package httpd

import (
	"go/ast"
	"go/parser"
	"go/token"
	"strconv"
	"strings"
	"testing"

	"github.com/barerepo/server/internal/gitx"
)

// Chapter 42.5: a route with no reservation is one an account can shadow, and it says a test must catch it.
func TestEveryTopLevelRouteIsAReservedName(t *testing.T) {
	fset := token.NewFileSet()
	file, err := parser.ParseFile(fset, "web.go", nil, 0)
	if err != nil {
		t.Fatal(err)
	}

	seen := map[string]bool{}
	ast.Inspect(file, func(n ast.Node) bool {
		be, ok := n.(*ast.BinaryExpr)
		if !ok || be.Op != token.EQL {
			return true
		}
		lit, ok := be.Y.(*ast.BasicLit)
		if !ok || lit.Kind != token.STRING || !isRequestPath(be.X) {
			return true
		}
		path, err := strconv.Unquote(lit.Value)
		if err != nil || !strings.HasPrefix(path, "/") {
			return true
		}
		first, _, _ := strings.Cut(strings.TrimPrefix(path, "/"), "/")
		if first != "" {
			seen[first] = true
		}
		return true
	})

	if len(seen) < 8 {
		t.Fatalf("only found %d top level routes, so this test is reading the wrong thing", len(seen))
	}
	for name := range seen {
		// A name holding a dot is a file and not something an account could ever be called.
		if strings.Contains(name, ".") {
			continue
		}
		if !gitx.Reserved(name) {
			t.Errorf("/%s is a route and not a reserved name, so an account can shadow it", name)
		}
	}
}

// isRequestPath reports whether an expression is r.URL.Path, which is what the route switch compares.
func isRequestPath(e ast.Expr) bool {
	sel, ok := e.(*ast.SelectorExpr)
	if !ok || sel.Sel.Name != "Path" {
		return false
	}
	inner, ok := sel.X.(*ast.SelectorExpr)
	return ok && inner.Sel.Name == "URL"
}