package bootstrap

import (
	"context"
	"encoding/json"
	"os"
	"path/filepath"
	"strings"
	"testing"
)

// imageFormManifest is a controller from before issue 213: it builds an image and runs a container.
const imageFormManifest = `{"module":"mesh-controller","version":"1","resources":[
  {"id":"server","type":"container","name":"mesh-controller","network":"host","artifact":"server"}],
  "build":{"artifacts":[{"name":"server","kind":"image","from":"Dockerfile"}]}}`

// processFormManifest is the controller's manifest as novox/mesh-controller declares it after issue
// 213: a Go bundle the host runs as a process, replacing the container it ran as.
const processFormManifest = `{
  "module": "mesh-controller", "version": "1", "slug": "control", "prepares": true,
  "claims": [{"name": "mesh-controller", "scope": "mesh"}],
  "accesses": [{"path": "/var/lib/mesh-broker-tls", "mode": "read"}],
  "own-secrets": {"inventory": "${dir:mesh-state}/inventory", "bus": "${dir:mesh-state}/bus"},
  "secrets-owner": "mesh-controller",
  "tools": ["status"],
  "resources": [
    {"id": "account", "type": "user", "name": "mesh-controller", "shell": "/usr/bin/nologin", "home": "/var/lib/mesh-controller"},
    {"id": "mesh-state", "type": "directory", "mode": "0700", "place": "mesh", "owner": "mesh-controller"},
    {"id": "controller", "type": "process", "name": "mesh-controller", "artifact": "controller",
     "run": ["./mesh-controller", "serve"], "user": "mesh-controller",
     "env": {"MESH_BROKER_CERTIFICATE": "/var/lib/mesh-broker-tls/tls.crt",
             "MESH_STORE_INVENTORY_FILE": "${dir:mesh-state}/inventory",
             "MESH_STORE_INVENTORY_PORT": "${seat:mesh-store:5432}",
             "MESH_BUS_NATS_FILE": "${dir:mesh-state}/bus"},
     "replaces": ["server"]}
  ],
  "build": {"artifacts": [{"name": "controller", "kind": "bundle", "language": "go", "system": "arch",
    "from": "cmd/mesh-controller", "binary": "mesh-controller"}]}
}`

// aRepository answers the carried builder's git as a clone of a repository holding this manifest and
// a Dockerfile, and hands every other command to then.
func aRepository(t *testing.T, manifest string, then func(string, []string) (string, error)) func(string, []string) (string, error) {
	t.Helper()
	return func(name string, args []string) (string, error) {
		if name == "docker" && len(args) > 5 && args[0] == "run" && args[4] == "--entrypoint" && args[5] == "git" {
			host := strings.TrimSuffix(args[3], ":/ws")
			joined := strings.Join(args, " ")
			switch {
			case strings.Contains(joined, " clone "):
				src := filepath.Join(host, "src")
				if err := os.MkdirAll(src, 0o755); err != nil {
					return "", err
				}
				if err := os.WriteFile(filepath.Join(src, "module.json"), []byte(manifest), 0o644); err != nil {
					return "", err
				}
				return "", os.WriteFile(filepath.Join(src, "Dockerfile"), []byte("FROM scratch\n"), 0o644)
			case strings.Contains(joined, "rev-parse"):
				return "a1b2c3d4e5f6\n", nil
			}
			return "", nil
		}
		return then(name, args)
	}
}

// novox/hq issue 223: a controller declared as a process is raised at genesis as a container built
// from its own Dockerfile, not by the builder — which has no Go toolchain at genesis and would refuse.
func TestAProcessFormControllerIsBuiltFromItsDockerfileAndRaisedAsAContainer(t *testing.T) {
	runtime := &asked{answer: aRepository(t, processFormManifest, func(name string, args []string) (string, error) {
		if name == "docker" && args[0] == "build" {
			return builtImage + "\n", nil
		}
		t.Fatalf("genesis ran %s %v; a process-form controller is built from its Dockerfile alone", name, args)
		return "", nil
	})}
	built, err := BuildControlPlane(context.Background(), runtime.run, "mesh-builder:test",
		Source{Repository: "https://example.invalid/mesh-controller.git", Ref: "a1b2c3d4"}, false, func(string) {})
	if err != nil {
		t.Fatal(err)
	}
	if built.Image != builtImage || built.Commit != "a1b2c3d4e5f6" {
		t.Errorf("built %q from %q", built.Image, built.Commit)
	}
	if runtime.ran("mesh-builder:test build") {
		t.Error("the builder was asked to build a controller it cannot build at genesis")
	}

