From 6d9aa8b022a8fca3e9b51e58eaa2778f679dbf72 Mon Sep 17 00:00:00 2001
From: mappu <mappu04@gmail.com>
Date: Fri, 10 Apr 2020 17:20:54 +1200
Subject: [PATCH] add normalisation pass (WIP)

---
 main.go          |  24 ++++++++---
 normalisealts.go | 101 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 120 insertions(+), 5 deletions(-)
 create mode 100644 normalisealts.go

diff --git a/main.go b/main.go
index 3d65166..2b4450a 100644
--- a/main.go
+++ b/main.go
@@ -33,25 +33,38 @@ func ConvertFile(filename string) (string, error) {
 	// Enable comments extraction
 	p.WithFreeFloating()
 
+	// Parse PHP content
 	p.Parse()
 	for _, err := range p.GetErrors() {
 		return "", errors.New(err.String())
 	}
+	n := p.GetRootNode()
 
-	// Walk and print JSON...
+	// Debug pass: Walk and print JSON...
 	if fh, err := os.OpenFile(filename+`.parse.json`, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0644); err == nil {
 		v := visitor.NewPrettyJsonDumper(fh, namespaces)
-		p.GetRootNode().Walk(v)
+		n.Walk(v)
 		fh.Close()
 	}
 
-	// Walk and print (converted)
-	ret, err := state.convert(p.GetRootNode())
+	// Pass 1: Normalise Alt** Stmt types
+	normPass := normaliseAltsPass{}
+	n.Walk(&normPass) // can't modify root node, but that's fine
+
+	// Debug pass: Walk and print JSON...
+	if fh, err := os.OpenFile(filename+`.parse2.json`, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0644); err == nil {
+		v := visitor.NewPrettyJsonDumper(fh, namespaces)
+		n.Walk(v)
+		fh.Close()
+	}
+
+	// Pass 2: Walk and print (converted)
+	ret, err := state.convert(n)
 	if err != nil {
 		return "", err
 	}
 
-	// Gofmt output
+	// Pass 3: Gofmt output
 	// TODO pass flags to get -s/-r equivalent for more agressive simplification
 	formatted, err := format.Source([]byte(ret))
 	if err != nil {
@@ -59,6 +72,7 @@ func ConvertFile(filename string) (string, error) {
 		return ret, nil
 	}
 
+	// Done
 	return string(formatted), nil
 }
 
diff --git a/normalisealts.go b/normalisealts.go
new file mode 100644
index 0000000..db719c2
--- /dev/null
+++ b/normalisealts.go
@@ -0,0 +1,101 @@
+package main
+
+import (
+	"fmt"
+	//"io/ioutil"
+
+	"github.com/z7zmey/php-parser/node"
+	"github.com/z7zmey/php-parser/node/stmt"
+	"github.com/z7zmey/php-parser/walker"
+)
+
+type normaliseAltsPass struct {
+}
+
+func (np *normaliseAltsPass) transformNonRecursive(n node.Node) (node.Node, bool) {
+
+	switch n := n.(type) {
+	case *stmt.AltIf:
+		// Build replacement node
+		ifStmt := stmt.NewIf(n.Cond, n.Stmt, n.ElseIf, n.Else)
+		ifStmt.FreeFloating = n.FreeFloating
+		ifStmt.Position = n.Position
+		// ifStmt has no .Attributes prop
+		return ifStmt, true
+
+	case *stmt.AltElse:
+		elseStmt := stmt.NewElse(n.Stmt)
+		elseStmt.FreeFloating = n.FreeFloating
+		elseStmt.Position = n.Position
+		return elseStmt, true
+
+	case *stmt.AltElseIf:
+		elifStmt := stmt.NewElseIf(n.Cond, n.Stmt)
+		elifStmt.FreeFloating = n.FreeFloating
+		elifStmt.Position = n.Position
+		return elifStmt, true
+
+	default:
+		return n, false // no change
+	}
+}
+
+func (np *normaliseAltsPass) walkMutateArray(stmts []node.Node) {
+	for i, _ := range stmts {
+		np.walkMutate(&stmts[i])
+	}
+}
+
+func (np *normaliseAltsPass) walkMutate(child *node.Node) {
+
+	v2, didChange := np.transformNonRecursive(*child)
+	if didChange {
+		v2.Walk(np)
+		*child = v2
+	} else {
+		(*child).Walk(np)
+	}
+}
+
+func (np *normaliseAltsPass) EnterNode(w walker.Walkable) bool {
+	n, ok := w.(node.Node)
+	if !ok {
+		panic(fmt.Errorf("Tried to walk non-node '%t'", w))
+	}
+
+	// We need to override the .Walk() behaviour for all possible *parents*
+	// of affected nodes. This is because the .Walk() interface does not give
+	// us any opportunity to override single elements by the time we get there
+	// Our custom Walk() implementation is not firing all EnterChildList/LeaveNode
+	// visitors - but - that's fine since they're all noops anyway
+
+	switch n := n.(type) {
+	case *stmt.StmtList:
+		np.walkMutateArray(n.Stmts) // mutate slice in place
+		return false                // Signal not to use upstream .Walk() implementation
+
+	case *node.Root:
+		np.walkMutateArray(n.Stmts) // mutate slice in place
+		return false                // Signal not to use upstream .Walk() implementation
+
+	case *stmt.AltIf:
+		panic("altif")
+		np.walkMutate(&n.Cond)
+		np.walkMutateArray(n.ElseIf)
+		np.walkMutate(&n.Else)
+		return false
+
+	default:
+		// No normalisation needed for this node type
+		// Recurse deeper
+		return true
+	}
+}
+
+func (np *normaliseAltsPass) LeaveNode(w walker.Walkable)                  {}
+func (np *normaliseAltsPass) EnterChildNode(key string, w walker.Walkable) {}
+func (np *normaliseAltsPass) LeaveChildNode(key string, w walker.Walkable) {}
+func (np *normaliseAltsPass) EnterChildList(key string, w walker.Walkable) {}
+func (np *normaliseAltsPass) LeaveChildList(key string, w walker.Walkable) {}
+
+var _ walker.Visitor = &normaliseAltsPass{} // interface assertion