package apply

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

// The forms a runtime's data root is said in (novox/hq issue 339, the third review): an ExecStart continued over
// lines, single quotes, a variable from Environment= or EnvironmentFile=, dockerd's --config-file, and TOML literal
// strings in podman's storage.conf. And the running runtimes are asked first: they say where they really keep it.
func TestEveryFormOfADataRootIsRead(t *testing.T) {
	dir := t.TempDir()
	write := func(name, content string) string {
		t.Helper()
		p := filepath.Join(dir, name)
		if err := os.MkdirAll(filepath.Dir(p), 0o755); err != nil {
			t.Fatal(err)
		}
		if err := os.WriteFile(p, []byte(content), 0o644); err != nil {
			t.Fatal(err)
		}
		return p
	}
	envFile := write("docker.env", "DOCKER_ROOT=/data/from-env-file\n")
	other := write("other-daemon.json", `{"data-root": "/data/from-config-file"}`)
	unit := write("lib/docker.service", "[Service]\nEnvironment=\"ROOT=/data/from-env\"\nEnvironmentFile=-"+envFile+"\n"+
		"ExecStart=/usr/bin/dockerd \\\n    -H fd:// \\\n    --data-root '/data/continued'\n")
	dropIn := write("etc/docker.service.d/root.conf", "[Service]\nExecStart=\nExecStart=/usr/bin/dockerd --data-root=$ROOT "+
		"--graph=${DOCKER_ROOT} --config-file "+other+"\n")
	storage := write("containers/storage.conf", "[storage]\ngraphroot = '/data/podman-literal'\n")
	before := runtimeConfigs
	runtimeConfigs = runtimeFiles{daemonJSON: filepath.Join(dir, "none.json"), units: []string{unit},
		dropInDirs: []string{filepath.Dir(dropIn)}, storageConf: storage}
	t.Cleanup(func() { runtimeConfigs = before })

	roots := strings.Join(readRuntimeRoots(context.Background(), nil), " ")
	for _, want := range []string{"/data/continued", "/data/from-env", "/data/from-env-file", "/data/from-config-file",
		"/data/podman-literal"} {
		if !strings.Contains(roots+" ", want+" ") {
			t.Errorf("%s was not read: %s", want, roots)
		}
	}

	// Asked of the running runtimes first; what they answer counts beside the files.
	asked := func(_ context.Context, name string, args ...string) (string, error) {
		switch name {
		case "docker":
			return "/srv/docker-live\n", nil
		case "podman":
			return "", errors.New("podman: not installed")
		}
		return "", errors.New("unexpected")
	}
	roots = strings.Join(readRuntimeRoots(context.Background(), asked), " ")
	if !strings.Contains(roots, "/srv/docker-live") || !strings.Contains(roots, "/data/continued") {
		t.Errorf("the running runtime's answer, or the files beside it, are missing: %s", roots)
	}
}