	var m map[string]any
	if err := json.Unmarshal(built.Manifest, &m); err != nil {
		t.Fatalf("the genesis manifest is not JSON: %v", err)
	}
	if _, has := m["prepares"]; has {
		t.Error("the genesis manifest prepares its state; the temporary controller already did, and a pinned image is nothing the controller can derive a step from")
	}
	if _, has := m["build"]; has {
		t.Error("the genesis manifest still says how it is built; it is handed over resolved")
	}
	var container map[string]any
	for _, raw := range m["resources"].([]any) {
		r := raw.(map[string]any)
		if r["type"] == "process" {
			t.Errorf("the genesis manifest still runs the process: %v", r)
		}
		if r["type"] == "container" {
			container = r
		}
	}
	if container == nil {
		t.Fatal("the genesis manifest runs no container")
	}
	for key, want := range map[string]any{"id": "server", "name": "mesh-controller", "image": builtImage,
		"network": "host"} {
		if container[key] != want {
			t.Errorf("the genesis container's %s is %v, not %v", key, container[key], want)
		}
	}
	if _, has := container["user"]; has {
		t.Error("the genesis container says a user; the host's container has no such field, the image's USER is who it runs as")
	}
	if m["secrets-owner"] != "65534:65534" {
		t.Errorf("the secrets belong to %v, which the container cannot read as", m["secrets-owner"])
	}
	volumes, _ := json.Marshal(container["volumes"])
	for _, want := range []string{"${dir:mesh-state}/inventory:${dir:mesh-state}/inventory:ro",
		"/var/lib/mesh-broker-tls/tls.crt:/var/lib/mesh-broker-tls/tls.crt:ro"} {
		if !strings.Contains(string(volumes), want) {
			t.Errorf("the container does not mount %s: %s", want, volumes)
		}
	}
	if strings.Contains(string(volumes), "seat:") {
		t.Errorf("a word that is not a path was mounted: %s", volumes)
	}

	// And it is what step 9 installs: pinned, its container found, its stores delivered from its
	// environment — the same path an image-form controller takes.
	pinned, _, err := pinImage(built.Manifest, built.Image, "registry.internal:5000/mesh-controller@sha256:"+strings.Repeat("e", 64), ControlPlaneModule)
	if err != nil {
		t.Fatal(err)
	}
	if id := controlPlaneResourceIn(pinned); id != "server" {
		t.Errorf("step 9 finds the controller's container as %q", id)
	}
	wanted, err := secretsByVariableIn(pinned)
	if err != nil {
		t.Fatalf("step 9 cannot deliver the stores into the genesis container: %v", err)
	}
	if wanted["MESH_STORE_INVENTORY"] != "inventory" {
		t.Errorf("step 9 delivers %v", wanted)
	}
}

// An older controller — an image and a container — is still built by the builder, as before.
func TestAnImageFormControllerIsStillBuiltByTheBuilder(t *testing.T) {
	manifest := `{"module":"mesh-controller","version":"1","resources":[` +
		`{"id":"server","type":"container","name":"mesh-controller","image":"` + builtImage + `"}]}`
	runtime := &asked{answer: aRepository(t, imageFormManifest, func(name string, args []string) (string, error) {
		if name == "docker" && args[0] == "build" {
			t.Fatal("an image-form controller was built from its Dockerfile rather than by the builder")
		}
		return `{"module":"mesh-controller","commit":"a1b2c3d4","manifest":` + manifest +
			`,"made":[{"name":"server","kind":"image","reference":"` + builtImage + `"}]}`, nil
	})}
	built, err := BuildControlPlane(context.Background(), runtime.run, "mesh-builder:test",
		Source{Repository: "https://example.invalid/mesh-controller.git", Ref: "a1b2c3d4"}, false, func(string) {})
	if err != nil {
		t.Fatal(err)
	}
	if string(built.Manifest) != manifest || !runtime.ran("mesh-builder:test build") {
		t.Errorf("the image form did not go through the builder: %s", built.Manifest)
	}
}

func TestAProcessFormNamingNoOneReplacementIsRefused(t *testing.T) {
	for _, bad := range []string{`"replaces": []`, `"replaces": ["a", "b"]`} {
		raw := strings.Replace(processFormManifest, `"replaces": ["server"]`, bad, 1)
		if _, err := processFormOf([]byte(raw)); err == nil {
			t.Errorf("a process saying %s was accepted; genesis would not know what to name its container", bad)
		}
	}
}