package main

import (
	"os"
	"path/filepath"
	"strings"
	"testing"
)

func tree(t *testing.T, files map[string]string) string {
	t.Helper()
	root := t.TempDir()
	for p, c := range files {
		full := filepath.Join(root, p)
		if err := os.MkdirAll(filepath.Dir(full), 0o755); err != nil {
			t.Fatal(err)
		}
		if err := os.WriteFile(full, []byte(c), 0o644); err != nil {
			t.Fatal(err)
		}
	}
	return root
}

const aMod = "module git.novox.be/novox/r/a\n\ngo 1.22\n"
const bMod = "module git.novox.be/novox/r/b/sub\n\ngo 1.22\n"

// A module that imports a package of a mesh module its go.mod does not require is refused, in a test file and behind a
// build tag too; the module's own packages, a required module's and a nested module's (only when required) are not.
func TestAModuleImportsOnlyWhatItRequires(t *testing.T) {
	src := func(imp string) string { return "package x\n\nimport _ \"" + imp + "\"\n" }
	for _, row := range []struct {
		name  string
		files map[string]string
		want  string
	}{
		{"its own package", map[string]string{"a/go.mod": aMod, "a/x.go": src("git.novox.be/novox/r/a/other")}, ""},
		{"a required module", map[string]string{"a/go.mod": aMod + "\nrequire git.novox.be/novox/r/b/sub v0.0.0\n", "a/x.go": src("git.novox.be/novox/r/b/sub/pkg"), "b/go.mod": bMod}, ""},
		{"a required module in a block", map[string]string{"a/go.mod": aMod + "\nrequire (\n\tgit.novox.be/novox/r/b/sub v0.0.0 // indirect\n)\n", "a/x.go": src("git.novox.be/novox/r/b/sub/pkg"), "b/go.mod": bMod}, ""},
		{"a module not required", map[string]string{"a/go.mod": aMod, "a/x.go": src("git.novox.be/novox/r/b/sub/pkg"), "b/go.mod": bMod}, "x.go imports git.novox.be/novox/r/b/sub/pkg"},
		{"a test file", map[string]string{"a/go.mod": aMod, "a/x_test.go": src("git.novox.be/novox/r/b/sub/pkg"), "b/go.mod": bMod}, "x_test.go imports"},
		{"an integration file", map[string]string{"a/go.mod": aMod, "a/x.go": "//go:build integration\n\n" + src("git.novox.be/novox/r/b/sub/pkg"), "b/go.mod": bMod}, "x.go imports"},
		{"a module the longest owner is not", map[string]string{"a/go.mod": aMod + "\nrequire git.novox.be/novox/r/b v0.0.0\n", "a/x.go": src("git.novox.be/novox/r/b/sub/pkg"), "b/go.mod": "module git.novox.be/novox/r/b\n", "b/sub/go.mod": bMod}, "does not require"},
		{"a testdata fixture", map[string]string{"a/go.mod": aMod, "a/testdata/x.go": src("git.novox.be/novox/r/b/sub/pkg"), "a/x.go": "package x\n"}, ""},
		{"an outside module", map[string]string{"a/go.mod": aMod, "a/x.go": src("github.com/x/y")}, ""},
	} {
		t.Run(row.name, func(t *testing.T) {
			got, err := Findings([]string{tree(t, row.files)}, nil)
			if err != nil {
				t.Fatal(err)
			}
			if all := strings.Join(got, "\n"); (row.want == "") != (all == "") || !strings.Contains(all, row.want) {
				t.Fatalf("findings = %q, want one containing %q", all, row.want)
			}
		})
	}
}

// The script's run of this check over the real tree (novox/hq ADR 0529 clause 2): the repositories cloned beside it, when
// the check says where, tell which module owns a path.
func TestEveryCatalogueModuleRequiresWhatItImports(t *testing.T) {
	var known []string
	if beside := os.Getenv("MESH_CHECK_BESIDE"); beside != "" {
		es, _ := os.ReadDir(beside)
		for _, e := range es {
			if e.IsDir() && e.Name() != "mesh-catalog" {
				known = append(known, filepath.Join(beside, e.Name()))
			}
		}
	}
	got, err := Findings([]string{filepath.Join("..", "..")}, known)
	if err != nil {
		t.Fatal(err)
	}
	for _, f := range got {
		t.Error(f)
	}
}