package main

import (
	"context"
	"io/fs"
	"os"
	"path/filepath"
	"strings"
	"testing"

	"git.novox.be/novox/mesh-sdk/go/forgekey"
)

// npmAsUmask077 installs as npm does under a umask of 077: node_modules with a package whose folders are 0700, its
// file 0600 and its program 0700.
func npmAsUmask077(f *fakeNpm) forgekey.Runner {
	return func(ctx context.Context, env []string, name string, args ...string) forgekey.Ran {
		ran := f.run(ctx, env, name, args...)
		for i, a := range args {
			if a == "--prefix" {
				pkg := filepath.Join(args[i+1], "node_modules", "typescript", "bin")
				os.MkdirAll(pkg, 0o700)
				os.WriteFile(filepath.Join(args[i+1], "node_modules", "typescript", "package.json"), []byte("{}"), 0o600)
				os.WriteFile(filepath.Join(pkg, "tsc"), []byte("#!/bin/sh\n"), 0o700)
			}
		}
		return ran
	}
}

// checkOpen fails unless every folder from the cache's toolchain down lets others enter and read it and every file lets
// others read it, a program others run, and nothing lets anyone but the owner write.
func checkOpen(t *testing.T, tc Toolchain) {
	t.Helper()
	root := filepath.Join(tc.Paths.Cache, "toolchain")
	err := filepath.WalkDir(root, func(p string, d fs.DirEntry, err error) error {
		if err != nil {
			return err
		}
		info, err := d.Info()
		if err != nil {
			return err
		}
		mode := info.Mode().Perm()
		switch {
		case mode&0o022 != 0:
			t.Errorf("%s is %o: writable by others than its owner", p, mode)
		case d.IsDir() && mode&0o005 != 0o005:
			t.Errorf("%s is %o: others may not enter and read it", p, mode)
		case !d.IsDir() && mode&0o004 == 0:
			t.Errorf("%s is %o: others may not read it", p, mode)
		case !d.IsDir() && mode&0o100 != 0 && mode&0o001 == 0:
			t.Errorf("%s is %o: a program others may not run", p, mode)
		}
		return nil
	})
	if err != nil {
		t.Fatal(err)
	}
}

// 1891 (ADR 0533 §2): a toolchain the module installs can be read by the other build module's integration level:
// its folders 0755 and its files 0644 (programs 0755), whatever umask npm ran under, and writable by its owner alone.
func TestAnInstalledToolchainIsReadableByOthersAndWritableByItsOwnerAlone(t *testing.T) {
	fake := &fakeNpm{}
	tc := toolchainIn(t, fake)
	tc.Run = npmAsUmask077(fake)
	npm := filepath.Join(tc.Paths.Cache, "npm")
	if err := os.MkdirAll(npm, 0o700); err != nil {
		t.Fatal(err)
	}
	if err := tc.Ensure(context.Background(), "v1"); err != nil {
		t.Fatal(err)
	}
	checkOpen(t, tc)
	if st, err := os.Stat(npm); err != nil || st.Mode().Perm() != 0o700 {
		t.Errorf("the npm download cache beside the toolchains is %v (%v), want 0700: only the toolchains are opened", st.Mode().Perm(), err)
	}
}

// 1891 (ADR 0533 §2): a toolchain installed before this release, shut to its owner, is opened by the next Ensure
// without installing it again.
func TestAToolchainInstalledShutIsOpenedWithoutAnInstall(t *testing.T) {
	fake := &fakeNpm{}
	tc := toolchainIn(t, fake)
	dir := tc.Paths.Dir("v1")
	os.MkdirAll(filepath.Join(dir, "node_modules", "esbuild", "bin"), 0o700)
	os.WriteFile(filepath.Join(dir, "node_modules", "esbuild", "bin", "esbuild"), []byte("x"), 0o700)
	os.WriteFile(filepath.Join(dir, "package-lock.json"), []byte("{}"), 0o600)
	os.WriteFile(filepath.Join(dir, installedMark), []byte("v1\n"), 0o600)
	os.Chmod(filepath.Join(tc.Paths.Cache, "toolchain"), 0o700)
	if err := tc.Ensure(context.Background(), "v1"); err != nil {
		t.Fatal(err)
	}
	if len(fake.calls) != 0 {
		t.Errorf("npm ran %d times for a toolchain already there", len(fake.calls))
	}
	checkOpen(t, tc)
}

