package runit

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

	"github.com/warkanum/unitdore/config"
	"github.com/warkanum/unitdore/service"
)

// setup points the backend at temp dirs with recorded commands.
func setup(t *testing.T) (b Backend, calls *[]string) {
	t.Helper()
	oldSv, oldRun, oldOut, oldRoot, oldWait := svDir, runCmd, outCmd, service.IsRoot, superviseWait
	t.Cleanup(func() { svDir, runCmd, outCmd, service.IsRoot, superviseWait = oldSv, oldRun, oldOut, oldRoot, oldWait })
	svDir = t.TempDir()
	superviseWait = 300 * time.Millisecond
	service.IsRoot = func() bool { return true }
	var recorded []string
	runCmd = func(name string, args ...string) error {
		recorded = append(recorded, name+" "+strings.Join(args, " "))
		return nil
	}
	return Backend{ServiceDir: t.TempDir()}, &recorded
}

func mustContain(t *testing.T, content string, wants ...string) {
	t.Helper()
	for _, w := range wants {
		if !strings.Contains(content, w) {
			t.Errorf("missing %q in:\n%s", w, content)
		}
	}
}

func read(t *testing.T, path string) string {
	t.Helper()
	b, err := os.ReadFile(path)
	if err != nil {
		t.Fatal(err)
	}
	return string(b)
}

func TestGenerate_Container(t *testing.T) {
	b, _ := setup(t)
	u := config.Unit{Name: "nginx", Runtime: "podman"}
	got, err := b.Generate(u, "", "")
	if err != nil {
		t.Fatal(err)
	}
	mustContain(t, got,
		"===== "+filepath.Join(svDir, "unitdore-nginx", "run")+" =====",
		"exec 2>&1",
		"exec /usr/bin/podman start -a nginx",
		"===== "+filepath.Join(svDir, "unitdore-nginx", "finish")+" =====",
		"/usr/bin/podman stop nginx || true",
		"exec sv down .",
	)
}

func TestGenerate_RestartPolicy(t *testing.T) {
	b, _ := setup(t)
	u := config.Unit{Name: "app", Runtime: "podman", Restart: true, RestartSec: 7}
	got, err := b.Generate(u, "", "")
	if err != nil {
		t.Fatal(err)
	}
	mustContain(t, got, `[ "$1" = 0 ] && exec sv down .`, "sleep 7")
	if strings.Contains(got, "\nexec sv down .\n") {
		t.Errorf("restarting unit must not always go down:\n%s", got)
	}
}

func TestGenerate_ScriptExecAndWorkingDir(t *testing.T) {
	b, _ := setup(t)
	u := config.Unit{
		Name: "agent", Runtime: config.RuntimeExec, Executable: "/opt/agent",
		Args: []string{"--config", "/etc/my agent.toml"}, WorkingDir: "/opt",
	}
	got, err := b.Generate(u, "", "")
	if err != nil {
		t.Fatal(err)
	}
	mustContain(t, got, "cd /opt || exit 1", `exec /opt/agent --config '/etc/my agent.toml'`)
}

func TestGenerate_Oneshot(t *testing.T) {
	b, _ := setup(t)
	u := config.Unit{Name: "shop", Runtime: "podman", Kind: config.KindStack, Project: "shop"}
	got, err := b.Generate(u, "", "")
	if err != nil {
		t.Fatal(err)
	}
	mustContain(t, got,
		"/usr/bin/podman pod start pod_shop || exit 1\nexec tail -f /dev/null",
		"/usr/bin/podman pod stop pod_shop || true",
	)
}

func TestGenerate_RootlessUser(t *testing.T) {
	b, _ := setup(t)
	u := config.Unit{Name: "app", Runtime: "podman", User: "root"}
	got, err := b.Generate(u, "", "")
	if err != nil {
		t.Fatal(err)
	}
	mustContain(t, got,
		"[ -d /run/user/0 ] || install -d -m 0700 -o root /run/user/0",
		"export HOME=/root",
		"export XDG_RUNTIME_DIR=/run/user/0",
		"exec chpst -u root /usr/bin/podman start -a app",
		"chpst -u root /usr/bin/podman stop app || true",
	)
}

