package configkit

import (
	"go/parser"
	"go/token"
	"io/fs"
	"path/filepath"
	"strconv"
	"strings"
	"testing"
)

func TestDependencyImportBoundary(t *testing.T) {
	t.Parallel()

	err := filepath.WalkDir(".", func(path string, entry fs.DirEntry, walkErr error) error {
		if walkErr != nil {
			return walkErr
		}
		if entry.IsDir() {
			if path == ".git" {
				return filepath.SkipDir
			}
			return nil
		}
		if filepath.Ext(path) != ".go" {
			return nil
		}
		file, err := parser.ParseFile(token.NewFileSet(), path, nil, parser.ImportsOnly)
		if err != nil {
			return err
		}
		for _, imported := range file.Imports {
			importPath, err := strconv.Unquote(imported.Path.Value)
			if err != nil {
				return err
			}
			if strings.HasPrefix(importPath, "go.yaml.in/yaml/") && !strings.HasPrefix(filepath.ToSlash(path), "internal/yaml/") {
				t.Errorf("%s imports private YAML dependency %s", path, importPath)
			}
			if strings.HasPrefix(importPath, "github.com/google/go-cmp/") && !strings.HasSuffix(path, "_test.go") {
				t.Errorf("%s imports test-only dependency %s", path, importPath)
			}
			production := !strings.HasSuffix(path, "_test.go")
			rootProduction := production && filepath.Dir(path) == "."
			internalProduction := production && strings.HasPrefix(filepath.ToSlash(path), "internal/")
			if rootProduction && strings.HasPrefix(importPath, "gitea.maximumdirect.net/eric/ConfigKit/internal/") && importPath != "gitea.maximumdirect.net/eric/ConfigKit/internal/engine" {
				t.Errorf("%s bypasses the engine boundary through %s", path, importPath)
			}
			if internalProduction && importPath == "gitea.maximumdirect.net/eric/ConfigKit" {
				t.Errorf("%s imports the public root package", path)
			}
		}
		return nil
	})
	if err != nil {
		t.Fatal(err)
	}
}