Feat: Add FallbackCommand for HTTP Strategy, refactor packages strategies (#175)

Add FallbackCommand for HTTP Strategy, refactor packages strategies, improve histories implementations.

historystore/history_store.go

@@ -0,0 +1,47 @@
+package historystore
+
+import (
+	"sync"
+
+	"github.com/mariocandela/beelzebub/v3/plugins"
+)
+
+// HistoryStore is a thread-safe structure for storing Messages used to build LLM Context.
+type HistoryStore struct {
+	sync.RWMutex
+	sessions map[string][]plugins.Message
+}
+
+// NewHistoryStore returns a prepared HistoryStore
+func NewHistoryStore() *HistoryStore {
+	return &HistoryStore{
+		sessions: make(map[string][]plugins.Message),
+	}
+}
+
+// HasKey returns true if the supplied key exists in the map.
+func (hs *HistoryStore) HasKey(key string) bool {
+	hs.RLock()
+	defer hs.RUnlock()
+	_, ok := hs.sessions[key]
+	return ok
+}
+
+// Query returns the value stored at the map
+func (hs *HistoryStore) Query(key string) []plugins.Message {
+	hs.RLock()
+	defer hs.RUnlock()
+	return hs.sessions[key]
+}
+
+// Append will add the slice of Mesages to the entry for the key.
+// If the map has not yet been initalised, then a new map is created.
+func (hs *HistoryStore) Append(key string, message ...plugins.Message) {
+	hs.Lock()
+	defer hs.Unlock()
+	// In the unexpected case that the map has not yet been initalised, create it.
+	if hs.sessions == nil {
+		hs.sessions = make(map[string][]plugins.Message)
+	}
+	hs.sessions[key] = append(hs.sessions[key], message...)
+}