package internal_test

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

func TestArchitecture_ModelAndServiceAreProtocolNeutral(t *testing.T) {
	for _, dir := range []string{"model", "service"} {
		imports := packageImports(t, dir)
		for _, forbidden := range []string{
			"net/http",
			"github.com/gin-gonic/gin",
			"github.com/dhao2001/mygo/internal/api",
		} {
			if imports[forbidden] {
				t.Fatalf("internal/%s imports forbidden package %q", dir, forbidden)
			}
		}
	}
}

func TestArchitecture_HTTPDoesNotImportRepositories(t *testing.T) {
	for _, dir := range []string{"handler", "middleware"} {
		imports := packageImports(t, dir)
		if imports["github.com/dhao2001/mygo/internal/repository"] {
			t.Fatalf("internal/%s imports internal/repository; use service boundaries instead", dir)
		}
	}
}

func packageImports(t *testing.T, dir string) map[string]bool {
	t.Helper()

	imports := map[string]bool{}
	pkgs := parsePackage(t, dir)
	for _, pkg := range pkgs {
		for _, file := range pkg.Files {
			for _, spec := range file.Imports {
				path, err := strconv.Unquote(spec.Path.Value)
				if err != nil {
					t.Fatalf("unquote import path %s: %v", spec.Path.Value, err)
				}
				imports[path] = true
			}
		}
	}
	return imports
}

func parsePackage(t *testing.T, dir string) map[string]*ast.Package {
	t.Helper()

	fset := token.NewFileSet()
	pkgs, err := parser.ParseDir(fset, dir, func(info os.FileInfo) bool {
		name := info.Name()
		return !strings.HasSuffix(name, "_test.go")
	}, parser.ParseComments)
	if err != nil {
		t.Fatalf("parse internal/%s: %v", dir, err)
	}
	return pkgs
}