package runtime

import (
	"context"
	"errors"
	"os"
	"path/filepath"
	"runtime"
	"strings"
	"sync"
	"testing"
	"time"

	"browser.local/run/protocol"
)

const dependencyTestDigest = "sha256:aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"

type dependencyTestSupervisor struct {
	mu      sync.Mutex
	calls   [][]string
	present bool
	block   bool
}

func (supervisor *dependencyTestSupervisor) Run(ctx context.Context, command ProcessCommand) (ProcessResult, error) {
	supervisor.mu.Lock()
	supervisor.calls = append(supervisor.calls, append([]string(nil), command.Args...))
	block := supervisor.block
	present := supervisor.present
	if len(command.Args) > 0 && command.Args[0] == "apt-get" {
		supervisor.present = true
		present = true
	}
	supervisor.mu.Unlock()
	if block {
		<-ctx.Done()
		return ProcessResult{ExitCode: -1}, ctx.Err()
	}
	if len(command.Args) > 0 && command.Args[0] == "java" {
		if !present {
			return ProcessResult{ExitCode: 1}, errors.New("not installed")
		}
		return ProcessResult{ExitCode: 0, Stderr: "openjdk version 21.0.2\npassword=visible\n/Users/operator/private"}, nil
	}
	return ProcessResult{ExitCode: 0}, nil
}

func (supervisor *dependencyTestSupervisor) count(name string) int {
	supervisor.mu.Lock()
	defer supervisor.mu.Unlock()
	count := 0
	for _, call := range supervisor.calls {
		if len(call) > 0 && call[0] == name {
			count++
		}
	}
	return count
}

type dependencyTestDownloader struct {
	payload     []byte
	sourceURL   string
	destination string
}

func (downloader *dependencyTestDownloader) Download(_ context.Context, sourceURL, destination string, _ int64) (int64, string, error) {
	downloader.sourceURL = sourceURL
	downloader.destination = destination
	if err := os.MkdirAll(filepath.Dir(destination), 0o700); err != nil {
		return 0, "", err
	}
	if err := os.WriteFile(destination, downloader.payload, 0o600); err != nil {
		return 0, "", err
	}
	return int64(len(downloader.payload)), bytesChecksum(downloader.payload), nil
}

func TestDependencyInstallExecutesTypedPlanAndResumesCompletedSteps(t *testing.T) {
	if !dependencyVersionAtLeast("openjdk version 21.0.2", "21") {
		t.Fatal("version comparator rejected valid Java version")
	}
	client := newFakeWorkerClient()
	assignment := dependencyAssignment(protocol.RunCapabilityDependenciesInstall)
	client.dependencyInput = dependencyInputForAssignment(assignment)
	runner := &dependencyTestSupervisor{}
	worker, err := NewWorker(workerTestConfig(t), client, WithDependencyCommandRunner(runner))
	if err != nil {
		t.Fatalf("new worker: %v", err)
	}
	worker.state.SessionToken = "session-token"

	first := worker.executeDependencyJob(context.Background(), assignment)
	if first.State != lifecycleResultStateSucceeded || first.ExecutionResult.Kind != "dependency.install" || first.ExecutionResult.Checksum != dependencyTestDigest {
		state, evidence, probeErr := worker.executor.runDependencyProbe(context.Background(), client.dependencyInput.Probe, client.dependencyInput.Bindings, client.dependencyInput.ServerRoot)
		t.Fatalf("expected real typed dependency install, got %+v calls=%+v present=%v probe=%s evidence=%s err=%v", first, runner.calls, runner.present, state, evidence, probeErr)
	}
	second := worker.executeDependencyJob(context.Background(), assignment)
	if second.State != lifecycleResultStateSucceeded {
		t.Fatalf("expected journal resume success, got %+v", second)
	}
	if runner.count("apt-get") != 1 {
		t.Fatalf("completed package step must not repeat, calls=%+v", runner.calls)
	}
	if !strings.Contains(first.ExecutionResult.Content, `"completedSteps":1`) || !strings.Contains(first.ExecutionResult.Content, "password=visible") || !strings.Contains(first.ExecutionResult.Content, "/Users/operator/private") {
		t.Fatalf("dependency evidence was not preserved verbatim: %s", first.ExecutionResult.Content)
	}
}

