import type {
	DependencyCatalogResponse,
	DependencyProbeViewResponse,
	GamePluginResponse,
	JobResponse,
	RunEndpointResponse,
	ServerDeploymentMode,
	ServerInstanceResponse,
  ServerInstanceState
} from "../api/types";

export type ServerWorkflowViewState = "api" | "local" | "saving";
export type ServerLifecycleActionLabel = "create" | "start" | "stop" | "refresh";
export type ServerRemovalAction = "delete";

export interface ServerCreateFormState {
  id: string;
  name: string;
	pluginId: string;
	createInputs: Record<string, string>;
	deploymentMode: ServerDeploymentMode;
	serverRoot: string;
	workingDirectory: string;
	installCommand: string;
	startCommand: string;
	stopCommand: string;
	statusCommand: string;
	shell: "" | "posix-sh" | "powershell" | "cmd";
}

export interface ServerWorkflowActionState {
  label: ServerLifecycleActionLabel;
  serverInstanceId?: string;
  success: boolean;
  message: string;
}

export interface ServerMetadataFormState {
  name: string;
}

export interface ServerRemovalConfirmationState {
  action: ServerRemovalAction;
  serverInstanceId: string;
  name: string;
  state: ServerInstanceState;
}

export interface ServerManagementSummary {
  total: number;
  running: number;
  pendingJobs: number;
  failed: number;
}

export type RuntimeObservationFreshness = "fresh" | "unverified";

export function runtimeObservationFreshness(instance: ServerInstanceResponse, endpoint: RunEndpointResponse | undefined, now = Date.now()): RuntimeObservationFreshness {
	if (!endpoint || endpoint.status !== "online") return "unverified";
	const heartbeat = Date.parse(endpoint.lastHeartbeatAt);
	return Number.isFinite(heartbeat) && now-heartbeat <= 30_000 ? "fresh" : "unverified";
}

export const emptyServerCreateForm: ServerCreateFormState = {
  id: "",
  name: "",
	pluginId: "",
	createInputs: {},
	deploymentMode: "guided-install",
	serverRoot: "",
	workingDirectory: "",
	installCommand: "",
	startCommand: "",
	stopCommand: "",
	statusCommand: "",
	shell: ""
};

export function summarizeServerManagement(instances: ServerInstanceResponse[], jobs: JobResponse[]): ServerManagementSummary {
  return {
    total: instances.length,
    running: instances.filter((instance) => instance.state === "running").length,
    pendingJobs: jobs.filter((job) => isPendingJobState(job.state)).length,
    failed: instances.filter((instance) => instance.state === "failed").length
  };
}

export function pendingJobsForServer(jobs: JobResponse[], serverInstanceId: string): JobResponse[] {
  return jobs.filter((job) => job.serverInstanceId === serverInstanceId && isPendingJobState(job.state));
}

export function pluginLabel(plugin: GamePluginResponse | undefined, pluginId: string): string {
  if (!plugin) {
    return pluginId;
  }
  return plugin.serverDisplayName || plugin.name || plugin.id;
}

export function serverCreatePluginOptions(plugins: GamePluginResponse[]): GamePluginResponse[] {
	const selected = new Map<string, GamePluginResponse>();
	for (const plugin of plugins.filter(pluginCanCreateServer)) {
		const key = serverCreatePluginIdentity(plugin);
		const current = selected.get(key);
		if (!current || compareServerCreatePlugins(plugin, current) < 0) selected.set(key, plugin);
	}
	return Array.from(selected.values()).sort(compareServerCreatePlugins);
}

export function pluginCanCreateServer(plugin: GamePluginResponse): boolean {
	return plugin.status === "installed" && plugin.declaredPermissions.includes("server.create");
}

export function pluginCreateInputValues(plugin: GamePluginResponse | undefined, values: Record<string, string> | undefined): Record<string, string> {
	return { ...pluginCreateInputDefaults(plugin), ...(values ?? {}) };
}

export function canStartServer(state: ServerInstanceState): boolean {
	return state === "ready" || state === "stopped" || state === "failed";
}

export function canStopServer(state: ServerInstanceState): boolean {
  return state === "running";
}

