Cleanup the print package

- Use strings.Builder instead of concatenation
- Move smart tree to a separate file
- Add missing docstrings

pkg/print/smart.go

@@ -0,0 +1,98 @@
+package print
+
+import (
+	"git-get/pkg/repo"
+	"path/filepath"
+	"strings"
+)
+
+// SmartPrinter implements Printer interface and provides methods for printing repos and their statuses.
+// It's "smart" because it automatically folds branches which only have a single child and indents branches with many children.
+type SmartPrinter struct {
+	// length is the size (number of chars) of the currently processed line.
+	// It's used to correctly indent the lines with branches status.
+	length int
+}
+
+// Print generates a list of repositories and their statuses.
+func (p *SmartPrinter) Print(root string, repos []*repo.Repo) string {
+	tree := buildTree(root, repos)
+
+	return p.printSmartTree(tree)
+}
+
+// printSmartTree recursively traverses the tree and prints its nodes.
+// If a node contains multiple children, they are be printed in new lines and indented.
+// If a node contains only a single child, it is printed in the same line using path separator.
+// For better readability the first level (repos hosts) is not indented.
+//
+// Example:
+// Following paths:
+//   /repos/github.com/user/repo1
+//   /repos/github.com/user/repo2
+//   /repos/github.com/another/repo
+//
+// will render a tree:
+//   /repos/
+//   github.com/
+//       user/
+//           repo1
+//           repo2
+//       another/repo
+//
+func (p *SmartPrinter) printSmartTree(node *Node) string {
+	if node.children == nil {
+		// If node is a leaf, print repo name and its status and finish processing this node.
+		value := node.val
+
+		// TODO: Ugly
+		// If this is called from tests the repo will be nil and we should return just the name without the status.
+		if node.repo.Repository == nil {
+			return value
+		}
+
+		value += " " + printWorktreeStatus(node.repo)
+
+		// Print the status of each branch on a new line, indented to match the position of the current branch name.
+		indent := "\n" + strings.Repeat(" ", p.length+len(node.val))
+		for _, branch := range node.repo.Status.Branches {
+			// Don't print the status of the current branch. It was already printed above.
+			if branch.Name == node.repo.Status.CurrentBranch {
+				continue
+			}
+
+			value += indent + printBranchStatus(branch)
+		}
+
+		return value
+	}
+
+	val := node.val + string(filepath.Separator)
+
+	shift := ""
+	if node.parent == nil {
+		// If node is a root, print its children on a new line without indentation.
+		shift = "\n"
+	} else if len(node.children) == 1 {
+		// If node has only a single child, print it on the same line as its parent.
+		// Setting node's depth to the same as parent's ensures that its children will be indented only once even if
+		// node's path has multiple levels above.
+		node.depth = node.parent.depth
+
+		p.length += len(val)
+	} else {
+		// If node has multiple children, print each of them on a new line
+		// and indent them once relative to the parent
+		node.depth = node.parent.depth + 1
+		shift = "\n" + strings.Repeat("    ", node.depth)
+		p.length = 0
+	}
+
+	for _, child := range node.children {
+		p.length += len(shift)
+		val += shift + p.printSmartTree(child)
+		p.length = 0
+	}
+
+	return val
+}