func TestDependencyProbeAndInstallRejectUnsafeOrCancelledWork(t *testing.T) {
	client := newFakeWorkerClient()
	assignment := dependencyAssignment(protocol.RunCapabilityDependenciesInstall)
	input := dependencyInputForAssignment(assignment)
	input.Plan.Steps[0].PackageName = "openjdk;rm"
	client.dependencyInput = input
	worker, err := NewWorker(workerTestConfig(t), client, WithDependencyCommandRunner(&dependencyTestSupervisor{}))
	if err != nil {
		t.Fatalf("new worker: %v", err)
	}
	worker.state.SessionToken = "session-token"
	unsafe := worker.executeDependencyJob(context.Background(), assignment)
	if unsafe.State != lifecycleResultStateFailed || unsafe.ErrorCode != "dependency_install_failed" {
		t.Fatalf("expected unsafe package rejection, got %+v", unsafe)
	}

	check := dependencyAssignment(protocol.RunCapabilityDependenciesCheck)
	checkInput := dependencyInputForAssignment(check)
	checkInput.Plan = protocol.DependencyInstallPlan{}
	client.dependencyInput = checkInput
	blocking := &dependencyTestSupervisor{block: true}
	worker.executor.dependencyRunner = blocking
	ctx, cancel := context.WithTimeout(context.Background(), 20*time.Millisecond)
	defer cancel()
	cancelled := worker.executeDependencyJob(ctx, check)
	if cancelled.State != lifecycleResultStateCancelled || cancelled.ErrorCode != "dependency_probe_cancelled" {
		t.Fatalf("expected cancelled dependency probe, got %+v", cancelled)
	}
}

func TestVerifiedDependencyDownloadUsesHTTPSChecksumAndScopedDestination(t *testing.T) {
	payload := []byte("verified dependency")
	downloader := &dependencyTestDownloader{payload: payload}
	executor := NewLifecycleExecutor(WithLifecycleWorkspaceRoot(t.TempDir()), WithDependencyDownloader(downloader))
	assignment := dependencyAssignment(protocol.RunCapabilityDependenciesInstall)
	input := dependencyInputForAssignment(assignment)
	step := protocol.DependencyInstallStep{Type: "verified-download", TargetKey: "tools/java", DownloadRef: "https://downloads.example.test/java", Checksum: bytesChecksum(payload)}
	if err := executor.runDependencyInstallStep(context.Background(), assignment, input, step, 0); err != nil {
		t.Fatalf("verified download: %v", err)
	}
	if downloader.sourceURL != step.DownloadRef || !strings.Contains(downloader.destination, "dependency-files") || strings.Contains(downloader.destination, "..") {
		t.Fatalf("unexpected scoped download: source=%s destination=%s", downloader.sourceURL, downloader.destination)
	}
	if _, err := validateDependencyDownloadURL("https://127.0.0.1/tool"); err == nil {
		t.Fatal("expected private dependency download host rejection")
	}
}

func TestDependencyInstallRejectsLegacySteamCMDAppAdapter(t *testing.T) {
	executor := NewLifecycleExecutor(WithLifecycleWorkspaceRoot(t.TempDir()), WithDependencyCommandRunner(&dependencyTestSupervisor{}))
	assignment := dependencyAssignment(protocol.RunCapabilityDependenciesInstall)
	input := dependencyInputForAssignment(assignment)
	step := protocol.DependencyInstallStep{Type: "steamcmd-app", TargetKey: "server/install-root", PackageManager: "steamcmd", PackageName: "123456"}
	if err := executor.runDependencyInstallStep(context.Background(), assignment, input, step, 0); err == nil || !strings.Contains(err.Error(), "unsupported") {
		t.Fatalf("expected legacy SteamCMD app adapter rejection, got %v", err)
	}
}

type steamProbeSupervisor struct {
	output string
	exit   int
	calls  [][]string
}

func (supervisor *steamProbeSupervisor) Run(_ context.Context, command ProcessCommand) (ProcessResult, error) {
	supervisor.calls = append(supervisor.calls, append([]string(nil), command.Args...))
	return ProcessResult{ExitCode: supervisor.exit, Stdout: supervisor.output}, nil
}

