refactor: move utility functions to independent package

ui.go

@@ -75,11 +75,11 @@ func onChannelsTreeSelected(n *tview.TreeNode) {
 				})
 
 				// Top-level channels
-				createTopLevelChannelsTreeNodes(n, g.Channels)
+				util.CreateTopLevelChannelsNodes(channelsTree, session.State, n, g.Channels)
 				// Category channels
-				createCategoryChannelsTreeNodes(n, g.Channels)
+				util.CreateCategoryChannelsNodes(channelsTree, session.State, n, g.Channels)
 				// Second-level channels
-				createSecondLevelChannelsTreeNodes(g.Channels)
+				util.CreateSecondLevelChannelsNodes(channelsTree, session.State, g.Channels)
 			}
 		}
 

util.go

@@ -1,88 +0,0 @@
-package main
-
-import (
-	"github.com/ayntgl/discordgo"
-	"github.com/ayntgl/discordo/util"
-	"github.com/rivo/tview"
-)
-
-func createTopLevelChannelsTreeNodes(
-	n *tview.TreeNode,
-	cs []*discordgo.Channel,
-) {
-	for _, c := range cs {
-		if (c.Type == discordgo.ChannelTypeGuildText || c.Type == discordgo.ChannelTypeGuildNews) &&
-			(c.ParentID == "") {
-			p, err := session.State.UserChannelPermissions(session.State.User.ID, c.ID)
-			if err != nil || p&discordgo.PermissionViewChannel != discordgo.PermissionViewChannel {
-				continue
-			}
-
-			var tag string
-			if util.ChannelIsUnread(session.State, c) {
-				tag = "[::b]"
-			} else {
-				tag = "[::d]"
-			}
-
-			cn := tview.NewTreeNode(tag + util.ChannelToString(c) + "[::-]").
-				SetReference(c.ID)
-			n.AddChild(cn)
-			continue
-		}
-	}
-}
-
-func createCategoryChannelsTreeNodes(
-	n *tview.TreeNode,
-	cs []*discordgo.Channel,
-) {
-CategoryLoop:
-	for _, c := range cs {
-		if c.Type == discordgo.ChannelTypeGuildCategory {
-			p, err := session.State.UserChannelPermissions(session.State.User.ID, c.ID)
-			if err != nil || p&discordgo.PermissionViewChannel != discordgo.PermissionViewChannel {
-				continue
-			}
-
-			for _, child := range cs {
-				if child.ParentID == c.ID {
-					cn := tview.NewTreeNode(c.Name).
-						SetReference(c.ID)
-					n.AddChild(cn)
-					continue CategoryLoop
-				}
-			}
-
-			cn := tview.NewTreeNode(c.Name).
-				SetReference(c.ID)
-			n.AddChild(cn)
-		}
-	}
-}
-
-func createSecondLevelChannelsTreeNodes(cs []*discordgo.Channel) {
-	for _, c := range cs {
-		if (c.Type == discordgo.ChannelTypeGuildText || c.Type == discordgo.ChannelTypeGuildNews) &&
-			(c.ParentID != "") {
-			p, err := session.State.UserChannelPermissions(session.State.User.ID, c.ID)
-			if err != nil || p&discordgo.PermissionViewChannel != discordgo.PermissionViewChannel {
-				continue
-			}
-
-			var tag string
-			if util.ChannelIsUnread(session.State, c) {
-				tag = "[::b]"
-			} else {
-				tag = "[::d]"
-			}
-
-			pn := util.GetTreeNodeByReference(channelsTree, c.ParentID)
-			if pn != nil {
-				cn := tview.NewTreeNode(tag + util.ChannelToString(c) + "[::-]").
-					SetReference(c.ID)
-				pn.AddChild(cn)
-			}
-		}
-	}
-}

util/ui.go

@@ -1,6 +1,9 @@
 package util
 
-import "github.com/rivo/tview"
+import (
+	"github.com/ayntgl/discordgo"
+	"github.com/rivo/tview"
+)
 