func TestGenerate_Invalid(t *testing.T) {
	b, _ := setup(t)
	if _, err := b.Generate(config.Unit{Name: "x", Runtime: config.RuntimeScript}, "", ""); err == nil {
		t.Error("expected validation error")
	}
}

func TestInstall_WritesDirLinkAndDown(t *testing.T) {
	b, _ := setup(t)
	u := config.Unit{Name: "nginx", Runtime: "podman"}
	dir := filepath.Join(svDir, "unitdore-nginx")
	link := filepath.Join(b.ServiceDir, "unitdore-nginx")

	if b.IsInstalled(u, "", "") {
		t.Fatal("should not be installed yet")
	}
	if err := b.Install(u, "", ""); err != nil {
		t.Fatal(err)
	}
	for _, name := range []string{"run", "finish"} {
		fi, err := os.Stat(filepath.Join(dir, name))
		if err != nil || fi.Mode().Perm()&0111 == 0 {
			t.Errorf("%s missing or not executable: %v", name, err)
		}
	}
	if _, err := os.Stat(filepath.Join(dir, "down")); err != nil {
		t.Error("fresh install must write a down file")
	}
	if target, err := os.Readlink(link); err != nil || target != dir {
		t.Errorf("link = %q, %v", target, err)
	}
	if !b.IsInstalled(u, "", "") {
		t.Error("should be installed")
	}
}

func TestInstall_ReinstallKeepsEnabled(t *testing.T) {
	b, _ := setup(t)
	u := config.Unit{Name: "nginx", Runtime: "podman"}
	dir := filepath.Join(svDir, "unitdore-nginx")

	if err := b.Install(u, "", ""); err != nil {
		t.Fatal(err)
	}
	if err := b.Enable(u, "", ""); err == nil {
		t.Log("enable ok") // may time out waiting for supervise; down file still removed
	}
	if _, err := os.Stat(filepath.Join(dir, "down")); !os.IsNotExist(err) {
		t.Fatal("enable must remove the down file")
	}

	u.Restart = true
	if err := b.Install(u, "", ""); err != nil {
		t.Fatal(err)
	}
	if _, err := os.Stat(filepath.Join(dir, "down")); !os.IsNotExist(err) {
		t.Error("re-install must keep an enabled service enabled")
	}
	if !strings.Contains(read(t, filepath.Join(dir, "finish")), `"$1" = 0`) {
		t.Error("re-install must rewrite scripts")
	}
}

func TestDisable_WritesDownAndStops(t *testing.T) {
	b, calls := setup(t)
	u := config.Unit{Name: "nginx", Runtime: "podman"}
	dir := filepath.Join(svDir, "unitdore-nginx")
	if err := b.Install(u, "", ""); err != nil {
		t.Fatal(err)
	}
	*calls = nil
	if err := b.Disable(u, "", ""); err != nil {
		t.Fatal(err)
	}
	if _, err := os.Stat(filepath.Join(dir, "down")); err != nil {
		t.Error("disable must write a down file")
	}
	if got := strings.Join(*calls, "|"); got != "sv stop "+filepath.Join(b.ServiceDir, "unitdore-nginx") {
		t.Errorf("calls = %q", got)
	}
}

func TestStartStop_UseSv(t *testing.T) {
	b, calls := setup(t)
	u := config.Unit{Name: "nginx", Runtime: "podman"}
	link := filepath.Join(b.ServiceDir, "unitdore-nginx")
	if err := b.Install(u, "", ""); err != nil {
		t.Fatal(err)
	}

