package main

import (
	"go/ast"
	"go/token"
	"reflect"
)

type simplifier struct{}

func (s simplifier) Visit(node ast.Node) ast.Visitor {
	switch n := node.(type) {
	case *ast.CompositeLit:
		// array, slice, and map composite literals may be simplified
		outer := n
		var keyType, eltType ast.Expr
		switch typ := outer.Type.(type) {
		case *ast.ArrayType:
			eltType = typ.Elt
		case *ast.MapType:

https://codereview.appspot.com/6849045/
`,
}

func netipv6zone(f *ast.File) bool {
	if !imports(f, "net") {
		return false
	}

	fixed := false
	walk(f, func(n any) {
		cl, ok := n.(*ast.CompositeLit)
		if !ok {
			return
		}
		se, ok := cl.Type.(*ast.SelectorExpr)
		if !ok {
			return
		}
		if !isTopName(se.X, "net") || se.Sel == nil {
			return
		}
		switch ss := se.Sel.String(); ss {

	{"BasicLit", `@0x123`},
	{"BasicLit", `@3.1415`},
	{"BasicLit", `@.2718`},
	{"BasicLit", `@1i`},
	{"BasicLit", `@'a'`},
	{"BasicLit", `@"abc"`},
	{"BasicLit", "@`abc`"},

	{"CompositeLit", `@{}`},
	{"CompositeLit", `T@{}`},
	{"CompositeLit", `struct{x, y int}@{}`},

	{"KeyValueExpr", `"foo"@: true`},
	{"KeyValueExpr", `"a"@: b`},

	{"FuncLit", `@func (){}`},
	{"ParenExpr", `@(x)`},
	{"SelectorExpr", `a@.b`},

}

func run(pass *analysis.Pass) (interface{}, error) {
	inspect := pass.ResultOf[inspect.Analyzer].(*inspector.Inspector)

	nodeFilter := []ast.Node{
		(*ast.AssignStmt)(nil),
		(*ast.CallExpr)(nil),
		(*ast.CompositeLit)(nil),
		(*ast.FuncDecl)(nil),
		(*ast.FuncLit)(nil),
		(*ast.GenDecl)(nil),
		(*ast.RangeStmt)(nil),
		(*ast.ReturnStmt)(nil),
	}
	inspect.Preorder(nodeFilter, func(node ast.Node) {

func filterCompositeLit(lit *ast.CompositeLit, filter Filter, export bool) {
	n := len(lit.Elts)
	lit.Elts = filterExprList(lit.Elts, filter, export)
	if len(lit.Elts) < n {
		lit.Incomplete = true
	}
}

func filterExprList(list []ast.Expr, filter Filter, export bool) []ast.Expr {
	j := 0
	for _, exp := range list {
		switch x := exp.(type) {
		case *ast.CompositeLit:
			filterCompositeLit(x, filter, export)

}

func printerconfig(f *ast.File) bool {
	if !imports(f, "go/printer") {
		return false
	}

	fixed := false
	walk(f, func(n any) {
		cl, ok := n.(*ast.CompositeLit)
		if !ok {
			return
		}
		se, ok := cl.Type.(*ast.SelectorExpr)
		if !ok {
			return
		}
		if !isTopName(se.X, "printer") || se.Sel == nil {
			return
		}

// unkeyed fields.
func run(pass *analysis.Pass) (interface{}, error) {
	inspect := pass.ResultOf[inspect.Analyzer].(*inspector.Inspector)

	nodeFilter := []ast.Node{
		(*ast.CompositeLit)(nil),
	}
	inspect.Preorder(nodeFilter, func(n ast.Node) {
		cl := n.(*ast.CompositeLit)

		typ := pass.TypesInfo.Types[cl].Type
		if typ == nil {
			// cannot determine composite literals' type, skip it
			return
		}
		typeName := typ.String()

		// case *ImportDecl:
		// case *ConstDecl:
		// case *TypeDecl:
		// case *VarDecl:
		// case *FuncDecl:

		// expressions
		// case *BadExpr:
		// case *Name:
		// case *BasicLit:
		case *CompositeLit:
			if n.Type != nil {
				m = n.Type
				continue
			}
			return n.Pos()
		case *KeyValueExpr:
			m = n.Key
		// case *FuncLit:
		// case *ParenExpr:
		case *SelectorExpr:
			m = n.X

	return
}

func filterCompositeLit(lit *CompositeLit, filter Filter, export bool) {
	n := len(lit.Elts)
	lit.Elts = filterExprList(lit.Elts, filter, export)
	if len(lit.Elts) < n {
		lit.Incomplete = true
	}
}

func filterExprList(list []Expr, filter Filter, export bool) []Expr {
	j := 0
	for _, exp := range list {
		switch x := exp.(type) {
		case *CompositeLit:
			filterCompositeLit(x, filter, export)

		}

	case *ast.BasicLit:
		buf.WriteString(x.Value)

	case *ast.FuncLit:
		buf.WriteByte('(')
		WriteExpr(buf, x.Type)
		buf.WriteString(" literal)") // shortened

	case *ast.CompositeLit:
		WriteExpr(buf, x.Type)
		buf.WriteByte('{')
		if len(x.Elts) > 0 {
			buf.WriteString("…")
		}
		buf.WriteByte('}')

	case *ast.ParenExpr:
		buf.WriteByte('(')
		WriteExpr(buf, x.X)