieldsToPrint = strings.Split("Cve,CveDesc,Cwe,CweDesc,Exploit,Refs,Cvssv2,Cvssv3,Software,Version", ",")
	}
	if *write != "" {
		if _, err := os.Stat(*write); err == nil {
			fmt.Println("This file exists")
			os.Exit(1)
		}
	}
}

func ValidateFields() []string {
	var out []string
	checkArray := strings.Split(*fields, ",")
	for _, toCheck := range checkArray {
		for _, allowed := range AllowedFields {
			if allowed == toCheck {
				out = append(out, toCheck)
			}
		}
	}
	return out
}

func ValidateCve() []string {
	var out []string
	for _, cves := range strings.Split(*cve, ",") {
		cveRegexp := regexp.MustCompile("[0-9]+")
		regexpArray := cveRegexp.FindAllString(cves, -1)
		cves = strings.Join(regexpArray, "")
		if len(cves) < 5 {
			fmt.Println("Please, insert at least year (YYYY) and ID number")
			Usage()
			os.Exit(71)
		}
		id := strings.TrimLeft(cves[4:], "0")
		cves := strings.Join([]string{"CVE", cves[0:4], id}, "-")
		out = append(out, cves)
	}
	return out
}

func PrintResults(resArray []db.Results, fields []string) {
	const padding = 2
	w := tabwriter.NewWriter(os.Stdout, 0, 0, padding, ' ', tabwriter.Debug)
	if *header {
		for _, f := range fields {
			fmt.Fprint(w, f, "\t")
		}
	}
	w.Flush()
	for i, res := range resArray {
		r := reflect.ValueOf(res)
		for _, f := range fields {
			fmt.Fprint(w, reflect.Indirect(r).FieldByName(f), "\t")
		}
		if i != 0 {
			fmt.Println()
		}
		w.Flush()
	}
}

func WriteCsv(resArray []db.Results) {
	if *write != "" {
		csvout, err := csv.Marshal(resArray)
		if err != nil {
			fmt.Println("Error durin marshalling [", err, "]")
		}
		//fmt.Println(string(*write))
		errWrite := ioutil.WriteFile(*write, csvout, 0644)
		if errWrite != nil {
			fmt.Println("Error during writing to file [", err, "]")
		}
	}
}