	// Not supervised yet: Start must give up with a clear error
	if err := b.Start(u, "", ""); err == nil || !strings.Contains(err.Error(), "not supervised") {
		t.Errorf("Start() err = %v", err)
	}

	if err := os.MkdirAll(filepath.Join(link, "supervise"), 0755); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(filepath.Join(link, "supervise", "ok"), nil, 0644); err != nil {
		t.Fatal(err)
	}
	*calls = nil
	if err := b.Start(u, "", ""); err != nil {
		t.Fatal(err)
	}
	if err := b.Stop(u, "", ""); err != nil {
		t.Fatal(err)
	}
	if got := strings.Join(*calls, "|"); got != "sv start "+link+"|sv stop "+link {
		t.Errorf("calls = %q", got)
	}
}

func TestUninstall_RemovesDirAndLink(t *testing.T) {
	b, calls := setup(t)
	u := config.Unit{Name: "nginx", Runtime: "podman"}
	if err := b.Install(u, "", ""); err != nil {
		t.Fatal(err)
	}
	*calls = nil
	if err := b.Uninstall(u, "", ""); err != nil {
		t.Fatal(err)
	}
	if b.IsInstalled(u, "", "") {
		t.Error("should be uninstalled")
	}
	if _, err := os.Lstat(filepath.Join(b.ServiceDir, "unitdore-nginx")); !os.IsNotExist(err) {
		t.Error("link should be gone")
	}
	if len(*calls) != 1 || !strings.HasPrefix((*calls)[0], "sv stop ") {
		t.Errorf("calls = %q", *calls)
	}
}

func TestServiceDirAutodetect(t *testing.T) {
	old := serviceDirCandidates
	t.Cleanup(func() { serviceDirCandidates = old })
	existing := t.TempDir()
	serviceDirCandidates = []string{filepath.Join(existing, "nope"), existing}
	if got := (Backend{}).serviceDir(); got != existing {
		t.Errorf("serviceDir() = %q, want %q", got, existing)
	}
	if got := (Backend{ServiceDir: "/custom"}).serviceDir(); got != "/custom" {
		t.Errorf("explicit serviceDir() = %q", got)
	}
}

func TestRequiresRoot(t *testing.T) {
	b, _ := setup(t)
	service.IsRoot = func() bool { return false }
	u := config.Unit{Name: "nginx", Runtime: "podman"}
	for name, err := range map[string]error{
		"install": b.Install(u, "", ""), "uninstall": b.Uninstall(u, "", ""),
		"start": b.Start(u, "", ""), "stop": b.Stop(u, "", ""),
		"enable": b.Enable(u, "", ""), "disable": b.Disable(u, "", ""),
	} {
		if err == nil {
			t.Errorf("%s should require root", name)
		}
	}
}

func TestParseStatus(t *testing.T) {
	tests := map[string]string{
		"run: /var/service/x: (pid 123) 5s":       "active",
		"down: /var/service/x: 3s, normally up":   "inactive",
		"finish: /var/service/x: (pid 9) 1s":      "deactivating",
		"fail: /var/service/x: runsv not running": "inactive",
		"warning: weird":                          "unknown",
	}
	for in, want := range tests {
		if got := parseStatus(in); got != want {
			t.Errorf("parseStatus(%q) = %q, want %q", in, got, want)
		}
	}
}

func TestGenerate_OrderAndDelay(t *testing.T) {
	b, _ := setup(t)
	u := config.Unit{Name: "web", Runtime: "podman", Enabled: true, After: []string{"db"}, StartDelay: 3 * time.Second}
	got, err := b.Generate(u, "", "")
	if err != nil {
		t.Fatal(err)
	}
	link := filepath.Join(b.ServiceDir, "unitdore-db")
	wait := "sv -w 30 check " + link + " >/dev/null 2>&1 || true\nsleep 3\n"
	if !strings.Contains(got, wait) {
		t.Errorf("missing %q in:\n%s", wait, got)
	}
	// waiting happens before the service command runs
	if strings.Index(got, "sleep 3") > strings.Index(got, "exec /usr/bin/podman") {
		t.Errorf("delay must precede exec:\n%s", got)
	}
}

func TestGenerate_NoOrderNoExtras(t *testing.T) {
	b, _ := setup(t)
	got, err := b.Generate(config.Unit{Name: "a", Runtime: "podman", Enabled: true}, "", "")
	if err != nil {
		t.Fatal(err)
	}
	if strings.Contains(got, "sv -w") || strings.Contains(got, "sleep") {
		t.Errorf("unexpected ordering output:\n%s", got)
	}
}