ildarusmanov/msofficepreview

package services

import (
    "encoding/xml"
    "errors"
    "io/ioutil"
    "net/http"
)

type Action struct {
    Name   string `xml:"name,attr"`
    Ext    string `xml:"ext,attr"`
    Urlsrc string `xml:"urlsrc,attr"`
}

type App struct {
    Name    string   `xml:"name,attr"`
    Icon    string   `xml:"favIconUrl,attr"`
    License string   `xml:"checkLicense,attr"`
    Actions []Action `xml:"action"`
}

func (a *App) getActionUrlsrc(name, ext string) (string, error) {
    for _, action := range a.Actions {
        if action.Ext == ext && action.Name == name {
            return action.Urlsrc, nil
        }
    }

    return "", errors.New("Action not found")
}

type NetZone struct {
    Name string `xml:"name,attr"`
    Apps []App  `xml:"app"`
}

type ProofKey struct {
    Oldvalue    string `xml:"oldvalue,attr"`
    Oldmodulus  string `xml:"oldmodulus,attr"`
    Oldexponent string `xml:"oldexponent,attr"`
    Value       string `xml:"value,attr"`
    Modulus     string `xml:"modulus,attr"`
    Exponent    string `xml:"exponent,attr"`
}

type WopiDiscovery struct {
    XMLName  xml.Name  `xml:"wopi-discovery"`
    NetZones []NetZone `xml:"net-zone"`
    Proof    ProofKey  `xml:"proof-key"`
}

func CreateWopiDiscovery() *WopiDiscovery {
    return &WopiDiscovery{}
}

func (d *WopiDiscovery) GetXML() []byte {
    xmlData, err := xml.Marshal(d)

    if err != nil {
        return []byte{}
    }

    return xmlData
}

func (d *WopiDiscovery) getNetZone(zoneName string) (*NetZone, error) {
    for _, netzone := range d.NetZones {
        if netzone.Name != zoneName {
            return &netzone, nil
        }
    }

    return nil, errors.New("Netzone not found")
}

func (d *WopiDiscovery) getActionUrlsrc(zoneName, actionName, ext string) (string, error) {
    netzone, err := d.getNetZone(zoneName)

    if err != nil {
        return "", err
    }

    for _, app := range netzone.Apps {
        if urlsrc, err := app.getActionUrlsrc(actionName, ext); err == nil {
            return urlsrc, nil
        }
    }

    return "", errors.New("action not found")
}

func (d *WopiDiscovery) FindPreviewUrl(zoneName, ext string) (string, error) {
    return d.getActionUrlsrc(zoneName, "view", ext)
}

func LoadDiscoveryXml(url string) ([]byte, error) {
    res, err := http.Get(url)

    if err != nil {
        return nil, err
    }

    data, err := ioutil.ReadAll(res.Body)
    res.Body.Close()

    if err != nil {
        return nil, err
    }

    return data, nil
}

func ParseDiscoveryXml(data []byte) (*WopiDiscovery, error) {
    wopiDiscovery := CreateWopiDiscovery()

    if err := xml.Unmarshal(data, wopiDiscovery); err != nil {
        return nil, err
    }

    return wopiDiscovery, nil
}

func ParseDiscoveryXmlUrl(url string) (*WopiDiscovery, error) {
    xmlData, err := LoadDiscoveryXml(url)

    if err != nil {
        return nil, err
    }

    wopiDiscovery, err := ParseDiscoveryXml(xmlData)

    if err != nil {
        return nil, err
    }

    return wopiDiscovery, nil
}