package main

// The after-upgrade check, its second part (novox/hq ADR 0508 §4; acceptance 1841/AC5): processes still mapping a
// replaced file, by unit or container and executable, never a command line or environment; DKMS built for every
// installed kernel.

import (
	"errors"
	"strings"
	"testing"
)

// standInProc is a process table in memory; it records every file read, so nothing else is read.
type standInProc struct {
	files map[string]string
	links map[string]string
	read  []string
}

func (p *standInProc) ReadDir(dir string) ([]string, error) {
	seen := map[string]bool{}
	var names []string
	for f := range p.files {
		if rest, ok := strings.CutPrefix(f, dir+"/"); ok {
			n, _, _ := strings.Cut(rest, "/")
			if !seen[n] {
				seen[n] = true
				names = append(names, n)
			}
		}
	}
	return names, nil
}

func (p *standInProc) ReadFile(name string) ([]byte, error) {
	p.read = append(p.read, name)
	if s, ok := p.files[name]; ok {
		return []byte(s), nil
	}
	return nil, errNoFile
}

func (p *standInProc) Readlink(name string) (string, error) {
	if s, ok := p.links[name]; ok {
		return s, nil
	}
	return "", errNoFile
}

const libcDeleted = "7f2a1c000000-7f2a1c028000 r--p 00000000 103:02 5513 /usr/lib/libc.so.6 (deleted)\n"

func TestAProcessMappingAReplacedFileIsNamedByItsUnitOrContainerAndExecutableOnly(t *testing.T) {
	p := &standInProc{files: map[string]string{
		"/proc/1/maps":      libcDeleted,
		"/proc/1/cgroup":    "0::/init.scope\n",
		"/proc/200/maps":    "5600-5700 r-xp 00000000 103:02 77 /usr/bin/sshd\n" + strings.Replace(libcDeleted, "libc.so.6", "libcrypto.so.3", 1),
		"/proc/200/cgroup":  "0::/system.slice/sshd.service\n",
		"/proc/201/maps":    libcDeleted,
		"/proc/201/cgroup":  "0::/system.slice/sshd.service\n",
		"/proc/300/maps":    libcDeleted,
		"/proc/300/cgroup":  "0::/system.slice/docker-0123456789abcdef0123456789abcdef.scope\n",
		"/proc/400/maps":    "7f00-7f10 rw-s 00000000 00:1a 9 /dev/shm/made-up (deleted)\n",
		"/proc/400/cgroup":  "0::/system.slice/made-up.service\n",
		"/proc/500/maps":    "5600-5700 r-xp 00000000 103:02 77 /usr/bin/made-up\n",
		"/proc/500/cmdline": "made-up --password=secret",
		"/proc/500/environ": "TOKEN=secret",
		"/proc/self/maps":   libcDeleted,
	}, links: map[string]string{
		"/proc/1/exe": "/usr/lib/systemd/systemd", "/proc/200/exe": "/usr/bin/sshd (deleted)", "/proc/201/exe": "/usr/bin/sshd (deleted)",
		"/proc/300/exe": "/usr/bin/made-up-server",
	}}
	got, err := MappedDeleted(p, "/proc")
	if err != nil {
		t.Fatal(err)
	}
	var said []string
	for _, m := range got {
		said = append(said, m.Unit+"|"+m.Container+"|"+m.Executable)
	}
	if strings.Join(said, " ") != "|0123456789ab|/usr/bin/made-up-server init.scope||/usr/lib/systemd/systemd sshd.service||/usr/bin/sshd" {
		t.Errorf("%v", said)
	}
	for _, r := range p.read {
		if strings.HasSuffix(r, "/cmdline") || strings.HasSuffix(r, "/environ") {
			t.Errorf("read %s: a process is named by its unit and executable, never its command line or environment", r)
		}
	}
}

func TestADKMSModuleNotBuiltForAnInstalledKernelFailsTheCheck(t *testing.T) {
	m := checkMachine("", "7.2.9-arch1-1")
	table := map[string]Ran{
		"systemctl list-units --state=failed --plain --no-legend --no-pager": {},
		"pacman -Qq":               {Stdout: "linux\nlinux-lts\n"},
		"pacman -Qlq -- linux":     {Stdout: "/usr/lib/modules/7.2.9-arch1-1/vmlinuz\n"},
		"pacman -Qlq -- linux-lts": {Stdout: "/usr/lib/modules/6.18.54-2-lts/vmlinuz\n"},
		"dkms status": {Stdout: "zfs/2.4.4, 6.18.54-2-lts, x86_64: installed\nzfs/2.4.4, 7.2.8-arch1-2, x86_64: installed\n" +
			"made-up-driver/1.0, 6.18.54-2-lts, x86_64: installed\nxpad/0.4: added\n"},
	}
	m.Run = byLine(table, nil)
	read := m.ReadFile
	m.ReadFile = func(path string) ([]byte, error) {
		if path == "/usr/src/made-up-driver-1.0/dkms.conf" {
			return []byte("BUILD_EXCLUSIVE_KERNEL=\"^6\\.\"\n"), nil
		}
		return read(path)
	}
	u := checkUpgrades(t, m)
	u.Root = &fakeRoot{mapped: []Mapped{{Unit: "sshd.service", Executable: "/usr/bin/sshd"}}}
	c := u.AfterCheck(checkedRun(StepStarted, StepFinished), &Record{})
	if len(c.Unbuilt) != 1 || c.Unbuilt[0] != (DKMSBuild{Module: "zfs", Version: "2.4.4", Kernel: "7.2.9-arch1-1"}) || c.Passed {
		t.Errorf("zfs not built for the new kernel fails the check (made-up-driver excludes it, xpad was never built): %+v", c)
	}
	if len(c.Mapped) != 1 || c.Mapped[0].Unit != "sshd.service" {
		t.Errorf("mapped: %+v", c.Mapped)
	}

	table["dkms status"] = Ran{Stdout: "zfs/2.4.4, 6.18.54-2-lts, x86_64: installed\nzfs/2.4.4, 7.2.9-arch1-1, x86_64: installed\n"}
	if c := u.AfterCheck(checkedRun(StepStarted, StepFinished), &Record{}); !c.Passed || len(c.Mapped) != 1 {
		t.Errorf("built for every kernel passes; a mapped file is said and does not fail it: %+v", c)
	}

	u.Root = &fakeRoot{mapsErr: errors.New("the root helper's socket is not there")}
	if c := u.AfterCheck(checkedRun(StepStarted, StepFinished), &Record{}); !strings.Contains(c.MappedError, "socket") {
		t.Errorf("unread mappings are said: %+v", c)
	}
	table["dkms status"] = Ran{Status: 1, Stderr: "dkms: permission denied\n"}
	if c := u.AfterCheck(checkedRun(StepStarted, StepFinished), &Record{}); c.Passed || c.DKMSError == "" {
		t.Errorf("unread DKMS builds do not pass: %+v", c)
	}
}