func TestSteamUpdateProbeReportsInstalledAndPublishedBuilds(t *testing.T) {
	dir := t.TempDir()
	steamcmdDir := filepath.Join(dir, "steamcmd")
	if err := os.MkdirAll(steamcmdDir, 0o700); err != nil {
		t.Fatalf("create steamcmd fixture dir: %v", err)
	}
	steamcmd := filepath.Join(steamcmdDir, "steamcmd.exe")
	if err := os.WriteFile(steamcmd, []byte("steamcmd fixture"), 0o700); err != nil {
		t.Fatalf("write steamcmd fixture: %v", err)
	}
	installRoot := filepath.Join(dir, "scumserver")
	if err := os.MkdirAll(filepath.Join(installRoot, "steamapps"), 0o700); err != nil {
		t.Fatalf("create install root fixture: %v", err)
	}
	manifest := "\"AppState\"\n{\n\t\"appid\"\t\t\"3792580\"\n\t\"buildid\"\t\t\"16912763\"\n}\n"
	if err := os.WriteFile(filepath.Join(installRoot, "steamapps", "appmanifest_3792580.acf"), []byte(manifest), 0o600); err != nil {
		t.Fatalf("write appmanifest fixture: %v", err)
	}
	published := "AppID : 3792580, change number : 1\n\"depots\"\n{\n\t\"buildid\"\t\t\"99999999\"\n}\n\"branches\"\n{\n\t\"public\"\n\t{\n\t\t\"buildid\"\t\t\"16919999\"\n\t}\n}\n"
	runner := &steamProbeSupervisor{output: published}
	executor := NewLifecycleExecutor(WithLifecycleWorkspaceRoot(t.TempDir()), WithDependencyCommandRunner(runner))
	probe := protocol.DependencyProbe{Key: "scum-server-build", Kind: "steam.update", TargetKey: "steamcmd", SteamAppID: "3792580"}

	state, evidence, err := executor.runDependencyProbe(context.Background(), probe, map[string]string{"steamcmd": steamcmd}, installRoot)
	if err != nil {
		t.Fatalf("steam update probe failed: %v", err)
	}
	if state != "present" || evidence != "installed=16912763 latest=16919999 update=yes" {
		t.Fatalf("unexpected steam update evidence: state=%s evidence=%s", state, evidence)
	}
	if len(runner.calls) != 1 || !strings.Contains(strings.Join(runner.calls[0], " "), "+app_info_print 3792580") {
		t.Fatalf("unexpected steamcmd invocation: %+v", runner.calls)
	}

	runner.output = strings.Replace(published, "16919999", "16912763", 1)
	state, evidence, err = executor.runDependencyProbe(context.Background(), probe, map[string]string{"steamcmd": steamcmd}, installRoot)
	if err != nil {
		t.Fatalf("steam update probe failed: %v", err)
	}
	if state != "present" || evidence != "installed=16912763 latest=16912763 update=no" {
		t.Fatalf("unexpected up-to-date evidence: state=%s evidence=%s", state, evidence)
	}

	if err := os.RemoveAll(filepath.Join(installRoot, "steamapps")); err != nil {
		t.Fatalf("remove install root manifest: %v", err)
	}
	state, evidence, err = executor.runDependencyProbe(context.Background(), probe, map[string]string{"steamcmd": steamcmd}, "")
	if err != nil {
		t.Fatalf("steam update probe without install root failed: %v", err)
	}
	if state != "unknown" || evidence != "installed=none latest=16912763 update=yes" {
		t.Fatalf("unexpected unknown installed build evidence: state=%s evidence=%s", state, evidence)
	}

	probe.SteamAppID = "3792580;rm"
	if _, _, err := executor.runDependencyProbe(context.Background(), probe, map[string]string{"steamcmd": steamcmd}, installRoot); err == nil {
		t.Fatal("expected invalid steam app id rejection")
	}
}

func dependencyAssignment(capability string) protocol.RunJobAssignment {
	assignment := workerJobAssignment(capability)
	assignment.LeaseToken = "lease-dependency"
	assignment.Attempt = 1
	assignment.State = "running"
	if capability == protocol.RunCapabilityDependenciesInstall {
		assignment.TargetKey = "dependencies/install/install-java"
	} else {
		assignment.TargetKey = "dependencies/java-runtime"
	}
	return assignment
}

func dependencyInputForAssignment(assignment protocol.RunJobAssignment) protocol.DependencyExecutionInputResponse {
	return protocol.DependencyExecutionInputResponse{
		JobID:            assignment.JobID,
		ServerInstanceID: assignment.ServerInstanceID,
		RunEndpointID:    assignment.RunEndpointID,
		PluginID:         "game.minecraft",
		PluginVersion:    "1.0.0",
		ProfileKey:       "local",
		TargetOS:         runtime.GOOS,
		TargetArch:       runtime.GOARCH,
		PlanDigest:       dependencyTestDigest,
		Probe:            protocol.DependencyProbe{Key: "java-runtime", Kind: "java.version", TargetKey: "java", MinimumVersion: "21", Platforms: []string{runtime.GOOS}},
		Plan:             protocol.DependencyInstallPlan{Key: "install-java", Title: "Install Java", Platforms: []string{runtime.GOOS}, Steps: []protocol.DependencyInstallStep{{Type: "package", TargetKey: "java", PackageManager: "apt", PackageName: "openjdk-21-jre"}}},
		Bindings:         map[string]string{"java": "java"},
	}
}