adding initial support for third-party addons and the basic framework for how they are registered by the system

1 files changed, 170 insertions, 0 deletions

diff --git a/system/addon/addon.go b/system/addon/addon.go
new file mode 100644
index 0000000..bf1a717
--- /dev/null
+++ b/system/addon/addon.go
@@ -0,0 +1,170 @@
+package addon
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/url"
+	"strings"
+
+	"github.com/ponzu-cms/ponzu/system/db"
+	"github.com/ponzu-cms/ponzu/system/item"
+)
+
+var (
+	// Types is a record of addons, like content types, of addon_reverse_dns:interface{}
+	Types = make(map[string]func() interface{})
+)
+
+const (
+	// StatusEnabled defines string status for Addon enabled state
+	StatusEnabled = "enabled"
+	// StatusDisabled defines string status for Addon disabled state
+	StatusDisabled = "disabled"
+)
+
+// Meta contains the basic information about the addon
+type Meta struct {
+	PonzuAddonName       string `json:"addon_name"`
+	PonzuAddonAuthor     string `json:"addon_author"`
+	PonzuAddonAuthorURL  string `json:"addon_author_url"`
+	PonzuAddonVersion    string `json:"addon_version"`
+	PonzuAddonReverseDNS string `json:"addon_reverse_dns"`
+	PonzuAddonStatus     string `json:"addon_status"`
+}
+
+// Addon contains information about a provided addon to the system
+type Addon struct {
+	item.Item
+	Meta
+}
+
+// Register sets up the system to use the Addon by:
+// 1. Adding Meta to the Addon struct
+// 2. Saving it to the __addons bucket in DB with id/key = addon_reverse_dns
+// 3. Checking that the Addon parent type was added to Types (likely via its init())
+func Register(meta Meta, addon Addon) error {
+	a := Addon{Meta: meta}
+
+	// get or create the reverse DNS identifier
+	if a.PonzuAddonReverseDNS == "" {
+		revDNS, err := reverseDNS(meta)
+		if err != nil {
+			return err
+		}
+
+		a.PonzuAddonReverseDNS = revDNS
+	}
+
+	if _, ok := Types[a.PonzuAddonReverseDNS]; !ok {
+		panic(`Addon "` + a.PonzuAddonName + `" has no record in the addons.Types map`)
+	}
+
+	// check if addon is already registered in db as addon_reverse_dns
+	if db.AddonExists(a.PonzuAddonReverseDNS) {
+		return nil
+	}
+
+	// convert a.Item into usable data, Item{} => []byte(json) => map[string]interface{}
+	kv := make(map[string]interface{})
+
+	data, err := json.Marshal(a.Item)
+	if err != nil {
+		return err
+	}
+
+	err = json.Unmarshal(data, &kv)
+	if err != nil {
+		return err
+	}
+
+	// save new addon to db
+	vals := make(url.Values)
+	for k, v := range kv {
+		vals.Set(k, v.(string))
+	}
+
+	vals.Set("addon_name", a.PonzuAddonName)
+	vals.Set("addon_author", a.PonzuAddonAuthor)
+	vals.Set("addon_author_url", a.PonzuAddonAuthorURL)
+	vals.Set("addon_version", a.PonzuAddonVersion)
+	vals.Set("addon_reverse_dns", a.PonzuAddonReverseDNS)
+	vals.Set("addon_status", StatusDisabled)
+
+	// db.SetAddon is like SetContent, but rather than the key being an int64 ID,
+	// we need it to be a string based on the addon_reverse_dns
+	err = db.SetAddon(vals)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// Deregister removes an addon from the system. `key` is the addon_reverse_dns
+func Deregister(key string) error {
+	err := db.DeleteAddon(key)
+	if err != nil {
+		return err
+	}
+
+	delete(Types, key)
+	return nil
+}
+
+// Enable sets the addon status to `enabled`. `key` is the addon_reverse_dns
+func Enable(key string) error {
+	err := setStatus(key, StatusEnabled)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// Disable sets the addon status to `disabled`. `key` is the addon_reverse_dns
+func Disable(key string) error {
+	err := setStatus(key, StatusDisabled)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func setStatus(key, status string) error {
+	a, err := db.Addon(key)
+	if err != nil {
+		return err
+	}
+
+	a.Set("addon_status", status)
+
+	err = db.SetAddon(a)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func reverseDNS(meta Meta) (string, error) {
+	u, err := url.Parse(meta.PonzuAddonAuthorURL)
+	if err != nil {
+		return "", nil
+	}
+
+	if u.Host == "" {
+		return "", fmt.Errorf(`Error parsing Addon Author URL: %s. Ensure URL is formatted as "scheme://hostname/path?query" (path & query optional)`, meta.PonzuAddonAuthorURL)
+	}
+
+	name := strings.Replace(meta.PonzuAddonName, " ", "", -1)
+
+	// reverse the host name parts, split on '.', ex. bosssauce.it => it.bosssauce
+	parts := strings.Split(u.Host, ".")
+	strap := make([]string, len(parts), len(parts))
+	for i := len(parts) - 1; i >= 0; i-- {
+		strap = append(strap, parts[i])
+	}
+
+	return strings.Join(append(strap, name), "."), nil
+}