package replays

import (
	"context"
	"fmt"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
	"testing"
	"time"
)

// **R145 — a web application that accepts TCP and answers nothing is raised within two looks** (novox/hq
// ADR 0240 Phase B, "how it is checked", rule 4; issue 145).
//
// For eleven hours a web application's port was open and its program ran while every request hung, and the
// mesh said its machine was healthy; a person found it. Liveness cannot see it and a TCP check cannot either.
// The replay is the whole chain, each half at its commit:
//
//  1. a web server whose application never answers is raised here, as the node-engine raises a module's;
//  2. the node-engine at MESH_REPLAY_HOST looks at it with the HTTP check its module declares, two looks,
//     and writes what it states (its TestReplaySilentWebAppIsSaidUnhealthy) — an engine older than the
//     declared check states it alive and nothing more;
//  3. the controller at MESH_REPLAY_CONTROLLER hears that statement on two looks in a row and raises the
//     module's condition on the second (its TestReplaySilentWebAppIsRaisedWithinTwoLooks).
//
// Needs a container runtime, Go, and MESH_TEST_POSTGRES for the controller's store; the container is removed
// after, whatever happened.
func TestReplaySilentWebApp(t *testing.T) {
	host := orDefault(os.Getenv("MESH_REPLAY_HOST"), filepath.Join("..", "..", "mesh-host"))
	controller := orDefault(os.Getenv("MESH_REPLAY_CONTROLLER"), filepath.Join("..", "..", "mesh-controller"))
	for _, dir := range []string{host, controller} {
		if _, err := os.Stat(filepath.Join(dir, "go.mod")); err != nil {
			t.Skipf("no checkout at %s (MESH_REPLAY_HOST and MESH_REPLAY_CONTROLLER name them)", dir)
		}
	}
	if os.Getenv("MESH_TEST_POSTGRES") == "" {
		t.Skip("no MESH_TEST_POSTGRES: the controller's half raises its condition in a store")
	}
	docker, ok := DockerFromEnv()
	if !ok {
		t.Skip("no container runtime: the web application is a container")
	}
	ctx, cancel := context.WithTimeout(t.Context(), 10*time.Minute)
	defer cancel()

	// 1. The silent web application (mesh-host internal/liveness SilentWebImage, SilentWebProgram).
	const image = "busybox:1.36"
	if err := docker.Pull(ctx, image); err != nil {
		t.Fatal(err)
	}
	name := fmt.Sprintf("mesh-replay-silent-web-%d", time.Now().UnixNano())
	id, address, err := docker.Start(ctx, Run{Image: image, Name: name, Restart: "unless-stopped",
		Labels: map[string]string{"mesh-host.id": "app.server"},
		Cmd: []string{"sh", "-c", "mkdir -p /www/cgi-bin && printf '#!/bin/sh\\nsleep 3600\\n' > /www/cgi-bin/app && " +
			"chmod +x /www/cgi-bin/app && exec httpd -f -p 8080 -h /www"}})
	if err != nil {
		t.Fatal(err)
	}
	defer docker.Remove(context.Background(), id)

	// 2. The node-engine at its commit looks at it, and says what it states.
	statement := filepath.Join(t.TempDir(), "statement.json")
	engine := exec.CommandContext(ctx, "go", "test", "-count=1", "-run", "^TestReplaySilentWebAppIsSaidUnhealthy$",
		"./internal/liveness/")
	engine.Dir = host
	engine.Env = append(os.Environ(), "MESH_REPLAY_CONTAINER="+name, "MESH_REPLAY_ADDRESS="+address,
		"MESH_REPLAY_STATEMENT="+statement, "GOFLAGS=")
	out, err := engine.CombinedOutput()
	switch {
	case err == nil && !strings.Contains(string(out), "no tests to run"):
		t.Logf("the node-engine said: %s", firstLineOf(statementOf(statement)))
	case judgesNothing(string(out)) || strings.Contains(string(out), "no tests to run"):
		// An engine older than the declared check: it states the application alive, and nothing more.
		t.Fatalf("the node-engine at this commit does not look at a declared HTTP check")
	default:
		t.Fatalf("the node-engine did not say the silent web application unhealthy: %v\n%s", err, lastOf(string(out), 12))
	}

	// 3. The controller at its commit raises the module's condition from what the engine said.
	raise := exec.CommandContext(ctx, "go", "test", "-count=1", "-run", "^TestReplaySilentWebAppIsRaisedWithinTwoLooks$",
		"./cmd/mesh-controller/")
	raise.Dir = controller
	raise.Env = append(os.Environ(), "MESH_REPLAY_STATEMENT="+statement, "GOFLAGS=-mod=vendor", "GOPROXY=off")
	out, err = raise.CombinedOutput()
	if err != nil {
		t.Fatalf("the controller did not raise the silent web application within two looks: %v\n%s", err, lastOf(string(out), 12))
	}
	if strings.Contains(string(out), "no tests to run") {
		t.Fatal("the controller at this commit has no half of the replay to run")
	}
}