feat(wopi): fetch discover endpoint

pkg/wopi/discovery.go

@@ -0,0 +1,77 @@
+package wopi
+
+import (
+	"encoding/xml"
+	"fmt"
+	"github.com/cloudreve/Cloudreve/v3/pkg/cache"
+	"net/http"
+)
+
+type ActonType string
+
+var (
+	ActionPreview = ActonType("embedview")
+	ActionEdit    = ActonType("edit")
+)
+
+const (
+	DiscoverResponseCacheKey = "wopi_discover"
+	DiscoverRefreshDuration  = 24 * 3600 // 24 hrs
+)
+
+// checkDiscovery checks if discovery content is needed to be refreshed.
+// If so, it will refresh discovery content.
+func (c *client) checkDiscovery() error {
+	c.mu.RLock()
+	if c.discovery == nil {
+		c.mu.RUnlock()
+		return c.refreshDiscovery()
+	}
+
+	c.mu.RUnlock()
+	return nil
+}
+
+// refresh Discovery action configs.
+func (c *client) refreshDiscovery() error {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	cached, exist := cache.Get(DiscoverResponseCacheKey)
+	if exist {
+		cachedDiscovery := cached.(WopiDiscovery)
+		c.discovery = &cachedDiscovery
+	} else {
+		res, err := c.http.Request("GET", c.config.discoveryEndpoint.String(), nil).
+			CheckHTTPResponse(http.StatusOK).GetResponse()
+		if err != nil {
+			return fmt.Errorf("failed to request discovery endpoint: %s", err)
+		}
+
+		if err := xml.Unmarshal([]byte(res), &c.discovery); err != nil {
+			return fmt.Errorf("failed to parse response discovery endpoint: %s", err)
+		}
+
+		if err := cache.Set(DiscoverResponseCacheKey, *c.discovery, DiscoverRefreshDuration); err != nil {
+			return err
+		}
+	}
+
+	// construct actions map
+	c.actions = make(map[string]map[string]Action)
+	for _, app := range c.discovery.NetZone.App {
+		for _, action := range app.Action {
+			if action.Ext == "" {
+				continue
+			}
+
+			if _, ok := c.actions["."+action.Ext]; !ok {
+				c.actions["."+action.Ext] = make(map[string]Action)
+			}
+
+			c.actions["."+action.Ext][action.Name] = action
+		}
+	}
+
+	return nil
+}