// 1891 (ADR 0533 §2): the cache directory lets other accounts enter it and not list it, so the toolchains beneath it
// can be reached by their path and the npm cache beside them (0700) cannot.
func TestTheCacheDirectoryIsEnteredByOthersNotListed(t *testing.T) {
	r := resource(t, readManifest(t), "cache")
	if r["mode"] != "0711" {
		t.Errorf("the cache directory's mode is %v, want 0711", r["mode"])
	}
}

// 1891 review (ADR 0533 §2): the registry credential npm is told is never written beneath the cache, so opening a
// toolchain can never open it: npm reads it from a file in the account's own home, readable by its owner alone, and
// the file is gone when Ensure returns.
func TestTheInstallCredentialIsNeverInTheFolderThatIsOpened(t *testing.T) {
	fake := &fakeNpm{}
	tc := toolchainIn(t, fake)
	var userconfig string
	inner := npmAsUmask077(fake)
	tc.Run = func(ctx context.Context, env []string, name string, args ...string) forgekey.Ran {
		for i, a := range args {
			if a == "--userconfig" {
				userconfig = args[i+1]
			}
		}
		if st, err := os.Stat(userconfig); err != nil || st.Mode().Perm() != 0o600 {
			t.Errorf("the credential file %s is %v (%v), want 0600", userconfig, st.Mode().Perm(), err)
		}
		return inner(ctx, env, name, args...)
	}
	if err := tc.Ensure(context.Background(), "v1"); err != nil {
		t.Fatal(err)
	}
	if rel, err := filepath.Rel(tc.Paths.Home, userconfig); err != nil || rel != filepath.Base(userconfig) {
		t.Errorf("the credential file %s is not in the account's home %s", userconfig, tc.Paths.Home)
	}
	if _, err := os.Stat(userconfig); err == nil {
		t.Errorf("the credential file %s is left after the install", userconfig)
	}
	filepath.WalkDir(tc.Paths.Cache, func(p string, d fs.DirEntry, err error) error {
		if err == nil && strings.Contains(d.Name(), "npmrc") {
			t.Errorf("a credential file %s lies beneath the cache", p)
		}
		return nil
	})
}

// 1891 review (ADR 0533 §2): open refuses a toolchain folder that holds an npm config file, naming it, and opens
// nothing of it, so a credential left by a dead install is never made readable.
func TestOpenRefusesAFolderHoldingAnNpmConfig(t *testing.T) {
	fake := &fakeNpm{}
	tc := toolchainIn(t, fake)
	dir := tc.Paths.Dir("v1")
	os.MkdirAll(filepath.Join(dir, "node_modules"), 0o700)
	left := filepath.Join(dir, ".npmrc-install")
	os.WriteFile(left, []byte("//x/:_auth=secret\n"), 0o600)
	os.WriteFile(filepath.Join(dir, installedMark), []byte("v1\n"), 0o600)
	err := tc.Ensure(context.Background(), "v1")
	if err == nil || !strings.Contains(err.Error(), left) {
		t.Errorf("Ensure = %v, want a refusal naming %s", err, left)
	}
	if st, _ := os.Stat(left); st.Mode().Perm() != 0o600 {
		t.Errorf("the credential file was opened to %o", st.Mode().Perm())
	}
	if st, _ := os.Stat(dir); st.Mode().Perm()&0o005 != 0 {
		t.Errorf("the folder holding it was opened to %o", st.Mode().Perm())
	}
}