package main

import (
	"bufio"
	"crypto/md5"
	"crypto/sha256"
	"errors"
	"fmt"
	"io"
	"os"
	"path/filepath"
	"strings"

	"go.wit.com/lib/cobol"
	"go.wit.com/lib/gui/shell"
	"go.wit.com/lib/protobuf/zoopb"
	"go.wit.com/log"
	"google.golang.org/protobuf/types/known/timestamppb"
)

func populateDebInfo(p *zoopb.Package) error {
	// SIMPLE SANITY CHECKS
	if p.DebInfo != nil {
		// already added p.DebInfo
		return nil
	}
	fullname := filepath.Join(me.pb.BaseDir, p.Filename)
	cmd := []string{"dpkg", "-I", fullname}
	r := shell.Run(cmd)
	if r.Error != nil {
		return r.Error
	}
	if r.Exit != 0 {
		return errors.New("dpkg returned -1")
	}
	stat, err := os.Stat(fullname)
	if err != nil {
		return err
	}
	filedata, err := os.Open(fullname)
	if err != nil {
		return err
	}
	defer filedata.Close()
	// SIMPLE SANITY CHECKS END

	// SHA256 HASH
	p.DebInfo = new(zoopb.DebInfo)

	hSHA256 := sha256.New()
	hMD5 := md5.New() // probably deprecate, but love md5sum too much
	// hSHA1 := sha1.New() // deprecated

	// TeeReader allows writing to multiple hashers at once
	// multiWriter := io.MultiWriter(hMD5, hSHA1, hSHA256)
	multiWriter := io.MultiWriter(hSHA256, hMD5)
	if _, err := io.Copy(multiWriter, filedata); err != nil {
		return err
	}
	p.DebInfo.SHA256 = fmt.Sprintf("%x", hSHA256.Sum(nil)) // should be the standard now
	p.DebInfo.MD5SUM = fmt.Sprintf("%x", hMD5.Sum(nil))    // probably deprecate
	// p.DebInfo.SHA1 = fmt.Sprintf("%x", hSHA1.Sum(nil))     // deprecated
	// SHA256 HASH END

	// set file create time
	p.Ctime = timestamppb.New(stat.ModTime())

	// PARSE "dpkg -I <p.Filename>", then exit as we are done
	starting := true
	all := strings.Join(r.Stdout, "\n")
	scanner := bufio.NewScanner(strings.NewReader(all))
	for scanner.Scan() {
		line := scanner.Text()
		parts := strings.Fields(line)
		if starting {
			if parts[0] == "new" {
				if argv.Verbose {
					log.Printf("new: %v\n", parts)
				}
				// skip the first dpkg -I line
				continue
			}
			if parts[0] == "size" {
				if argv.Verbose {
					log.Printf("size: %v\n", parts)
				}
				// todo: make this correct
				p.DebInfo.Size = parts[1]
				p.DebInfo.InstalledSize = parts[1]
				// scan all the entries from size
				for scanner.Scan() {
					line = scanner.Text()
					parts = strings.Fields(line)
					if strings.HasPrefix(line, "  ") {
						if argv.Verbose {
							log.Printf("sizeline: %v\n", parts)
						}
						continue
					}
					starting = false
					break
				}
			}
			if starting {
				if argv.Verbose {
					log.Printf("parts: %v\n", parts)
				}
				continue
			}
		}
		varname := strings.TrimSuffix(parts[0], ":")
		varval := strings.Join(parts[1:], " ")
		// log.Printf("varname:%s varval:%s\n", varname, varval)
		switch varname {
		case "Package":
			p.Package = varval
		case "Filename":
			log.Printf("Filename: varname:%s varval:%s\n", varname, varval)
			// p.Package = varval
		case "Version":
			p.Version = varval
		case "Architecture":
			p.Architecture = varval
		case "GoPath":
			p.Namespace = varval
		case "Maintainer":
			p.DebInfo.Maintainer = varval
		case "Packager":
			p.DebInfo.Packager = varval
		case "Depends":
			p.DebInfo.Depends = varval
		case "Source":
			p.DebInfo.Source = varval
		case "URL":
			p.DebInfo.URL = varval
		case "Build-Depends":
			p.DebInfo.BuildDepends = varval
		case "Installed-Size:":
		case "Installed-Size":
			p.DebInfo.InstalledSize = varval
		case "Homepage":
			p.DebInfo.URL = varval
		case "Conflicts":
			p.DebInfo.Conflicts = varval
		case "Source-Date":
			t, err := cobol.GetTime(varval)
			if err == nil {
				p.GitDate = timestamppb.New(t)
			} else {
				if argv.Verbose {
					log.Info("FIXME: Package-Build-Date", varval, err)
				}
			}
		case "Build-Date":
		case "Package-Build-Date":
			t, err := cobol.GetTime(varval)
			if err == nil {
				p.BuildDate = timestamppb.New(t)
			} else {
				if argv.Verbose {
					log.Info("FIXME: Package-Build-Date", varval, err)
				}
			}
		case "Git-Tag-Date":
			if argv.Verbose {
				log.Info("FIXME: Git-Tag-Date", varval)
			}
		case "Description":
			description := varval
			for scanner.Scan() {
				line := scanner.Text()
				if strings.HasPrefix(line, "  ") {
					line = strings.TrimSpace(line)
					description += line + "\n"
					continue
				}
				break
			}
			p.DebInfo.Description = description
		default:
			// This forces me(it could be you!) to fix this parser
			varname2 := strings.TrimSuffix(varname, ":")
			log.Printf("UNKNOWN: varname:%s varval:%s varname2=%s\n", varname, varval, varname2)
			panic("fix mirrors populateDebInfo()")
		}
	}
	// pb.DebInfo should be correctly populated. You can verify these with "mirrors --verify"
	return nil
}