package apply

import (
	"context"
	"errors"
	"os"
	"os/user"
	"path/filepath"
	"strings"
	"testing"

	"github.com/novox/mesh-host/internal/store"
)

// A run-once process is a step run where, how and as whom it was declared (novox/hq design 38
// WP4c): its bundle's directory, its environment and environment files, its user. Run directly,
// it started in the host's own directory with none of them.
func TestARunOnceProcessRunsAsItsOneshotUnit(t *testing.T) {
	units, bundles := t.TempDir(), t.TempDir()
	wasUnits, wasBundles := unitDir, daemonRoot
	unitDir, daemonRoot = units, bundles
	t.Cleanup(func() { unitDir, daemonRoot = wasUnits, wasBundles })

	me, err := user.Current()
	if err != nil {
		t.Fatal(err)
	}
	body, digest := anArchive(t, map[string]string{"bootstrap/index.js": "console.log(1)\n"})
	var commands []string
	fail := false
	run := func(ctx context.Context, name string, args ...string) (string, error) {
		commands = append(commands, name+" "+strings.Join(args, " "))
		if fail && name == "systemctl" && len(args) > 0 && args[0] == "start" {
			return "", errors.New("exit status 1")
		}
		return "", nil
	}
	d := declare(t, `{"id":"mosquitto.bootstrap","type":"process","name":"mosquitto-bootstrap","source":"`+serving(t, body)+
		`","digest":"`+digest+`","run":["node","bootstrap/index.js"],"run-once":true,"user":"`+me.Username+`",`+
		`"env":{"MESH_ADMIN":"mesh-admin"},"env-file":["/var/lib/mesh/mosquitto/bootstrap.env"]}`)

	if _, _, err := Apply(context.Background(), archHost(t), d, store.State{}, store.OriginDeclared, run, nil, nil); err != nil {
		t.Fatal(err)
	}
	unit, err := os.ReadFile(filepath.Join(units, "mosquitto-bootstrap.service"))
	if err != nil {
		t.Fatalf("no unit was written for the step: %v", err)
	}
	for _, want := range []string{
		"WorkingDirectory=" + filepath.Join(bundles, "mosquitto-bootstrap"),
		"EnvironmentFile=/var/lib/mesh/mosquitto/bootstrap.env",
		`Environment="MESH_ADMIN=mesh-admin"`,
		"User=" + me.Username,
		"Type=oneshot",
		"ExecStart=node bootstrap/index.js",
	} {
		if !strings.Contains(string(unit), want) {
			t.Errorf("the step's unit lacks %q:\n%s", want, unit)
		}
	}
	for _, never := range []string{"Restart=always", "[Install]", "Type=simple"} {
		if strings.Contains(string(unit), never) {
			t.Errorf("a step's unit says %q:\n%s", never, unit)
		}
	}
	joined := strings.Join(commands, "; ")
	if !strings.Contains(joined, "systemctl start mosquitto-bootstrap.service") {
		t.Errorf("the step was not started as its unit: %s", joined)
	}
	if strings.Contains(joined, "node bootstrap/index.js") || strings.Contains(joined, "enable mosquitto-bootstrap") {
		t.Errorf("the step was run directly or enabled: %s", joined)
	}

	// A step that fails fails the apply, and is not recorded as done.
	fail = true
	d2 := declare(t, `{"id":"mosquitto.bootstrap","type":"process","name":"mosquitto-bootstrap","source":"`+serving(t, body)+
		`","digest":"`+digest+`","run":["node","bootstrap/index.js"],"run-once":true,"env":{"MESH_ADMIN":"changed"}}`)
	if _, _, err := Apply(context.Background(), archHost(t), d2, store.State{}, store.OriginDeclared, run, nil, nil); err == nil {
		t.Error("a step that failed did not fail the apply")
	}
}