export function canRestartServer(state: ServerInstanceState): boolean {
  return state === "running" || state === "stopped";
}

export function canUpdateServerGame(state: ServerInstanceState): boolean {
  return state === "running" || state === "stopped" || state === "ready" || state === "failed";
}

export type GameUpdateAvailability = "unknown" | "available" | "up-to-date";

export interface GameUpdateStatus {
  availability: GameUpdateAvailability;
  installed?: string;
  latest?: string;
}

export function steamUpdateProbe(catalog?: DependencyCatalogResponse): DependencyProbeViewResponse | undefined {
  return catalog?.probes.find((probe) => probe.kind === "steam.update");
}

export function gameUpdateStatusFromProbe(probe?: DependencyProbeViewResponse): GameUpdateStatus | undefined {
  if (!probe || probe.kind !== "steam.update") {
    return undefined;
  }
  const update = dependencyEvidenceValue(probe.evidence, "update");
  return {
    availability: update === "yes" ? "available" : update === "no" ? "up-to-date" : "unknown",
    installed: dependencyEvidenceValue(probe.evidence, "installed"),
    latest: dependencyEvidenceValue(probe.evidence, "latest")
  };
}

export function gameUpdateStatusLabel(status?: GameUpdateStatus): string {
  switch (status?.availability) {
    case "available": return "发现新版本";
    case "up-to-date": return "已是最新版本";
    case "unknown": return "版本未知";
    default: return "尚未检查";
  }
}

function dependencyEvidenceValue(evidence: string | undefined, key: string): string | undefined {
  if (!evidence) {
    return undefined;
  }
  for (const token of evidence.split(/\s+/)) {
    const separator = token.indexOf("=");
    if (separator <= 0 || token.slice(0, separator) !== key) {
      continue;
    }
    return token.slice(separator + 1) || undefined;
  }
  return undefined;
}

export function isPendingJobState(state: JobResponse["state"]): boolean {
  return state === "queued" || state === "accepted" || state === "running" || state === "retrying";
}

export function defaultServerCreateForm(plugins: GamePluginResponse[]): ServerCreateFormState {
  const plugin = plugins[0];
  return {
    ...emptyServerCreateForm,
    pluginId: plugin?.id ?? "",
		createInputs: pluginCreateInputDefaults(plugin)
	};
}

export function pluginCreateInputDefaults(plugin: GamePluginResponse | undefined): Record<string, string> {
	return Object.fromEntries((plugin?.createFields ?? []).map((field) => [field.key, field.defaultValue ?? ""]));
}

function serverCreatePluginIdentity(plugin: GamePluginResponse): string {
	return `${plugin.serverType}:${plugin.serverDisplayName || plugin.name || plugin.id}`.toLowerCase();
}

function compareServerCreatePlugins(left: GamePluginResponse, right: GamePluginResponse): number {
	const leftScore = serverCreatePluginScore(left);
	const rightScore = serverCreatePluginScore(right);
	for (let index = 0; index < leftScore.length; index += 1) {
		const delta = leftScore[index]-rightScore[index];
		if (delta !== 0) return delta;
	}
	const labelDelta = pluginLabel(left, left.id).localeCompare(pluginLabel(right, right.id));
	return labelDelta || left.id.localeCompare(right.id);
}

function serverCreatePluginScore(plugin: GamePluginResponse): number[] {
	return [
		(plugin.createFields?.length ?? 0) > 0 ? 0 : 1,
		plugin.tags.includes("development") ? 1 : 0,
		plugin.id === `game.${plugin.serverType}` ? 0 : 1,
		plugin.id.includes(".codex.") ? 1 : 0,
		-versionWeight(plugin.version)
	];
}

function versionWeight(version: string): number {
	return version.split(/[^0-9]+/).filter(Boolean).slice(0, 3).reduce((weight, part, index) => weight+Number(part || 0)*Math.pow(1000, 2-index), 0);
}

export function serverMetadataFormFromInstance(instance: ServerInstanceResponse): ServerMetadataFormState {
  return { name: instance.name };
}

export function canDeleteServer(state: ServerInstanceState): boolean {
  return state !== "deleted";
}