package promptkit_test

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

const formerModulePath = "gitea.maximumdirect.net/eric/" + "scrip" + "torium"

func TestRepositoryDoesNotImportFormerModule(t *testing.T) {
	violations, err := findFormerModuleImports(".")
	if err != nil {
		t.Fatalf("inspect repository imports: %v", err)
	}
	if len(violations) > 0 {
		t.Fatalf("repository imports the former module:\n%s", strings.Join(violations, "\n"))
	}
}

func TestFormerModuleGuardFindsNestedImport(t *testing.T) {
	root := t.TempDir()
	nested := filepath.Join(root, "nested", "package")
	if err := os.MkdirAll(nested, 0o755); err != nil {
		t.Fatalf("create nested package: %v", err)
	}

	sourcePath := filepath.Join(nested, "violation.go")
	source := "package nested\n\nimport _ " + strconv.Quote(formerModulePath+"/internal/domain") + "\n"
	if err := os.WriteFile(sourcePath, []byte(source), 0o600); err != nil {
		t.Fatalf("write nested source: %v", err)
	}

	violations, err := findFormerModuleImports(root)
	if err != nil {
		t.Fatalf("inspect nested imports: %v", err)
	}
	if len(violations) != 1 {
		t.Fatalf("violations = %v, want one nested import", violations)
	}
	if !strings.Contains(violations[0], "violation.go") ||
		!strings.Contains(violations[0], formerModulePath+"/internal/domain") {
		t.Fatalf("violation = %q, want file and import path", violations[0])
	}
}

func findFormerModuleImports(root string) ([]string, error) {
	var violations []string
	err := filepath.WalkDir(root, func(path string, entry fs.DirEntry, walkErr error) error {
		if walkErr != nil {
			return walkErr
		}
		if entry.IsDir() {
			switch entry.Name() {
			case ".git", "generated", "vendor":
				return filepath.SkipDir
			}
			return nil
		}
		if filepath.Ext(path) != ".go" {
			return nil
		}

		file, err := parser.ParseFile(token.NewFileSet(), path, nil, parser.ImportsOnly|parser.ParseComments)
		if err != nil {
			return err
		}
		if ast.IsGenerated(file) {
			return nil
		}
		for _, spec := range file.Imports {
			importPath, err := strconv.Unquote(spec.Path.Value)
			if err != nil {
				return err
			}
			if importPath == formerModulePath || strings.HasPrefix(importPath, formerModulePath+"/") {
				violations = append(violations, path+": "+importPath)
			}
		}
		return nil
	})
	return violations, err
}