package main

// This action is reading all _patchinfo files,
// finds the highest incident number
// and updates all _patchinfo files which have not
// set their incident attribute to a number.

import (
	"encoding/xml"
	"log"
	"io/ioutil"
	"os"
	"strings"
	"strconv"
        "path/filepath"
	"github.com/sethvargo/go-githubactions"
)

type PatchinfoSimple struct {
	XMLName  struct{} `xml:"patchinfo"`
	Incident string   `xml:"incident,attr,omitempty"`
	Version  string   `xml:"version,attr,omitempty"`
	Inner    []byte   `xml:",innerxml"`
}

func updateIncident(filename string, incident string) {
    data, err := ioutil.ReadFile(filename)
    if err != nil {
    	log.Fatal(err)
    }

    d := PatchinfoSimple{}
    if err := xml.Unmarshal(data, &d); err != nil {
        panic(err)
    }
    d.Incident = incident
    content, err := xml.Marshal(d)
    if err != nil {
        panic(err)
    }

//    fmt.Println(string(content))
    if err := os.WriteFile(filename, content, 0644); err != nil {
        panic(err)
    }
}

func readIncident(filename string) string {
    data, err := ioutil.ReadFile(filename)
    if err != nil {
    	log.Fatal(err)
    }

    d := PatchinfoSimple{}
    if err := xml.Unmarshal(data, &d); err != nil {
        panic(err)
    }
    return d.Incident
}

func main() {
    root := "."

    max_incident := 0

    files_to_update := []string{}
    prefix := githubactions.GetInput("prefix")

    // read all _patchinfo files and find highest existend incident
    filepath.Walk(root, func(path string, info os.FileInfo, err error) error {
      if err == nil && info.Name() == "_patchinfo" {
        incident:= readIncident(path)
	if strings.HasPrefix(incident, prefix) {
          incident_nr, err := strconv.Atoi(strings.TrimPrefix(incident, prefix))
	  if err != nil {
	    files_to_update = append(files_to_update, path)
	  } else if max_incident < incident_nr {
            max_incident = incident_nr
          }
	} else {
	  files_to_update = append(files_to_update, path)
        }
      }
      return nil
    })

    // set incident of new _patchinfo files
    for _, file := range files_to_update {
       max_incident++
       incident := prefix + strconv.Itoa(max_incident)
       println("Update " + file + " with " + incident)
       updateIncident(file, incident)
    }
}