 // GetTreeNodeByReference walks the root `*TreeNode` of the given `*TreeView` *treeView* and returns the TreeNode whose reference is equal to the given reference *r*. If the `*TreeNode` is not found, `nil` is returned instead.
 func GetTreeNodeByReference(treeView *tview.TreeView, r interface{}) (mn *tview.TreeNode) {
@@ -15,3 +18,86 @@ func GetTreeNodeByReference(treeView *tview.TreeView, r interface{}) (mn *tview.
 
 	return
 }
+
+// CreateTopLevelChannelsNodes builds and creates `*tview.TreeNode`s for top-level (channels that have an empty parent ID and of type GUILD_TEXT, GUILD_NEWS) channels. If the client user does not have the VIEW_CHANNEL permission for a channel, the channel is excluded from the parent.
+func CreateTopLevelChannelsNodes(treeView *tview.TreeView, s *discordgo.State, n *tview.TreeNode, cs []*discordgo.Channel) {
+	for _, c := range cs {
+		if (c.Type == discordgo.ChannelTypeGuildText || c.Type == discordgo.ChannelTypeGuildNews) &&
+			(c.ParentID == "") {
+			if !HasPermission(s, c.ID, discordgo.PermissionViewChannel) {
+				continue
+			}
+
+			n.AddChild(CreateChannelNode(s, c))
+			continue
+		}
+	}
+}
+
+// CreateCategoryChannelsNodes builds and creates `*tview.TreeNode`s for category (type: GUILD_CATEGORY) channels. If the client user does not have the VIEW_CHANNEL permission for a channel, the channel is excluded from the parent.
+func CreateCategoryChannelsNodes(treeView *tview.TreeView, s *discordgo.State, n *tview.TreeNode, cs []*discordgo.Channel) {
+CategoryLoop:
+	for _, c := range cs {
+		if c.Type == discordgo.ChannelTypeGuildCategory {
+			if !HasPermission(s, c.ID, discordgo.PermissionViewChannel) {
+				continue
+			}
+
+			for _, child := range cs {
+				if child.ParentID == c.ID {
+					n.AddChild(CreateChannelNode(s, c))
+					continue CategoryLoop
+				}
+			}
+
+			n.AddChild(CreateChannelNode(s, c))
+		}
+	}
+}
+
+// CreateSecondLevelChannelsNodes builds and creates `*tview.TreeNode`s for second-level (channels that have a non-empty parent ID and of type GUILD_TEXT, GUILD_NEWS) channels. If the client user does not have the VIEW_CHANNEL permission for a channel, the channel is excluded from the parent.
+func CreateSecondLevelChannelsNodes(treeView *tview.TreeView, s *discordgo.State, cs []*discordgo.Channel) {
+	for _, c := range cs {
+		if (c.Type == discordgo.ChannelTypeGuildText || c.Type == discordgo.ChannelTypeGuildNews) &&
+			(c.ParentID != "") {
+			if !HasPermission(s, c.ID, discordgo.PermissionViewChannel) {
+				continue
+			}
+
+			pn := GetTreeNodeByReference(treeView, c.ParentID)
+			if pn != nil {
+				pn.AddChild(CreateChannelNode(s, c))
+			}
+		}
+	}
+}
+
+// CreateChannelNode builds (encorporates unread channels in bold tag, otherwise dim, etc.) and returns a node according to the type of the given channel *c*.
+func CreateChannelNode(s *discordgo.State, c *discordgo.Channel) *tview.TreeNode {
+	var cn *tview.TreeNode
+	switch c.Type {
+	case discordgo.ChannelTypeGuildText, discordgo.ChannelTypeGuildNews:
+		tag := "[::d]"
+		if ChannelIsUnread(s, c) {
+			tag = "[::b]"
+		}
+
+		cn = tview.NewTreeNode(tag + ChannelToString(c) + "[::-]").
+			SetReference(c.ID)
+	case discordgo.ChannelTypeGuildCategory:
+		cn = tview.NewTreeNode(c.Name).
+			SetReference(c.ID)
+	}
+
+	return cn
+}
+
+// HasPermission returns a boolean that indicates whether the client user has the given permission *p* in the given channel ID *cID*.
+func HasPermission(s *discordgo.State, cID string, p int64) bool {
+	perm, err := s.UserChannelPermissions(s.User.ID, cID)
+	if err != nil {
+		return false
+	}
+
+	return perm&p == p
+}